Journal articles: 'Antioxidant enzymes'

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Zulaikhah, Siti Thomas. "The Role of Antioxidant to Prevent Free Radicals in The Body." Sains Medika 8, no. 1 (April 4, 2017): 39. http://dx.doi.org/10.26532/sainsmed.v8i1.1012.

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AbstractAntioxidants are compounds that can counteract or reduce the negative impact oxidants in the body. Antioxidants work by donating an electron to compounds that are oxidant so that the oxidant compound activity can be inhibited. Antioxidants are classified into two, namely antioxidant enzymes and non-enzyme. Antioxidant enzymes as enzyme superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), a non-enzyme antioxidant found in many vegetables and fruits, which include reduced glutathione (GSH), vitamin C, E, β- carotene, flavonoids, isoflavones, flavones, antosionin, catechins, and isokatekin, and lipoic acid. Low antioxidant enzymes can be used as a marker of high levels of free radicals in the body. Following review aims to provide an overview of the role of antioxidants in preventing the formation of free radicals in the body.

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Zulaikhah, Siti Thomas. "The Role of Antioxidant to Prevent Free Radicals in The Body." Sains Medika : Jurnal Kedokteran dan Kesehatan 8, no. 1 (April 4, 2017): 39. http://dx.doi.org/10.30659/sainsmed.v8i1.1012.

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AbstractAntioxidants are compounds that can counteract or reduce the negative impact oxidants in the body. Antioxidants work by donating an electron to compounds that are oxidant so that the oxidant compound activity can be inhibited. Antioxidants are classified into two, namely antioxidant enzymes and non-enzyme. Antioxidant enzymes as enzyme superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), a non-enzyme antioxidant found in many vegetables and fruits, which include reduced glutathione (GSH), vitamin C, E, β- carotene, flavonoids, isoflavones, flavones, antosionin, catechins, and isokatekin, and lipoic acid. Low antioxidant enzymes can be used as a marker of high levels of free radicals in the body. Following review aims to provide an overview of the role of antioxidants in preventing the formation of free radicals in the body.

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Nikitina, O. A., M. A. Darenskaya, N. V. Semenova, and L. I. Kolesnikova. "Antioxidant defense system: regulation of metabolic processes, genetic determinants, methods of determination." Сибирский научный медицинский журнал 42, no. 3 (June 26, 2022): 4–17. http://dx.doi.org/10.18699/ssmj20220301.

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An increase in peroxidation activity is considered as a nonspecific process characteristic of the pathogenesis of various diseases accompanied by antioxidant deficiency. As bioregulators that can increase defense, antioxidants are important links in a multi-stage system of regulation and coordination of various body functions. The structure and function of enzymes involved in the regulation of oxidative stress can be significantly affected by genetic polymorphism. To date, the role of genes encoding the activity of enzymes of the antioxidant system in the pathogenesis of many diseases remains unexplored, which is of great interest to researchers from various fields. The article presents a review and analysis of data from modern scientific literature on the role of antioxidant defense components in the regulation of metabolic processes, their genetic determinant, and summarizes data on modern methods for the determination of some antioxidants. When writing the review, the database of the scientific electronic library eLibrary was used, the keywords are oxidative stress, free radical oxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, antioxidant response element, research methods; filters – publication years 2012–2022, publications with full text, publications available for viewing; English-language database of medical and biological publications, created by the National Center for Biotechnology Information (NCBI), keywords – lipid peroxidation, antioxidant protection, antioxidants, antioxidant enzymes, enzyme genes, oxidative stress, metabolism, methods.

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Oliveira, Luciana S., Maria S. M. Rufino, Carlos F. H. Moura, Fabio R. Cavalcanti, Ricardo E. Alves, and Maria R. A. Miranda. "The influence of processing and long-term storage on the antioxidant metabolism of acerola (Malpighia emarginata) purée." Brazilian Journal of Plant Physiology 23, no. 2 (2011): 151–60. http://dx.doi.org/10.1590/s1677-04202011000200007.

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This study evaluated the effect of the processing and long-term storage on the antioxidant potential and activity of antioxidant enzymes of frozen purées from six acerola clones. Ripe acerolas from clones BRS 235, BRS 236, BRS 237, BRS 238, II47/1 and BRS 152 were harvested; the pulp was processed, packed in sealed polyethylene plastic bags and stored in a domestic freezer at -18°C for 11 months. Samples of each clone were analyzed on harvest/processing day and every 30 days after for bioactive antioxidant compounds, antioxidant enzyme activity and total antioxidant activity. Acerola purées presented a decrease of non-enzyme antioxidants and an increase of antioxidant enzymes activities, indicatives of a compensatory mechanism between enzymatic and non-enzymatic antioxidants. In acerola purée, anthocyanin and polyphenols are strongly correlated to soluble solids content and vitamin C seems a major contributor to total antioxidant activity. Clone II47/1 had an outstanding performance regarding the antioxidant potential of its purée and the best storage period at -18ºC would be 150 days, for all clones studied.

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Kolesnikova, L. I., T. A. Bairova, and O. A. Pervushina. "GENES OF ANTIOXIDANT ENZYMES." Annals of the Russian academy of medical sciences 68, no. 12 (December 10, 2013): 83–88. http://dx.doi.org/10.15690/vramn.v68i12.865.

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Oxidative stress plays an important role in the pathogenesis the most of diseases. Important components of protecting cells from oxidative stress are antioxidant enzymes. Antioxidant enzymes are characterized by population differences in enzyme activity. The purpose of the study to summarize and discuss information on genetic polymorphisms of antioxidant enzymes in the most pathology. The development plays of the role of oxidative stress.

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Nirwal, Mr Arjun, and Aamarpali Roy. "IMBALANCE OF ANTIOXIDANT ENZYMES AND CANCER." GENESIS 8, no. 2 (June 10, 2021): 1–7. http://dx.doi.org/10.47211/tg.2021.v08i02.001.

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Oxidants are the substances which are produced in the body normally during a healthy and normal cellular metabolism. These chemical reactions are catalyzed by enzymes. Antioxidants refer to a substance that inhibits the oxidation process. Oxygen is a molecule which is highly reactive, and creates damage to living species by producing oxygen-based compounds that are reactive. The damage that is caused to the macromolecules at a cellular level is a main reason given for origin of many, life threatening illness including cancer. To protect itself, the body produces multiple antioxidant enzymes. Antioxidant enzymes refer to the proteins which are involved in the reactive oxygen species transformation which is a catalytic reaction along with their by -products into stable molecules which are non-toxic, and thereby representing a defense mechanism which is very important against the damage of cell because of the criteria oxidative stress-induced. The main Antioxidant enzymes are GPx (Glutathione Peroxidase), SOD (Superoxide Dismutase), CAT (Catalases), GST (Glutathione S- Transferase), and GR (Glutathione Reductase). An imbalance of any of these enzymes has serious repercussions. A study of cancer cells, showed an imbalance in the antioxidant enzyme level which is prevalent in almost all the types of Cancers. Low enzyme levels are commonly seen in human and animal cancer cells. It is significant to analyze and study the effects of these enzyme in case if unbalancing occur, as well as how and what type of reactions occur leading to the growth of cancer cells in the human body.

