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Pradheeba, M., M. Pugalenthi, M. A. Deepa, S. Vishnu Kumar e G. Vasukipridharshini. "Evaluation of Phytochemical Profile and In Vitro Antioxidant, Anti-bacterial and Anti-inflammatory activity of Piper schmidtii Hook. fil. A Wild Edible Fruit". Asian Pacific Journal of Health Sciences 9, n. 3 (16 aprile 2022): 191–97. http://dx.doi.org/10.21276/apjhs.2022.9.3.39.
Abstract (sommario):
Aim: The present study aims at screening the phytochemical components and evaluates the antioxidant, anti-bacterial, and anti-inflammatory activity of fruit of Piper schmidtii, an endemic plant species from The Nilgiris, Tamil Nadu. Materials and Method: The different polar solvents such as petroleum ether, chloroform, ethyl acetate, methanol, and water were used and extraction was carried out using the soxhlet apparatus. The extracts were screened for qualitative and quantitative phytochemical analysis. The extracts of P. schmidtii were also subjected to in vitro-antioxidant activity by DPPH assay, Phosphomolybdenum assay, Ferric reducing antioxidant power (FRAP), superoxide radical scavenging activity, and reducing power assay. Results: Among all the extracts, methanol extract exhibited the maximum amount of phenolics (731.91 mg GAE/g extract), tannin (726.6 milligrams of Gallic acid equivalent/g extract), and ethyl acetate extract depicted the maximum quantity of flavonoids (698.17 mg QE/g extract). Methanol extract of P. schmidtii revealed the higher antioxidant activity in all the assays with IC50 values of 15.19 μg/ml (DPPH), 135.67 mg AAE/g (Phosphomolybdenum assay), 380.98 mM Fe/mg (FRAP), 60.94% (Superoxide) and higher reducing power was depicted in the ethyl acetate extract, respectively. Further anti-bacterial activity revealed that the methanol extract shows highest inhibitory activity against the tested bacterial pathogens. The methanol extract showed high degree of inhibition (71.24%) in anti-inflammatory assay. Conclusion: Thus, the result support that P. schmidtii is a potential source of natural antioxidant that can inhibit bacterial growth and subside inflammation.
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Chakraborty, Rajdeep, Charbel Darido, Honghua Hu, Karen Vickery e Shoba Ranganathan. "A novel drug combination strategy that redesigns the pharmacological management of oral cancer." Journal of Clinical Oncology 40, n. 16_suppl (1 giugno 2022): e18053-e18053. http://dx.doi.org/10.1200/jco.2022.40.16_suppl.e18053.
Abstract (sommario):
e18053 Background: Biofilm formation is a continuous process in oral cancer patients, despite proper extirpation/elimination of a bacterial plaque via a surgical procedure or antibiotic treatment. Also, elimination of a bacterial plaque does not necessarily remove extant bacterial antigen-stimulated oral cancer cells. Therefore, combination drug treatment may be an appropriate approach to elucidate the confounding effects of bacterial antigens on anti-cancer drugs. Methods: Our drug combination strategy addressed both Gram-positive (Lipoteichoic acid [LTA]) and Gram-negative (Lipopolysaccharide [LPS]) bacterial antigens, to determine the effect of anti-cancer drugs on LPS/LTA/LPS+LTA-stimulated preclinical oral cancer models (SCC4, SCC9, SCC25, and Cal 27). The drug combination strategy was designed in six phases of treatment. In phase 1, plated cells were treated with different combinations of bacterial antigens in combination with anti-cancer drugs. In the phases 2 and 3, inhibitory drugs were introduced in the presence of bacterial antigens after 24 hours and 72 hours of bacterial antigen stimulation. In phases 4 and 5, inhibitory drugs were added after 24 hours and 72 hours of bacterial antigen stimulation. In phase 6, inhibitory drugs were applied in the absence of, and without stimulation with, bacterial antigens. Metabolic assays, reverse transcription quantitative PCR, Western blot, Proteome Profiler, apoptotic and ELISA assays were performed to validate the novel drug combination strategy. Results: Anti-cancer drug treatment on preclinical oral cancer models resulted in 43.6% ± 3.3% of precancerous models being apoptotic. To mimic pre-existing unhygenic conditions in oral cancer patients, prior stimulation of preclinical model with LPS+LTA 72 hours before drug treatment, reduced apoptosis to 32.2% ± 1.1% of cells. Apoptosis was almost annulled (2.98% ± 0.3%; p < 0.01) when drug treatment was carried out along with bacterial antigens. Treatment with drugs in the absence of bacterial antigens resulted in significantly more apoptotic cells than in presence of bacterial antigens (p < 0.0001). Metabolic and viability assay showed similar results like apoptotic assay. Conclusions: Bacterial antigens mimic the presence of Gram-negative and Gram-positive bacteria and thus severely affect the efficacy of anti-cancer drugs. The novel drug combination strategy redesigns the pharmacological management of oral squamous cell carcinoma.
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S, Sarah, e Shanmugharaju , V. "Bacterial Protease Inhibitors as Antibacterial agents to prevent Bacterial Infections Associated with Biofilms". Journal of University of Shanghai for Science and Technology 23, n. 10 (9 ottobre 2021): 398–412. http://dx.doi.org/10.51201/jusst/21/10730.
Abstract (sommario):
Isolation of protease inhibitor producing bacteria from microbial mat and investigating its anti-biofilm potential against biofilm producing organism was selected as the main objective of the present study. Protease inhibitor (PI) was produced from bacterial isolates and purified using ammonium sulphate precipitation methods. Primary and secondary protease inhibitor assay was carried out separately to confirm the inhibition of protease enzyme activity both qualitatively and quantitatively. Antibacterial activity and anti-biofilm assay was performed to determine the biofilm prevention capabilities of PI. Three isolates (B1PI, B2PI and B3PI) were screened and B2PI bacterial culture was selected based on the results of primary and secondary protease inhibitor assay. Maximum trypsin inhibition of 77.5±0.25% was recorded for the isolate B2PI. Antibacterial activity of the B2PI protease inhibitor fractions exhibited inhibitory zones of 22.3±1.04mm and 20.2±0.25mm against Escherichia coli and Staphylococcus aureus respectively. Anti-biofilm assay of protease inhibitor fractions expressed 31.2μl/ml of MBIC against Escherichia coli and Staphylococcus aureus. The results conclude that, the protease inhibitor from the microbial mat isolate will be an effective alternative to the commercial antibiotics either alone or in combination with other drugs synergistically which shall be studied elaborately in future.
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O. Elansary, Hosam, Agnieszka Szopa, Marta Klimek-Szczykutowicz, Karolina Jafernik, Halina Ekiert, Eman A. Mahmoud, Ahmed Abdelmoneim Barakat e Diaa O. El-Ansary. "Mammillaria Species—Polyphenols Studies and Anti-Cancer, Anti-Oxidant, and Anti-Bacterial Activities". Molecules 25, n. 1 (29 dicembre 2019): 131. http://dx.doi.org/10.3390/molecules25010131.
Abstract (sommario):
Discovering new natural resources of polyphenols is the aim of many recent studies in the field of natural product research. This study tentatively investigated the polyphenols profile of the stems of seven Mammillaria species (M. rhodantha, M. spinosissima, M. hahniana, M. crucigera, M. candida, M. albilanata, and M. muehlenpfordtii) using high performance liquid chromatography with DAD detector (HPLC-DAD) method. Furthermore, the anti-cancer, anti-oxidant, and anti-bacterial potentials of these extracts as well as major identified phenols were explored. The HPLC-DAD study confirmed the availability of six phenolic acids, including gentisic acid, chlorogenic acid, caffeic acid, protocatechuic acid, sinapic acid, and p-hydroxybenzoic acid. The dominant compounds were: gentisic acid in M. rhodantha and M. spinosissima; chlorogenic acid in M. muehlenpfordtii, M. crucigera, and M. rhodantha; and caffeic acid in M. rhodantha, M. crucigera, and M. spinosissima. Stems of Mammillaria sp. showed antiproliferative effects against HeLa, MCF-7, and Jurkat cells. In HeLa and MCF-7 cells, the best antiproliferative activities were found in the treatments with M. rhodantha, M. spinosissima, and M. muehlenpfordtii. The apoptotic assay of M. rhodantha, M. spinosissima, and M. muehlenpfordtii showed accumulation of necrotic cells in the early and late apoptotic phase. M. rhodantha, M. spinosissima, and M. muehlenpfordtii showed the highest anti-oxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene bleaching, and ferric reducing anti-oxidant power (FRAP) assays. M. rhodantha was the best source of antioxidants. Mammillaria sp. showed moderate anti-bacterial effects against bacteria and the highest effects were found using the extracts of M. rhodantha, M. spinosissima, M. crucigera and M. muehlenpfordtii against most bacteria. The anti-bacterial activities were attributed to other phenolic compounds (e.g., chlorogenic acid) than gentisic acid, which was not active against most bacteria. Mammillaria sp. could be considered to be an important natural source of phenolic acids with anti-cancer, anti-bacterial, and anti-oxidant activities.
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Nofiani, Risa, Rizky Rizky e Ridho Brilliantoro. "Antibacterial Activities and Toxicity of Streptosporangium sp. SM1P". Molekul 16, n. 3 (15 novembre 2021): 210. http://dx.doi.org/10.20884/1.jm.2021.16.3.780.
Abstract (sommario):
This study aims to explore the anti-bacterial and toxicity activities from a rare actinobacterium isolated from mangrove, Mempawah District, West Kalimantan. The mangrove mud sample from Mempawah district was inoculated on ISP4 agar using a pour plate method. After 4 days of incubation, a colony of suspected actinobacterium was appeared, then isolated and coded as SM1P. SM1P was characterized based on morphological and biochemical traits and identified as a genus of Streptroporangium then called Streptroporangium sp. SM1P. Streptroporangium sp. SM1P was carried out anti-bacterial assay on both ISP1 agar and ISP4 agar media using the cross-streak method for the solid-state fermentation. The result showed that Streptroporangium sp. SM1P could inhibit Streptococcus sp. and Salmonella typhi on ISP1 agar and treptococcus sp., Escherichia coli, Vibrio cholerae, Staphylococcus aureus and Salmonella typhi on ISP4 agar. Streptroporangium sp. SM1P was cultivated on ISP1 broth and extracted using ethyl acetate, then evaporated to obtain crude extract. The crude extract was used for anti-bacterial assay (well-diffusion method for liquid-state fermentation) and toxicity assay (brine shrimp lethality test). The crude extract was active against 2 of the test bacteria (Streptococcus sp. and E. coli). The best medium and state fermentation for anti-bacterial assay were ISP4 agar with the condition of solid-state fermentation. The extract SM1P prepared on ISP1 broth showed toxic activity based on LC50 (106.094 µg/mL). Therefore, Streptroporangium sp. SM1P have a potential source to explore secondary metabolites having anti-bacterial and toxicity activities.
