CASP3 and hepatocellular carcinoma: In conclusion, the present study demonstrates that the decoction of Nigella sativa seeds, Hemidesmus indicus roots and Smilax glabra rhizomes can induce apoptosis in human hepatocellular carcinoma HepG2 cell, in a dose and time dependent manner through the activation of caspase-3 and caspase-9, and up regulation of pro-apoptotic Bax and down regulation of anti-apoptotic Bcl-2 genes which are involved in intrinsic or mitochondrial pathway of apoptosis.