Evaluation of antioxidant and immuno-enhancing activities of Purslane polysaccharides in gastric cancer rats.

In the last three decades, numerous polysaccharides and polysaccharide-protein complexes have been isolated from plant or animal and used as a promising source of therapeutic agents for cancer. In this study, we examined the effects of Purslane polysaccharides (PPs) on the oxidative injury and immune status in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric cancer rats. PPs administration (200, 400 or 800mg/kg body weight) could not only increase the body weight, peripheral white blood cells (WBC) count, thymus and spleen indexes, but also remarkably promote splenocytes proliferation of gastric cancer rats. Furthermore, the production of serum cytokines in gastric cancer rats, such as interleukin-2 (IL-2), interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-α) was enhanced by PPs treatment. Besides, treatment with PPs was found to provide a dose-dependent protection against MNNG-induced oxidative injury by enhancing SOD, CAT, GSH-Px activities of gastric cancer rats. Taken together, we concluded that enhancement of antioxidants and immune response might be responsible for the anticancer effect of PPs in gastric cancer.