Optimization for the extraction of polysaccharides from Ganoderma lucidum and their antioxidant and antiproliferative activities

► Response surface methodology was used to optimize extraction of polysaccharide. ► The optimal extraction conditions were: ultrasonic power 320 W, 70 °C, 34 min. ► The polysaccharide was separated into four fractions by ultrafiltration membranes. ► The antioxidant and antiproliferative activities of all fractions were evaluated. ► GLP1 and GLP2 fractions had stronger bioactivities than the other fractions.