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Al-Jubouri, A. K., N. H. Al-Saadi e M. A. Kadhim. "ANTI- INFLAMMATORY AND ANTI- BACTERIAL ACTIVITY OF COPPER NANOPARTICLES SYNTHESIZED FROM MYRTUS COMMUNIS LEAVES EXTRACT". IRAQI JOURNAL OF AGRICULTURAL SCIENCES 53, n. 3 (29 giugno 2022): 698–711. http://dx.doi.org/10.36103/ijas.v53i3.1580.
Abstract (sommario):
A variety of organisms, including plants and bacteria, fungi, seaweeds, and microalgae, are involved in the biological synthesis of nanoparticles. Copper nanoparticles (CuNPs) can be synthesized using plant extracts, which is considered to be one of the safest methods in green chemistry. Copper-NPs were synthesized from the leaves of M. communis, which were extracted with water. The first indication that CuNPs have been synthesized is the change in color of the solution from light yellow to dark brown. Several different techniques were used to characterize CuNPs. The Surface Plasmon Resonance (SPR) of the nanoparticles in the range of 300 to 700 nm was investigated using ultraviolet-visible absorption spectroscopy (UV-Vis), and the Fourier Transforming Infrared analysis (FT-IR) was used to identify functional groups in biomolecules that act as a reducing and capping agent for NPs. The X-ray diffraction (XRD) analysis of CuNPs revealed that they are crystalline. In this study, the size and surface properties of biosynthesized nanoparticles were determined using atomic force microscopy (AFM). Copper-NPs had an average size of 53.55 nm, according to the results. In this study, the antibacterial and anti-inflammatory activity of CuNPs and extract were investigated. The antibacterial activity of CuNPs and M. communis extract was evaluated against Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, and Lactobacillus salivarins). Zone inhibition of up to 25 mm was observed in Staphylococcus aureus when the extract concentration was 100000 µg/mL. At various concentrations, the anti-inflammatory activity of both the extract and the CuNPs was assessed in vitro using the assays (albumin denaturation assay, membrane stabilization assay, and proteinase inhibitory activity). According to the findings, CuNPs demonstrated a significant anti-inflammatory activity when compared to a standard drug.
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Pattni, Ramesh, Hitesh Kumarkhaniya, Bharat Maitreya e Nainesh Modi. "PHYTOCHEMICAL ANALYSIS, ANTI-OXIDANT ACTIVITY AND ANTI-BACTERIAL ACTIVITY OF SALVADORA OLEOIDES L." International Association of Biologicals and Computational Digest 2, n. 1 (14 maggio 2023): 183–90. http://dx.doi.org/10.56588/iabcd.v2i1.127.
Abstract (sommario):
Salvadora oleoides L. is a facultative and mesomorphic xerophyte adapted to arid and semi-arid regions. It is commonly known as meetha jal in Gujarat and Rajasthan. These plant species populations were grown in different ecological regions such as Punjab, Rajasthan, and Kutch. The present study analyzed the presence of secondary metabolites and also their amount. The anti-oxidant assay such as DPPH and ABTS determine the reducing agent which is present in plant. Anti-bacterial activity checked against the pseudomonas bacteria is 5 mm (Zone of inhibition) at concentration of 1 mg/ml.
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Said, Bibie, Loveness Charlie, Emnet Getachew, Catherine Lydiah Wanjiru, Mekdelawit Abebe e Tsegahun Manyazewal. "Molecular bacterial load assay versus culture for monitoring treatment response in adults with tuberculosis". SAGE Open Medicine 9 (gennaio 2021): 205031212110334. http://dx.doi.org/10.1177/20503121211033470.
Abstract (sommario):
The lack of rapid, sensitive, and deployable tuberculosis diagnostic tools is hampering the early diagnosis of tuberculosis and early detection of treatment failures. The conventional sputum smear microscopy or Xpert MTB/RIF assay cannot distinguish between alive and dead bacilli and the culture method delays providing results. Tuberculosis molecular bacterial load assay is a reverse transcriptase real-time quantitative polymerase chain reaction that quantifies viable tuberculosis bacillary load as a marker of treatment response for patients on anti-tuberculosis therapy. However, results are not synthesized enough to inform its comparative advantage to tuberculosis culture technique which is yet the gold standard of care. With this review, we searched electronic databases, including PubMed, Embase, and Web of Science, from March 2011 up to February 2021 for clinical trials or prospective cohort studies that compared tuberculosis molecular bacterial load assay with tuberculosis culture in adults. We included eight studies that meet the inclusion criteria. Tuberculosis molecular bacterial load assay surpasses culture in monitoring patients with tuberculosis during the first few weeks of anti-tuberculosis treatment. It is more desirable over culture for its shorter time to results, almost zero rates of contamination, need for less expertise on the method, early rate of decline, lower running cost, and reproducibility. Its rapid and specific tuberculosis treatment monitoring competency benefits patients and healthcare providers to monitor changes of bacillary load among isolates with drug-susceptible or resistance to anti-tuberculosis regimens. Despite of the high installing cost of the tuberculosis molecular bacterial load assay method, molecular expertise, and a well-equipped laboratory, tuberculosis molecular bacterial load assay is a cost-effective method with comparison to culture in operational running. To achieve maximum utility in high tuberculosis burden settings, an intensive initial investment in nucleic acid extraction and polymerase chain reaction equipment, training in procedures, and streamlining laboratory supply procurement systems are crucial. More evidence is needed to demonstrate the potential large-scale and sustainable use of tuberculosis molecular bacterial load assay over culture in resource-constrained settings.
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Emrich, Stefanie, Anja Schuster, Thomas Schnabel e Gertie Janneke Oostingh. "Antimicrobial Activity and Wound-Healing Capacity of Birch, Beech and Larch Bark Extracts". Molecules 27, n. 9 (28 aprile 2022): 2817. http://dx.doi.org/10.3390/molecules27092817.
Abstract (sommario):
Bark is a major by-product of woodworking industries. The contents of several wood species are known to harbor antimicrobial, antiviral, anti-inflammatory and wound-healing capacities. The aim of this work was to identify beneficial properties of Austrian larch, birch and beech bark extracts for their potential usage as additives or active ingredients in dermatological applications. Bacterial agar diffusion assay and resazurin-based broth microdilution assay were used to evaluate anti-bacterial activity. To gain more insight into the cellular response to bark extracts, viability-, scratch-assays and ELISAs were performed. Birch and beech extracts showed strong antimicrobial activities against Gram-positive bacteria, including Cutibacterium acnes, Staphylococcus epidermidis and MRSA. Wound closure was enhanced with birch and beech extracts as compared to controls in the scratch-assays. Whereas beneficial properties of birch bark components have previously been described, the similar effects of beech extracts are novel. The combined positive effect on wound-healing and antimicrobial activity has great potential for the treatment of various skin diseases, including acne in future dermal applications.
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Sheu, Shew-Meei, Bor-Shyang Sheu, Hsiao-Bai Yang, Huan-Yao Lei e Jiunn-Jong Wu. "Anti-Lewis X Antibody Promotes Helicobacter pylori Adhesion to Gastric Epithelial Cells". Infection and Immunity 75, n. 6 (19 marzo 2007): 2661–67. http://dx.doi.org/10.1128/iai.01689-06.
Abstract (sommario):
ABSTRACT Lewis X (Lex) antigen is expressed on the human gastric mucosa and the O-specific chain of lipopolysaccharides of Helicobacter pylori. This antigen can induce autoantibodies, which may be involved in bacterial colonization and thus deserve further investigation. Flow cytometry was used to examine the effects of anti-Le monoclonal antibodies (MAbs) on H. pylori adhesion. A babA2 mutant was also constructed to evaluate the effect of an anti-Lex MAb on adhesion. The bacterial agglutination and in situ adhesion assays were used to confirm the anti-Lex MAb effect on H. pylori adhesion. This study revealed that an anti-Lex MAb, but not an anti-Leb MAb or an anti-Ley MAb, could enhance the adhesion of H. pylori strains that expressed high levels of Lex antigen to AGS cells. The enhancement was not found on an H. pylori strain with a low level of Lex antigen. Anti-Lex MAb could increase the adhesion of both the wild-type strain and its isogenic babA2 mutant to AGS cells. When AGS cells were pretreated with anti-Lex MAb, the adhesion of the babA2 mutant also increased. Only anti-Lex MAb could promote bacterial agglutination, and the in situ adhesion assay further confirmed that adding anti-Lex MAb resulted in denser bacterial adhesion on the gastric epithelia collected from clinical patients. These results suggest anti-Lex MAb could specifically enhance the adhesion abilities of H. pylori strains through a mechanism by which anti-Lex MAb promotes bacterial aggregation and mediates bivalent interaction (antigen-antibody-antigen) between bacteria and host cells.
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Yu, Moxi, Yachen Hou, Meiling Cheng, Yongshen Liu, Caise Ling, Dongshen Zhai, Hui Zhao et al. "Antibacterial Activity of Squaric Amide Derivative SA2 against Methicillin-Resistant Staphylococcus aureus". Antibiotics 11, n. 11 (28 ottobre 2022): 1497. http://dx.doi.org/10.3390/antibiotics11111497.
Abstract (sommario):
Methicillin-resistant Staphylococcus aureus (MRSA)-caused infection is difficult to treat because of its resistance to commonly used antibiotic, and poses a significant threat to public health. To develop new anti-bacterial agents to combat MRSA-induced infections, we synthesized novel squaric amide derivatives and evaluated their anti-bacterial activity by determining the minimum inhibitory concentration (MIC). Additionally, inhibitory activity of squaric amide 2 (SA2) was measured using the growth curve assay, time-kill assay, and an MRSA-induced skin infection animal model. A scanning electron microscope and transmission electron microscope were utilized to observe the effect of SA2 on the morphologies of MRSA. Transcriptome analysis and real-time PCR were used to test the possible anti-bacterial mechanism of SA2. The results showed that SA2 exerted bactericidal activity against a number of MRSA strains with an MIC at 4–8 µg/mL. It also inhibited the bacterial growth curve of MRSA strains in a dose-dependent manner, and reduced the colony formation unit in 4× MIC within 4–8 h. The infective lesion size and the bacterial number in the MRSA-induced infection tissue of mice were reduced significantly within 7 days after SA2 treatment. Moreover, SA2 disrupted the bacterial membrane and alanine dehydrogenase-dependent NAD+/NADH homeostasis. Our data indicates that SA2 is a possible lead compound for the development of new anti-bacterial agents against MRSA infection.
