• Nutrition Research and Practice
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• v.3 no.4
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• pp.265-271
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• 2009

The role that antioxidants play in the process of carcinogenesis has recently gained considerable attention. $\alpha$-Lipoic acid, a naturally occurring disulfide molecule, is a powerful antioxidant that reportedly exerts beneficial effects in patients with advanced cancer by reducing the level of reactive oxygen species and increasing glutathione peroxidase activity. In this study, we examined changes in the protein and mRNA expression associated with cell proliferation and apoptosis in MDA-MB-231 breast cancer cultured in the presence of various concentrations (0, 250, 500, and 1000 ${\mu}mol/L$) of $\alpha$-lipoic acid. The results revealed that $\alpha$-lipoic acid inhibited the growth of breast cancer cells in a dose-independent manner (P < 0.05). Additionally, $ErbB_2$ and $ErbB_3$ protein and mRNA expressions were significantly decreased in a dose-dependent manner in response to $\alpha$-lipoic acid (P < 0.05). Furthermore, the protein expression of phosphorylated Akt (p-Akt) levels and total Akt, and the mRNA expression of Akt were decreased dose-dependently in cells that were treated with $\alpha$-lipoic acid (P < 0.05). Bcl-2 protein and mRNA expressions were also decreased in cells that were treated with $\alpha$-lipoic acid (P < 0.05). However, Bax protein and mRNA expressions were increased in cells treated with $\alpha$-lipoic acid (P < 0.05). Finally, caspase-3 activity was significantly increased in a dose-dependent manner in cells treated with $\alpha$-lipoic acid (P < 0.05). In conclusion, we demonstrated that $\alpha$-lipoic acid inhibits cell proliferation and induces apoptosis in MDA-MB-231 breast cancer cell lines.

• Toxicological Research
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• v.17
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• pp.271-280
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• 2001

We report on the applicability oj a method recently developed in our laboratory for measuring the antioxidant potential of isolated chemicals and extracts derived from natural products. Peroxyl radicals generated by thermal homolysis of 2,2'-azobis-amidinopropane (ABAP) oxidize $\alpha$-keto-${\gamma}$-methiolbutyric acid (KMBA) to ethylene, which is monitored by gas chromatography. Inhibition of ethylene formation in the presence of antioxidants that compete with KMBA for peroxyl radicals is the basis of the Total Oxyradical Scavenging Capacity Assay (TOSCA; Winston et al., 1998). Antioxidative activities of water-soluble extracts of American green tea, the anti-hepatotoxic flavonolignan from milk thistle (Silybum marianum) silybin, Ginkgo biloba extract EGb 761, and a series of naturally occuring sesquiterpene lactones (all ger-macranolides found in in fungi, liverworts, and plants) were studied. The specific TOSC value per $\mu$M silybin was 5.2, which is essentially comparable to that of Trolo $x^{ⓡ}$, a water-soluble vitamine E analog. Tea and Ginkgo extracts exhibited potent peroxyl radical scavenging capacity with values, respectively of =1700 and 1000 $\mu$mols Trolo $x^{ⓡ}$ equivalent per gram dry matter. The known anti-inflammatory activity of some germacranolides prompted study of their antioxidant capacity. None of the lactones exhibited antioxidant capacity toward peroxyl radicals comparable to Trolo $x^{ⓡ}$; costunilide, the most lipophilic, had a TOSC value = to glutathione. The potential role of peroxyl radicals in lipidperoxidation, other cellular damage, and var-ious disease states suggest a possible preventive role for silybin, green tea and Ginkgo biloba in oxidative stress caused by these free radical species.ecies.