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Verma, Nibha, and Manjula Vinayak. "Semecarpus anacardium nut extract promotes the antioxidant defence system and inhibits anaerobic metabolism during development of lymphoma." Bioscience Reports 29, no. 3 (March 3, 2009): 151–64. http://dx.doi.org/10.1042/bsr20080035.

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Antioxidants are substances that fight against ROS (reactive oxygen species) and protect the cells from their damaging effects. Production of ROS during cellular metabolism is balanced by their removal by antioxidants. Any condition leading to increased levels of ROS results in oxidative stress, which promotes a large number of human diseases, including cancer. Therefore antioxidants may be regarded as potential anticarcinogens, as they may slow down or prevent development of cancer by reducing oxidative stress. Fruits and vegetables are rich source of antioxidants. Moreover, a number of phytochemicals present in medicinal plants are known to possess antioxidant activity. Therefore the aim of the present study was to investigate antioxidant activity of the aqueous extract of nuts of the medicinal plant Semecarpus anacardium in AKR mouse liver during the development of lymphoma. Antioxidant action was monitored by the activities of antioxidant enzymes catalase, superoxide dismutase and glutathione transferase. The effect of S. anacardium was also studied by observing the activity of LDH (lactate dehydrogenase), an enzyme of anaerobic metabolism. LDH activity serves as a tumour marker. The activities of antioxidant enzymes decreased gradually as lymphoma developed in mouse. However, LDH activity increased progressively. Administration of the aqueous extract of S. anacardium to lymphoma-transplanted mouse led to an increase in the activities of antioxidant enzymes, whereas LDH activity decreased significantly, indicating a decrease in carcinogenesis. The aqueous extract was found to be more effective than doxorubicin, a classical anticarcinogenic drug, with respect to its action on antioxidant enzymes and LDH in the liver of mice with developing lymphomas.

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Danuyanti, I. Gusti Ayu Nyoman, and Ersandhi Resnhaleksmana. "THE USE OF BLACK SOYBEAN (Glycine max L) EXTRACT AGAINST THE ACTIVITY OF LIVER ENZYMES (AST - ALT) AND ANTIOXIDANT SUPEROXIDE DISMUSTASE (SOD) OF WHITE RAT." Jurnal Kesehatan Prima 12, no. 1 (July 24, 2018): 54. http://dx.doi.org/10.32807/jkp.v12i1.93.

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Abstract: Strenuous physical activity can increase the activity of enzymes AST (aspartate aminotransaminase) and ALT (alanine aminotransaminase) in the blood as a sign of hepatic dysfunction caused by oxidative stress as a result. Excessive free radicals that damage macromolecules in cells. The supplementation of black soybean (Glycine max L) contains anthocyanin as an antioxidant is expected to reduce the formation of free radicals thus the activity of liver enzymes and the levels of SOD enzymes as intracellular antioxidant can be maintained. The purpose of this study was to determine the effect of using extracts of black soybean (Glycine max L) on the activity of liver enzymes (AST-ALT) and the antioxidant superoxide dismutase (SOD) of white rats that were given a maximum of physical activity. The research was control group post test design in vivo that used black soya extract treatment given to white rats (Rattus norvegicus) Wistar strain given maximum physical activity. The results indicated black soybean extract 40% was the most powerful retaining the activity of liver enzymes and blood levels of antioxidants SOD. The conclusion is there is an effect of black soybean extract against the activity of liver enzymes (AST-ALT) in rats given maximal activity, whereas SOD enzymes can inhibit the decline of SOD enzyme level to 37.8% but statistically there is no significant influence.Keywords: AST-ALT enzymes; antioxidants SOD; Soybean black; Physical activity maximum.

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Sree Kumar, K., Yashesh N. Vaishnav, and Joseph F. Weiss. "Radioprotection by antioxidant enzymes and enzyme mimetics." Pharmacology & Therapeutics 39, no. 1-3 (January 1988): 301–9. http://dx.doi.org/10.1016/0163-7258(88)90076-9.

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Wang, Shan, Guolin He, Meng Chen, Tao Zuo, Wenming Xu, and Xinghui Liu. "The Role of Antioxidant Enzymes in the Ovaries." Oxidative Medicine and Cellular Longevity 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/4371714.

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Proper physiological function of the ovaries is very important for the entire female reproductive system and overall health. Reactive oxygen species (ROS) are generated as by-products during ovarian physiological metabolism, and antioxidants are indicated as factors that can maintain the balance between ROS production and clearance. A disturbance in this balance can induce pathological consequences in oocyte maturation, ovulation, fertilization, implantation, and embryo development, which can ultimately influence pregnancy outcomes. However, our understanding of the molecular and cellular mechanisms underlying these physiological and pathological processes is lacking. This article presents up-to-date findings regarding the effects of antioxidants on the ovaries. An abundance of evidence has confirmed the various significant roles of these antioxidants in the ovaries. Some animal models are discussed in this review to demonstrate the harmful consequences that result from mutation or depletion of antioxidant genes or genes related to antioxidant synthesis. Disruption of antioxidant systems may lead to pathological consequences in women. Antioxidant supplementation is indicated as a possible strategy for treating reproductive disease and infertility by controlling oxidative stress (OS). To confirm this, further investigations are required and more antioxidant therapy in humans has to been performed.

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Vaidya, NA. "Antioxidant enzymes and antioxidants in children with Pneumonia." IOSR Journal of Dental and Medical Sciences 8, no. 6 (2013): 01–05. http://dx.doi.org/10.9790/0853-0860105.

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Živković, Jelena, Slavica Sunarić, Nataša Trutić, Marko Denić, Gordana Kocić, and Tatjana Jovanović. "Antioxidants and Antioxidant Capacity of Human Milk / Antioksidansi i antioksidativni kapacitet humanog mleka." Acta Facultatis Medicae Naissensis 32, no. 2 (June 1, 2015): 115–25. http://dx.doi.org/10.1515/afmnai-2015-0012.

