Punarnavine Induces Apoptosis in B16F-10 Melanoma Cells by Inhibiting NF-kB Signaling

The objective of this study was to assess the effect of Punarnavine, an alkaloid isolated from Boerhaaviadiffusa, on apoptosis in B16F-10 melanoma cells. Treatment of B16F-10 melanoma cells with nontoxicconcentrations of Punarnvine resulted in the presence of apoptotic bodies and DNA fragmentation in a dosedependent manner. Cell cycle analysis and TUNEL assays also confirmed the observation. The apoptotic genesp53 and caspase-3 were found upregulated in Punarnavine treated cells, whereas the antiapoptotic gene Bcl-2was downregulated. The inhibited nuclear translocation of NF-κBp65, NF-κBp50, NF-κB-c-Rel, c-Fos, ATF-2and CREB-1 in Punarnavine treated B16 F-10 cells pointed to suppression of NF-κB signaling by Punarnavine.All these results demonstrate that Punarnavine induces apoptosis via activation of p53 induced caspase-3 mediatedpro-apoptotic signaling and suppression of NF-κB induced Bcl-2 mediated survival signaling.