Antioxidant and hepatoprotective potentials of miliusa velutina stem bark extract
Miliusa velutina (MV) stem bark has various medicinal uses, but its hepatoprotective effect has not yet been studied. This study investigated the antioxidant and hepatoprotective activity of the ethanol extract of MV stem bark against carbon tetrachloride (CCl4)-induced liver injury. The ethanol extract of MV stem bark was evaluated for in vitro antioxidant activity which exhibited good antioxidant activity in terms of ferric reducing-antioxidant power assay (EC50, FRAP=4.04±0.00 µg/mL), total antioxidant capacity assay (EC50, TAC=8.73±1.08 µg/mL) and 1,1-diphenyl-2-picrylhydrazyl (EC50, DPPH=9.33±0.07 µg/mL) radical scavenging assay. Mice were pretreated with CCl4 (2.5 mL/kg body wight per day) in 4 consecutive weeks. After one hour taking CCl4 by oral administration, mice were treated with the ethanol stem bark extract of MV at various concentrations of 100, 200, and 400 mg/kg body weight. The MV stem bark at the dose of 400 mg/kg body weight effectively reduced the level of alanine transaminase (38±6.78 U/L) and aspartate transaminase (AST) in serum. Besides, the MV stem bark at the dose 400 mg/kg body weight reduced the malondialdehyde (3.12±1,19 nM MDA/g tissue) level, and increased the activity of reduced glutathione (896.21±22.69 nM GSH/g tissue) in liver. The observation of the microscopic cross section of liver tissue also revealed that the mice treated with stem bark extract of MV at the dose of 200 and 400 mg/kg body weight had significantly improvement in liver tissues compared to the non-treated control group. Histological analyses of the MV-treated group exhibited reducing inflammatory process and preventing liver necrosis and fibrosis. In summary, the hepatoprotective effect of MV stem bark was seemingly associated with its antioxidant activity.