Yanghee You

In vitro and in vivo hepatoprotective effects of the aqueous extract from Taraxacum officinale (dandelion) root against alcohol-induced oxidative stress

The protective effects of Taraxacum officinale (dandelion) root against alcoholic liver damage were investigated in HepG2/2E1 cells and ICR mice. When an increase in the production of reactive oxygen species was induced by 300 mM ethanol in vitro, cell viability was drastically decreased by 39%. However, in the presence of hot water extract (TOH) from T. officinale root, no hepatocytic damage was observed in the cells treated with ethanol, while ethanol-extract (TOE) did not show potent hepatoprotective activity. Mice, which received TOH (1 g/kg bw/day) with ethanol revealed complete prevention of alcohol-induced hepatotoxicity as evidenced by the significant reductions of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase activities compared to ethanol-alone administered mice. When compared to the ethanol-alone treated group, the mice receiving ethanol plus TOH exhibited significant increases in hepatic antioxidant activities, including catalase, glutathione-S-transferase, glutathione peroxidase, glutathione reductase, and glutathione. Furthermore, the amelioration of malondialdehyde levels indicated TOHs protective effects against liver damage mediated by alcohol in vivo. These results suggest that the aqueous extract of T. officinale root has protective action against alcohol-induced toxicity in the liver by elevating antioxidative potentials and decreasing lipid peroxidation.

Hepatoprotective effects of fermented Curcuma longa L. on carbon tetrachloride-induced oxidative stress in rats.

The hepatoprotective effect of fermented Curcuma longa L. (FC) was investigated in rats under CCl4-induced oxidative stress. FC at a dose of 30 or 300 mg/kg body weight (b.w.) was orally administered for 14 days followed by a single dose of CCl4 (1.25 mL/kg b.w. in 20% corn oil) on day 14. Pretreatment with FC drastically prevented the elevated activities of serum AST, ALT, LDH, and ALP caused by CCl4-induced hepatotoxicity. Histopathologically evident hepatic necrosis was significantly ameliorated by FC pretreatment. When compared to the CCl4-alone treated group, rats pretreated with FC displayed the reduced level of malondialdehyde. Furthermore, FC enhanced antioxidant capacities with higher activities of catalase, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase, and level of reduced glutathione. These results suggest that FC could be a candidate used for the prevention against various liver diseases induced by oxidative stress via elevating antioxidative potentials and decreasing lipid peroxidation.

Stimulatory Effects of Ferulic Acid on Endurance Exercise Capacity in Mice

Ferulic acid was orally administered to mice in order to investigate its effects on exercise endurance capacity. When a single administration of ferulic acid was given to the mice in an adjustable-current water pool, the duration of exhaustive swimming was longer than that exhibited by the mice in the control group. Also, when the mice were exhaustively exercised for 3 consecutive days, no change in swimming time was found in the ferulic acid-administered group on the final day, and a large decrease in the untreated mice. Administration of ferulic acid efficiently activated the hepatic antioxidative defense system during exercise. The mice that received ferulic acid showed significant increases in the activity of hepatic antioxidant enzymes such as superoxide dismutase, catalase, and glutathione-S-transferase. Furthermore, an increased glutathione level was observed, while the malondialdehyde content was reduced. These results suggest that ferulic acid possesses stimulatory effects that can enhance exercise endurance capacity and reduce fatigue by elevating antioxidative potentials.

Stimulatory effects of Pseudosasa japonica leaves on exercise performance

The performance-enhancing effects of Pseudosasa japonica were investigated in mice using an adjustable-current water pool. Compared to the control group, a 1.5-fold increase in swimming time was observed in the mouse group administered an 80% ethanol extract (PJE) of the leaves of P. japonica. The blood lactate level, an important indicator of fatigue, was significantly lower (28%, P<0.05) in PJE group than in the control group. These results suggest that PJE possesses stimulatory effects that can enhance exercise endurance and reduce fatigue.

Fatigue-Alleviating Effect on Mice of an Ethanolic Extract from Rubus coreanus

The fatigue-alleviating effects on mice of Rubus coreanus were investigated by using an adjustable-current water pool. The mice were exhaustively exercised for 2 consecutive days, and those administered with the 80% ethanol extract (RCE) of R. coreanus displayed a lower reduction (20%) in swimming time on day 2 than the control group (41% reduction). RCE significantly prevented the depletion of hepatic antioxidants during exercise-induced fatigue. These results suggest that RCE alleviated fatigue by elevating the antioxidative potential.

Anti-obesity effect of extract from fermented Curcuma longa L. through regulation of adipogenesis and lipolysis pathway in high-fat diet-induced obese rats

Background Even though Curcuma longa L. possesses various biological activities, it has strong flavor and taste, which decrease consumer palatability and limit industrial applications in food. Objective The present study investigates the effects of C. longa L. fermented with Aspergillus oryzae supplementation in 60% high-fat diet-induced obese rats measured by the activation of adipogenesis and lipolysis. Design Rats were divided into four groups (n=6 per group) after 1 week of acclimatization: a normal diet group comprised rats fed the AIN76A rodent diet; a high-fat diet-induced obese group with rats fed a 60% high-fat diet; a Garcinia cambogia treated group (positive control) with rats fed a 60% high-fat diet with G. cambogia 500 g/kg body weight (b.w.)/day; and an fermented C. longa L. 50% ethanolic extract treated group (FCE50) with rats fed a 60% high-fat diet with FCE50 500 g/kg b.w./day. Each group received the appropriate vehicle or sample daily by gastric intubation for 12 weeks. Results We found that FCE50 administration suppressed b.w. gain and reduced white adipose tissue weight, serum triglyceride (TG), and cholesterol in high-fat diet-induced obese rats. These results can be associated with the suppression of adipocyte differentiation and lipogenesis with a decrease in the mRNA expressions of fatty acid synthase, acetyl-CoA carboxylase, adipocyte protein 2, and lipoprotein lipase induced by FCE50 administration. In addition, FCE50 increased lipolysis and β-oxidation by up-regulating the expression of lipases such as adipose triglyceride lipase, hormone-sensitive lipase, adiponectin, and AMP-activated protein kinase. Conclusions These results suggest that FCE50 can be a candidate for the prevention of obesity via suppressing adipogenesis and promoting lipolysis.

