Enzymatic extraction optimization, anti-HBV and antioxidant activities of polysaccharides from Viscum coloratum (Kom.) Nakai.

An enzyme-assisted extraction method had been optimized by single factor experiments and orthogonal test design, to improve the extract yield of polysaccharides from the leaves of Viscum coloratum (Kom.) Nakai (VCP). The anti-HBV activity of VCP in vitro was investigated by PCR-fluorescent probing (FQ-PCR) and ELISA methods. Moreover the antioxidant activity of VCP in vitro was studied in terms of the reducing power, 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) test radical-scavenging activity and hydroxyl radicals-scavenging activity. The results demonstrated that the optimum extraction conditions were solid-liquid ratio of 1:40, enzyme concentrations of 2.5%, enzyme action time of 40 min, enzyme action temperature of 50 °C, enzymatic pH of 5. Under these conditions, the extraction yield of VCP was 21.83 ± 0.45%. VCP could inhibit the replication of HBV-DNA and the secretion of HBV antigens in a dose-dependent manner, and showed better antioxidant capacity. These findings suggest that VCP could be a good potential natural antiviral agent and antioxidant.