• Reproductive and Developmental Biology
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• v.38 no.3
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• pp.93-98
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• 2014

The objective of this study was to investigate the changes of oxidative stress and antioxidant enzyme during in vitro development with washing culture oil in porcine embryos. During the culture, the four types of culture oil such as paraffin oil with or without washing and mineral oil with or without washing were examined. The oil was washed with PZM-3 during 7 days and collected oil only. The embryos were stained with CellTracker$^{TM}$ Red, DCFDA and Hoechst 33342 to confirm the effects of the oil. As a results, Cleavage rates and total cell number were no difference among the four oil groups. However, ${\geq}16$ cell embryos were significantly different in fore type oil treatment and blastocyst rate was significantly higher washing paraffin treatment than in other group(p<0.05). Also, the expression of free radical were lower in washing paraffin oil than in other groups (p<0.05). On the other hand, the expression of glutathione were not significant different among paraffin oil with or without washing and mineral oil with or without washing, however washing paraffin oil and washing mineral groups were higher than other treatment groups. In conclusion, the washing oil was expected with positive effects on in vitro development in porcine embryos.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.8
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• pp.1194-1201
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• 2015

This study investigated the effect of oxidized soybean oil in the diet of young chickens on growth performance and intestinal oxidative stress, and indices of intestinal immune function. Corn-soybean-based diets containing 2% mixtures of fresh and oxidized soybean oil provided 6 levels (0.15, 1.01, 3.14, 4.95, 7.05, and $8.97meqO_2/kg$) of peroxide value (POV) in the diets. Each dietary treatment, fed for 22 d, had 6 replicates, each containing 30 birds (n = 1,080). Increasing POV levels reduced average daily feed intake (ADFI) of the broilers during d 1 to 10, body weight and average daily gain at d 22 but did not affect overall ADFI. Concentrations of malondialdehyde (MDA) increased in plasma and jejunum as POV increased but total antioxidative capacity (T-AOC) declined in plasma and jejunum. Catalase (CAT) activity declined in plasma and jejunum as did plasma glutathione S-transferase (GST). Effects were apparent at POV exceeding $3.14meqO_2/kg$ for early ADFI and MDA in jejunum, and POV exceeding $1.01meqO_2/kg$ for CAT in plasma and jejunum, GST in plasma and T-AOC in jejunum. Relative jejunal abundance of nuclear factor kappa B ($NF-{\kappa}B$) P50 and $NF-{\kappa}B$ P65 increased as dietary POV increased. Increasing POV levels reduced the jejunal concentrations of secretory immunoglobulin A and cluster of differentiation (CD) 4 and CD8 molecules with differences from controls apparent at dietary POV of 3.14 to $4.95meqO_2/kg$. These findings indicated that growth performance, feed intake, and the local immune system of the small intestine were compromised by oxidative stress when young broilers were fed moderately oxidized soybean oil.

• Journal of Nutrition and Health
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• v.35 no.1
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• pp.30-36
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• 2002

This study was conducted to evaluate the effect of regular exercise and other relating factors on the activities of erythrocyte antioxidant enzymes and plasma total radical-trapping antioxidant potential (TRAP) in 61 healthy male college students. The study population were divided in two groups ; small amount of exerciser (exorcise time less than 30min/d) and moderate amount of exerciser (exorcise time more than 30min/d) according to their physical exercise habits measured by a questionnaire. Dietary intake of vitamin C and vitamin E, Plasma lipid Profiles, erythrocyte superoxide dismutase(SOD), glutathione peroxidase(GSH-Px) and catalase activities, as well as plasma TRAP levels were determined. Plasma TRAP level was significantly higher in moderate amount of exercisers than that in small amount of exercisers. No significant differences were observed in erythrocryte SOD, catalase and GSH-Px between the two groups. Mean exercise time was positively correlated with the plasma level of TRAP significantly, and amount of alcohol consumption was negatively correlated with the erythrocyte SOD activity, Dietary vitamin C and I intakes did not correlated with either erythrocyte enzyme activities or plasma TRAP levels. There were positive correlations between plasma HDL-cholesterol, and erythrocyte GSH-Px or plasma TRAP levels. Plasma vitamin C concentrations was negatively correlated with plasma TRAP levels and erythrocyte SOD activity, however plasma vitamin C concentration was positively correlated with erythrocyte GSH-Px activity, The results would suggest that regular moderate exercise, nonsmoking, high HDL-cholesterol and high plasma vitamin E concentration enhance antioxidant defences against reactive oxygen species and may increase the likelihood of a healthier life span.

