• Journal of Microbiology
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• v.41 no.1
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• pp.28-33
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• 2003

Pycnogenol (PYC) is believed to have potential as a therapeutic agent against free radical-mediated oxidative stress. It is important, therefore, to understand the interactions between PYC and cellular defenses against oxidative stress. Toward this end, we analyzed the survival rates on the gene expression responses of E. coli sod katG mutants to PYC after pre-treatment of PQ or H$_2$O$_2$-mediated stress under aerobic conditions. We identified SOD induced by PYC, but not HP1 in sod hate mutants. A striking result was the PYC induction of SOD with antioxidant property in single katG mutant cells, particularly MnSOD and CuZnSOD. These inductions were further increased with oxidative stress, while HP1 was not induced in these conditions. The effects of pycnogenol treatment on these cells depend in part on its concentration on the stress response. Protective effects of PYC exposure which affected gene expression in cells were consistent with cell survival rates. Our results demonstrate that pycnogenol may alter the stress response gene expression in a specific manner such as SOXRS because PYC induction of single mutant only worked under increased PQ stress. All together our data indicate that SOD activity is essential for the cellular defense against PQ-mediated oxidative stress, suggesting that PYC may not be effective as an antioxidant in only oxidative stress conditions. On the other hand, it was expected that PYC may play a role as a pro-oxidant and if it is available for use, it should be evaluated carefully.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.222-228
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• 2022

This study was conducted to investigate the effect of waterlogging stress on the physiological response and growth characteristics of the five Italian ryegrass varieties. For all varieties, the germination rate of seed decreased by 10-15% as the waterlogging period increased, but the waterlogging stress treatment after the early seedling stage increased the growth of shoot and root length. Photosynthetic activity (Fv/Fm) according to waterlogging stress treatment decreased in all vareity, and Florida 80 showed the least decrease with 1.5%. Waterlogging stress treatment was found to reduce the accumulation of reactive oxygen species (malondialdehyde, MDA) and the activities of antioxidant enzymes. These results suggest that other mechanisms may be involved in the defense mechanism of Italian ryegrass against waterlogging stress, such as promoting root growth to escape from waterlogging stress, in addition to the antioxidant enzyme system.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.463-470
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• 2023

This study confirmed the change in functional composition and alcohol-induced acute liver injury in Aloe arborescens after fermentation. An acute liver injury was induced by administration of ethanol (3 g/kg/day) to C57BL/6J mice for 5 days. A fermented A. arborescens Miller leaf (FAAL) extract was orally administered 30 minutes before ethanol treatment. After fermentation, the emodin content was approximately 13 times higher than that of the raw material. FAAL extract significantly attenuated ethanol-induced aspartate aminotransferase, alanine aminotransferase, and triglyceride increases in serum and liver tissue. Histological analysis revealed that FAAL extract inhibits inflammatory cell infiltration and fat accumulation in liver tissues. The cytochrome P450 2E1, superoxide dismutase, and glutathione (GSH), which involved in alcohol-induced oxidative stress, were effectively regulated by FAAL extract in serum and liver tissues, except for GSH. FAAL also maintained the antioxidant defense system by upregulating heme oxygenase 1 and nuclear factor erythroid 2-related factor 2 protein expression. In addition, FAAL extract inhibited the decrease in alcohol dehydrogenase and aldehyde dehydrogenase activity, which promoted alcohol metabolism and prevented the activation of inflammatory response. Our results suggest that FAAL could be used as a potential therapeutic agent for ethanol-induced acute liver injury.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.393-407
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• 2022

The effect of Neobacillus sp. JC05 extract on the defense response in cucumber plants against root-knot nematode (RKN) was evaluated. As a result of drench treatment of JC05-extract in cucumber plants, formation of egg mass per plants and disease severity were significantly decreased compared to untreated control plants; the malondialdehyde contents also decreased in JC05-extract treated plants. When eggs of Meloidogyne incognita were inoculated, cucumber plants treated with JC05-extract elevated pathogenesis-related gene expression such as chitinase and lipoxygenase, these are well known as inducing resistance in plants, in addition, peroxidase among antioxidant enzymes was significantly activated. Moreover, the JC05-extract enhanced FDAse activity in soils grown cucumber plants inoculated by eggs of M. incognita. Taken together, these results suggest that the JC05-extract could involve in activation of defense-related mechanisms of cucumber plants and result in decrease of disease occurrence caused by M. incognita.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.677-683
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• 2010

