Extraction, purification of Lycium barbarum polysaccharides and bioactivity of purified fraction

Polysaccharides was extracted from dried Lycium barbarum fruits. The ion-exchange chromatography was used to isolate and purify the polysaccharides to afford a complex water-soluble polysaccharide, named LBPF5 with a molecular mass of 5.3 × 104 Da. LBPF5 consisted of arabose, mannose, xylose, glucose and rhamnose. Preliminary tests in vitro showed strong free radicals scavenging activities. The oxidative hemolysis of erythrocytes induced by AAPH was suppressed by the LBPF5 in a concentration- and time-dependent manner. In addition, LBPF5 and anthocyan could inhibit the growth of human bladder carcinoma cell line BIU87 and induce BIU87 apoptosis. Furthermore, anthocyan displayed stronger antitumor activities. From these results, it was demonstrated that LBPF5 has the ability to protect against damage from oxidative stress in vitro and in vivo.