• Nutrition Research and Practice
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• v.3 no.2
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• pp.95-101
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• 2009

It has been reported that dietary polyunsaturated fats (PUFA) increase liver injury in response to ethanol feeding. We tested the hypothesis that diets rich in linoleic acid (18:2n-6) would affect acute liver injury after acetaminophen injection and that protein restriction might exacerbate the liver injury. We examined effects of feeding diets with either 15% (wt/wt) corn oil or 14% beef tallow and 1% corn oil for six weeks with either 6 or 20 g/100 g protein on acute hepatotoxicity. After the feeding period, liver injury was induced by injecting either with 600 mg/kg body weight acetaminophen suspended in gum arabic-based vehicle, or with vehicle alone during fasting status. Samples of liver and plasma were taken for analyses of hepatic glutathione (GSH) levels and liver-specific enzymes [(Glutamate-pyruvate transaminase (GPT) and glutamate-oxaloacetate transaminase (GOT)], respectively. Whereas GSH level was significantly lower in only group fed 15% corn oil with 6 g/100 g protein among acetaminophen-treated groups, activities of GPT and GOT were significantly elevated in all groups except the one fed beef tallow with 20 g/100 g protein, suggesting low protein might exacerbate drug-induced hepatotoxicity. The feeding regimens changed the ratio of 18:2n-6 to oleic acid (18:1n-9) in total liver lipids approximately five-fold, and produced modest changes in arachidonic acid (20:4n-6). We conclude that diets with high 18:2n-6 promote acetaminophen-induced liver injury compared to diets with more saturated fatty acids (SFA). In addition, protein restriction appeared to exacerbate the liver injury.

• Nutrition Research and Practice
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• v.8 no.2
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• pp.172-176
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• 2014

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is becoming an important public health problem as metabolic syndrome and type 2 diabetes have become epidemic. In this study we investigated the protective effect of Cordyceps militaris (C. militaris) against NAFLD in an obese mouse model. MATERIALS/METHODS: Four-week-old male ob/ob mice were fed an AIN-93G diet or a diet containing 1% C. militaris water extract for 10 weeks after 1 week of adaptation. Serum glucose, insulin, free fatty acid (FFA), alanine transaminase (ALT), and proinflammatory cytokines were measured. Hepatic levels of lipids, glutathione (GSH), and lipid peroxide were determined. RESULTS: Consumption of C. militaris significantly decreased serum glucose, as well as homeostasis model assessment for insulin resistance (HOMA-IR), in ob/ob mice. In addition to lowering serum FFA levels, C. militaris also significantly decreased hepatic total lipids and triglyceride contents. Serum ALT activities and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) levels were reduced by C. militaris. Consumption of C. militaris increased hepatic GSH and reduced lipid peroxide levels. CONCLUSIONS: These results indicate that C. militaris can exert protective effects against development of NAFLD, partly by reducing inflammatory cytokines and improving hepatic antioxidant status in ob/ob mice.

