In this study, the protective effects of EGCG on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced oxidative cell death in catecholaminergic PC12 cells, the in vitro model of Parkinson's disease, were investigated. Treatment with L-DOPA at concentrations higher than 150 µM caused cytotoxicity in PC12 cells, as determined using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry detection. The apoptotic ratio was similar in cells treated with 100 µM EGCG plus 150 µM L-DOPA (5.02%) and the control (0.96%) (P > 0.05), and was lower than that of cells treated with L-DOPA only (32.24%, P < 0.05). The generation level of ROS (% of control) in cells treated with EGCG plus L-DOPA was lower than that in cells treated with L-DOPA only (123.90% vs 272.32%, P < 0.05). The optical density in production of TBARS in cells treated with L-DOPA only was higher than that in the control (0.27 ± 0.05 vs 0.08 ± 0.04, P < 0.05), and in cells treated with EGCG only (0.14 ± 0.02, P < 0.05), and EGCG plus L-DOPA (0.13 ± 0.02, P < 0.05). The intracellular level of GSH in cells treated with EGCG plus L-DOPA was higher than that in cells treated with L-DOPA only (233.25 ± 16.44 vs 119.23 ± 10.25, P < 0.05). These results suggest that EGCG protects against L-DOPA-induced oxidative apoptosis in PC12 cells, and might be a potent neuroprotective agent.

This study was performed to investigate the effects of ramie (Boehmeria nivea) leaf powder on improvements in lipid metabolism in serum, liver and adipose tissue, and the anti-obesity effect in rats fed a high fat/high cholesterol diet for 4 weeks to induce a hyperlipidemic and obese model rat. Male Sprague-Dawley rats weighting 210 g were divided into four groups; a normal diet group (N), a high fat/high cholesterol diet group (HFC), a high fat/high cholesterol diet with 5% ramie leaf powder group (HFC-RL), and a high fat/high cholesterol diet with 10% ramie leaf powder group (HFC-RH). The body weight gain increased with a high fat/high cholesterol diet, but gradually decreased in the ramie leaf powder fed groups compared with the HFC group. The liver index in the HFC group was highest among the four groups, although the difference was not significant compared with the ramie leaf powder fed groups. The adipose tissues weight in the HFC group was heavier than that of the N group, whereas those of groups fed ramie leaf powder decreased gradually. Alkaline phosphatase activity was not different between the HFC groups, but serum alkaline aminotransferase and lactate dehydrogenase activities decreased significantly after ramie leaf powder feeding. Levels of serum triglyceride, total cholesterol, LDL-cholesterol, atherogenic index and cardiac risk factors tended to decrease in the ramie leaf powder fed groups compared with the HFC group, whereas serum HDL-cholesterol level decreased in the HFC group and markedly increased in the ramie leaf powder fed groups. Levels of triglyceride and total cholesterol in the liver were significantly lower in the ramie leaf powder fed groups than in the HFC group. Levels of triglyceride and total cholesterol in adipose tissues were also lower in the ramie leaves powder fed groups than in the HFC group. The activities of heparinreleasable lipoprotein lipase (LPL) and total-extractable LPL in adipose tissues increased in the HFC group compared to that of the N group, but those of the ramie leaf powder fed groups decreased significantly. These results suggest that ramie leaf powder may improve lipid metabolism in serum, liver and adipose tissue and potentially reduce lipid storage.

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BACKGROUND/OBJECTIVESWe investigated the effect of Pycnogenol (Pyc) on survival and immune dysfunction of C57BL/6 mice induced by low micronutrient supplementation.MATERIALS/METHODSFemale C57/BL/6 mice were fed a diet containing 7.5% of the recommended amount of micronutrients for a period of 12 wks (immunological assay) and 18 wks (survival test). For immunological assay, lymphocyte proliferation, cytokine regulation, and hepatic oxidative status were determined.RESLUTSPyc supplementation with 50 and 100 mg·kg-1·bw·d-1 resulted in partial extension of the median survival time. Pyc supplementation led to increased T and B cell response against mitogens and recovery of an abnormal shift of cytokine pattern designated by the decreased secretion of Th1 cytokine and increased secretion of Th2 cytokine. Hepatic vitamin E level was significantly decreased by micronutrient deficiency, in accordance with increased hepatic lipid peroxidation level. However, Pyc supplementation resulted in a dose-dependent reduction of hepatic lipid peroxidation, which may result from restoration of hepatic vitamin E level.CONCLUSIONFindings of this study suggest that Pyc supplementation ameliorates premature death by restoring immune dysfunction, such as increasing lymphocyte proliferation and regulation of cytokine release from helper T cells, which may result from the antioxidative ability of Pyc.