Chronic effect of ferulic acid from Pseudosasa japonica leaves on enhancing exercise activity in mice.

Ferulic acid derived from Pseudosasa japonica leaves, which possessed antioxidative potentials with DPPH‐ (54%) and ABTs‐ (65%) radical scavenging activities, and lipid‐peroxidation inhibitory activity (71%), was orally administered to mice for 12 days in order to investigate its effects on exercise endurance capacity and alterations of antioxidant defense systems. Exhaustive swimming time was increased in the ferulic acid‐supplemented group compared with the control group on days 6 and 12 (1.7‐ and 1.8‐fold, respectively). When the mice were exhaustively exercised for 2 consecutive days, a high decrease (53%) was shown in the control group, but no change was found in the ferulic acid‐treated group. The administration of ferulic acid significantly protected the depletion of enzymatic‐ and non enzymatic‐antioxidants due to exhaustive exercise. Also, lipid‐peroxidation levels decreased in the ferulic acid‐treated group compared with the non exercised‐ and control‐groups. These results suggest that ferulic acid from Pseudosasa japonica leaves has a chronic effect on endurance exercise capacity, which is attributed to its ability to ameliorate oxidative stress by improving antioxidant potentials. Copyright

The Potential Effects of Ethyl Acetate Fraction from Curcuma longa L. on Lipolysis in Differentiated 3T3-L1 Adipocytes

The effects of the turmeric ethyl acetate fraction (TEF) from the methanolic extract from Curcuma longa L. on lipid metabolism and underlying mechanisms of lipolysis were investigated in 3T3-L1 adipocytes. The intracellular lipid droplets were stained with Oil red O dye and quantified. Compared to the control, lipid accumulation was significantly decreased by 46.6% with treatment by TEF at the concentration of 20 microg/mL. The intracellular triglyceride (TG) level was also reduced by 37.9% at the concentration of 20 microg/mL. To determine the mechanism for TG content reduction, levels of glucose uptake and glycerol release were measured. Incubation of the 3T3-L1 adipocytes with TEF for 4 hours significantly lowered the cellular level of glucose in a dose-dependent manner. Furthermore, cellular expression of insulin-responsive glucose transporter (GLUT)-4 was decreased by 46%, indicating that reduced glucose uptake was due to a decrease in cellular GLUT-4 expression. In addition, the level of free glycerol released into the cultured medium was increased by 36.4% with the treatment by TEF. In subsequent measurements using quantitative real-time polymerase chain reaction, mRNA levels of hormone-sensitive lipase (HSL) and adipose TG lipase (ATGL) were elevated by 34.8% and 16.9%, respectively, at the concentration of 20 microg/mL. These results suggest that TEF partially inhibits lipogenesis by the suppression of glucose uptake via the decreased expression of cellular GLUT-4 and stimulates lipolysis through the induction of HSL and/or ATGL gene expression, resulting in the increased glycerol release.

Hepatoprotective Effects of Hovenia dulcis Fruit on Ethanol-Induced Liver Damage in vitro and in vivo

Dept. Food Science and Nutrition, Suwon University, Gyeonggi 445-743, KoreaAbstractThe hepatoprotective effect of ethanol extract from Hovenia dulcis fruit (HD) against ethanol-induced oxidative damage was investigated. Ethanol-induced reactive oxygen species (ROS) generation and liver damage on HepG2/2E1 cells were protected by 100 μg/mL ethanolic extract from HD. Male C57BL/6 mice were divided into 3 groups; control (NC), ethanol (ET), ethanol plus 1 g/kg body weight ethanolic extract of HD (ET-HD). The activities of serum alanine amintransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were significantly increased in ethanol-treated group. However, ET-HD group showed protective effect by lowering serum activities. The ET group markedly decreased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione-s-transferase (GST) with the reduced level of glutathione (GSH) in liver. On the other hand, ET-HD group increased the activities of SOD and GST, and the level of GSH. Lipid peroxidation level, which was increased after ethanol administration, was significantly reduced in ET-HD group. Based upon these results, it could be assumed that ethanolic extract of HD protected the liver against ethanol-induced oxidative damage by possibly inhibiting the suppression of antioxidant activity and reducing the rate of lipid peroxidation in vitro and in vivo. Therefore, extract of Hovenia dulcis fruit might be used as a protective agent for ethanol-induced hepatic damages.Key words: alcohol, oxidative damage, hepatoprotective effect, HepG2/2E1, Hovenia dulcis

Rosa rugosa Aqueous Extract Alleviates Endurance Exercise-Induced Stress

This study was performed to investigate the effect of water extract from Rosa rugosa (RRW) on endurance exercise-induced stress in mice. The mice were orally administered with distilled water or RRW, respectively. The endurance capacity was evaluated by exhaustive swimming using an adjustable-current water pool. Mice administered RRW swam longer before becoming exhausted. Also, RRW administration resulted in less lipid peroxidation, lower muscular antioxidant enzyme activities, and lower cortisol level. The results suggest that RRW can prevent exercise-induced stress by decreasing oxidative stress levels.