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SUMMARY Milk contains plenty of enzymatic and non-enzymatic antioxidant components that probably account for the vital antioxidant protection of the infants at early stages of life against the development of complications induced by oxygen free radicals. Indigenous milk enzymes play a key role in regulating lactogenesis, including active involution of mammary gland. Moreover, they are essential constituents of antioxidation and the innate immune system of milk. Among antioxidant enzymes, superoxide dismutase, catalase and selenium-containing glutathione peroxidase have been demonstrated in human milk. Mainly, the enzyme content of colostrum is higher than that in corresponding mature milk. Beside lipophilic antioxidant in human milk, tocopherols, carotenoids and vitamin A are of great interest. Those components demonstrate the highest levels in colostrum and decline during early lactation, despite the fact that total lipids increase. The complete list of active antioxidant components in human milk is not yet known. This review reports the main findings of enzymatic and non-enzymatic antioxidants, as well as antioxidant capacity of human milk. Synergism of action of several antioxidants helps to eliminate free radicals in newborns. Bearing in mind that milk contains a number of antioxidants, many reactions are possible and it is difficult to define the exact contribution and function of each antioxidant. Besides qualitative and quantitative analysis of human milk antioxidants, the measurement of total antioxidant capacity could be a useful tool for examination of this dynamic, complex fluid

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Dmochowska-Ślęzak, Kamila, Małgorzata Dmitryjuk, Ewa Zaobidna, and Krystyna Żółtowska. "The antioxidant defense system of Varroa destructor mites facilitates the infestation of Apis mellifera." Journal of Apicultural Science 60, no. 1 (June 1, 2016): 163–66. http://dx.doi.org/10.1515/jas-2016-0010.

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Abstract Varroa destructor is a parasitic mite of the Western honey bee. The activity of five antioxidant enzymes of V. destructor were analysed. Glutathione content and total antioxidant status was also evaluated. Our results suggest that antioxidant enzymes constitute the main line of defense against ROS in V. destructor, whereas low-molecular-weight antioxidants play a limited role in the antioxidant system of mites.

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Badwan, Sami, Elizabeth Bailey, and James M. Harper. "Do Antioxidants Extend Longevity in Invertebrate and Vertebrate Animals?" OBM Geriatrics 07, no. 01 (March 7, 2023): 1–17. http://dx.doi.org/10.21926/obm.geriatr.2301226.

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In the 1950’s Denham Harman proposed the Free Radical Theory of Aging whereby species lifespan and individual longevities are the consequence of free radical driven damage to biomolecules. This led to decades of research to ascertain the effect of altered antioxidant defense systems on aging and mortality in an array of species using reverse genetics and dietary manipulation. Within invertebrates, the data generally support the Free Radical Theory in that overexpression of antioxidant enzymes or dietary supplementation with antioxidant compounds increases longevity and resistance to oxidative damage. Likewise, genetic knockdown of antioxidant defenses generally shortens longevity within invertebrates. On the other hand, for endothermic vertebrates (i.e., birds and mammals) the results have been equivocal. Downregulation of antioxidant enzymes typically results in an increased oxidative burden, but without an appreciable effect on longevity, while dietary supplementation with antioxidants has little-to-no effect, at least at the concentrations used. Upregulation of antioxidant enzyme genes also fails to increase longevity in vertebrates most of the time. Interestingly, manipulating antioxidant defenses in fishes increases longevity in conjunction with reduced oxidative damage akin to what is seen in invertebrates. Since invertebrates and fishes are both exothermic this raises the possibility that the evolution of endothermy interferes with the ability of antioxidants to slow the aging process.

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Roy, Uttam Kumer, Birthe Vejby Nielsen, and John James Milledge. "Antioxidant Production in Dunaliella." Applied Sciences 11, no. 9 (April 27, 2021): 3959. http://dx.doi.org/10.3390/app11093959.

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Microalgae have become an attractive natural source of a diverse range of biomolecules, including enzymatic and non-enzymatic antioxidants; nevertheless, economically sustainable production of such compounds from microalgae biomass is still challenging. The main hurdles are: (a) increasing microalgae yield; (b) achieving optimal cultivation conditions; (c) energy-efficient and cost-effective downstream processing (extraction and purification); (d) optimal storage of post-processed antioxidant molecules. This review provides a detailed overview of enzymatic and non-enzymatic antioxidants in the cellular metabolism of the commercially important microalgae Dunaliella, industrial applications of antioxidant enzymes, strategies to enhanced antioxidant accumulation in cells, and the opportunities and limitations of current technologies for antioxidant enzymes production from microalgae biomass as an alternative to common microbial sources.

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Mir, Brashna, Ayesha Mushtaq, Sabeena Rizwan, Farrukh Bashir, Uzma Jabeen, Farida Behlil, and Saba Afzal. "Comparison of Antioxidant Enzymes in Natural and Commercial Honey." Pak-Euro Journal of Medical and Life Sciences 5, no. 1 (March 31, 2022): 31–38. http://dx.doi.org/10.31580/pjmls.v5i1.2422.

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Honey is popular all over the world and used commonly in medicines and food. This study was designed to compare the natural and commercial honey for their antioxidant enzymes. In this study, 11 different honey samples were collected from different areas of Balochistan. The activity of different antioxidants like superoxide dismutase, peroxidase and catalase enzymes were measured and compared by standard curves of pure enzymes moreover, protein content was also determined by using Bradford Assay. Results showed that highest protein content was found in one of the natural honey samples (4.42 ± 0.02 U/mg) enzymes like superoxide dismutase showed highest activity of (4.93 ± 0.06 U/mg) secondly peroxidase activity of (0.34 ± 0.02 U/mg) and third catalase activity of (0.22 ± 0.01 U/mg) in different natural honey samples. The current study demonstrated that higher concentration of protein content and antioxidant enzymes were found in natural honey which means they are good source of antioxidants. Therefore, antioxidant enzymes can be used as markers for determining the purity and quality of honey.

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Staerck, Cindy, Amandine Gastebois, Patrick Vandeputte, Alphonse Calenda, Gérald Larcher, Louiza Gillmann, Nicolas Papon, Jean-Philippe Bouchara, and Maxime J. J. Fleury. "Microbial antioxidant defense enzymes." Microbial Pathogenesis 110 (September 2017): 56–65. http://dx.doi.org/10.1016/j.micpath.2017.06.015.

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Trivedi, Shilpa, and Nand Lal. "Antioxidant enzymes in periodontitis." Journal of Oral Biology and Craniofacial Research 7, no. 1 (January 2017): 54–57. http://dx.doi.org/10.1016/j.jobcr.2016.08.001.

