European Journal of Biomedical and Pharmaceutical Sciences

EFFECT OF METHANOL ROOT EXTRACT OF NAUCLEA LATIFOLIA SMITH (RUBIACEAE) ON PARACETAMOL-INDUCED TOXICITY IN RATS

*Paul A. Nwafor, Akpan U. Ekanem, Idorenyin U. Umoh and Kingsley A. Okon

ABSTRACT

Objective: The effect of methanol root extract of Nauclea latifolia was investigated in paracetamol-induced toxicity in rats. The investigation was done due to numerous claims of this plant parts in management of poisoning, malaria and gastrointestinal disorders among others. The aim of this investigation is to ascertain whether it can ameliorate paracetamol – induced toxicity in rats, and through what mechanism does it mediate its effects. Methods: The root was harvested from the wild, identified and authenticated by a Taxonomist in the Department of Botany and Ecological Studies of this University. It was macerated in methanol for 72 h, filtered and dried to constant weigh. The rats were divided into seven groups of 6 rats per cage. Groups 1 and 2 were administered with normal saline (0.5ml p.o). Groups 3-5 were given extract (40, 80 and 120 mg/kg b.w. of animal, respectively) while group 6 was given silymarin (100 mg/kg; i.p. b.w.). Group 7 received extract (80 mg/kg. p.o.b.w.), 10 min later silymarin (100 mg/kg b.w.) was administered. The above doses of drugs and extract were given for 7 days. On the same day (7th day), groups 2-7 received paracetamol (2000 mg/kg p.o.). All animals were weighed before and after experimentation and were observed for physical signs of toxicity for 24 h and were sacrificed following ether anaesthesia. Result: The extract dose - dependently increased the alanine aminotransferase (ALT) and alkaline phosphatase (ALP) concentrations while the increase in aspartate aminotransferase (AST) was not dose - dependent. These effects were statistically significant (p ˂ 0.001). There were significant (p ˂ 0.001) increases in creatinine and urea plasma concentrations. Total plasma protein decreased in a dose - dependent fashion while the concentration of plasma albumin and total bilirubin remained insignificantly equivocal. However, in the presence of the extract, silymarin decreased the plasma concentrations of creatinine and total protein while urea, albumin and total bilirubin remained elevated. On the electrolyte ions, the extract decreased serum sodium and phosphate concentrations. Potassium and chloride ions were insignificantly changed. The extract lowered concentrations/percentages of haemoglobin, packed cell volume and platelets induced by paracetamol. Other parameters elevated were neutrophils, lymphocytes and monocytes. The effects of extract on the wet weight of testis, epididymis, kidney and spleen were insignificant. There were however increases in the wet weight of liver and total animal weight. Conclusion: Mild to moderate increases and decreases of the parameters observed indicated that the extract was moderately toxic. The use of the plant parts in the communities and the effects observed were in part due to the secondary metabolites of the extract.

Keywords: Nauclea latifolia, paracetamol, rats, methanol, toxicity.