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Amiin, Muhammad Kholiqul, e Almira Fardani Lahay. "Anti-Bacterial Effectiveness Of Cymodocea Rotundata Extract And Assay For Primary Bioactive Composition." Journal of Aquatropica Asia 8, n. 1 (8 aprile 2023): 6–12. http://dx.doi.org/10.33019/joaa.v8i1.3920.
Abstract (sommario):
Anti-bacterial is a compound that can be used to inhibit bacterial growth. The compounds that play a role in damaging the cell membrane are phenols, flavonoids, and alkaloids. The phytochemical compounds above have the potential as natural Anti-bacterial on pathogenic bacteria, for example against Escherichia coli. Escherichia coli is a pathogenic microbe in humans that can cause digestive disorders and disrupt the work system of the stomach organs. Seagrass C. rotundata has compounds that are antibacterial, such as alkaloids, flavonoids, phenols, steroids, and tannins. C. rotundata can be seen in Indonesian waters. However, it has not been widely used. This study aims to determine the difference in concentration of seagrass extract of C. rotundata against E. coli anti-bacterial activity. The research method used was experimental laboratories with different concentrations of seagrass extract (10%, 20%, 30%, and 40%). The results showed that the seagrass extract of C. rotundata was effective as an antibacterial with a middle category, which is the inhibition zone ranging from 5-10 mm. Based on the studies conducted, 72 hours incubation period at 40% concentration was the best concentration to prevent E. coli at the 8.5 mm inhibition zone. Furthermore, bioactive compounds produced by C. rotundata are flavonoid compounds by showing changes in the color of the solution to yellow-orange. In addition, also produces phenol bioactive compounds by showing a change in the color of the solution to greenish, and also produces tannin bioactive compounds by showing a change in the color of the solution to blackish green. The results showed that C. rotundata can be used as a recommendation for the development of Anti-bacterial drugs in the future.
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Rambaran, Neervana, Yougasphree Naidoo, Farzana Mohamed, Hafizah Y. Chenia e Himansu Baijnath. "Antibacterial and Anti-Quorum Sensing Properties of Silver Nanoparticles Phytosynthesized Using Embelia ruminata". Plants 13, n. 2 (8 gennaio 2024): 168. http://dx.doi.org/10.3390/plants13020168.
Abstract (sommario):
The rise in antibiotic resistance (AR) poses an imminent threat to human health. Nanotechnology, together with mechanisms such as quorum sensing (QS), which relies on communication between bacterial cells, may decrease the selective pressure for AR. Thus, this study aimed to investigate the effectiveness of silver nanoparticles (AgNPs) synthesized at room temperature (Rt) and 80 °C using Embelia ruminata leaf, stem-bark, and fruit extracts as antibacterial and anti-QS agents. The phytosynthesized AgNPs solutions were subjected to various characterization assays and assessed for their antibacterial activities. Quantitative QS assays were performed using Chromobacterium subtsugae CV017 and Chromobacterium violaceum ATCC 12472. Synthesized AgNPs were spherical-to-near-spherical in shape, poly-dispersed, and crystalline, with a size range of 21.06–32.15 nm. Fruit AgNPs showed stronger antibacterial activity than AgNPs from other plant organs against selected bacterial strains. In the QS assays, fruit 80 °C AgNPs demonstrated the most significant violacein inhibition in an assay performed using the short-chain acyl homoserine lactone CV017 biosensor, while the leaf and fruit Rt AgNPs demonstrated the most violacein inhibition in an assay performed using the long-chain acyl homoserine lactone ATCC 12472 biosensor. The investigations carried out in this study lay the groundwork for future innovative research into antibacterial and anti-QS strategies using E. ruminata.
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Baszczynski, Chris L. "A rapid immunoprecipitation assay for neomycin phosphotransferase II expression in transformed bacteria and plant tissues". Biochemistry and Cell Biology 68, n. 6 (1 giugno 1990): 983–87. http://dx.doi.org/10.1139/o90-145.
Abstract (sommario):
Anti-kanamycin antibodies produced in rabbits, following coupling of the antibiotic to bovine serum albumin, were used to immunoprecipitate radioactively labelled phosphorylated kanamycin from transformed bacterial or plant extracts in a novel assay system, for the detection of neomycin phosphotransferase II (NPTII) activity. Radioactive counts in the immunoprecipitated pellet give a semiquantitative measure of the kanamycin phosphorylation and hence the amount of NPTII activity. This assay is sensitive, uses very small amounts of radioactivity, and is very rapid, allowing many samples to be processed within a few hours. Immunoprecipitated counts from reactions with bacteria carrying a kanamycin resistance gene or from tobacco and Brassica napus plants transformed with NPTII gene-containing vectors were consistently higher than counts from nontransformed controls. Results obtained with this assay correlate well with those from the previously described gel overlay and dot-blot assays, but can be obtained in an appreciably shorter time frame.Key words: anti-kanamycin antibodies, immunoprecipitation, neomycin phosphotransferase II assay, transformation.
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Saranya, J., S. Preethi, Mohammed Rafi Shaik, Merajuddin Khan, Mujeeb Khan e Baji Shaik. "Development of Cerium Oxide/Chitosan/Graphene Oxide Nanocomposite: An Investigation toward Its Biological Applications under In Vitro Conditions". Crystals 13, n. 9 (19 settembre 2023): 1393. http://dx.doi.org/10.3390/cryst13091393.
Abstract (sommario):
A ternary nanocomposite was prepared using cerium oxide, chitosan, and graphene oxide (CeO2/CS/GO) using a simple and cost-effective wet chemical method. The physicochemical properties of the developed ternary nanocomposite were examined using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and ultraviolet-visible spectroscopy. Furthermore, the therapeutic behavior of the developed CeO2/CS/GO composite was assessed using anti-bacterial, anti-fungal, and anti-cancer assays. For Escherichia coli, Staphylococcus aureus, and Salmonella species, 750 µg/mL of the CeO2/CS/GO composite showed effective anti-bacterial activity, with a zone of inhibition of 9 mm. Additionally, the CeO2/CS/GO composite’s anti-fungal activity against Aspergillus niger was studied. The anti-cancer properties of different concentrations of the CeO2/CS/GO composite were assessed on MCF-7 cells, and 18.8% of cells were found to be viable at the maximum concentration of 1000 µg/mL CeO2/CS/GO and 46.37% at 125 µg/mL. The results of the hemolysis assay performed using human red blood cells and various concentrations of the CeO2/CS/GO composite indicated that the nanocomposite possesses biological properties. Overall, it can act as a therapeutic platform for breast cancer, bacterial and fungal infections.
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Akhtar, Sultan, Suriya Rehman, Munirah A. Almessiere, Firdos Alam Khan, Yassine Slimani e Abdulhadi Baykal. "Synthesis of Mn0.5Zn0.5SmxEuxFe1.8−2xO4 Nanoparticles via the Hydrothermal Approach Induced Anti-Cancer and Anti-Bacterial Activities". Nanomaterials 9, n. 11 (18 novembre 2019): 1635. http://dx.doi.org/10.3390/nano9111635.
Abstract (sommario):
Manganese metallic nanoparticles are attractive materials for various biological and medical applications. In the present study, we synthesized unique Mn0.5Zn0.5SmxEuxFe1.8−2xO4 (0.01 ≤ x ≤ 0.05) nanoparticles (NPs) by using the hydrothermal approach. The structure and surface morphology of the products were determined by X-ray powder diffraction (XRD), transmission electron and scanning electron microcopies (TEM and SEM), along with energy dispersive X-ray spectroscopy (EDX). We evaluated the impact of Mn0.5Zn0.5SmxEuxFe1.8−2xO4 NPs on both human embryonic stem cells (HEK-293) (normal cells) and human colon carcinoma cells (HCT-116) (cancerous cells). We found that post-48 h of treatment of all products showed a significant decline in the cancer cell population as revealed by microscopically and the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay. The inhibitory concentration (IC50) values of the products ranged between 0.75 and 2.25 µg/mL. When tested on normal and healthy cells (HEK-293), we found that the treatment of products did not produce any effects on the normal cells, which suggests that all products selectively targeted the cancerous cells. The anti-bacterial properties of the samples were also evaluated by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays, which showed that products also inhibited the bacterial growth.
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Wu, Meng, Bingjian Zhang, Guoping Sun e Leping Jiang. "Determination of lacquer contained in samples of cultural relics by enzyme-linked immunosorbent assay". New Journal of Chemistry 41, n. 14 (2017): 6226–31. http://dx.doi.org/10.1039/c7nj00831g.
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Saravanan, Renuka, Ravichandran Natesan, Sumathi C Samiappan e Sivakumar Ramalingam. "Anti-Oxidant, Anti-Bacterial and Anti-Cancer Activity of Mentha Piperita Against Mcf-7 Cells". Biomedical and Pharmacology Journal 14, n. 3 (30 settembre 2021): 1685–93. http://dx.doi.org/10.13005/bpj/2270.
Abstract (sommario):
The study evaluates the antioxidant, antibacterial and anticancer activities of different extracts of Menthapiperitaleaves against the MCF-7 cell line. The leaves of Menthapiperitawere extracted with aqueous, ethyl acetate, and chloroform. These extracts were subjected to qualitative phytochemical screening, antibacterial activity, cytotoxic activity, and AO/ErBr assay for cells' apoptotic effect against the MCF-7 cell line. Qualitative analysis of the leaves' different extracts revealed glycosides, alkaloids, flavonoids, terpenoids, tannin, and saponin. The antibacterial activity of the leaf extracts was examined against four different bacterial species (Bacillus cereus, Pseudomonasfluorescens, Aeromonas hydrophila, and Klebsiella pneumoniae). The aqueous extract exhibited a high level of antibacterial activity (18.66mm ±1.1 in Bacillus cereus).Free‑radicalscavenging activity of chloroform extractof M. piperita leaves was found to be more than aqueous and ethyl acetate extracts. Further, aqueous, ethyl acetate,and chloroform extracts exerted a cytotoxic effect with the IC50value of 45±1.5μg/ml, 29±1.2μg/ml, and 24±1.0μg/ml, respectively.From this study, we have observed that chloroform extract showed a concentration-dependent apoptotic effect against MCF-7 cellsdetermined by AO/EtBr assay.The resultsfurther depicted that the selected traditionalMentha piperita could be used as a potential anticancer, antibacterial, and good antioxidant agent against the MCF-7 cell line.