• Environmental Analysis Health and Toxicology
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• v.23 no.1
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• pp.41-45
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• 2008

Algal fucoidan is a marine polysaccharide containing sulfur with a wide variety of biological activities including anti-inflammatory and anti-thrombotic effects. Although antioxidants can inhibit inflammatory signals through inhibiting activator protein-1 and/or nuclear factor-kappaB activation, it is obscure whether fucoidan directly scavenges oxy-radicals or indirectly regulates oxidant production and/or antioxidant defense system. The antioxidant activities of fucoidan against peroxyl radicals, peroxynitrites and hydroxyl radicals were determined by the total oxy-radical scavenging capacity (TOSC) assay. The specific TOSC values of fucoidan against peroxyl radicals, peroxynitrites or hydroxyl radicals were $282{\pm}60$, $43{\pm}1$ or $40{\pm}1\;TOSC/mg/mL$, respectively. These specific TOSC values against peroxyl radicals, peroxynitrites or hydroxyl radicals are 23, 12, or 13% of the specific TOSC values of glutathione, a positive control, respectively. These results suggest that fucoidan has direct oxy-radical scavenging capacity, which may be related with anti-inflammatory effect of fucoidan.

• Nutrition Research and Practice
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• v.6 no.2
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• pp.155-161
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• 2012

Excessive oxidative stress and abnormal blood lipids may cause chronic diseases. This risk can be reduced by consuming an antioxidant- and fiber-rich vegetarian diet. We compared biomarkers of oxidative stress, antioxidant capacity, and lipid profiles of sex- and age-matched long-term vegetarians and omnivores in Korea. Forty-five vegetarians (23 men and 22 women; mean age, $49.5{\pm}5.3$ years), who had maintained a vegetarian diet for a minimum of 15 years, and 30 omnivores (15 men and 15 women; mean age, $48.9{\pm}3.6$ years) participated in this study. Their 1-day, 24-h recall, and 2-day dietary records were analyzed. Oxidative stress was measured by the levels of diacron reactive oxygen metabolites (d-ROM). Antioxidant status was determined by the biological antioxidant potential (BAP) and levels of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. We observed that vegetarians had a significantly lower body fat percentage ($21.6{\pm}6.4%$) than that of omnivores ($25.4{\pm}4.6%$; $P$ < 0.004). d-ROM levels were significantly lower in vegetarians than those in omnivores ($331.82{\pm}77.96$ and $375.80{\pm}67.26$ Carratelli units; $P$ < 0.011). Additionally, total cholesterol levels in the vegetarians and omnivores were $173.73{\pm}31.42$ mg/dL and $193.17{\pm}37.89$ mg/dL, respectively ($P$ < 0.018). Low-density lipoprotein cholesterol was $101.36{\pm}23.57$ mg/dL and $120.60{\pm}34.62$ mg/dL ($P$ < 0.005) in the vegetarians and omnivores, respectively, indicating that vegetarians had significantly lower lipid levels. Thus, oxidative stress, body fat, and cholesterol levels were lower in long-term vegetarians than those in omnivores.

• Journal of Nutrition and Health
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• v.39 no.8
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• pp.801-807
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• 2006

To elucidate the effect of soy isoflavone supplementation on bone mineral density and antioxidant enzyme activity in 60 postmenopausal women residing in Iksan area were recruited. There were 31 participants in the treatment group and 29 in the control group. The treatment group consumed isoflavone extract capsules daily (which contained 90 mg of soy isoflavones) for 12 weeks. The study compared before and after isoflavone intake in the following areas. Physical examination, diet survey, bone mineral density (BMD) and antioxidant enzyme activity (superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (TA)). The average age of the treatment group was 64.6 years and that of the control group was 66.5 years. There were no significant differences between the two groups in terms of height, weight and body mass index. Both groups maintained a regular diet pattern in terms of their average daily nutrient intake. There were no significant differences between the treatment group (23.3 mg) and the control group (24.0 mg) in terms of daily isoflavone intake based on diet. Isoflavone supplementation of 12 weeks did not resulted in any significant changes in BMD or parameters of antioxidant enzyme activity, implying the necessity of more intensive intervention for a substantial change. In conclusion, this study revealed that antioxidant enzyme activity holds a significant relationship with the bone mineral density in postmenopausal women and further systematic research on dose and period of isoflavone supplementation is needed to clearify the positive effect of isoflavone on BMD and/or blood antioxidant capacity in postmenopausal women.