Gynostemma pentaphyllum polysaccharide prevents the growth of h22 ascites tumour by enhancing immunity rather than cytotoxicity in mice

Polysaccharide from Gynostemma pentaphyllum Makino (GPP) could prevent H22 tumour growth and have immunostimulatory in mice, but the mechanism is largely unknown. In this study, we further investigated whether GPP prevents tumour growth by inducing cytotoxicity to the tumour cells or enhancing immunity in H22 ascites tumour-bearing mice. The results showed that GPP prevented the H22 ascites tumour growth in vivo, but showed little effect on cell viability and cycles to H22 cells in vitro. GPP improved the proportion and mitochondrial level of T cells, and promoted the secretion of IL-2 and IFN-γ in the ascites of the mice. Furthermore, GPP in vitro enhanced the cell viability and promoted activation (in particular T cells), proliferation, and the secretion of IL-2 and IFN-γ of lymphocyte. Taken together, our results demonstrated that GPP prevents H22 ascites tumour growth by enhancing immunity rather than cytotoxicity in mice.