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Schaller, Alain, Zhonghe Sun, Yongping Yang, Akos Somoskovi e Ying Zhang. "Salicylate Reduces Susceptibility of Mycobacterium tuberculosis to Multiple Antituberculosis Drugs". Antimicrobial Agents and Chemotherapy 46, n. 8 (agosto 2002): 2636–39. http://dx.doi.org/10.1128/aac.46.8.2636-2639.2002.
Abstract (sommario):
ABSTRACT Salicylate induces multiple antibiotic resistance in various bacterial species. Here we investigated the effect of salicylate on the susceptibility of Mycobacterium tuberculosis to a range of antituberculosis (anti-TB) drugs. In the presence of salicylate, the killing effects of isoniazid (INH), rifampin (RMP), ethambutol (EMB), streptomycin (STR), and p-aminosalicylate (PAS) were reduced, as shown with a tetrazolium redox dye viability assay and a bacterial survival assay. Salicylate-induced resistance was more pronounced for PAS, STR, and EMB but was not apparent for INH and RMP when salicylate and the anti-TB agents were incorporated into 7H11 plates. The significance of these findings for TB treatment needs to be further evaluated in vivo.
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Ökmen, Gülten, Zafer Cantekin, Mohammmad Intakhab Alam, Onur Türkcan e Yaşar Ergün. "Antibacterial and Antioxidant Activities of Liquidambar Orientalis Mill. Various Extracts Against Bacterial Pathogens Causing Mastitis". Turkish Journal of Agriculture - Food Science and Technology 5, n. 8 (26 agosto 2017): 883. http://dx.doi.org/10.24925/turjaf.v5i8.883-887.1163.
Abstract (sommario):
Antibiotic resistance is being constantly developed worldwide. Coagulase Negative Staphylococci (CNS) and Staphylococcus aureus are common causes of bovine subclinical mastitis. Bioactive compound of medicinal plants shows anti-microbial, anti-mutagenic and anti-oxidant effects. The anti-bacterial and anti-oxidant activities of Liquidambar orientalis (L. orientalis) extracts on subclinical mastitis causing bacteria in cows have not been reported to date. The aim of the present study was to examine anti-bacterial and anti-oxidant effects of L. orientalis leaf extracts on S. aureus and CNS isolated from cows with subclinical mastitis symptoms. In this study, 3.2 mg/mL minimum inhibitory concentration (MIC) of ethanol extracts of L. orientalis has shown to be a most potent anti-bacterial and anti-oxidant for all isolated bacterial species from mastitis cows. In this study, it was investigated anti-bacterial and anti-oxidant potentials of acetone, methanol and ethanol extracts of the L. orientalis. The acetone extract showed maximum inhibition zone against S. aureus numbered 17 (12 mm). In addition to anti-bacterial properties, anti-oxidant activity of L. orientalis extract was examined by ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)] free radical assay. Trolox was used as a positive control anti-oxidant. Ethanol extract exhibited a strong anti-oxidant activity like Trolox anti-oxidant which was effective at 2.58 mM concentration. Bioactive compounds of sweet gum may be useful to screening mastitis causing bacteria for clinical applications.
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Maidment, Clem, Zosia Dembny e Paul King. "Investigations into the anti-bacterial properties of garlic using the disc assay method". Journal of Biological Education 32, n. 3 (settembre 1998): 162–65. http://dx.doi.org/10.1080/00219266.1998.9655616.
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Abuei, Haniyeh, Abbas Behzad-Behbahani, Fatemeh Faghihi, Ali Farhadi, Gholam Reza Rafiei Dehbidi, Mohammad Pirouzfar e Farahnaz Zare. "The Effect of Bacterial Peptide p28 on Viability and Apoptosis Statusof P53-null HeLa Cells". Advanced Pharmaceutical Bulletin 9, n. 4 (24 ottobre 2019): 668–73. http://dx.doi.org/10.15171/apb.2019.078.
Abstract (sommario):
Purpose: Despite all the efforts for discovery of efficient anti-cancer therapeutics, cancer is stilla major health concern worldwide. p28 is a bacterial small peptide which has been widelyinvestigated due to its preferential cell internalization and anti-cancer activities. Intracellularly,p28 offers its anti-cancer traits by impeding the degradation of tumor-suppressor protein "p53".In this study, we investigated the potency of p28 in inducing apoptosis or decreasing cellviability in p53-null "HeLa" cell line.Methods: The coding sequence for p28 peptide was obtained from Pseudomonas aeruginosaby PCR amplification of the p28 gene. The coding gene was cloned in pET-28a vector andtransformed into E. coli bacterial host. Subsequently, the expressed peptide was purified usingNi-NTA chromatography system and introduced into the target cells. The anti-proliferative andapoptotic activity of p28 on HeLa and HEK-293 cells were investigated using MTT and PEAnnexinV Flowcytometry assays.Results: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Westernblotting confirmed the expression of p28 peptide in the bacterial host. Bradford assay revealeda concentration of 0.05 mg/mL for the purified p28. MTT assay of cells treated with p28 atconcentrations of 0, 0.5, 1, 2 and 2.5 μM indicated 24h viability values of 97%, 89%, 88%,87% and 84% for HeLa cells, respectively. Data obtained from flowcytometry analyses revealed24h apoptosis rate of 7.17%, 8.05%, 8.63% and 8.84% for HeLa cells treated with 0, 0.5, 1,and 2 μM p28, respectively.Conclusion : MTT and flowcytometry apoptosis assays suggest no statistically significant effectof p28 on the viability and apoptosis status of p53-null HeLa cells when results compared todata obtained from HEK-293 cells (P > 0.05). These results imply that anti-cancer efficacy of p28is directly dependent on the presence of p53, suggesting p28 as an inappropriate therapeuticagent for treatment of cancers with negative p53 status.<br />
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Yust-Katz, Shlomit, Elinor Gigi, Deborah Rosenberg, Andrew A. Kanner, Yoseph Laviv, Alexandra Benouaich-Amiel, Tali Siegal, Adva Levi Barda e Ravid Straussman. "TAMI-40. TUMOR MICROBIOME AND GLIOBLASTOMA (GBM)". Neuro-Oncology 22, Supplement_2 (novembre 2020): ii221—ii222. http://dx.doi.org/10.1093/neuonc/noaa215.928.
Abstract (sommario):
Abstract Bacteria have been found to play major roles in many physiologic/disease processes including cancer. The presence of bacteria within brain tumors has never been explored. The aim of this study was to examine the microbiome of Glioblastoma. A cohort of 40 glioblastoma samples (FFPE), from two medical centers served for DNA extraction using a specialized extraction protocol that includes a bead beating step to ensure complete bacterial DNA recovery. A set of negative controls was introduced at different steps of the assay to identify and monitor contaminating bacterial DNA. We measured the levels of bacterial DNA in the samples using a RT-qPCR assay, amplifying the bacterial 16S rRNA gene and detected bacterial DNA in over 40% of the samples. To characterize the bacterial taxa that are present in GBM tumors, we applied 16S DNA sequencing on the samples. After implementing a stringent set of filters on the sequencing data, eliminating contaminating signal, we detected a total of 22 bacterial taxa in GBM tumors. To visualize bacteria in GBM tissues and learn about their localization within the tissue we used immunohistochemistry staining with anti-lipopolysaccharide (LPS) and anti-lipoteichoic acid (LTA) antibodies detecting gram negative and gram positive bacteria (correspondingly). Bacteria were also visualized by staining bacterial RNA using a 16S rRNA in situ hybridization assay. Staining of a human GBM tissue microarray (TMA) containing 32 cases of GBM showed that the majority of cases stained positive for LPS and ~40% were positive for 16S rRNA staining. Bacterial LPS and 16S rRNA were localized mainly inside the tumor cells. Our study demonstrates, for the first time, that bacteria or bacterial components are present in human Glioblastoma tumors. We are currently expanding our study cohort in order to better define the bacteria found within glioblastoma samples and assess their possible effects
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Mihalache, Madalina, Alina Banciu, Lucian Ionescu e Mihai Nita-Lazar. "Elisa preliminary studies of immobilization and specific detection of bacterial strains". Romanian Journal of Ecology & Environmental Chemistry 2, n. 2 (14 ottobre 2020): 64–69. http://dx.doi.org/10.21698/rjeec.2020.209.
Abstract (sommario):
The paper aims to emphasize the specific detection of bacterial strains using enzyme-linked immunosorbent assay. The assay is based on the specific binding of polyclonal antibody anti-E. coli tagged with FITC to E.coli and monoclonal antibody anti-Ps. aeruginosa tagged with Alexa Fluor 647 tagged to Ps. aeruginosa and on subsequent enzymatic immunological demonstration of the conjugated enzyme. In this experiment, the negative control was the Salmonella enterica strain. The two antibodies had no interaction with the negative control, instead, they were specific for E. coli and Ps. aeruginosa strains. When both strains were in the same well, the fluorescence intensity given by the presence of E. coli was 2.3 times higher than that given by Ps. aeruginosa, and the intensity of fluorescence decreased if there are both bacterial strains in the wells.
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Janosch, D., S. Dubbert, K. Eiteljörge, B. W. K. Diehl, U. Sonnenborn, L. V. Passchier, T. M. Wassenaar e R. von Bünau. "Anti-genotoxic and anti-mutagenic activity of Escherichia coli Nissle 1917 as assessed by in vitro tests". Beneficial Microbes 10, n. 4 (19 aprile 2019): 449–61. http://dx.doi.org/10.3920/bm2018.0113.
Abstract (sommario):
Anti-genotoxic or anti-mutagenic activity has been described for a number of Gram-positive probiotic bacterial species. Here we present evidence that Gram-negative Escherichia coli Nissle 1917 (EcN) also displays anti-genotoxic/anti-mutagenic activity, as assessed in vitro by the Comet Assay and the Ames Test, respectively. This activity was demonstrated by use of the mutagens 4-nitroquinoline-1-oxide (NQO), hydrogen peroxide (H2O2) and benzo(a) pyrene (B[a]P). For both assays and all three test agents the anti-genotoxic/anti-mutagenic activity of EcN was shown to be concentration dependent. By the use of extracts of bacteria that were inactivated by various procedures (heat treatment, ultrasound sonication or ultraviolet light irradiation), mechanistic explanations could be put forward. The proposed mechanisms were enforced by treating the bacterial material with proteinase K prior to testing. The mutagen H2O2 is most likely inactivated by enzymic activity, with catalase a likely candidate, while several explanations can be put forward for inactivation of B[a]P. NQO is most likely inactivated by metabolising enzymes, since the formation of the metabolite 4-aminoquinoline could be demonstrated. In conclusion, the in vitro results presented here make a strong case for antimutagenic properties of EcN.
