Modulation of Oxidative Stress and Inflammatory Cytokines as Therapeutic Mechanisms of Ocimum americanum L Extract in Carbon Tetrachloride and Acetaminophen-Induced Toxicity in Rats

Liver diseases have now become a global canker due to increasing drug abuse and several viral infections. The current medicines on the market are woefully inadequate and limited in the application against these diseases. Fortunately, medicinal plants continue to serve as a potential source of drug discovery that could be explored to improve the situation. The present study, therefore, evaluated the hepatoprotective activities of the aqueous extract of various parts (leaves, flower and stem) of Ocimum americanum L on carbon tetrachloride (CCl₄)- and acetaminophen-induced toxicity in rats. The protective effect of the plant was assessed using biochemical parameters, histology, levels of liver antioxidants, and expression of some pro-inflammatory cytokines (NF-κβ and IL-1) in the liver. The leaves and stem extracts, orally administered for 7 days at 250 mg/kg, effectively prevented CCl₄-induced elevation of serum biochemical parameters, prooxidants, as well as the expression of NFk-B and IL-1, which were comparable to Silymarin (standard drug). A comparative histopathological analyses of the liver exhibited virtually normal architecture compared with CCl₄-treated group. The findings showed that the hepatoprotective effect of Ocimum americanum was probably due to the inhibition of oxidative stress and downregulation of proinflammatory cytokines by the effective parts of the medicinal plant.

Keywords: Ocimum americanum; acetaminophen; carbon tetracloride; hepatoprotective; inflammation; medicinal plants.