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Harris, Edward D. "Regulation of Antioxidant Enzymes." Journal of Nutrition 122, suppl_3 (March 1, 1992): 625–26. http://dx.doi.org/10.1093/jn/122.suppl_3.625.

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Kahl, Regine, Andreas Kampkötter, Wim Wätjen, and Yvonni Chovolou. "Antioxidant Enzymes and Apoptosis." Drug Metabolism Reviews 36, no. 3-4 (January 2004): 747–62. http://dx.doi.org/10.1081/dmr-200033488.

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Asaduzzaman Khan, Md, Mousumi Tania, Dian-zheng Zhang, and Han-chun Chen. "Antioxidant enzymes and cancer." Chinese Journal of Cancer Research 22, no. 2 (June 2010): 87–92. http://dx.doi.org/10.1007/s11670-010-0087-7.

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Chang, Caroline, Beth L. Worley, Rébécca Phaëton, and Nadine Hempel. "Extracellular Glutathione Peroxidase GPx3 and Its Role in Cancer." Cancers 12, no. 8 (August 6, 2020): 2197. http://dx.doi.org/10.3390/cancers12082197.

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Mammalian cells possess a multifaceted antioxidant enzyme system, which includes superoxide dismutases, catalase, the peroxiredoxin/thioredoxin and the glutathione peroxidase systems. The dichotomous role of reactive oxygen species and antioxidant enzymes in tumorigenesis and cancer progression complicates the use of small molecule antioxidants, pro-oxidants, and targeting of antioxidant enzymes as therapeutic approaches for cancer treatment. It also highlights the need for additional studies to investigate the role and regulation of these antioxidant enzymes in cancer. The focus of this review is on glutathione peroxidase 3 (GPx3), a selenoprotein, and the only extracellular GPx of a family of oxidoreductases that catalyze the detoxification of hydro- and soluble lipid hydroperoxides by reduced glutathione. In addition to summarizing the biochemical function, regulation, and disease associations of GPx3, we specifically discuss the role and regulation of systemic and tumor cell expressed GPx3 in cancer. From this it is evident that GPx3 has a dichotomous role in different tumor types, acting as both a tumor suppressor and pro-survival protein. Further studies are needed to examine how loss or gain of GPx3 specifically affects oxidant scavenging and redox signaling in the extracellular tumor microenvironment, and how GPx3 might be targeted for therapeutic intervention.

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Pathak, Chandramani, Yogesh K. Jaiswal, and Manjula Vinayak. "Queuine promotes antioxidant defence system by activating cellular antioxidant enzyme activities in cancer." Bioscience Reports 28, no. 2 (April 1, 2008): 73–81. http://dx.doi.org/10.1042/bsr20070011.

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Constant generation of ROS (reactive oxygen species) during normal cellular metabolism of an organism is generally balanced by a similar rate of consumption by antioxidants. Imbalance between ROS production and antioxidant defence results in an increased level of ROS, causing oxidative stress, which leads to promotion of malignancy. Queuine is a hyper-modified base analogue of guanine, found at the first anticodon position of the Q-family of tRNAs. These tRNAs are completely modified with respect to queuosine in terminally differentiated somatic cells; however, hypo-modification of Q-tRNAs is closely associated with cell proliferation. Q-tRNA modification is essential for normal development, differentiation and cellular function. Queuine is a nutrient factor for eukaryotes. It is found to promote the cellular antioxidant defence system and inhibit tumorigenesis. The activities of antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase are found to be low in the DLAT (Dalton's lymphoma ascites transplanted) mouse liver compared with normal mouse liver. However, exogenous administration of queuine to the DLAT cancerous mouse improves the activities of antioxidant enzymes. These results suggest that queuine promotes the antioxidant defence system by increasing antioxidant enzyme activities and in turn inhibits oxidative stress and tumorigenesis.

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Han, Kyu-Ho. "Relationships among alcoholic liver disease, antioxidants, and antioxidant enzymes." World Journal of Gastroenterology 22, no. 1 (2016): 37. http://dx.doi.org/10.3748/wjg.v22.i1.37.

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Anantachoke, Natthinee, Pattamapan Lomarat, Wasin Praserttirachai, Ruksinee Khammanit, and Supachoke Mangmool. "Thai Fruits Exhibit Antioxidant Activity and Induction of Antioxidant Enzymes in HEK-293 Cells." Evidence-Based Complementary and Alternative Medicine 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/6083136.

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The cellular antioxidant enzymes play the important role of protecting the cells and organisms from the oxidative damage. Natural antioxidants contained in fruits have attracted considerable interest because of their presumed safety and potential nutritional value. Even though antioxidant activities of many fruits have been reported, the effects of phytochemicals contained in fruits on the induction of antioxidant enzymes in the cells have not been fully defined. In this study, we showed that extracts fromAntidesma ghaesembilla,Averrhoa bilimbi,Malpighia glabra,Mangifera indica, Sandoricum koetjape,Syzygium malaccense,andZiziphus jujubainhibited H2O2-induced intracellular reactive oxygen species production in HEK-293 cells. Additionally, these Thai fruit extracts increased the mRNA and protein expressions of antioxidant enzymes, catalase, glutathione peroxidase-1, and manganese superoxide dismutase. The consumption of Thai fruits rich in phenolic compounds may reduce the risk of oxidative stress.

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Lei, Xin Gen, Jian-Hong Zhu, Wen-Hsing Cheng, Yongping Bao, Ye-Shih Ho, Amit R. Reddi, Arne Holmgren, and Elias S. J. Arnér. "Paradoxical Roles of Antioxidant Enzymes: Basic Mechanisms and Health Implications." Physiological Reviews 96, no. 1 (January 2016): 307–64. http://dx.doi.org/10.1152/physrev.00010.2014.

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Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate “paradoxical” outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of “antioxidant” nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that “paradoxical” roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways.

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Hong, Yu Ah, and Cheol Whee Park. "Catalytic Antioxidants in the Kidney." Antioxidants 10, no. 1 (January 18, 2021): 130. http://dx.doi.org/10.3390/antiox10010130.

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Reactive oxygen species and reactive nitrogen species are highly implicated in kidney injuries that include acute kidney injury, chronic kidney disease, hypertensive nephropathy, and diabetic nephropathy. Therefore, antioxidant agents are promising therapeutic strategies for kidney diseases. Catalytic antioxidants are defined as small molecular mimics of antioxidant enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, and some of them function as potent detoxifiers of lipid peroxides and peroxynitrite. Several catalytic antioxidants have been demonstrated to be effective in a variety of in vitro and in vivo disease models that are associated with oxidative stress, including kidney diseases. This review summarizes the evidence for the role of antioxidant enzymes in kidney diseases, the classifications of catalytic antioxidants, and their current applications to kidney diseases.