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Clare, Rachel H., Darren A. N. Cook, Kelly L. Johnston, Louise Ford, Stephen A. Ward e Mark J. Taylor. "Development and Validation of a High-Throughput Anti-Wolbachia Whole-Cell Screen". Journal of Biomolecular Screening 20, n. 1 (2 ottobre 2014): 64–69. http://dx.doi.org/10.1177/1087057114551518.
Abstract (sommario):
There is an urgent need to develop new, safe, and affordable macrofilaricidal drugs for onchocerciasis and lymphatic filariasis treatment and control. The Anti- Wolbachia Consortium (A·WOL) aims to provide a novel treatment with macrofilaricidal activity by targeting the essential bacterial symbiont Wolbachia. The consortium is currently screening a diverse range of compounds to find new chemical space to drive this drug discovery initiative and address this unmet demand. To increase the throughput and capacity of the A·WOL cell-based screen, we have developed a 384-well format assay using a high-content imaging system (Operetta) in conjunction with optimized Wolbachia growth dynamics in the C6/36 Aedes albopictus mosquito cell line. This assay uses texture analysis of cells stained with SYTO 11 as a direct measure of bacterial load. This validated assay has dramatically increased the capacity and throughput of the A·WOL compound library screening program 25-fold, enriching the number of new anti- Wolbachia hits identified for further development as potential macrofilaricides for onchocerciasis and lymphatic filariasis.
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Xie, Huijun, Chao Niu, Zeyang Chao, Nuramina Mamat e Haji Akber Aisa. "Synthesis and Activity of New Schiff Bases of Furocoumarin". Heterocyclic Communications 26, n. 1 (31 dicembre 2020): 176–84. http://dx.doi.org/10.1515/hc-2020-0115.
Abstract (sommario):
AbstractFurocoumarins, such as 8-MOP, are the most common medications used to relieve the symptoms of vitiligo clinically. Some furocoumarins also showed excellent performance in an anti-bacterial assay. This paper describes the synthesis of a series of novel Schiff bases (6a-6k), and their promotion in melanogenesis and anti-bacterial properties were studied in vitro.The pigment production of B16 cells and bacterial inhibition ring assay were applied for the bioactivity of 6a-6k. According to the results, a stronger promotion on pigment content was observed, when six compounds co-cultured with cells, compared with positive control (8-MOP). Significantly, compound 6k (237%) as the most active was found to increase the amount of melanin more than 1.7 times compared with 8-MOP activation rate (136%). All the compounds could moderately retard C. albicans growth. Interestingly, aldehyde 5, which possessed a broader antibacterial spectrum, showed the highest inhibition against C. albicans as well and much better than the positive control (Amphotericin B).Studies of 6k in animal models of vitiligo and related molecular mechanism are presently under way, with the aim of discovering an anti-vitiligo leading compound.
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Matotoka, Mashilo Mash, e Peter Masoko. "Evaluation of the Antioxidant, Cytotoxicity, Antibacterial, Anti-Motility, and Anti-Biofilm Effects of Myrothamnus flabellifolius Welw. Leaves and Stem Defatted Subfractions". Plants 13, n. 6 (15 marzo 2024): 847. http://dx.doi.org/10.3390/plants13060847.
Abstract (sommario):
The formation of biofilms underscores the challenge of treating bacterial infections. The study aimed to assess the antioxidant, cytotoxicity, antibacterial, anti-motility, and anti-biofilm effects of defatted fractions from Myrothamnus flabellifolius (resurrection plant). Antioxidant activity was assessed using DPPH radical scavenging and hydrogen peroxide assays. Cytotoxicity was screened using a brine shrimp lethality assay. Antibacterial activity was determined using the micro-dilution and growth curve assays. Antibiofilm potential was screened using the crystal violet and tetrazolium reduction assay. Liquid–liquid extraction of crude extracts concentrated polyphenols in the ethyl acetate and n-butanol fractions. Subsequently, these fractions had notable antioxidant activity and demonstrated broad-spectrum antibacterial activity against selected Gram-negative and Gram-positive bacteria and Mycobacterium smegmatis (MIC values < 630 μg/mL). Growth curves showed that the bacteriostatic inhibition by the ethyl acetate fractions was through the extension of the lag phase and/or suppression of the growth rate. The sub-inhibitory concentrations of the ethyl acetate fractions inhibited the swarming motility of Pseudomonas aeruginosa and Klebsiella pneumoniae by 100% and eradicated more than 50% of P. aeruginosa biofilm biomass. The polyphenolic content of M. flabellifolius plays an important role in its antibacterial, anti-motility, and antibiofilm activity, thus offering an additional strategy to treat biofilm-associated infections.
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Kaur, Atinderpal, Reema Gabrani e Shweta Dang. "Nanoemulsions of Green Tea Catechins and Other Natural Compounds for the Treatment of Urinary Tract Infection: Antibacterial Analysis". Advanced Pharmaceutical Bulletin 9, n. 3 (1 agosto 2019): 401–8. http://dx.doi.org/10.15171/apb.2019.047.
Abstract (sommario):
Purpose: Nanoemulsions (NEs) of polyphenon 60 (P60) and cranberry (NE I) and P60 and curcumin (NE II) were prepared with the aim to enhance anti-bacterial potential and to understand the mechanism of anti-bacterial action of the encapsulated compounds. Methods: To evaluate the antibacterial potential of the developed NE, microtiter biofilm formation assay was performed. The cytotoxicity analysis was done to assess the toxicity profile of the NEs. Further antibacterial analysis against uropathogenic strains was performed to check the developed NEs were effective against these strains. Results: In microtiter dish biofilm formation assay, both NE formulations inhibited the growth more effectively (Av. % inhibition ~84%) as compared to corresponding aqueous solution (Av. % inhibition ~64%) and placebo (Av. % inhibition ~59%) at their respective minimum inhibitory concentration (MIC) values. Cytotoxicity analysis using 3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT assay) showed that the formulations were nontoxic to Vero cells. The antibacterial studies against uropathogenic resistant strains also showed that NEs effectively inhibited the growth of bacterial strains. Conclusion: From different studies it was concluded that both the NE’s were able to inhibit bacterial strains and could be further used for the treatment of urinary tract infection (UTI). The antibacterial activity of developed NEs showed that these could be used as alternative therapies for the treatment of UTI.
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Baker, Brett. "1289. Pravibismane is a Potent, Broad Spectrum Anti-Infective Small Molecule that Rapidly Disrupts Bacterial Bioenergetics and Halts Bacterial Growth". Open Forum Infectious Diseases 7, Supplement_1 (1 ottobre 2020): S659—S660. http://dx.doi.org/10.1093/ofid/ofaa439.1472.
Abstract (sommario):
Abstract Background The rise in resistance to existing antimicrobials has prompted a need for the development of novel antibiotics. Microbion has identified a novel compound, pravibismane, with potent broad spectrum anti-infective and anti-biofilm activity. Methods Here we used a variety of assays, including Bacterial Cytological Profiling (BCP), to analyze pravibismane in E.coli to gain insight into its likely mechanism of action (MOA). The BCP profile of pravibismane suggested it rapidly shut down cell growth, potentially by turning off cellular gene or protein expression. This was confirmed using a plasmid based GFP induction assay in E.coli tolC that showed pravibismane strongly reduced expression of GFP. The kinetics, reversibility and MOA of pravibismane was further characterized by using time-lapse microscopy, wash out experiments and measurements of both membrane potential and relative intracellular ATP levels. Results We found that pravibismane acts rapidly (within 30 mins) to completely halt cell growth rather than causing immediate cell lysis such as that observed with non-specific cell damaging agents bleach or detergent. Inhibitor wash out experiments in which cells were exposed to pravibismane for 2 hours, washed to remove the compound, and then observed using time-lapse microscopy revealed that the effect of pravibismane is reversible and that cells recovered 8-12 hrs after removing the compound. Wash out experiments with an E.coli tolC strain carrying a plasmid with an IPTG inducible GFP demonstrated that transcription and translation ultimately resumed in most cells after washout. The bioenergetics of the membrane was measured using DiBAC 4(5), a membrane potential sensitive dye which can enter depolarized cells, which revealed that pravibismane caused depolarization of the membrane within 30 mins of exposure in a concentration dependent manner. Finally, a luciferase assay determined pravibismane reduced ATP levels (resulting in decreased luminescence) within 15 mins of exposure in a concentration dependent manner unlike antibiotic controls that had modest or no effect on luminescence. Conclusion Our results suggest that pravibismane acts rapidly to disrupt cellular bioenergetics, resulting in the immediate cessation of cell growth and protein expression. Disclosures Brett Baker, M.Sc., D.C., Microbion Corporation (Board Member, Employee)
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Parveen, Romana, Tooba Naz Shamsi, Himanshu Kumar e Sadaf Fatima. "PHYTOCHEMICAL ANALYSIS AND IN VITRO BIOLOGICAL CHARACTERIZATION OF AQUEOUS AND METHANOLIC EXTRACT OF BACOPA MONNIERI". International Journal of Pharmacy and Pharmaceutical Sciences 8, n. 12 (1 dicembre 2016): 90. http://dx.doi.org/10.22159/ijpps.2016v8i12.14739.
