Safety and risk assessment of methanol extract of Ocimum gratissimum leaf on Wistar rats

Methanol extract of Ocimum gratissimum was investigated for its effects on Wistar rats using some kidney and liver functional indices as ‘markers’. Twenty- eight (28) albino rats weighing 180-200 g was randomly assigned into four groups (A-D) of seven animals each. Animals in groups B-D was orally administered on daily basis with 0.5 ml of the extract corresponding to 50,100 and 200 mg/kg body weight of the extract respectively for 14 days while those in the control group received orally 0.5 ml of distilled water. Rats in all the groups were sacrificed 24 hours after the completion of their respective doses and serum, liver and kidney tissue samples were collected for biochemical parameters. The extract significantly (p<0.05) decreased serum, liver and kidney ALP, AST and ALT. The extract also significantly (p<0.05) reduced serum urea, uric acid and creatinine. Contrastingly, the extract significantly (p < 0.05) increase in serum albumin, globulin and total protein respectively when compared with the normal control at 50, 100 and 200 mg/kg body weight respectively. The effect of administration of the extract on serum Na+, K+, Cl- and HCO3- ions shows a significant (p<0.05) decrease when compared with the normal control with the exception of an increase in K+ ion concentration at 200 mg/kg bwt when compared with the normal control. The biochemical alterations from this result suggest that the extract of Ocimum gratissimum may induce hyponatremia and hypokalaemia at high dosage possibly by altering the Na + /H – exchanger with aldosterone without causing assault or injury to the hepatic, nephrotic and /or tubular function.