• ALGAE
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• v.28 no.2
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• pp.131-147
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• 2013

Major progress has been made in the past decade towards understanding of the biosynthesis of red carotenoid astaxanthin and its roles in stress response while exploiting microalgae-based astaxanthin as a potent antioxidant for human health and as a coloring agent for aquaculture applications. In this review, astaxanthin-producing green microalgae are briefly summarized with Haematococcus pluvialis and Chlorella zofingiensis recognized to be the most popular astaxanthin-producers. Two distinct pathways for astaxanthin synthesis along with associated cellular, physiological, and biochemical changes are elucidated using H. pluvialis and C. zofingiensis as the model systems. Interactions between astaxanthin biosynthesis and photosynthesis, fatty acid biosynthesis and enzymatic defense systems are described in the context of multiple lines of defense mechanisms working in concert against photooxidative stress. Major pros and cons of mass cultivation of H. pluvialis and C. zofingiensis in phototrophic, heterotrophic, and mixotrophic culture modes are analyzed. Recent progress in genetic engineering of plants and microalgae for astaxanthin production is presented. Future advancement in microalgal astaxanthin research will depend largely on genome sequencing of H. pluvialis and C. zofingiensis and genetic toolbox development. Continuous effort along the heterotrophic-phototrophic culture mode could lead to major expansion of the microalgal astaxanthin industry.

• Journal of Life Science
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• v.19 no.4
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• pp.429-435
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• 2009

Oxidative stress is a consequence of an imbalance of the defense system against cellular damage generated by reactive oxygen species (ROSs) such as superoxide anions (menadione; MD). Most organisms have evolved a variety of defense systems to protect cells from adverse conditions. In order to evaluate stress tolerance against oxidative stress generating MD, comparative analyses of antioxidant capacity, or free radical scavenger ability, were performed between S. cerevisiae KNU5377 (KNU5377) and three wild-type S. cerevisiae strains. In a medium containing 0.4 mM MD, the KNU5377 strain showed higher cell viability and antioxidant ability, and contained higher levels of trehalose, superoxide dismutase, thioredoxin system, glucose-6-phosphate dehydrogenase, and some heat shock proteins. The KNU5377 strain also produced a lower level of oxidative stress biomarker than the other three yeast strains. These results indicate that S. cerevisiae KNU5377 has a higher level of tolerance to oxidative stress due to the increased expression of cell rescue proteins and molecules, thus alleviating cellular damage more efficiently than other S. cerevisiae strains.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.109-117
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• 2018

Recently, cancer incidence in modern society is increasing sharply. DNA damage is caused by intrinsic or extrinsic factors in the human body, cells protect themselves by defense mechanism against DNA damage. Also, Aberrant DNA and deficient DNA repair are closely associated with various diseases, including aging and cancer. Researchers are interested in search for proper materials to inhibition for DNA damage. As knew the side effects of synthetic antioxidant, some researches have been conducted about cancer prevention materials derived from nature. Root of Smilax china, in Liliaceae, is used detoxification and tumor treatments traditionally. However, studies on the inhibitory effect of DNA damage haven't progressed. In this study, antioxidant activity and protective effects on oxidative DNA damage of S. china root were confirmed, relationship between those activities and contents of phenolic compounds in plants were established. S. china root effectively removed 1,1-diphenyl-2-picryl-hydrazyl radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid radicals. The quantification and identification of phenolic compounds were confirmed by high performance liquid chromatography analysis, its antioxidant activity was associated with some phenolic compounds. In addition, protective effects against hydroxyl radicals and ferrous ion-induced oxidative DNA damage were confirmed in plasmid DNA. In the cellular levels, S. china root suppressed the expression of ${\gamma}$-H2AX and p53 protein in NIH 3T3. Besides, S. china root suppressed H2AX and p53 mRNA levels. In conclusion, S. china root had the effect on DNA protection and antioxidant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.36-41
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• 2005

Effect of chitosan oligo saccharides (COS) on the level of serum lipids, antioxidant enzyme activities and lipid peroxidation was investigated in rats fed with high cholesterol diet for 4 weeks, The rats were divided into three experimental groups that is, high cholesterol diet group (0.5% cholesterol; control). high cholesterol diet and 1.0% or 2.0% COS-supplemented groups (COS I , COS II). Serum total cholesterol, LDL-cholesterol and triglyceride level were significantly decreased and relative HDL-cholesterol level in total cholesterol significantly increased in COS II group. Liver TBARS level and activities of SOD and catalase of COS I were also significantly reduced. These results suggest that supplement of chitosan oligosaccharides reduce levels of serum cholesterol and reduce oxidative damage by activating hepatic antioxidative defense system in rats fed with high cholesterol diets.