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Kletkiewicz, Hanna, Maciej Klimiuk, Alina Woźniak, Celestyna Mila-Kierzenkowska, Karol Dokladny, and Justyna Rogalska. "How to Improve the Antioxidant Defense in Asphyxiated Newborns—Lessons from Animal Models." Antioxidants 9, no. 9 (September 21, 2020): 898. http://dx.doi.org/10.3390/antiox9090898.

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Oxygen free radicals have been implicated in brain damage after neonatal asphyxia. In the early phase of asphyxia/reoxygenation, changes in antioxidant enzyme activity play a pivotal role in switching on and off the cascade of events that can kill the neurons. Hypoxia/ischemia (H/I) forces the brain to activate endogenous mechanisms (e.g., antioxidant enzymes) to compensate for the lost or broken neural circuits. It is important to evaluate therapies to enhance the self-protective capacity of the brain. In animal models, decreased body temperature during neonatal asphyxia has been shown to increase cerebral antioxidant capacity. However, in preterm or severely asphyxiated newborns this therapy, rather than beneficial seems to be harmful. Thus, seeking new therapeutic approaches to prevent anoxia-induced complications is crucial. Pharmacotherapy with deferoxamine (DFO) is commonly recognized as a beneficial regimen for H/I insult. DFO, via iron chelation, reduces oxidative stress. It also assures an optimal antioxidant protection minimizing depletion of the antioxidant enzymes as well as low molecular antioxidants. In the present review, some aspects of recently acquired insight into the therapeutic effects of hypothermia and DFO in promoting neuronal survival after H/I are discussed.

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Furulyás, D., F. Nyéki, M. Stéger-Máté, É. Stefanovits-Bányai, and Sz Bánvölgyi. "Effects of pectolytic enzyme treatment and microfiltration on antioxidant components of elderberry juice." Acta Universitatis Sapientiae, Alimentaria 10, no. 1 (October 1, 2017): 116–26. http://dx.doi.org/10.1515/ausal-2017-0008.

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AbstractIn this study, pectolytic enzymes (Pectinex BE XXL,Trenolin Rot, andFructozym P) were investigated for their influence on phenolic, anthocyanin content, and antioxidant activities of elderberry (Sambucus nigraL.) pulps during juice processing. Prior to pressing the berries, three different enzymes were added to pulps in order to evaluate the effect of different pectolytic enzyme treatments on the valuable components of elderberry juice. Control sample was prepared without enzyme. After treatment, squeezing, and clarification steps, microfiltration was carried out with ceramic membrane. The effect of this technology on the antioxidant capacity, total polyphenol content, and total anthocyanin content of the clarified elderberry juices has been evaluated in permeate and retentate samples, and membrane retention was calculated. Significantly lower antioxidant capacity was detected in the case of control sample than that obtained using enzyme-treated juices. Retention of antioxidant content on the microfiltration membrane was greatly reduced by using the enzymes. Higher valuable component yield was obtained usingFructozym Penzyme compared withPectinex BE XXLused in industry.

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Tchamgoue, Armelle D., Lauve R. Y. Tchokouaha, Protus A. Tarkang, Jules-Roger Kuiate, and Gabriel A. Agbor. "Costus aferPossesses Carbohydrate Hydrolyzing Enzymes Inhibitory Activity and Antioxidant CapacityIn Vitro." Evidence-Based Complementary and Alternative Medicine 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/987984.

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Diabetes mellitus is a metabolic disorder of glucose metabolism which correlates with postprandial hyperglycemia and oxidative stress. Control of blood glucose level is imperative in the management of diabetes. The present study tested the hypothesis thatCostus afer, an antihyperglycemic medicinal plant, possesses inhibitory activity against carbohydrate hydrolyzing enzymes. Hexane, ethyl acetate, methanol, and water extracts were prepared from the leaf, stem, and rhizome ofC. aferand subjected to phytochemical screening, assayed forα-amylase andα-glucosidase inhibitory activities and antioxidant capacity (determined by total phenolic and total flavonoids contents, ferric reducing antioxidant power (FRAP), and DPPH radical scavenging activity). All extracts inhibitedα-amylase andα-glucosidase activities. Ethyl acetate rhizome and methanol leaf extracts exhibited the best inhibitory activity againstα-amylase andα-glucosidase (IC50: 0.10 and 5.99 mg/mL), respectively. Kinetic analysis revealed two modes of enzyme inhibition (competitive and mixed). All extracts showed antioxidant capacity, with hexane extracts exhibiting the best activity. DPPH assay revealed that methanol leaf, rhizome, and ethyl acetate stem extracts (IC50< 5 mg/mL) were the best antioxidants. The presence of bioactive compounds such as flavonoids, alkaloids, phenols, and tannins may account for the antioxidant capacity and carbohydrate hydrolyzing enzyme inhibitory activity ofC. afer.

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Vrianty, Dela, Rismawati Laila Qodariah, Wahyu Widowati, Ade Putra Fratama Sinaga, Dewi Fibrina, Edy Fachrial, and I. Nyoman Ehrich Lister. "Comparison of Antioxidant and Anti-Tyrosinase Activities of Pineapple (Ananas comosus) Core Extract and Luteolin Compound." Jurnal Kedokteran Brawijaya 30, no. 4 (August 30, 2019): 240. http://dx.doi.org/10.21776/ub.jkb.2019.030.04.2.

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Free radicals and UV exposure can cause aging. Aging prevention needs substances that can prevent molecular oxidation reactions in cells and inhibit the activity of enzymes that trigger aging. Research on pineapple skin and flesh extract (Ananas comosus (L.) Merr.) reported the presence of luteolin compound which functions as antioxidants and antityrosinase. However, in this study, the object used was pineapple core extract (PCE), which has not been widely known for its antioxidant and antityrosinase activity. Therefore, the purpose of this study was to determine the content of phytochemical compounds, antioxidant activity, and inhibitory activity of tyrosinase enzymes by PCE and then compared with the luteolin (LT) compound test results using Fansworth method, DPPH scavenging activity assay and tyrosinase enzyme inhibition assay. Based on the study results, the phytochemical compounds contained in PCE were tannins and triterpenoids. PCE and LT produced the highest DPPH scavenging activity, which was 64.86% and 59.32% (final concentration 200μg/ml and 6.25μg/ml) and the highest tyrosinase inhibition activity, which was 60.52% and 85.02% (final concentration 100 μg/ml). Antioxidant activity was determined based on IC50 of 87.46µg/mL and 4.17 µg/ml respectively. IC50 tyrosinase enzyme inhibition EBN and LT respectively at 62.27µg/ml and 5.25 µg/ml. Antioxidant activity through DPPH free radical scavenging test and tyrosinase enzyme inhibition activity by PCE was lower than LT.

