β-Carotene down-regulates inducible nitric oxide synthase gene expression and induces apoptosis by suppressing bcl-2 expression and activating caspase-3 and p53 genes in B16F-10 melanoma cells

The objective of this research was to assess the effect of fl-carotene on the regulation of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha production and stimulation of apoptosis in B1617-10 melanoma cells. P-Carotene at a concentration of 10 mu g/mL could significantly (P <.01) inhibit NO and TNF-oc production in B1617-10 melanoma cells. This was further evidenced by the regulatory effect of beta-carotene on the inhibition of inducible nitric oxide synthase gene expression in B16F-10 cells. We investigated the effect of fl-carotene on induction of apoptosis in B16F-10 cells. Incubation of B16F-10 cells with fl-carotene showed the presence of apoptotic bodies and induced DNA fragmentation. Furthermore, fl-carotene showed inhibitory effect on bcl-2 expression and upregulated p53 and caspase-3 gene expression in B16F-10 melanoma cells. In conclusion, the observed results suggest that beta-carotene could regulate NO and TNF-alpha production and stimulates apoptosis in B16F-10 melanoma cells by regulating bcl-2, p53, and caspase-3 genes. (C) 2007 Elsevier Inc. All rights reserved.