Sub-Chronic Hepatotoxicity in Adult Wistar Rats Following Administration of Ocimum gratissimum Aqueous Extract

Background & Aims: Ocimurn gratissimum is an herbaceous plant commonly found in tropical Asia and in the coastal areas of Nigeria, where it is used for the treatment of ailments such as diarrhoea, urinary infections, fever and dysentery. However, information concerning the toxic effect of continuous administration of aqueous preparation of Ocimum gratissimum on some important organs of the body such as the liver is lacking. The study was designed to evaluate the effects of oral administration of the aqueous extract of Ocimum gratissimum at varying doses on the liver of adult male wistar rats.
Materials and Methods: The rats (n=30) of average weight of 185g were randomly assigned into four treatment groups A, B, C, D (n=6) and control group E (n=6). Aqueous extract of leaves of Ocimum gratissimum (OG) at doses of 0.4, 0.8, 1.6 and 3.2 g/kg body weight were administered orally to the four treatment groups A, B, C and D respectively for twenty one days. The control rats received quantities of distilled water equivalent to those in the treatment groups. The rats were sacrificed on the twenty second day of the experiment. The abdomen of the rats were carefully dissected and some blood was carefully collected by cardio-puncture into lithium heparinized sterile bottles for biochemical enzyme assay, also the liver was carefully dissected out and quickly fixed in 10% formol saline for routine histological study using haematoxylin and eosin method. Decrease in body weights of the treated, rats at the end of the study were statistically significant (p < 0.05) in the treatment groups B, C and D.
Results: The histological findings after H&E method indicated that the treated sections of the liver showed evidence of dilations of the central veins, which contained lysed red blood cells and cyto-architectural distortions of the hepatocytes, cytoplasmic hemorrhage, atrophic and degenerative changes. The biochemical results showed finding in line with the histopathological analysis. Quantitative analysis of serum liver enzymes in the treated' groups A, B, C and D showed significant increase (P < 0.05) in the serum levels of Alanine aminotransaminase, aspartate aminotransaminase and alkaline phosphatase as compared to the control (untreated) groups.
Conclusion: These findings indicate that high doses of aqueous extract of Ocimum gratissimum may have some adverse effects on the liver of adult wistar rats which may ultimately impair hepatic functions.