The chemical character of polysaccharides from processed Morindae officinalis and their effects on anti-liver damage

The medicinal plant Morinda officinalis How and its root have long been used in traditional medicines in China. The aims of the present study were to investigate the chemical composition and liver-protective effect of crude polysaccharides (MOP-100) from the processed root of Morinda officinalis against Concanavalin A (ConA)-induced liver damage in vivo and vitro. The processed root of the herbal medicine was extracted with water at 100 °C, then precipitated with ethanol, dialyzed and freeze-dried to obtain MOP-100. The molecular weight of MOP-100 was a wide distribution. However, the processed root was extracted consecutively at 60 °C and 100 °C to obtain two crude polysaccharides MOP-60 and MOP-60-100. MOP-60 mainly contained an inulin-type fructooligosaccharide with molecular weight of 2071 Da. MOP-100 significantly inhibited the infiltration of neutrophils and macrophages into liver, improved the hepatic injury induced by ConA in mice. It stimulated the proliferation of human liver LO2 cells and decreased the cell death induced by ConA. MOP-100 also significantly inhibited the HBeAg secretion of Hep2.5.5 hepatocytes in vitro. MOP-60 and MOP-60-100 both exhibited good activity of protecting hepatocytes against ConA-induced damage in vitro. These results suggested Morinda officinalis polysaccharides exert significant hepatoprotective effect, and it might be used for treatment of immune-mediated liver disease in the future.