Abstract (sommario):
<p><strong>Objective</strong>:<strong> </strong>The present study was designed to identify the phytocompounds, to compare the antibacterial, antioxidant, and anti-inflammatory effects of aqueous and methanolic extract of <em>Bacopa monnieri</em>.</p><p><strong>Methods</strong>:<strong> </strong>Antioxidant activity was determined by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), Super oxide dismutase (SOD), Reduced glutathione (GSH), Catalase assays. Anti-inflammatory activity was measured with inhibition of albumin denaturation and trypsin inhibitory assay. Finally, extracts were tested against various pathogenic bacterial and fungal strains by broth dilution assay and disc diffusion assay respectively.</p><p><strong>Results: </strong>Results showed the presence of alkaloids, flavonoids, phenols, quinines and glycosides etc while steroids and carboxylic acid were absent. The extracts demonstrated free radical-scavenging activity quite comparable with standard ascorbic acid. Methanolic extract exerted comparative higher antioxidant and anti-inflammatory activity than aqueous extract. Both extracts were most effective against <em>Bacillus subtilis</em><em> </em>and lowest inhibition against<em> Staphylococcus aureus</em>.</p><p><strong>Conclusion: </strong>The results obtained clearly indicated a promising potential of <em>B. monnieri</em> for serving as a strong ROS scavenger, might be used as anti-arthritic and strong natural antibiotic agent for effective treatment of various oxidative stressed disorders (cancer, cardiovascular diseases), inflammatory disorders (rheumatoid arthritis) and various bacterial infections.</p>
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Heneghan, Michael A., Ciaran F. McCarthy, Daiva Janulaityte e Anthony P. Moran. "Relationship of Anti-Lewis x and Anti-Lewis y Antibodies in Serum Samples from Gastric Cancer and Chronic Gastritis Patients toHelicobacter pylori-Mediated Autoimmunity". Infection and Immunity 69, n. 8 (1 agosto 2001): 4774–81. http://dx.doi.org/10.1128/iai.69.8.4774-4781.2001.
Abstract (sommario):
ABSTRACT Lewis (Le) antigens have been implicated in the pathogenesis of atrophic gastritis and gastric cancer in the setting ofHelicobacter pylori infection, and H. pylori-induced anti-Le antibodies have been described that cross-react with the gastric mucosa of both mice and humans. The aim of this study was to examine the presence of anti-Le antibodies in patients with H. pylori infection and gastric cancer and to examine the relationships between anti-Le antibody production, bacterial Le expression, gastric histopathology, and host Le erythrocyte phenotype. Anti-Le antibody production and H. pylori Le expression were determined by enzyme-linked immunosorbent assay, erythrocyte Le phenotype was examined by agglutination assays, and histology was scored blindly. Significant levels of anti-Lex antibody (P < 0.0001, T = 76.4, DF = 5) and anti-Ley antibody (P < 0.0001, T = 73.05, DF = 5) were found in the sera of patients with gastric cancer and other H. pylori-associated pathology compared with H. pylori-negative controls. Following incubation of patient sera with synthetic Le glycoconjugates, anti-Lex and -Ley autoantibody binding was abolished. The degree of the anti-Lex and -Leyantibody response was unrelated to the host Le phenotype but was significantly associated with the bacterial expression of Lex (r = 0.863,r 2 = 0.745, P < 0.0001) and Ley (r = 0.796,r 2 = 0.634, P < 0.0001), respectively. Collectively, these data suggest that anti-Le antibodies are present in most patients with H. pyloriinfection, including those with gastric cancer, that variability exists in the strength of the anti-Le response, and that this response is independent of the host Le phenotype but related to the bacterial Le phenotype.
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Zhu, Yifan, Hiroki Kawai, Satoshi Hashiba, Mohan Amarasiri, Masaaki Kitajima, Satoshi Okabe e Daisuke Sano. "The Effect of GD1a Ganglioside-Expressing Bacterial Strains on Murine Norovirus Infectivity". Molecules 25, n. 18 (7 settembre 2020): 4084. http://dx.doi.org/10.3390/molecules25184084.
Abstract (sommario):
In this study, we investigated the impact of GD1a-expressing bacterial strains on the infectivity of murine norovirus (MNV). Eligible bacterial strains were screened from a sewage sample using flow cytometry, and their genetic sequences of 16S rRNA were determined. The enzyme-linked immunosorbent assay (ELISA) was employed to analyze the binding between bacteria and MNV particles, and the plaque assay was used to assess the effects of GD1a-positive and negative strains on MNV infectivity. The result from ELISA shows that MNV particles are able to bind to both GD1a-positive and negative bacterial strains, but the binding to the GD1a-positive strain is more significant. The infectivity assay result further shows that the MNV infectious titer declined with an increasing concentration of GD1a-positive bacteria. The addition of anti-GD1a antibody in the infectivity assay led to the recovery of the MNV infectious titer, further confirming that the binding between MNV particles and bacterial GD1a ganglioside compromises MNV infectivity. Our findings highlight the role indigenous bacteria may play in the lifecycle of waterborne enteric viruses as well as the potential of exploiting them for virus transmission intervention and water safety improvement.
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Mensah, John Kenneth, e Philip Teye Thompson. "Anti-oxidant, anti-microbial and anti-inflammatory activities of <i>Saba thompsonii</i> fruit extracts". International Journal of Biological and Chemical Sciences 17, n. 4 (19 settembre 2023): 1323–40. http://dx.doi.org/10.4314/ijbcs.v17i4.4.
Abstract (sommario):
Aqueous extracts of the fruits of Saba thompsonii are used topically in ethnomedicine in Ghana for healthy wound healing and wound repair. The objective of this study was to comparatively assess the methanolic and the diethylether extracts of the plant phytochemicals for three bioactivities indicative of wound repairs. Using standard laboratory assays involving broth dilution, carrageenan-induced foot swelling of 7-day old chicks and DPPH radical scavenging, this study assessed the anti-microbial, anti-inflammatory and anti-oxidant activities of the methanolic and the diethylether extracts of the fruits of Saba thompsonii. Findings demonstrate that the methanolic extract of Saba thompsonii is a potent anti-inflammatory agent that suppresses carrageenan induced swelling of chick feet dose- dependently (with concentrations that ranges from 30 mg/kg through 100 mg/kg to 300 mg/kg). The methanolic extract demonstrated broad-spectrum activity against a panel of clinical isolates of bacterial and fungi pathogens in vitro (with MIC ranges of 25-100 mg/mL). Furthermore, the methanolic extract displayed a higher overall anti-oxidant status with demonstrable higher free radical scavenging action in the DPPH radical scavenging assay (IC50 of 416.8) and in the H2O2 scavenging assay (IC50 of 562.1). This methanolic extract’s enhanced bioactivity likely resulted from its higher phytochemical content relative to that of the diethylether extract. Altogether, the study supports the ethnomedicinal use of the aqueous extract of the fruits of Saba thompsonii for wound repair.
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Kicheeva, Arina G., Ekaterina S. Sushko, Lyubov S. Bondarenko, Kamila A. Kydralieva, Denis A. Pankratov, Nataliya S. Tropskaya, Artur A. Dzeranov, Gulzhian I. Dzhardimalieva, Mauro Zarrelli e Nadezhda S. Kudryasheva. "Functionalized Magnetite Nanoparticles: Characterization, Bioeffects, and Role of Reactive Oxygen Species in Unicellular and Enzymatic Systems". International Journal of Molecular Sciences 24, n. 2 (6 gennaio 2023): 1133. http://dx.doi.org/10.3390/ijms24021133.
Abstract (sommario):
The current study evaluates the role of reactive oxygen species (ROS) in bioeffects of magnetite nanoparticles (MNPs), such as bare (Fe3O4), humic acids (Fe3O4-HA), and 3-aminopropyltriethoxysilane (Fe3O4-APTES) modified MNPs. Mössbauer spectroscopy was used to identify the local surrounding for Fe atom/ions and the depth of modification for MNPs. It was found that the Fe3O4-HA MNPs contain the smallest, whereas the Fe3O4-APTES MNPs contain the largest amount of Fe2+ ions. Bioluminescent cellular and enzymatic assays were applied to monitor the toxicity and anti-(pro-)oxidant activity of MNPs. The contents of ROS were determined by a chemiluminescence luminol assay evaluating the correlations with toxicity/anti-(pro-)oxidant coefficients. Toxic effects of modified MNPs were found at higher concentrations (>10−2 g/L); they were related to ROS storage in bacterial suspensions. MNPs stimulated ROS production by the bacteria in a wide concentration range (10−15–1 g/L). Under the conditions of model oxidative stress and higher concentrations of MNPs (>10−4 g/L), the bacterial bioassay revealed prooxidant activity of all three MNP types, with corresponding decay of ROS content. Bioluminescence enzymatic assay did not show any sensitivity to MNPs, with negligible change in ROS content. The results clearly indicate that cell-membrane processes are responsible for the bioeffects and bacterial ROS generation, confirming the ferroptosis phenomenon based on iron-initiated cell-membrane lipid peroxidation.
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Kaleeswaran, Sampath, Padmanabhan Sriram, Daivasigamani Prabhu, Chinnathambi, Vijayakumar e Lalgudi Narayanan Mathuram. "Anti- and pro-mutagenic effects of silymarin in the ames bacterial reverse mutation assay". Phytotherapy Research 23, n. 10 (ottobre 2009): 1378–84. http://dx.doi.org/10.1002/ptr.2772.
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Martı́nez-Govea, A., J. Ambrosio, L. Gutiérrez-Cogco e A. Flisser. "Identification and Strain Differentiation of Vibrio cholerae by Using Polyclonal Antibodies against Outer Membrane Proteins". Clinical Diagnostic Laboratory Immunology 8, n. 4 (1 luglio 2001): 768–71. http://dx.doi.org/10.1128/cdli.8.4.768-771.2001.
Abstract (sommario):
ABSTRACT Cholera is caused only by O1 and O139 Vibrio cholerae strains. For diagnosis, 3 working days are needed for bacterial isolation from human feces and for biochemical characterization. Here we describe the purification of bacterial outer membrane proteins (OMP) from V. cholerae O1 Ogawa, O1 Inaba, and O139 strains, as well as the production of specific antisera and their use for fecal Vibrio antigen detection. Anti-OMP antisera showed very high reactivity and specificity by enzyme-linked immunosorbent assay (ELISA) and dot-ELISA. An inmunodiagnostic assay for V. cholerae detection was developed; this assay avoids preenrichment and costly equipment and can be used for epidemiological surveillance and clinical diagnosis of cases, considering that prompt and specific identification of bacteria is mandatory in cholera.
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Di, Da, Mythili Dileepan, Shamim Ahmed, Yuying Liang e Hinh Ly. "Recombinant SARS-CoV-2 Nucleocapsid Protein: Expression, Purification, and Its Biochemical Characterization and Utility in Serological Assay Development to Assess Immunological Responses to SARS-CoV-2 Infection". Pathogens 10, n. 8 (16 agosto 2021): 1039. http://dx.doi.org/10.3390/pathogens10081039.
