Degradation enhances the anticoagulant and antiplatelet activities of polysaccharides from Lycium barbarum L. leaves

Abstract

In the current study, a carboxyl-rich polysaccharide purified from Lycium barbarum L. leaves (hereafter, LP) and its degradation with ascorbic acid and hydrogen peroxide were characterized. Degradation decreased the molecular weight of LP from 4.63 × 10⁴ to 3.45 × 10⁴ Da, and increased its zeta potential from -8.01 to -5.35 mV. In vitro experiments showed that degradation significantly increased the anticoagulant activity and, in particular, antiplatelet activity of LP (p < 0.05). The polysaccharide with the highest degree of degradation had higher inhibitory activity than aspirin against arachidonic acid- and thrombin-induced platelet aggregation at 0.5 g/mL. A reduction in uronic acids between LP and its degradation products significantly decreased their antiplatelet activity (p < 0.05). Further analysis confirmed that polysaccharides changed from a compact spherical structure to a random coil in aqueous solution following degradation, which facilitated the interaction of polysaccharides and platelets.

Keywords: Carboxylic acid; Goji; Heparin; NMR; Ribose; Thrombosis.