• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.168-195
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• 1992

Pulmonary system is a target organ and primary defense mechanism against environmental oxidants and polutants. Enzymatic and nonenzymatic antioxdant defense mechanisms undoubtedly protect the lung from oxidants even endogenous oxidative stress. In addition, new ways of augmenting pulmonary antioxidant defenses are developed, which can be used to support the intrinsic antioxidants. Therefore, improved understanding of antioxidant defense mechanisms will increase our knowledge of the cause and will suggest rational approaches for treating and preventing oxidant-induced lung injury. In this review, we discuss the formation and scavenging of free radicals, and the strategies for antioxidant defense of pulmonary system.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.117-122
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• 2014

As a Chinese herbal medicine used in East Asia for thousands years, Cortex Magnoliae Officinalis (CMO) was observed to possess a protective effect against OH-induced DNA damage in the study. To explore the mechanism, the antioxidant effects and chemical contents of five CMO extracts were determined by various methods. On the basis of mechanistic analysis, and correlation analysis between antioxidant effects & chemical contents, it can be concluded that CMO exhibits a protective effect against OH-induced DNA damage, and the effect can be attributed to the existence of phenolic compounds, especially magnolol and honokiol. They exert the protective effect via antioxidant mechanism which may be mediated via hydrogen atom transfer (HAT) and/or sequential electron proton transfer (SEPT). In the process, the phenolic-OH moiety in phenylpropanoids is oxidized to the stable quinine-like form and the stability of quinine-like can be ultimately responsible for the antioxidant.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.4
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• pp.250-256
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• 2016

The prevalence of renal disease is increased with the overweight and obesity. High fat diet-associated oxidative stress increases production of reactive oxygen species (ROS) and induces apoptosis. There are two types of antioxidant defense mechanisms for oxidative stress. One is the enzyme defense mechanism by antioxidant enzymes such as superoxide dismutase (SOD), and catalase (CAT). The other is non-enzyme defense mechanism by signaling molecules such as nuclear factor-like 2 (Nrf-2), HO-1. In this study, we induced obesity in mice with high fat diet for six weeks and thereafter administered orally Viola mandshurica for 4 weeks. V. mandshurica is known to clear heat, detoxify and cool blood, and subside a swelling effect. In the V. mandshurica administered group, the immunoreactive signal of the Tunel staining was weaker than that of obesity group. Proapoptotic Bax, caspase 3 immunoreactives of the V. mandshurica administered group was lower than those of obesity group, whereas anti-apoptotic Bcl-2 immunoreactity was higher in the V. mandshurica administered group. Antioxidant enzyme mechanism such as superoxide dismutase 2 (SOD2), catalase (CAT) immunoreactives of the V. mandshurica administered group and Antioxidant non-enzyme mechanism such as Nuclear factor-like 2 (Nrf2), Heme Oxygenase 1 (HO-1) immunoreactives of the V. mandshurica administered group was higher than those of obesity group. These results demonstrate that V. mandshurica had the antioxidant and anti-apoptosis effects on obese mice.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1881-1891
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• 2004

Daejowhan-gamibang(DJG) is used to prevention and treatment of cerebrovascular disease, heart disease, dementia, hyperlipdemia circulatory disturbance. Korean traditional herbal prescriptions and herb medicines in neuronal cells, which have been used for the treatment of stroke and brain diseases in Korean traditional medicine were screened to study the antioxidant effects and its mechanism. Daejowhan-gamibang water extract(DJGWE) was tested on their antioxidant activity using radical scavenging effects against ABTS. It showed significant antioxidant capacities at 50㎍ concentration. The antioxidant activity of DJGWE was determined in the different concentration (10㎍, 50 ㎍, and 100㎍). At the same time, the antiperoxidation effects was determined. Lipid peroxidation in brain homogenates induced by NADPH and ADP-Fe/sup 2+/ was significantly inhibited by DJGWE in vitro. DJGWE showed a potent antioxidant and antiperoxidative activity, further investigation, in vitro and in vivo, will be needed for the confirm of possibility as an antioxidant therapeutic agents and their optimal treatment of brain diseases in human. In searching the mechanism of antioxidant effects of DJGWE, it showed the inhibition of activity of JNK, p38, ERK and caspase 3 induced by hypoxia. So, DJGWE should be surveyed for the use of the potential therapeutic prescription for stroke and brain degenerative diseases such as pakinson's disease, dementia.

• Animal Bioscience
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• v.34 no.3_spc
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• pp.345-353
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• 2021

Phytobiotics, also known as phytochemicals or phytogenics, have a wide variety of biological activities and have recently emerged as alternatives to synthetic antibiotic growth promoters. Numerous studies have reported the growth-promoting effects of phytobiotics in chickens, but their precise mechanism of action is yet to be elucidated. Phytobiotics are traditionally known for their antioxidant activity. However, extensive investigations have shown that these compounds also have anti-inflammatory, antimicrobial, and transcription-modulating effects. Phytobiotics are non-nutritive constituents, and their bioavailability is low. Nonetheless, their beneficial effects have been observed in several tissues or organs. The health benefits of the ingestion of phytobiotics are attributed to their antioxidant activity. However, several studies have revealed that not all these benefits could be explained by the antioxidant effects alone. In this review, I focused on the bioavailability of phytobiotics and the possible mechanisms underlying their overall effects on intestinal barrier functions, inflammatory status, gut microbiota, systemic inflammation, and metabolism, rather than the specific effects of each compound. I also discuss the possible mechanisms by which phytobiotics contribute to growth promotion in chickens.