• Nutrition Research and Practice
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• v.4 no.2
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• pp.114-120
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• 2010

The effects of grape seeds extract and grape peels extract prepared from grape pomace on the activity of antioxidant enzymes, degree of lipid peroxidation in serum and liver tissue were investigated in rabbits fed on high cholesterol diet. New Zealand white rabbits were divided as follows ; 1) NOR (normal group); 2) CHOL (cholesterol group); 3) GSH (cholesterol + grape seed extract group); 4) GPE (cholesterol + grape peel extract); 5) GSP (cholesterol + grape seed powder); 6) GPP (cholesterol + grape peel powder); 7) GE (cholesterol + grape seed and peel extract); 8) GP (cholesterol + grape seed and peel powder). Eight groups of rabbits were studied for 8 weeks. At the end of the experimental period, rabbits were sacrificed and the liver tissue were removed. Then, GSH, GPx, GST, CAT and MDA in the liver were measured. In liver tissues, total glutathione contents (GSH), glutathione peroxidase (GPx) and catalase (CAT) activity, which was significantly higher by grape seed extract supplementation. The level of malondialdehyde (MDA) was lower in the serum of rabbits fed grape seed extract or grape peel powder plus cholesterol than in the serum of rabbits fed cholesterol alone. It is therefore likely that grape seed extract prepared from grape pomace functioned as antioxidants in vivo, negating the effects of the oxidative stress induced by 1% cholesterol diet. The grape seed extract was found effective in converting the oxidized glutathione into reduced glutathione, and in removing $H_2O_2$ that is created by oxidative stress. The grape peel powder was found to have small influence on reduced glutathione content, CAT and GPX activity, but it increased GST activity in liver tissues, resulting in promoting the combination of lipid peroxide and glutathione (GSH), and further, lowering the formation of lipid peroxide in the serum. Therefore, grape pomace (grape seed extract and grape peel powder) supplementation is considered to activate the antioxidant enzyme system and prevent damage with hypercholesterolemia.

• Journal of Nutrition and Health
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• v.43 no.5
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• pp.443-452
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• 2010

Elevated plasma concentration of total homocysteine (ptHcy) is known as an independent risk factor of cardiovascular disease (CVD) and oxidative stress is also commonly implicated in CVD. An association between ptHcy and oxidative stress has recently been suggested. The study objective is to examine the relationship between ptHcy and oxidative stress markers in 103 healthy college students (62 males and 41 females). Plasma levels of ptHcy, oxidative stress markers (conjugated diene, erythrocyte catalase, TRAP, lymphocyte DNA damage), antioxidant vitamins ($\alpha$-tocopherol, $\gamma$-tocopherol, carotenoids), and lipid parameters (total cholesterol, triglyceride, HDL cholesterol) were determined. The results show that the concentration of ptHcy was significantly higher in male subjects ($22.17\;{\pm}\;2.14\;{\mu}mole/L$) than in female subjects ($12.28\;{\pm}\;0.45\;{\mu}mole/L$). There was a negative association between ptHcy and plasma ${\beta}$-carotene in male subjects (p $lt; 0.05), but no correlation between ptHcy and other plasma antioxidant vitamin levels in either gender. However, there were the negative correlations between ptHcy and plasma ${\alpha}$-carotene or ${\beta}$-carotene, and a positive correlation between ptHcy and lymphocyte DNA damage. A significantly low level of ${\alpha}$-carotene or ${\beta}$-carotene was found in male subjects with elevated ptHcy (${\geq}\;15\;{\mu}mol/L$), as compared to those with lower plasma homocysteine. These study results confirmed the views on the association between plasma homocysteine and oxidative stress markers in humans and support the hypothesis that homocysteine promotes the oxidative environment by counteracting the antioxidant defense mechanism.

• The Korean Journal of Community Living Science
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• v.16 no.3
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• pp.127-132
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• 2005

The aim of this study is to investigate the effects of hot water soluble extract from Angelicae Radix on the components of serum and liver and the effects on the antioxidant system. For this purpose, five experimental groups were set up. And for fat source, perila oil enough with unsaturated fatty acid and beef tallow enough with saturated fatty acid were supplemented to the rats together with hot water soluble extract from Angelicae Radixs. Five experimental groups kept eight Sprague-Dawley rats respectively. They were CO group supplemented with basic diet of AIN-93, PO group supplemented with perila oil, POA group supplemented with perila oil and hot water soluble extract from Angelicae Radix, BT group supplemented with beef tallow, and BTA group supplemented with beef tallow and hot water soluble extract from Angelicae Radix. The results were; 1) Final weight, weight gain, fluid intake and FER were not different significantly among the experimental groups, 2) Significant difference of food intake was observed(p<0.05) in BTA group only, 3) No significant difference was observed in serum total lipid, serum triglyceride and HDL cholesterol among experimental groups. Serum total cholesterol and LDL cholesterol were significantly low(p<0.05) in the group supplemented with beef tallow which was with hot water soluble extract from Angelicae Radix (BTA group). 4)Liver total cholesterol in liver was low in groups supplemented with perila oil and hot water soluble extract from Angelicae Radix. In summary, hot water soluble extract from Angelicae Radix did not affect the weight gain, fluid intake and food efficiency ratio among the experimental groups, but had an effect of lowering food intake, serum total cholesterol and serum LDL cholesterol significantly in the groups which were supplemented with beef tallow and hot water soluble extract from Angelicae Radix. The effect of lowering liver total cholesterol with the supplementation of hot water soluble extract from AnRelicae Radix was observed in perila oil group only. The effect of lowering cholesterol with the supplementation of hot water soluble extract from Angelicae Radix was observed both in serum and in liver.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.605-613
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• 2014

