Anticancer and immunoregulatory activity of Gynostemma pentaphyllum polysaccharides in H22 tumor-bearing mice

A neutral polysaccharide fraction (CGPP) was extracted from Gynostemma pentaphyllum by water extraction and ethanol precipitation. Gas chromatography (GC) analysis showed that the CGPP was mainly composed of mannose, glucose, arabinose, rhamnose, galactose and glucuronic acid in molar ratios of 2.0:2.2:1.3:2.2:1.2:2.5. The present study aimed at evaluating the antitumor potentials of CGPP on the growth of H22 tumor transplanted in mice and the underlying mechanism. The results showed that CGPP (50 and 200 mg/kg) could effectively inhibit the solid tumor growth of H22 hepatocarcinoma transplanted in ICR mice. Besides, the body weight, spleen/thymus indexes and splenocytes proliferation of H22 tumor bearing mice were also improved in CGPP-treated groups. Furthermore, the level of the cytokines, such as IL-2, TNF-α and IFN-γ, as well as the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL) in tumor-bearing mice were markedly promoted by CGPP oral administration. In addition, CGPP treatment greatly prolonged the survival period in H22 ascites tumor-bearing mice. Taken together, these findings indicate that CGPP has antitumor activity in vivo at least partly via improving immune responses of host organism, and seems to be a safe and effective supplementary agent for the treatment of hepatocellular carcinoma (HCC).