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Doklega, Samar M. A., Sally F. Abo El-Ezz, Nada A. Mostafa, Eldessoky S. Dessoky, Awatif M. Abdulmajeed, Doaa Bahaa Eldin Darwish, Fahad Mohammed Alzuaibr, et al. "Effect of Titanium and Vanadium on Antioxidants Content and Productivity of Red Cabbage." Horticulturae 8, no. 6 (May 28, 2022): 481. http://dx.doi.org/10.3390/horticulturae8060481.

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The present work studied the effect of foliar spray of different concentrations of titanium (Ti, applied as titanium dioxide) and vanadium (V, applied as vanadium pentoxide) on growth, chemical composition, antioxidant contents, antioxidant enzymes, antioxidant capacity, yield and quality criteria of red cabbage plants. For this purpose, 2.0, 4.0 and 6.0 mg L−1 of Ti and V were used to treat red cabbage plants. The control plants were treated with tap water. Our results showed that plants treated with 4.0 mg L−1 of Ti recorded the highest values of plant growth and bioactive compounds, while antioxidant capacity was decreased compared to the other treatments. In addition, plants treated with Ti and V at 2.0 and 4.0 mg L−1, respectively, showed higher values of all of the growth, yield, non-enzymatic antioxidants and antioxidants enzymes’ parameters compared to the untreated plants. Based on the obtained results, it could be concluded that the low concentrations of both Ti and V (2.0 and 4.0 mg L−1) were able to enhance red cabbage growth and yield, as well as the antioxidant contents, enzymes and capacity.

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Powers, Scott K., Erica Goldstein, Matthew Schrager, and Li Li Ji. "Exercise Training and Skeletal Muscle Antioxidant Enzymes: An Update." Antioxidants 12, no. 1 (December 25, 2022): 39. http://dx.doi.org/10.3390/antiox12010039.

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The pivotal observation that muscular exercise is associated with oxidative stress in humans was first reported over 45 years ago. Soon after this landmark finding, it was discovered that contracting skeletal muscles produce oxygen radicals and other reactive species capable of oxidizing cellular biomolecules. Importantly, the failure to eliminate these oxidant molecules during exercise results in oxidation of cellular proteins and lipids. Fortuitously, muscle fibers and other cells contain endogenous antioxidant enzymes capable of eliminating oxidants. Moreover, it is now established that several modes of exercise training (e.g., resistance exercise and endurance exercise) increase the expression of numerous antioxidant enzymes that protect myocytes against exercise-induced oxidative damage. This review concisely summarizes the impact of endurance, high-intensity interval, and resistance exercise training on the activities of enzymatic antioxidants within skeletal muscles in humans and other mammals. We also discuss the evidence that exercise-induced up-regulation of cellular antioxidants reduces contraction-induced oxidative damage in skeletal muscles and has the potential to delay muscle fatigue and improve exercise performance. Finally, in hopes of stimulating further research, we also discuss gaps in our knowledge of exercise-induced changes in muscle antioxidant capacity.

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Pastor, Rosario, and Josep A. Tur. "Antioxidant Supplementation and Adaptive Response to Training: A Systematic Review." Current Pharmaceutical Design 25, no. 16 (August 23, 2019): 1889–912. http://dx.doi.org/10.2174/1381612825666190701164923.

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Background: Antioxidant supplementation has become a common practice among athletes to theoretically achieve a reduction in oxidative stress, promote recovery and improve performance. Objective: To assess the effect of antioxidant supplements on exercise. Methods: A systematic literature search was performed up to January 2019 in MEDLINE via EBSCO and Pubmed, and in Web of Sciences based on the following terms: “antioxidants” [Major] AND “exercise” AND “adaptation”; “antioxidant supplement” AND “(exercise or physical activity)” AND “(adaptation or adjustment)” [MesH]. Thirty-six articles were finally included. Results: Exhaustive exercise induces an antioxidant response in neutrophils through an increase in antioxidant enzymes, and antioxidant low-level supplementation does not block this adaptive cellular response. Supplementation with antioxidants appears to decrease oxidative damage blocking cell-signaling pathways associated with muscle hypertrophy. However, upregulation of endogenous antioxidant enzymes after resistance training is blocked by exogenous antioxidant supplementation. Supplementation with antioxidants does not affect the performance improvement induced by resistance exercise. The effects of antioxidant supplementation on physical performance and redox status may vary depending on baseline levels. Conclusion: The antioxidant response to exercise has two components: At the time of stress and adaptation through genetic modulation processes in front of persistent pro-oxidant situation. Acute administration of antioxidants immediately before or during an exercise session can have beneficial effects, such as a delay in the onset of fatigue and a reduction in the recovery period. Chronic administration of antioxidant supplements may impair exercise adaptations, and is only beneficial in subjects with low basal levels of antioxidants.

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Hébert, Claire, and Claude Willemot. "Antioxidant Potential and Strawberry Preservation." HortScience 32, no. 3 (June 1997): 434C—434. http://dx.doi.org/10.21273/hortsci.32.3.434c.

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Plant antioxidants have gained considerable interest because of their importance for the preservation of produce and also because of their therapeutic properties. There is increasing evidence that these compounds protect plant tissues from stress and that they delay senescence. Seven strawberry cultivars were analyzed to investigate the possible relationship between their antioxidant potential and fruit shelf-life. The antioxidant defense systems studied were free radical scavenging enzymes (SOD, catalase, glutathione reductase, GSH, ascorbate peroxidase, ascorbate free radical reductase), ascorbic acid, and ellagic acid. Enzyme assays were performed using spectrophotometric kinetic measurements. Ascorbic acid and ellagic acid were determined by HPLC. The antioxidant potential of the tissues had an incidence on fruit quality and shelf-life. The impact of these antioxidative parameters will be discussed with respect to breeding criteria for reduced perishability of strawberries.

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Rickett, G. M., and F. J. Kelly. "Developmental expression of antioxidant enzymes in guinea pig lung and liver." Development 108, no. 2 (February 1, 1990): 331–36. http://dx.doi.org/10.1242/dev.108.2.331.