We have previously shown that paraquat (PQ)-induced oxidative stress causes dramatic damage in various human cell lines. Naringenin (NG) is an active flavanone, which has been reported to have beneficial bioactivities, including antioxidative, anti-inflammatory, and antitumorigenic activities, with a relatively low toxicity to normal cells. In this study, we intended to assess the cytoprotective effect of NG against PQ-induced toxicity in the human bronchial epithelial BEAS-2B cell line. Co-treatment with NG in PQ-treated BEAS-2B cells can reduce PQ-induced cellular toxicity. NG can also decrease the generation of intracellular ROS caused by PQ treatment. We also observed that treatment with NG in PQ-exposed BEAS-2B cells can significantly induce the expression of antioxidant-related genes, including GPX2, GPX3, GPX5, and GPX7. NG co-treatment can also activate the NRF2 transcription factor and promote its nuclear translocation. In addition, NG co-treatment can induce the expression of NRF2-downstream target genes such as that of heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). A small interfering RNA study revealed that the knockdown of NRF2 can abrogate NG-mediated protection of the cells from PQ-induced cellular toxicity. We propose that NG effectively alleviates PQ-induced cytotoxicity in human bronchial epithelial BEAS-2B cells through the NRF2-regulated antioxidant defense pathway, and NG might be a good therapeutic candidate molecule in oxidative stress-related diseases.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1162-1167
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• 2004

The present study was designed to define whether dietary conjugated linoleic acid (CLA) could affect antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione S transferase (GST), and the level of malondialdehyde (MDA), a marker of lipid peroxidation, in the small intestine and liver from broiler chickens. A total of twenty-four 3 wk-old male broiler chickens were assigned to three dietary treatments (1.5% corn oil, 0.75% corn oil plus 0.75% CLA, and 1.5% CLA, isocalorically), and fed a grower-finisher diet from 22 to 35 days. In the small intestinal mucosae, the specific activities of SOD, GSH-Px, CAT, and GST, and the level of MDA were not substantially influenced by dietary CLA. In the liver, the specific activities of SOD, GSH-Px, and GST, and the level of MDA were also unaffected by dietary CLA at the level of either 0.75% or 1.5% compared with corn oil at the level of 1.5%. However, the broiler chickens fed the diet containing 1.5% CLA resulted in a significant increase in peroxisomal CAT activity and a marked decrease in total lipid and non-esterified fatty acids (NEFA) from liver tissues compared with those fed the diet containing 1.5% corn oil. In conclusion, ability of CLA to increase hepatic CAT activity suggest that dietary CLA may affect, at least in part, antioxidant defense system as well as lipid metabolism in the liver of broiler chickens.

• Advances in Traditional Medicine
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• v.9 no.4
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• pp.307-314
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• 2009

Oxidative stress plays an important role in the pathogenesis of various diabetic complications and small intestine is vulnerable to damage resulting in morphological and functional changes. In this study, the effects of Asystasia gangetica leaf extract (AGLE) on oxidative stress status in small intestine of diabetic rats were examined. The leaves of Asystasia gangetica was extracted with 70% ethanol. Oral administration of AGLE once daily (100 mg/kg and 200 mg/kg b.w.) for 28 days to diabetic rats significantly (P < 0.05) increased antioxidant levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione, GSSH, carbohydrate metabolizing enzyme, glucose-6-phosphate dehydrogenase. The increased levels of protein carbonyl content, lipid peroxidation and xanthine oxidase/xanthine dehydrogenase in diabetic rats were reverted back to near normal levels on treatment with AGLE. Both doses of AGLE offered significant activity (P < 0.01) against oxidative damage and were comparable with standard, glibenclamide. The results revealed the occurrence of oxidative stress in small intestine during diabetes and suggest the potential of AGLE as an antioxidant in protecting the tissue defense system against oxidative damage in streptozotocin-induced diabetes.