Ultrasound extraction optimization of Acanthopanax senticosus polysaccharides and its antioxidant activity

In this study, effects of several experimental parameters, including ultrasonic time, ratio of water to material, extraction temperature and ultrasonic power on the extraction yield of polysaccharides from Acanthopanax senticosus stem (ASS) were investigated by single factor experiment and an orthogonal test design (L9(3)4) was used to optimize the ultrasound extraction conditions. The polysaccharides from Acanthopanax senticosus stem (ASSP) and fruit (ASFP) were further fractionated by stepwise ethanol precipitation and the anti-oxidation activities of those fractions were evaluated by hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Under the optimal conditions (ultrasonic time 75 min, ratio of water to material 50 ml/g, extraction temperature 80 °C and ultrasonic power 100 W), the yield was 10.9 mg/g. All fractions of ASP possessed considerable antioxidant activity. The results indicated that the ultrasound extraction was a very useful method for the extraction of ASP and the polysaccharides could be explored as a potential antioxidant agent for use in medicine or functional food.