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Antioxidant enzyme activities, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and total glutathione concentration were determined in guinea pig lung and liver over the final period of gestation (days 50–68) and at several ages post-partum. Pulmonary antioxidant capacity increased markedly over the final days of gestation, individual changes ranging from 29% (glutathione) to 198% (GSH-Px). Liver antioxidant capacity was always 4-fold to 10-fold greater than that of the lung and exhibited very similar developmental profiles to those observed in the lung. From day 60 gestation to term (68 days), activity of the liver antioxidants increased, ranging from 246% (CAT) to 610% (glutathione). A number of antioxidants in both lung and liver exhibited either immediate pre- or post-birth decreases in activity. These falls could not be attributed to the way in which the results were expressed: i.e. they were similar, expressed per unit DNA, per unit protein, or per g wet wt. Following birth, liver antioxidant capacity increased such that the highest enzyme activities or glutathione concentration were recorded at 66 days post-partum. In lung, only Mn-SOD and glutathione exhibited higher levels at 66 days postpartum than at birth. In combination, these results of pulmonary and hepatic antioxidant enzyme activity indicate that the lung is not unique in acquiring increased antioxidant protection in the final period of gestation. They also suggest that a tissue's antioxidant requirement is dictated more by metabolic rate (hence free radical production) than incident partial pressure of oxygen.

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Kiziltas, Hatice, Ahmet Ceyhan Goren, Saleh H. Alwasel, and İlhami Gulcin. "Sahlep (Dactylorhiza osmanica): Phytochemical Analyses by LC-HRMS, Molecular Docking, Antioxidant Activity, and Enzyme Inhibition Profiles." Molecules 27, no. 20 (October 14, 2022): 6907. http://dx.doi.org/10.3390/molecules27206907.

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Studies have shown an inverse correlation among age-related illnesses like coronary heart disease and cancer and intake of fruit and vegetable. Given the probable health benefits of natural antioxidants from plants, research on them has increased. Dactylorhiza osmanica is consumed as a food and traditional medicine plant in some regions of Turkey, so evaluation of the biological ability of this species is important. In this study, the amount of phenolic content (LC-HRMS), antioxidant activities and enzyme inhibitory properties of an endemic plant, D. osmanica, were investigated. The antioxidant capacities of an ethanol extract of D. osmanica aerial parts (EDOA) and roots (EDOR) were evaluated with various antioxidant methods. Additionally, the enzyme inhibitory effects of EDOA and EDOR were examined against acetylcholinesterase (AChE), α-glycosidase, and α-amylase enzymes, which are associated with common and global Alzheimer’s disease and diabetes mellitus. The IC50 values of EDOA against the enzymes were found to be 1.809, 1.098, and 0.726 mg/mL, respectively; and the IC50 values of EDOR against the enzymes were found to be 2.466, 0.442, and 0.415 mg/mL, respectively. Additionally, LC-HRMS analyses revealed p-Coumaric acid as the most plentiful phenolic in both EDOA (541.49 mg/g) and EDOR (559.22 mg/g). Furthermore, the molecular docking interaction of p-coumaric acid, quercitrin, and vanillic acid, which are the most plentiful phenolic compounds in the extracts, with AChE, α-glucosidase, and α-amylase, were evaluated using AutoDock Vina software. The rich phenolic content and the effective antioxidant ability and enzyme inhibition potentials of EDOA and EDOR may support the plant’s widespread food and traditional medicinal uses.

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Gurol, Gonul, and Ali Aslan. "Lipid peroxidation and antioxidant enzymes." Sakarya Medical Journal 3, no. 1 (2013): 5–7. http://dx.doi.org/10.5505/sakaryamj.2013.87609.

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YILDIRIM, Z., N. I. UCGUN, N. KILIC, E. GURSEL, and A. SEPICI-DINCEL. "Antioxidant Enzymes and Diabetic Retinopathy." Annals of the New York Academy of Sciences 1100, no. 1 (April 1, 2007): 199–206. http://dx.doi.org/10.1196/annals.1395.019.

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CROUCH, ROSALIE K., PATRICE GOLETZ, ARTHUR SNYDER, and WILLIAM H. COLES. "Antioxidant Enzymes in Human Tears." Journal of Ocular Pharmacology and Therapeutics 7, no. 3 (January 1991): 253–58. http://dx.doi.org/10.1089/jop.1991.7.253.

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Harris, Edward D. "Regulation of antioxidant enzymes 1." FASEB Journal 6, no. 9 (June 1992): 2675–83. http://dx.doi.org/10.1096/fasebj.6.9.1612291.

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Singh, Inderjit, Gursev S. Dhaunsi, John K. Orak, and Avtar K. Singh. "Antioxidant enzymes system in peroxisomes." Free Radical Biology and Medicine 15, no. 5 (November 1993): 536. http://dx.doi.org/10.1016/0891-5849(93)90429-x.

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MatÉs, JosÉ M., Cristina Pérez-Gómez, and Ignacio Núñez De Castro. "Antioxidant enzymes and human diseases." Clinical Biochemistry 32, no. 8 (November 1999): 595–603. http://dx.doi.org/10.1016/s0009-9120(99)00075-2.

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Ramkumar, Vickram, Zhongzhen Nie, Leonard P. Rybak, and Sanjay B. Maggirwar. "Adenosine, antioxidant enzymes and cytoprotection." Trends in Pharmacological Sciences 16, no. 9 (September 1995): 283–85. http://dx.doi.org/10.1016/s0165-6147(00)89051-3.

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Huchzermeyer, Bernhard, Ekta Menghani, Pooja Khardia, and Ayushi Shilu. "Metabolic Pathway of Natural Antioxidants, Antioxidant Enzymes and ROS Providence." Antioxidants 11, no. 4 (April 11, 2022): 761. http://dx.doi.org/10.3390/antiox11040761.

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Based on the origin, we can classify different types of stress. Environmental factors, such as high light intensity, adverse temperature, drought, or soil salinity, are summarized as abiotic stresses and discriminated from biotic stresses that are exerted by pathogens and herbivores, for instance. It was an unexpected observation that overproduction of reactive oxygen species (ROS) is a common response to all kinds of stress investigated so far. With respect to applied aspects in agriculture and crop breeding, this observation allows using ROS production as a measure to rank the stress perception of individual plants. ROS are important messengers in cell signaling, but exceeding a concentration threshold causes damage. This requires fine-tuning of ROS production and degradation rates. In general, there are two options to control cellular ROS levels, (I) ROS scavenging at the expense of antioxidant consumption and (II) enzyme-controlled degradation of ROS. As antioxidants are limited in quantity, the first strategy only allows temporarily buffering of a certain cellular ROS level. This way, it prevents spells of eventually damaging ROS concentrations. In this review, we focus on the second strategy. We discuss how enzyme-controlled degradation of ROS integrates into plant metabolism. Enzyme activities can be continuously operative. Cellular homeostasis can be achieved by regulation of respective gene expression and subsequent regulation of the enzyme activities. A better understanding of this interplay allows for identifying traits for stress tolerance breeding of crops. As a side effect, the result also may be used to identify cultivation methods modifying crop metabolism, thus resulting in special crop quality.

