Punarnavine induces apoptosis in B16F-10 melanoma cells by inhibiting NF-kappaB signaling.

The objective of this study was to assess the effect of Punarnavine, an alkaloid isolated from Boerhaavia diffusa, on apoptosis in B16F-10 melanoma cells. Treatment of B16F-10 melanoma cells with nontoxic concentrations of Punarnvine resulted in the presence of apoptotic bodies and DNA fragmentation in a dose dependent manner. Cell cycle analysis and TUNEL assays also confirmed the observation. The apoptotic genes p53 and caspase-3 were found upregulated in Punarnavine treated cells, whereas the antiapoptotic gene Bcl-2 was downregulated. The inhibited nuclear translocation of NF-kappaBp65, NF-kappaBp50, NF-kappaB-c-Rel, c-Fos, ATF-2 and CREB-1 in Punarnavine treated B16 F-10 cells pointed to suppression of NF-kappaB signaling by Punarnavine. All these results demonstrate that Punarnavine induces apoptosis via activation of p53 induced caspase-3 mediated pro-apoptotic signaling and suppression of NF-kappaB induced Bcl-2 mediated survival signaling.