Abstract (sommario):
The SARS-CoV-2 nucleocapsid protein (N) binds a single-stranded viral RNA genome to form a helical ribonucleoprotein complex that is packaged into virion particles. N is relatively conserved among coronaviruses and consists of the N-terminal domain (NTD) and C-terminal domain (CTD), which are flanked by three disorganized regions. N is highly immunogenic and has been widely used to develop a serological assay as a diagnostic tool for COVID-19 infection, although there is a concern that the natural propensity of N to associate with RNA might compromise the assay’s specificity. We expressed and purified from bacterial cells two recombinant forms of SARS-CoV-2 N, one from the soluble fraction of bacterial cell lysates that is strongly associated with bacterial RNAs and the other that is completely devoid of RNAs. We showed that both forms of N can be used to develop enzyme-linked immunosorbent assays (ELISAs) for the specific detection of human and mouse anti-N monoclonal antibodies (mAb) as well as feline SARS-CoV-2 seropositive serum samples, but that the RNA-free form of N exhibits a slightly higher level of sensitivity than the RNA-bound form to react to anti-N mouse mAb. Using the electrophoretic mobility shift assay (EMSA), we also showed that N preferentially binds ssRNA in a sequence-independent manner and that both NTD and CTD of N contribute to RNA-binding activity. Collectively, our study describes methods to express, purify, and biochemically characterize the SARS-CoV-2 N protein and to use it for the development of serological assays to detect SARS-CoV-2 infection.
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Xie, Yanxuan, Jingxin Chen, Bo Wang, Ai-Yun Peng, Zong-Wan Mao e Wei Xia. "Inhibition of Quorum-Sensing Regulator from Pseudomonas aeruginosa Using a Flavone Derivative". Molecules 27, n. 8 (10 aprile 2022): 2439. http://dx.doi.org/10.3390/molecules27082439.
Abstract (sommario):
Quorum sensing (QS) is a cell-to-cell communication process that controls bacterial collective behaviors. The QS network regulates and coordinates bacterial virulence factor expression, antibiotic resistance and biofilm formation. Therefore, inhibition of the QS system is an effective strategy to suppress the bacterial virulence. Herein, we identify a phosphate ester derivative of chrysin as a potent QS inhibitor of the human pathogen Pseudomonas aeruginosa (P. aeruginosa) using a designed luciferase reporter assay. In vitro biochemical analysis shows that the chrysin derivative binds to the bacterial QS regulator LasR and abrogates its DNA-binding capability. In particular, the derivative exhibits higher anti-virulence activity compared to the parent molecule. All the results reveal the potential application of flavone derivative as an anti-virulence compound to combat the infectious diseases caused by P. aeruginosa.
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Praiwala, B., S. Priyanka, N. Raghu, N. Gopenath, A. Gnanasekaran, M. Karthikeyan, R. Indumathi et al. "In vitro anti-bacterial activity of Tinospora cordifolia leaf extract and its phytochemical screening". Journal of Biomedical Sciences 5, n. 2 (17 aprile 2019): 10–17. http://dx.doi.org/10.3126/jbs.v5i2.23633.
Abstract (sommario):
Background: Antimicrobial resistance is the main concern worldwide to combat infectious. Over the years studies on leaf extracts Tinospora cordifolia have demonstrated the potent role its antibacterial property. The current study is an attempt to test its antibacterial property against Escherichia coli cell division.
Material and methods: Phytochemical screening assay of T. cordifolia leaf extract was done using standard procedure and the results showed the presence of alkaloid, carbohydrate, terpenoid, steroid, tannin, amino acid, flavonoid and glycoside components.
Results: HPLC analysis revealed the presence of berberine in T. cordifolia leaf extract. Further E. coli cells were treated with berberine to study its efficacy in inhibiting cell division. Antibacterial assay was performed by using disc diffusion method.
Conclusion: Among aqueous, methanolic, ethanolic, chloroform, hexane and acetone extract only methanolic extract showed zone of inhibition.
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Wibawa, I. P. A. H., M. Hanafi, A. S. Li’aini, A. Rahayu, I. N. Lugrayasa, V. M. Butardo e P. J. Mahon. "Total phenolic and flavonoid contents of Aphanamixis polystachya (Wall.) R.Parker leaf extract and its potential as antioxidant and inhibitor of α-glucosidase". IOP Conference Series: Earth and Environmental Science 1255, n. 1 (1 ottobre 2023): 012016. http://dx.doi.org/10.1088/1755-1315/1255/1/012016.
Abstract (sommario):
Abstract Indonesia is one of the countries with the highest plant diversity in the world, including the Aphanamixis genus, and they use the plants in this genus as traditional medicine. The genus Aphanamixis has a wide variety of compounds with different activities, such as insecticidal, leishmanicidal, antimicrobial, anticancer, cytotoxic against some cancer cells, and antioxidant The focus of this research is to find out about the anti-oxidant, anti-diabetic, and anti-bacterial activities of Aphanamixis polystachya leaf extract from the Bali Botanical Garden plant collection. The antioxidant activity assay was carried out by scavenging the free radical 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenyl ethylamino) propane hydrochloride (DPPH). The antidiabetic assay was carried out by inhibiting the activity of the α-glucosidas eenzyme, while the antibacterial test was carried out by the agar diffusion method. Based on the data generated in this study, the active ingredients of A. polystachya leaf extracts have high potency as antioxidants and α-glucosidase enzyme inhibitors, but the extract was not effective in inhibiting bacterial growth.
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Nabil-Adam, Asmaa, Mohamed A. Shreadah, Nehad M. Abd El Moneam e Samy A. El-assar. "Pesudomance sp. Bacteria Associated with Marine Sponge as a Promising and Sustainable Source of Bioactive Molecules". Current Pharmaceutical Biotechnology 20, n. 11 (30 settembre 2019): 964–84. http://dx.doi.org/10.2174/1389201020666190619092502.
Abstract (sommario):
Background: The study was conducted to identify the bacterial strain associated with marine sponge Hyrtiosaff. erectus collected from the Red Sea coastal water and to assess the utilization of their secondary metabolites for human benefit as antioxidant, anti-Alzheimer, anti-viral, anticancer and anti-inflammatory agent. Methods: After biochemical identification of Pesudomance sp. bacterial strain, the total polyphenol contents, cytotoxic, antioxidant, anti-Alzheimer, anti-viral, anticancer and anti-inflammatory activity of the Pesudomance sp. ethyl acetate extract were investigated by applying different biochemical assays. Polyphenol contents were investigated using spectrophotometric techniques. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and 2,2/-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical scavenging activity assays. The cytotoxic effects were investigated by using the human cancerous cell lines. Results: The anti-Alzheimer, anti-viral, anticancer and anti-inflammatory activities were determined using ELISA. Qualitative phytochemical analysis of the Pesudomance sp. extract demonstrated the presence of a large and diverse group of substances such as alkaloids, carbohydrates, flavonoids, phenols, terpenoids, saponins, and tannins. The strong antioxidant activity of the Pesudomance sp. extract was mainly attributed to the protective role of polyphenols against reactive oxygen. It was also observed that Pesudomance sp. extract possessed significant anti-Alzheimer activity with 94% at 1 mg. The extract showed also high antiviral activity (90%) using reverse transcriptase enzymes inhibition assay. The examination of the anticancer activity by applying two experimental models, i.e., PTK and SHKI cleared out high significant percentages of 76.19 and 83.09 %; respectively. Conclusion: The anti-inflammatory profiling using TNF, COX1, COX2, IL6 also revealed high antiinflammatory activity with different metabolic pathway of 62.70, 75.444, 79.27 and 54.15 %; respectively. The present study concluded that ethyl acetate extract of Pesudomance sp. possessed strong antioxidant, anti-Alzheimer, and anti-viral, anticancer and anti-inflammatory activities. Further studies are required to purify the bioactive compounds.
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Priya B e Vijayachitra A. "Anti-atherosclerotic and Anti-Biofilm properties of Pleurotus ostreatus Metabolites". International Journal of Research in Pharmaceutical Sciences 11, n. 4 (26 settembre 2020): 5533–38. http://dx.doi.org/10.26452/ijrps.v11i4.3187.
Abstract (sommario):
To investigate the anti-biofilm and anti-atherosclerotic properties of metabolites from a mushroom, Pleurotus ostreatus was selected as the main objective of present study. The study involved the following series of steps to meet the objective. Coating the metal stents with fungal metabolites and vitamin-E, to study the anti-biofilm properties against biofilm producing bacterial species (Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa), to determine the drug release behaviour from the coated stents, and to investigate the cytotoxic assay and biocompatibility of the coated stents using MTT assay method. Anti-biofilm activity of the developed Metabolite-Vitamin E (MVE) combinations showed significant activity against Staphylococcus epidermidis (0.5mg/ml) and Pseudomonas aeruginosa (0.75mg/ml). Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus expressed respective anti-biofilm values of 0.5mg/ml, 0.25mg/ml and 0.5mg/ml. Drug release behaviour analysis revealed controlled and sustained release of fungal metabolites from the stents coated with Metabolite-Vitamin E mixture. In vitro MTT assay revealed that Metabolite-Vitamin E did not inhibit the growth of L929 fibroblast cells; indicating the biocompatibility of the coated stents. Mushrooms producing pharmacologically significant metabolites could be exploited in treating cardiovascular diseases in human beings to a greater extent. Future analysis could be useful in identifying the significant chemical compounds present in the metabolites.
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Soingam, Tanyapohn, e Moltira Srithaworn. "Anti-tyrosinase, anti-skin pathogenic bacterial, and antioxidant activities and phytochemical constituents of Dracaena cochinchinensis (Lour.) S.C. Chen extract". Bioscience Journal 39 (31 marzo 2023): e39050. http://dx.doi.org/10.14393/bj-v39n0a2023-66896.
Abstract (sommario):
Dracaena cochinchinensis (Lour.) S.C. Chen (Chandaeng) is an important traditional medicinal plant used in ancient Thai household remedies. This research focused on investigating the biological properties, including the antibacterial, anti-tyrosinase, antioxidant activities, and phytochemical characteristics of crude Chandaeng extracts. Dried Chandaeng heartwood powder was extracted using ethanol, methanol, and deionized water. The antibacterial activities of the extracts were then tested against skin pathogens, including Cutibacterium acnes (DMST14916), Staphylococcus epidermidis (TISTR518), and Staphylococcus aureus (TISTR321). The ethanolic extract showed antibacterial activity. In a time-kill assay, all bacteria were completely killed after being exposed to it, while the cell membranes were found to have leaked when viewed under a scanning electron microscope. Antioxidant potential was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2¢-azino-bis -3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. According to the findings, the crude ethanolic extract of Chandaeng showed the highest level of antioxidant activity. Furthermore, the potential of the extract to treat skin hyperpigmentation by inhibiting tyrosinase, an important melanin synthesis enzyme, was determined and the ethanolic extract was found to be an anti-tyrosinase agent. Finally, the crude ethanolic extract showed the highest total phenolic compound and flavonoid content. In conclusion, crude Chandaeng extract showed significant potential in activity against skin pathogenic bacteria, antioxidant activity, and tyrosinase inhibition. These properties of the extract could be applied to skincare cosmetics.
