Extraction, optimization and bioactivities of alcohol-soluble polysaccharide from Grifola frondosa

摘要

Traditional extraction methods for polysaccharides are water extraction and ethanol precipitation, while the alcohol-soluble polysaccharides would be abandoned. The extraction process of alcohol-soluble polysaccharide from the fungus Grifola frondosa(GFAP) optimized by orthogonal test and the bioactivities (antitumor and antioxidant) were investigated in this study. The optimum extraction conditions were determined as follows: Solid–liquid ratio of 1:20 g/mL, extraction temperature of 65 °C, extraction time of 4.5 h, assistant factors of ultrasound-assisted extraction and extraction times of 2, under these conditions, the experimental yield of GFAP was 36.34±1.26%. High Performance Gel Permeation Chromatography and chemical component analysis showed that the contents of total sugar, protein and uronic acid in GFAP were 95.83%, 0.34% and 0.21%, respectively, and its molecular weight was about 2.9 kDa. Additionally, results of MTT assay showed that GFAP could significantly inhibit the proliferation of Hepatocellular Carcinoma cell line (HepG2) in time- and dose- dependent manners. The in vitro antioxidant results showed that GFAP possessed excellent scavenging effects on ABTS+ (61.2%), DPPH (90.3%) and HO (49.2%) at the concentration of 2 mg/mL. These results demonstrated that GFAP is a relatively abundant polysaccahride in Grifola frondosa with strong antitumor and antioxidant activities. Our data provided a theoretical basis for the practical application of GFAP in the future.