This study investigated the effect of young Phragmites communis (Pc) leaves on lipid profiles, lipid metabolism and erythrocyte antioxidant defense system in high-fat diet fed mice. Three groups of mice were fed different diets for 8 weeks: normal diet (Normal), high-fat diet (High-fat; 37% calories from fat) and high-fat diet supplemented with 1% Pc (wt/wt, HF-Pc). Body weight, daily food intake and energy intake tended to decrease by Pc supplement in high-fat fed mice. Pc supplementation significantly lowered plasma triglyceride and total cholesterol concentrations compared to the high-fat control group. Pc also lowered hepatic and heart cholesterol contents, whereas it significantly increased fecal excretion of triglyceride and cholesterol compared to the high-fat control group. Pc significantly inhibited fatty acid synthase, 3-hydroxy-3-methylglutaryl CoA reductase and acyl-CoA:cholesterol acyltransferase activities compared to the high-fat control group. Erythrocyte superoxide dismutase and catalase activities were also significantly higher in the high-fat group than in the normal group, however Pc supplementation reversed these changes. The Pc supplementation significantly lowered erythrocyte lipid peroxidation level compared to the high-fat control group. Accordingly, these results suggest that Pc improves lipid metabolism and erythrocyte antioxidant defense system in high-fat diet fed mice.

• BMB Reports
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• v.34 no.2
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• pp.144-149
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• 2001

Antioxidant enzymes, scavengers of the reactive oxygen intermediate (ROI), are involved in numerous defense systems in cells. In the present study, we investigated the effects of the hot-water extracts of two medicinally potent mushrooms (Ganoderma lucidum and Phellinus linteus) on the activity and expression of antioxidant enzymes in vitro and in vivo. The mushroom extracts stimulated the catalase activity in a dose-dependent manner in vitro, whereas the other antioxidant enzymes (such as superoxide dismutase (SOD), glutathione peroxidase (GPx)) were unaffected by the extracts. The catalytic activity of catalase in the liver and brain was significantly increased after the oral treatment of the mushroom extracts (2.5 g/kg) to ICR mice for 2 months. Western blot analysis of the liver and brain tissues revealed that the expression level of catalase in the mice, treated with both mushroom extracts, was significantly increased compared to that of the control mice. However, the level of the SOD expression in the mice treated with the natural product extracts was unchanged under the same experimental conditions. Although the mechanisms for the stimulatory effect of the catalase expression by these extracts remains unclear, these results suggest that the ingredients of the Ganoderma lucidum and Phellinus linteus extracts act as an activator of catalase, and regulate the expression of catalase at the translational or transcriptional level.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1695-1699
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• 2004

