Inhibitory effect of capsaicin on B16-F10 melanoma cell migration via the phosphatidylinositol 3-kinase/Akt/Rac1 signal pathway

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide), the major pungent ingredient of red pepper, has been reported to possess anti-carcinogenic and anti-mutagenic activities. In this study, the anti-migration activity of capsaicin on highly metastatic B16-F10 melanoma cells was investigated. Capsaicin significantly inhibited the migration of melanoma cells without showing obvious cellular cytotoxicity at low doses. This effect correlated with the down-regulation of phosphatidylinositol 3-kinase (PI3-K) and its downstream target, Akt. Although B16-F10 cell migration was increased by the PI3-K activator through the activation of Akt, these PI3-K activator-induced phenomena were attenuated by capsaicin. Moreover, capsaicin was found to significantly inhibit Rac1 activity in a pull-down assay. These results demonstrate that capsaicin inhibits the migration of B16-F10 cells through the inhibition of the PI3-K/Akt/Rac1 signal pathway. The present investigation suggests that capsaicin targets PI3-K/Akt/ Rac1-mediated cellular events in B16-F10 melanoma cells. Consequently, capsaicin administration should be considered an effective approach for the suppression of invasion and metastasis in malignant melanoma chemotherapy.

Effect of Treadmill Exercise Training and Dietary Intake of Garcinia Cambogia Extract, Soypeptide and L-Carnitine Mixture on Body Weight Reduction in Rats Fed High-Fat Diet

This study was undertaken to examine effects of dietary intake of garcinia cambogia extract, soy peptide and L-carnitine mixture on body weight gain and obesity-related bio-markers in rats fed high-fat diet for 9 weeks with or without regular treadmill exercise. Forty 5-week-old male Sprague-Dawley rats were randomly divided into four groups; sedentary control group (SC), exercised control group (EC), sedentary formula-fed group (SF), and exercised formula-fed group (EF). The SC and EC rats were fed high-fat control diet (fat comprises 40% of total caloris), and SF and EF rats were fed high-fat formula (composed of garcinia cambogia, soy peptide and L-carnitine) supplemented diet. Statistical analyses by two-way ANOVA indicated that the regular treadmill exercise significantly lowered cumulative body weight gain, total visceral fat mass, and epididymal, perirenal and retroperitoneal fat pad weights, and serum concentrations of total cholesterol and LDL + VLDL cholesterol, insulin, c-peptide and leptin. Feeding the formula also resulted in significant reductions in cumulative body weight gain and visceral fat pad weights, along with other related parameters including serum total and LDL + VLDL cholesterol levels, and hepatic enzyme activities involved in fatty acid synthesis. Statistical analyses by one-way ANOVA revealed that the formula consumption significantly improved body weight gain (18% reduction), total visceral fat weight (20% reductions), and serum total (43% reduction) and LDL + VLDL cholesterol (54% reduction) levels, as well as serum levels of insulin (49% reduction), and c-peptide (41% reduction) in sedentary rats, but failed to exhibit significant reductions in these indices in animals under treadmill exercise program. Taken together, these results suggest that the treadmill exercise per se exhibited significant improvements in body fat reduction and other related bio-markers, and so the formula consumption did not achieve a further significant reductions in these bio-markers in exercised rats. Nevertheless, animals fed the formula with regular exercise showed the most efficient weight reduction compared to other groups either fed formula without exercise or received regular exercise without dietary supplementation.