The hepatoprotective activity of Olax viridis Oliv. (Olacaceae Juss.) methanol root extracts were tested in vivo andin vitro. The plant material was defatted with n-hexane and extracted with 70% methanol, respectively. The methanol extract was recovered in 11.73% w/w yield. An oral 100 mg kg-1 administration of the methanol extract significantly reduced pentobarbitone-induced sleep in rats poisoned with acetaminophen (p<0.05). In this model, a protection of 87% against the cytotoxicity of acetaminophen was obtained by pretreatment with the methanol extract as compared to a protection of 91% when the animals were pretreated with silymarin. The n-hexane extract was without a significant hepatoprotective effect in this model. Intraperitoneal injection of the methanol extract into rats showed no significant effect on pentobarbitone-induced hypnosis (p<0.05). The elevation of serum glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP) and urea induced by paracetamol intoxication in rats was also significantly attenuated by the methanolic extract (p<0.05). These findings demonstrated that O. viridis root extract has protective effects on experimental model of liver diseases in rats and validates its use in Nigerian traditional medicine for the prevention of liver diseases. Even in its crude form, the effects were comparable to that of silymarin, a flavanolignan with proven antihepatotoxic activity. This suggests that the extract could be a potential source of a novel antihepatotoxic agent.
C.U. Nwaigwe, I.I. Madubunyi, S.C. Udem and C.O. Nwaigwe, 2012. Methanolic Root Extract of Olax viridis Protects the Liver against Acetaminophen-induced Liver Damage. Research Journal of Medicinal Plant, 6: 395-405.