The antioxidant enzymes, lipid peroxidation and free radicals assessment were made of the effects of selenium, copper and magnesium on bovine endemic fluorosis under high fluoride, low selenium and low copper productive conditions. Thirty-two beef cattle were selected from high fluoride area, and randomly divided into four groups with eight cattle each as follows: (1) high fluoride control group (HFC); (2) supplemented group with 0.25 mg/kg selenium (HFSe); (3) supplemented group with 15 mg/kg copper (HFCu) and (4) supplemented group with 0.25 mg/kg selenium+15 mg/kg copper+1 mg/kg magnesium (HFSeCuMg) per day for 83 days. Moreover, eight beef cattle were selected from non-high fluoride area as normal control group. Blood samples were collected from cattle on 0 d, 30 d and 83 d respectively, to analyze the enzyme activities and concentration of GSH-px, CAT, SOD, MDA and free radicals. The results showed that the contents of free radicals and MDA in HFC group were significantly higher, and the whole blood GSH-px, CAT, erythrocyte SOD activities were lower than the normal control group. Free radicals, metabolic imbalance and antioxidant disorder therefore, play an important role in fluorosis. However, GSH-px, CAT and SOD activities in HFSe group and HFSeCuMg group at 30 d and 83 d were markedly higher than the same groups at the 0 d and the HFC group at the same time. Likewise, there was a corresponding reduction in the contents of free radicals and MDA. These findings indicated that supplementation with selenium, copper and magnesium elevated high fluoride bovine antioxidant enzymes, and decreased MDA and free radicals contents. But, the activities of supplementation selenium group did not increase until day 83. These results demonstrated that fluorosis was associated with lower serum Se and Cu levels than in the control, and it was therefore concluded that fluorosis is associated with decreased serum levels of these minerals. Long-term high fluoride intake under productive condition enhances oxidative stress in the blood, thereby disturbing the antioxidant defense of cattle. Increased oxidative stress could be one of the mediating factors in the pathogenesis of toxic manifestations of fluoride. It is benefical for high fluoride cattle supplemented with proper selenium, copper and magnesium to increase fluoride excretion and obtain the protective impact of the activity of oxidative enzymes, and to decrease lipid peroxidation and free radicals contents.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• Journal of Life Science
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• v.27 no.5
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• pp.536-544
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• 2017

Abeliophyllum distichum Nakai is deciduous shrubs of flowering plant in Oleaceae. It is important plant resources and consists of one species in the world. Also the endemic plant of A. distichum has been protected and designed endangered plant in Korea. For this reason, study on the immature seeds of A. distichum (ADS) hasn't progressed. In the present study, we evaluated the antioxidant activity and inhibitory effects on proteins and mRNA levels were related in the whitening effect in B16F10 cells. ADS was effective for reaction oxygen species (ROS). ROS causes various diseases such as aging, inflammation, cancer, and etc. Antioxidant properties were evaluated DPPH, ABTS radical scavenging activity and Reducing power. Plants were known that contained phenolic compounds were related in antioxidant activity. Phenolic compounds were phytochemicals commonly named natural polyphenols. These are secondary metabolites of plants involved in the defense against different types of stresses. In results, ADS suppressed the expression and transcription of Tyrosinase, TRP-1, TRP-2, and Microphthalmia-associated transcription factor (MITF). Tyrosinase, tyrosinase-related protein 1 (TRP-1), tyrosinase-related protein 1 (TRP-2) are known to play an important role in melanin biosynthesis. MITF regulated the expression and transcription of Tyrosinase, TRP-1, and TRP-2. In conclusion, ADS was effective in both antioxidant activities and whitening effects. Also, they were associated with the content of phenolic compounds. We suggested that ADS can be use antioxidants and skin-whitening functional cosmetics material derived from natural plant resources.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.311-318
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• 2022

Salicylic acid (SA), a phenolic compound, plays a pivotal role in regulating a wide range of physiological and metabolic processes in plants such as antioxidant cellular defense, photosynthesis, and biotic and abiotic stress responses during the growth and development. We examined the effect of exogenous SA application (100 mg·L^-1) on the growth, yield, photosynthetic characteristics, lipid peroxidation, and antioxidant enzyme activity of chili pepper plants under high temperature and drought stress conditions. SA treatment induced increases of net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) under the stress condition with the highest level after the third treatment. The contents of malondialdehyde and H₂O₂ were significantly lower in the third treatment of SA compared to the control. The activity of ascorbate peroxidase, catalase, peroxidase and superoxide dismutase, increased in treated plants by up to 247, 318, 55 and 54%, respectively compared to the nontreated control. There was no significant difference in the growth characteristics between SA-treated and nontreated plants, while the SA treatment increased marketable yield (kg/10a) by about 15% compared to the nontreated control. Taken together, these results suggest that foliar application of SA alleviates physiological damages caused by the combination of drought and heat stress, and enhances the photosynthetic capacity and antioxidant enzyme activities, thereby improving tolerance to a combination of water deficit and heat stress in chili pepper plants.