['Hepatocellular carcinoma (HCC) is a rapidly progressive cancer with poor prognosis. However, there have been no significant new developments in treating liver cancer. To search for an effective agent against HCC progression, we prepared a polyphenolic extract of Solanum nigrum L. (SNPE), a herbal plant indigenous to Southeast Asia and commonly used in oriental medicine, to evaluate its inhibitive effect on hepatocarcinoma cell growth. The growth inhibition of HepG2 cells in vitro and in vivo was determined in the presence of SNPE.', 'We found 1 µg mL(-1) SNPE-fed mice showed decreased tumor weight and tumor volume by 90%. Notably, 2 µg mL(-1) SNPE resulted in almost complete inhibition of tumor weight as well as tumor volume. In line with this notion, SNPE reduced the viability of HepG(2) cells in a dose-dependent manner. HepG(2) cells were arrested in the G(2)/M phase of the cell cycle; meanwhile, the protein levels of cell CDC25A, CDC25B, and CDC25C were clearly reduced. Moreover, sub-G(1) phase accumulation and caspases-3, 8, and 9 cleavages were induced by SNPE.'] Does solanum nigrum L. polyphenolic extract inhibit hepatocarcinoma cell growth by inducing G2/M phase arrest and apoptosis?