Antioxidant and Hepatoprotective Effects of Orthosiphon aristatus on
Liver Damage Induced by CCl4 in Mice
Orthosiphon aristatus Blume, is a popular medicinal herb in Vietnam. The extract of this plant have been proven to exert a diuretic, anti-diabetic and lipid lowering activities. In this study, fractions obtained by liquid-liquid distribution between water and chloroform (CHCl3-F), ethyl acetate (Et-F) and n-butanol (Bu-F) of the ethanol extract of Orthosiphon aristatus Blume were tested for their antioxidative activity on in vitro (FRAP and DPPH assays), ex vivo (mouse liver cells intoxicated by CCl4) and in vivo (mice intoxicated by CCl4) tests. The results showed that Bu-F fraction had higher FRAP than those of other fractions while Et-F had higher antioxidative ability than those of the others in DPPH, ex vivo and in vivo assays. The IC50 (2.80 mg/ml) of DPPH• radical scavenging assay of Et-F was better antioxidative activity than the pure natural antioxidant ascorbic acid (IC50 = 3.24 mg/ml). In vivo hepatoprotective activity of Et-F on liver injury induced by CCl4 in mice was dose dependent and comparable to Silymarin at dose 16 mg/kg but weaker than Silymarin at dose 8 mg/ml. The results obtained in the present study demonstrated that O. aristatus is a potential source of natural antioxidants and hepatoprotective agents.