Anthraquinones Extract from Morinda angustifolia Roxb. Root Alleviates Hepatic Injury Induced by Carbon Tetrachloride through Inhibition of Hepatic Oxidative Stress.

In Southwestern China, the root of Morinda angustifolia Roxb. has been employed as a folk medicine for treating various types of hepatitis and jaundice. The purpose of this study was to evaluate the hepatoprotective effects of anthraquinones extract from M. angustifolia root (AEMA) in carbon tetrachloride- (CCl₄-) induced liver injury in mice and identify the main bioactive components. Results indicated that AEMA pretreatment could significantly, in a dose-dependent manner, attenuate the increased levels of ALT and AST in mice serum induced by CCl₄. At doses of 100 and 200 mg/kg, AEMA exhibited significant suppression of the elevated hepatic levels of malondialdehyde (MDA), as well as marked upregulatory effects on the activities of antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in mice exposed to CCl₄. However, AEMA treatment had no effect on the antioxidant enzyme catalase (CAT) or the nonenzymatic antioxidant glutathione (GSH). Furthermore, two anthraquinone constituents were isolated from AEMA and identified as soranjidiol and rubiadin-3-methyl ether. Soranjidiol exhibited similar protective effects to those of AEMA on liver damage induced by CCl₄. Overall, our research clearly demonstrated the hepatoprotective effects of the AEMA, and anthraquinones, particularly soranjidiol, should be considered as the main hepatoprotective principles of M. angustifolia. In addition, the underlying mechanism may be, at least in part, related to its antioxidant properties.