Characterization, antioxidant and antitumor activities of polysaccharides from Salvia miltiorrhiza Bunge

Polysaccharides were extracted from Salvia miltiorrhiza Bunge using response surface methodology (RSM) with ultrasonication. A Box–Behnken design was used to optimize the extraction parameters to maximize the polysaccharide extraction yield. The polysaccharide SMP-U1 was isolated and characterized; then the antioxidant and antiproliferation activities were evaluated in vitro. The modified optimal conditions were an ultrasonic power of 180 W, an extraction temperature of 54 °C, and an extraction time of 32 min, achieving an extraction yield of 40.54 ± 0.25%. The results indicate that SMP-U1 has significant antioxidant activity, scavenging the free radical 2,2-diphenyl-1-picrylhydrazyl. It has also exhibited effect on the proliferation of human breast carcinoma cells Bcap-37 and human esophageal carcinoma cells Eca-109, especially at a concentration of 0.30 mg/mL. In conclusion, SMP-U1 has remarkable in vitro antioxidant and antiproliferation activity, and has potential for application as a natural antioxidant or antitumor agent.