The extraction, structure, and immunomodulation activities in vivo of polysaccharides from Salvia miltiorrhiza

Salvia miltiorrhiza polysaccharides were generally extracted using distilled water as solvent and showed various bioactivities in vivo, however, the preparation, structure, and immunomodulatory effects of polysaccharides with 60 % ethyl alcohol extraction were rarely reported. In the present study, S. miltiorrhiza polysaccharides was prepared using 60 % ethanol and the extraction process was optimized, then the structural characteristics and immunomodulation activity were investigated. Results showed that optimal extraction conditions for crude polysaccharides were determined as follows: liquid/solid ratio of 22 mL/g, extraction temperature of 60 °C, ultrasonic power of 205 W, ultrasonic time of 125 min, and the yields reached to 5.99 ± 0.09 %. Structural determination results demonstrated the purified polysaccharides showed a average molecular weight of 6.50 × 103 Da with Galactose/Glucose/Fructose ratio of 1.00:0.45:0.28. Animal experiments indicated that the polysaccharides could effectively enhance immune cells activities, and improve lymphocytes subsets proportions and immune-related cytokines expression levels dose-dependently in cyclophosphamide-treated mice. These results would provide a theoretical basis for industrial production and practical application of the novel polysaccharides as an immunoregulation adjuvant.