Studies on immunoregulatory and anti-tumor activities of a polysaccharide from Salvia miltiorrhiza Bunge

In this study, we purified and characterized a polysaccharide (SMP-W1) from Salvia miltiorrhiza and investigated its anticancer and immunoregulatory potential in vitro and in vivo. The monosaccharide composition, protein content, uronic acid content, total carbohydrate content, viscosity and molecular weight of SMP-W1 were analyzed. In vitro, SMP-W1 had an antiproliferative effect on hepatocellular carcinoma H22 cells, especially at the high concentration of 400 μg/ml. Simultaneously the polysaccharide SMP-W1 significantly inhibited tumor growth and increased serum superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities in rats, as well as the secretion of TNF-α. In addition, the body weight, spleen index and thymus index in tumor-bearing mice were significantly improved by SMP-W1 treatment. Taken together, these results indicated that SMP-W1 possessed strong in vivo and in vitro anti-tumor activity and improves the immune response in tumor-bearing mice. Therefore, it could be developed as an anti-tumor agent with immunomodulatory activity.