• Nutrition Research and Practice
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• v.11 no.3
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• pp.206-213
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• 2017

BACKGROUN/OBJECTIVES: Although studies have revealed that black garlic is a potent antioxidant, its antioxidant mechanism remains unclear. The objective of this study was to determine black garlic's antioxidant activities and possible antioxidant mechanisms related to nuclear factor erythroid 2-like factor 2 (Nrf2)-Keap1 complex. METHODS/MATERIALS: After four weeks of feeding rats with a normal fat diet (NF), a high-fat diet (HF), a high-fat diet with 0.5% black garlic extract (HF+BGE 0.5), a high-fat diet with 1.0% black garlic extract (HF+BGE 1.0), or a high-fat diet with 1.5% black garlic extract (HF+BGE 1.5), plasma concentrations of glucose, insulin,homeostatic model assessment of insulin resistance (HOMA-IR) were determined. As oxidative stress indices, plasma concentrations of thiobarbituric acid reactive substances (TBARS) and 8-isoprostaglandin $F2{\alpha}$ (8-iso-PGF) were determined. To measure antioxidant capacities, plasma total antioxidant capacity (TAC) and activities of antioxidant enzymes in plasma and liver were determined. The mRNA expression levels of antioxidant related proteins such as Nrf2, NAD(P)H: quinone-oxidoreductase-1 (NQO1), heme oxygenase-1 (HO-1), glutathione reductase (GR), and glutathione S-transferase alpha 2 (GSTA2) were examined. RESULTS: Plasma glucose level, plasma insulin level, and HOMA-IR in black garlic supplemented groups were significantly (P < 0.05) lower than those in the HF group without dose-dependent effect. Plasma TBARS concentration and TAC in the HF+BGE 1.5 group were significantly decreased compared to those of the HF group. The activities of catalase and glutathione peroxidase were significantly (P < 0.05) increased in the HF+BGE 1.0 and HF+BGE 1.5 groups compared to those of the HF group. The mRNA expression levels of hepatic Nrf2, NQO1, HO-1, and GSTA2 were significantly (P < 0.05) increased in the HF with BGE groups compared to those in the HF group. CONCLUSIONS: The improvements of blood glucose homeostasis and antioxidant systems in rats fed with black garlic extract were related to mRNA expression levels of Nrf2 related genes.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2213-2216
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• 2013

Recently, use of natural products available from marine sources, and especially algae products, are receiving more attention. Scientific evidence for claimed nutraceutical and therapeutical effects of one such marine algae product, fucoxanthin, is discussed in this paper with a summary of the currently available literature regarding its antioxidant, anti-obesity and anticancer activities. It is safe for use in humans, but as it has poor solubility a nano-suspension mode of delivery may be adopted to improve efficacy of supplments. We conclude from ourliterature review that the marine algae product fucoxanthin has significant antioxidant, anti-obesity and anticancer activity with established mechanisms of action.

• BMB Reports
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• v.42 no.9
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• pp.561-567
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• 2009

Although many plant-derived phenolic compounds display antioxidant effects in biological systems, their mechanism of action remains controversial. In this study, the mechanism by which p-coumaric acid (p-CA) performs its antioxidant action was investigated in bovine aortic endothelial cells under oxidative stress due to high levels of glucose (HG) and arachidonic acid (AA), a free fatty acid. p-CA prevented lipid peroxidation and cell death due to HG+AA without affecting the production of reactive oxygen species. The antioxidant effect of p-CA was not decreased by buthionine-(S,R)-sulfoximine, an inhibitor of cellular GSH synthesis. In contrast, pretreatment with p-CA caused the induction of peroxidases that decomposed t-butyl hydroperoxide in a p-CA-dependent manner. Furthermore, the antioxidant effect of p-CA was significantly mitigated by methimazole, which was shown to inhibit the catalytic activity of 'p-CA peroxidases' in vitro. Therefore, it is suggested that the induction of these previously unidentified 'p-CA peroxidases' is responsible for the antioxidant effect of p-CA.

• BMB Reports
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• v.37 no.5
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• pp.618-624
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• 2004

All members of R. glutinosa show the unique characteristic of intrinsic tolerance to paraquat (PQ). Antioxidant enzymes have been proposed to be the primary mechanism of PQ resistance in several plant species. Therefore, the antioxidant enzyme systems of R. glutinosa were evaluated by comparatively analyzing cellular antioxidant enzyme levels, and their responses of oxidative stresses and hormones. The levels of ascorbate peroxidase (APX), glutathione reductase (GR), non-specific peroxidase (POX), and superoxide dismutase (SOD) were 7.3-, 4.9-, 2.7- and 1.6-fold higher in PQ-tolerant R. glutinosa than in PQ-susceptible soybeans. However, the activity of catalase (CAT) was about 12-fold higher in the soybeans. The activities of antioxidant enzymes reduced after PQ treatment in the two species, with the exception of POX and SOD in R. glutinosa, which increased by about 40%. Interestingly, the activities of APX, SOD and POX in R. glutinosa, relative to those in soybeans, were further increased by 49, 67 and 93% after PQ treatment. The considerably higher intrinsic levels, and increases in the relative activities of antioxidant enzymes in R. glutinosa under oxidative stress support the possible role of these enzymes in the PQ tolerance of R. glutinosa. However, the relatively lower levels of SOD versus PQ tolerance, and the mixed responses of antioxidant enzymes to stresses and hormones, suggest a possible alternative mechanism(s) for PQ tolerance in R. glutinosa.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.132-135
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• 1990

Polyhydroxystilbenes including resveratrol were reported to competitively inhibit monoamine oxidase-A-without structural relation with substrates and cynthetic inhibitors for the enzyme. We attempt to explore a plausible mechanism for their inhibitory activity on MAO-A. All the polyhydroxystilbenes tested showed the antioxidant activity on liver homogenate. Furthermore, the antioxidant activity turned out to closely correlate with the MAO-A inhibitory activity.