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Laserna, Kris Corinne D. C., Christian Deo T. Deguit, Wilfred F. Ong e Drexel H. Camacho. "Lipophilic halogen-free ionic liquid with antibacterial and anti-biofilm activities against Pseudomonas aeruginosa". KIMIKA 29, n. 2 (28 dicembre 2018): 23–29. http://dx.doi.org/10.26534/kimika.v29i2.23-29.
Abstract (sommario):
A halogen-free ionic liquid (IL) designed with long alkyl chain anion is reported. 1-methylimidazolium stearate (MIM stearate) synthesized through Bronsted acid-base reaction has shown improved lipophilic character and is able to penetrate bacterial cell walls. Antimicrobial activities against Gram-negative bacteria, Escherichia coli, and Pseudomonas aeruginosa were observed. Anti-biofilm assays showed effectivity against the biofilm of Pseudomonas aeruginosa. At 50 µg/mL the %biofilm inhibition of MIM stearate towards P. aeruginosa biofilm formation is comparable to the Bromofuran positive control. Brine shrimp lethality assay showed weak toxicity indicating the IL to be safe and benign. The synthesized MIM stearate showed good promise as an antimicrobial and anti-biofilm agent.
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Barker, Emilia, Lina AlQobaly, Zahab Shaikh, Kirsty Franklin, Johanna Thurlow, Behfar Moghaddam, Jonathan Pratten e Keyvan Moharamzadeh. "Biological Evaluation of Oral Care Products Using 3D Tissue-Engineered In Vitro Models of Plaque-Induced Gingivitis". Dentistry Journal 12, n. 5 (6 maggio 2024): 126. http://dx.doi.org/10.3390/dj12050126.
Abstract (sommario):
Background: The aim of this study was to investigate and visualize the anti-inflammatory and anti-bacterial effects of different oral care products using an infected and inflamed 3D tissue-engineered gingival mucosal model. Methods: A 3D full-thickness oral mucosal model was engineered inside tissue culture inserts using collagen hydrogels populated with human gingival fibroblasts and THP-1 monocytes and layered with oral epithelial cell lines. Oral saliva bacteria were cultured and added to the surface of the models and inflammation was further simulated with lipopolysaccharide (LPS) of Escherichia coli. The 3D models were exposed to three different types of toothpastes, a chlorhexidine antiseptic mouthwash, different antibiotics, and a mechanical rinse with phosphate-buffered saline (PBS) prior to biological evaluation using the PrestoBlue tissue viability assay, histology, optical coherence tomography (OCT), confocal microscopy, and measurement of the release of the inflammatory markers IL-1β, IL-6, and IL-8 with ELISA. Results: Multiple-endpoint analyses of the infected oral mucosal models treated with different anti-bacterial agents showed consistent outcomes in terms of tissue viability, histology, OCT, and confocal microscopy findings. In terms of anti-inflammatory testings, the positive control group showed the highest level of inflammation compared with all other groups. Depending on the anti-bacterial and anti-inflammatory potential of the test groups, different levels of inflammation were observed in the test groups. Conclusions: The inflamed 3D oral mucosal model developed in this study has the potential to be used as a suitable in vitro model for testing the biocompatibility, anti-inflammatory, and anti-bacterial properties of oral care products including mouthwashes and toothpastes. The results of this study indicate that the chlorhexidine mouthwash has both anti-bacterial and cytotoxic effects on the 3D oral mucosal model. Hyaluronic-acid-containing toothpaste has significant anti-bacterial and anti-inflammatory effects on the 3D oral mucosal model.
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Rashtchian, A., J. Eldredge, M. Ottaviani, M. Abbott, G. Mock, D. Lovern, J. Klinger e G. Parsons. "Immunological capture of nucleic acid hybrids and application to nonradioactive DNA probe assay." Clinical Chemistry 33, n. 9 (1 settembre 1987): 1526–30. http://dx.doi.org/10.1093/clinchem/33.9.1526.
Abstract (sommario):
Abstract Antibodies specific for DNA:RNA hybrids were coated onto polystyrene test tubes and applied to hybridization assays involving DNA and RNA. Synthetic DNA probes complementary to 16S rRNA of Campylobacter were labeled with biotin and hybridized to ribosomal RNA directly in lysates of bacterial cells. After hybridization, DNA:RNA hybrids were captured with immobilized anti-DNA:RNA antibody, and the biotinylated probe was detected with streptavidin-horseradish peroxidase (EC 1.11.1.7) conjugate. The assay was optimized to detect as few as 70,000 Campylobacter cells in a sample. We compared the utility of this hybridization assay with that of conventional microbiology methods by examination of 1448 stool samples from hospital clinical laboratories. The DNA hybridization assay had a sensitivity of 98.7% (75/76) and a specificity of 98.2% (1347/1372) and overall agreed with 98.2% of the conventional results for a test population that had a 5.2% incidence (76/1448) of Campylobacter infection. The assay is simple to perform and yields results within 2.5 h.
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SobhZadehi, Mahdieh, Hojjatollah Zamani e Mohammad Hossein YektaKooshali. "Curcumin Aattenuates the Expression of Metalloprotease (AHA_0978) and Serine Protease (AHA_3857) Genes in Aeromonas Hydrophila". Galen Medical Journal 12 (17 dicembre 2023): e3038. http://dx.doi.org/10.31661/gmj.v12i.3038.
Abstract (sommario):
Background: Aeromonas hydrophila is a pathogenic bacterium responsible for various infections in humans and animals. Bacterial exoproteases are considered an important determinant in the pathogenicity of A. hydrophila. Serine protease and metalloprotease, that are regulated by the bacterial Quorum sensing (QS) system are important virulent factors in the pathogenicity of A. hydrophila. Anti-QS potential of curcumin has been reported, previously. In this work, we characterized the effect of curcumin on the expression of the metalloprotease and serine protease genes in A. hydrophila. Materials and Methods: The minimum inhibitory concentration (MIC) of curcumin was measured by the agar macro-dilution method and a sub-inhibitory concentration (1/2 MIC) was used in subsequent experiments. The expression level of the metalloprotease and serine protease genes among the treated and control bacteria was evaluated using quantitative PCR (qPCR) assay. Bacterial proteolytic activity was also measured by skim milk agar plate assay. Results: MIC of curcumin for bacterial strain was 1024 μg/ml curcumin, and at 512 µg/mL (1/2 MIC) it remarkably attenuated the expression of the metalloprotease and serine protease genes up to 66 and 77%, respectively. Also, the proteolytic activity of A. hydrophila was considerably reduced by curcumin. Conclusion: Due to the promising inhibitory effect on bacterial proteolysis, curcumin could be considered an anti-virulence agent against A. hydrophila.
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Laegreid, William, Mark Hoffman, James Keen, Robert Elder e Jimmy Kwang. "Development of a Blocking Enzyme-Linked Immunosorbent Assay for Detection of Serum Antibodies to O157 Antigen ofEscherichia coli". Clinical Diagnostic Laboratory Immunology 5, n. 2 (1 marzo 1998): 242–46. http://dx.doi.org/10.1128/cdli.5.2.242-246.1998.
Abstract (sommario):
ABSTRACT The O157 antigen of Escherichia coli shares structural elements with lipopolysaccharide (LPS) antigens of other bacterial species, notably Brucella abortus and Yersinia enterocolitica O9, a fact that confounds the interpretation of assays for anti-O157 antibodies. To address this problem, a blocking enzyme-linked immunosorbent assay (bELISA) was designed with E. coli O157:H7 LPS as the antigen and a monoclonal antibody specific for E. coli O157, designated 13B3, as the competing antibody. The bELISA had equivalent sensitivity to, and significantly higher specificity than, the indirect ELISA (iELISA), detecting anti-O157 antibodies in sera from cattle experimentally inoculated with O157:H7. Only 13% of sera from naive heifers vaccinated for or experimentally infected with B. abortus had increased anti-O157 bELISA titers, while 61% of anti-O157 iELISA titers were increased. The bELISA is a sensitive and specific method for the detection of serum antibodies resulting from exposure to E. coli O157.
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Wolfson, Goldie, Ronit Vogt Sionov, Reem Smoum, Maya Korem, Itzhack Polacheck e Doron Steinberg. "Anti-Bacterial and Anti-Biofilm Activities of Anandamide against the Cariogenic Streptococcus mutans". International Journal of Molecular Sciences 24, n. 7 (24 marzo 2023): 6177. http://dx.doi.org/10.3390/ijms24076177.
Abstract (sommario):
Streptococcus mutans is a cariogenic bacterium in the oral cavity involved in plaque formation and dental caries. The endocannabinoid anandamide (AEA), a naturally occurring bioactive lipid, has been shown to have anti-bacterial and anti-biofilm activities against Staphylococcus aureus. We aimed here to study its effects on S. mutans viability, biofilm formation and extracellular polysaccharide substance (EPS) production. S. mutans were cultivated in the absence or presence of various concentrations of AEA, and the planktonic growth was followed by changes in optical density (OD) and colony-forming units (CFU). The resulting biofilms were examined by MTT metabolic assay, Crystal Violet (CV) staining, spinning disk confocal microscopy (SDCM) and high-resolution scanning electron microscopy (HR-SEM). The EPS production was determined by Congo Red and fluorescent dextran staining. Membrane potential and membrane permeability were determined by diethyloxacarbocyanine iodide (DiOC2(3)) and SYTO 9/propidium iodide (PI) staining, respectively, using flow cytometry. We observed that AEA was bactericidal to S. mutans at 12.5 µg/mL and prevented biofilm formation at the same concentration. AEA reduced the biofilm thickness and biomass with concomitant reduction in total EPS production, although there was a net increase in EPS per bacterium. Preformed biofilms were significantly affected at 50 µg/mL AEA. We further show that AEA increased the membrane permeability and induced membrane hyperpolarization of these bacteria. AEA caused S. mutans to become elongated at the minimum inhibitory concentration (MIC). Gene expression studies showed a significant increase in the cell division gene ftsZ. The concentrations of AEA needed for the anti-bacterial effects were below the cytotoxic concentration for normal Vero epithelial cells. Altogether, our data show that AEA has anti-bacterial and anti-biofilm activities against S. mutans and may have a potential role in preventing biofilms as a therapeutic measure.