Effects of alpha-lipoic acid on cell proliferation and apoptosis in MDA-MB-231 human breast cells

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 micromol/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, ErbB2 and ErbB3 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.

Effects of Xylooligosaccharide Intake on Fecal Bifidobacteria,Lactic acid and Lipid Metabolism in Korean Young Women

This study investigated the effects of xylooligosaccharide on feces bifidobacteria proliferation, lactic acid concen-tration and lipid metabolism in healthy woman. Fourteen volunteers were randomly assigned to 2 groups : 1.4 g/day xylooligosaccharide intake group, 2.8 g/day xylooligosaccharide intake group. The duration of the study was 28 days. The amount of feces and excretion time were not affected by xylooligosaccharide intake. The color of feces changed to yellow brown, and hardness of stool and effort to evacuation were reduced by xylooligosaccharide intake. Xylooligo-saccharide intake reduced the fecal pH significantly after 14 days in 2.8 g/day intake group (p <0.05 ). The number of fecal bifidobacteria were significantly increased after 28 days in 1.4 g/day intake group (p <0.05 ), and in 2.8 g/day in-take group, the number of fecal bifidobacteria significantly increased after 14 days (p <0.05 ). Water contents of feces were not affected by xyloolgosacchride intake. The fecal triglyceride and cholesterol concentrations were increased in 2.8 g/day intake group (p <0.05 ), and in 1.4 g/day intake group, fecal cholesterol concentration only was increased (p <0.05 ). The fecal lactic acid concentration was significantly increased in 2.8 g/day intake group (p <0.05 ). Serum trigly-ceride, cholesterol and glucose concentration were significantly decreased in 2.8 g/day intake group (p <0.05 ). In conclusion, xylooligosaccharide dietary supplementation may be beneficial to gastrointestinal health and lipid metabolism, and 2.8 g/day intake was more effective than 1.4 g/day intake.