Oral toxicity studies of a Nigerian polyherbal health tonic tea extract in rat

Abstract

Summary In the present study, acut e and suhchronic oral toxicity studies of an aqueous extract of a Nigerian Polyherbal Health Tonic {PHI ) were investigated in adult Wistar rats of both sexes and weighting between 110- 200 g. Acute toxicity study was conducted using limit dose test of Up and Down Procedure under computer guided statistical software program (AOT 425 StatPgm). The suhchronic toxicity was evaluated in 4 groups of rats mad e up of six rats/group, administered single, daily oral doses of 10 ml/kg distilled water (DW), 125. 500 and 1500 mg/kg of PH'l\ respectively, for 90 days. On the 91M day, blood samples for haemalological and biochemical assays were collected through cardiac puncture and selected vital organs harvested en bloc for histopathological examination under inhaled anaesthesia. Results showed PUT to be relatively safe on acute toxicity with an estimated LD50 value greater than 5000 mg/ kg/oral route. On prolonged exposure, PHT induced initial weight gain in the Ist 6 week followed by significant (/>dose related elevation of the full blood count parameters, dose unrelated elevation of serum urea, liver enzymes, serum proteins, albumin, total and conjugated bilirubin. On histology, PHI induced dose dependent gastric mucosal denudation, bile ductal lining distortion, diffuse pulmonary interstitial fibrous proliferation and diffuse splenic lymphocytic proliferation. Thus, our results showed that PHI use may be relatively safe on acute exposure but toxic on chronic exposure to high doses, although reversibility of these toxic effects was not studied in the present study