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Munkres, Kenneth D. "Pharmacogenetics of cyclic guanylate, antioxidants, and antioxidant enzymes in nuerospora." Free Radical Biology and Medicine 9, no. 1 (January 1990): 29–38. http://dx.doi.org/10.1016/0891-5849(90)90047-m.

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Oyaneder-Terrazas, Javiera, Diego Figueroa, Oscar F. Araneda, and Carlos García. "Saxitoxin Group Toxins Accumulation Induces Antioxidant Responses in Tissues of Mytilus chilensis, Ameghinomya antiqua, and Concholepas concholepas during a Bloom of Alexandrium pacificum." Antioxidants 11, no. 2 (February 15, 2022): 392. http://dx.doi.org/10.3390/antiox11020392.

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Saxitoxin (STX) group toxins consist of a set of analogues which are produced by harmful algal blooms (HABs). During a HAB, filter-feeding marine organisms accumulate the dinoflagellates and concentrate the toxins in the tissues. In this study, we analyze the changes in antioxidant enzymes and oxidative damage in the bivalves Mytilus chilensis and Ameghinomya antiqua, and the gastropod Concholepas concholepas during a bloom of Alexandrium pacificum. The results show that during the exponential phase of the bloom bivalves show an increase in toxicity and activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathinoe reductase, p < 0.05), while in the gastropods, increased activity of antioxidant enzymes was associated with the bioaccumulation of toxins through the diet. At the end of the bloom, decreased activity of antioxidant enzymes in the visceral and non-visceral tissues was detected in the bivalves, with an increase in oxidative damage (p < 0.05), in which the latter is correlated with the detection of the most toxic analogues of the STX-group (r = 0.988). In conclusion, in areas with high incidence of blooms, shellfish show a high activity of antioxidants, however, during the stages involving the distribution and bioconversion of toxins, there is decreased activity of antioxidant enzymes resulting in oxidative damage.

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Zhang, Xia, HaiBo Yin, ShiHua Chen, Jun He, and ShanLi Guo. "Changes in Antioxidant Enzyme Activity and Transcript Levels of Related Genes inLimonium sinenseKuntze Seedlings under NaCl Stress." Journal of Chemistry 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/749047.

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The halophyteLimonium sinenseKuntze is used in traditional Chinese medicine for clearing heat and for detoxification. To examine the detoxification and salt-tolerance mechanisms of this plant, we analyzed antioxidant enzyme activities and transcript levels of genes encoding antioxidant enzymes inL. sinenseseedlings under salt stress (500 mmol/L NaCl). Catalase showed the largest increase in activity, peaking on day 4 of the 7-day NaCl treatment. Peroxidase and superoxide dismutase activities also increased, peaking on days 2 and 3 of the NaCl treatment, respectively. The activities of antioxidant enzymes decreased as the duration of the NaCl treatment extended. The transcript levels of genes encoding antioxidant enzymes were upregulated under NaCl stress. The peak in theLsCATtranscript level was earlier than the peaks inLsAPXandLsGPXtranscript levels. The malondialdehyde content only slightly increased inL. sinenseseedlings under NaCl stress. This was indicative of a low level of lipid peroxidation, consistent with the increased antioxidant enzyme activities and gene transcript levels. These results show that, under NaCl stress, the antioxidant system ofL. sinenseis activated and effectively scavenges reactive oxygen species. This reduces oxidative damage and allows the plant to maintain growth under NaCl stress.

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YILDIZ, Hülya. "Effects of glutathione on mitochondrial DNA and antioxidant enzyme activities in Drosophila melanogaster." International Journal of Secondary Metabolite 9, no. 4 (December 10, 2022): 377–86. http://dx.doi.org/10.21448/ijsm.1084592.

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The free radical theory in aging assumes that the accumulation of macromolecular damage induced by toxic reactive oxygen species plays a central role in the aging process. The intake of nutritional antioxidants can prevent this damage by neutralizing reactive oxygen derivatives. Glutathione (GSH; en-L-Glutamyl-L-cysteinyl glycine) is the lowest molecular weight thiol in the cells and as a cofactor of many enzymes and a potent antioxidant plays an important role in maintaining normal cell functions by destroying toxic oxygen radicals. In this study, the effects of GSH on SOD, GST and catalase enzymes and mtDNA damage were investigated at various time intervals by giving reduced glutathione to Drosophila. It was observed that 3-week GSH administration did not have a statistically significant effect on SOD and GST activities whereas GSH application decreased the catalase enzyme activities significantly. Although the decrease in antioxidant capacity with age was observed in SOD and catalase enzymes, such a situation was not observed in GST enzyme activities. There was no statistically significant difference between the control and GSH groups in mtDNA copy number values, while in the GSH group, oxidative mtDNA damage was high. These results may be due to the prooxidant effect of GSH at the dose used in this study.

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Salami, Maryam, Ali Akbar Moosavi-Movahedi, Faezeh Moosavi-Movahedi, Mohammad Reza Ehsani, Reza Yousefi, Mohammad Farhadi, Amir Niasari-Naslaji, Ali Akbar Saboury, Jean-Marc Chobert, and Thomas Haertlé. "Biological activity of camel milk casein following enzymatic digestion." Journal of Dairy Research 78, no. 4 (September 13, 2011): 471–78. http://dx.doi.org/10.1017/s0022029911000628.

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The aim of this study was to investigate the effects of enzymatic hydrolysis with digestive enzymes of camel whole casein and beta-casein (β-CN) on their antioxidant and Angiotensin Converting Enzyme (ACE)-inhibitory properties. Peptides in each hydrolysate were fractionated with ultra-filtration membranes. The antioxidant activity was determined using a Trolox equivalent antioxidant capacity (TEAC) scale. After enzymatic hydrolysis, both antioxidant and ACE-inhibitory activities of camel whole casein and camel β-CN were enhanced. Camel whole casein and β-CN showed significant ACE-inhibitory activities after hydrolysis with pepsin alone and after pepsinolysis followed by trypsinolysis and chymotrypsinolysis. Camel β-CN showed high antioxidant activity after hydrolysis with chymotrypsin. The results of this study suggest that when camel milk is consumed and digested, the produced peptides start to act as natural antioxidants and ACE-inhibitors.

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Journal articles on the topic 'Antioxidant enzymes'

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