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

► The root of Salvia miltiorrhiza is a popular traditional Chinese herbal medicines. ► The polysaccharide (SMP-W1) was purified from S. miltiorrhiza. ► SMP-W1 displayed efficient tumor growth inhibitory effect in vitro and in vivo. ► Antioxidase activities and immune response were improved by SMP-W1. ► SMP-W1 could be developed as a safe antitumor agent.