Extraction optimization and antioxidant activity of Phyllanthus urinaria polysaccharides

Abstract Three extraction parameters including extraction time, material to solvent ratio, and extraction temperature for the extraction yield of Phyllanthus urinaria polysaccharides were optimized by response surface methodology. The results revealed that the optimal extraction process was extraction time of 5.3 h, extraction temperature of 93 °C, and material to solvent ratio of 1:47 g/mL, under which the polysaccharide yield was 6.40%; The three parameters had significant effect on the polysaccharide yield, and the influence of extraction time was the greatest and that of extraction temperature was the lowest. The antioxidant activity test indicated that the equivalent scavenging ability of Phyllanthus urinaria polysaccharides on DPPH and ABTS free radicals was 0.88 and 0.84 μg TBHQ/μg of polysaccharides, respectively; while the reducing power and total antioxidant capacity of Phyllanthus urinaria polysaccharides was equivalent to 93.62% and 93.55% of TBHQ, respectively. The Phyllanthus urinaria polysaccharides had good antioxidant activity.