In vitro induction of differentiation by ginsenoside Rh2 in SMMC-7721 hepatocarcinoma cell line

The aim of this study was to investigate the effects of ginsenoside Rh(2) (G-Rh(2)) on differentiation of SMMC-7721 hepatocarcinoma cell line in culture. We studied G-Rh(2)-induced differentiation of SMMC-7721 cells through cell proliferation, cell morphology, ultrastructure, cell cycle, cell function and metabolism. The proliferation of treated cells was inhibited, the morphology and ultrastructure seemed normal, the secretory amount and expression of alpha-foetoprotein, and the specific activity of gamma-glutamyl transpeptidase, and heat-resistant alkaline phosphatase were all significantly decreased, the secretory amount of albumin and alkaline phosphatase activity were remarkably increased, and the cell was arrested at the G(1)/G(0) phase. Furthermore, G-Rh(2) induced elevated expression of the cyclin-dependent kinase inhibitor p21(WAF1) and p16(INK4a), and declined expressions of cyclin D1 and cyclin E. In addition, G-Rh(2) almost completely inhibited telomerase activity, as measured by polymerase chain reaction-based telomeric repeat amplification protocol coupled with enzyme-linked immune sorbent assay, and human telomerase reverse transcriptase mRNA. Based on these data, it is suggested that G-Rh(2) could induce cell differentiation tending to normal and effectively reduce telomerase activity with affecting transcription levels of human telomerase reverse transcriptase, paralleling the induction of cell differentiation.