77ACUTE AND SUBCHRONIC TOXICITY STUDY OF THE AQUEOUS AND ETHANOLIC EXTRACTS OF MITRAGYNA INERMIS BARK IN ALBINO RATSIn traditional medicine in Nigeria, the leaf, bark and root extracts of Mitragynainermis (Wild) O. kuntze is commonly used to manage diverse medical conditions including long-term ailments such as diabetes and epilepsy. The aim of this study was to ascertain the acute and subchronic toxicity profile of aqueous and ethanolic bark extracts of Mitragynainermis administered orally in albino rats. Acute toxicity test was carried out using modified Lorke’s method. Subchronic toxicity evaluation was done using seven groups of five rats each. The first group served as control, while groups two, three and four received 200, 400 and 800 mg/kg of aqueous bark extract respectively for twenty eight days. Similarly, groups five, six and seven received 200, 400 and 800 mg/kg of ethanolic bark extract respectively. The results of acute toxicity study showed the aqueous bark extract of Mitragynainermis did not cause any signs of toxicity or produce mortality in rats. However, the LD50 of the ethanol extract was 1587.45 mg/kg intraperitoneally and 4298.84 mg/kg orally. Results also showed that subchronic administration of the aqueous extract did not significantly affect food consumption, renal and hepatic functions at the doses used. However, significant number of hematological parameters was found be altered due to the aqueous bark extract. Ethanol bark extract even though relatively safe on hematological parameters, there was a significant increase in the levels of ASAT and ALAT (p<0.05) at the tested doses indicating hepatic damage. The finding of this study indicates that the aqueous and ethanol bark extracts of Mitragynainermis is acutely safe when administered orally. However, its effects on long-term use, especially on hematological and hepatic function needs to be further investigated.satiye2002@gmail.comResearch512015Mitragynainermis,Aqueous,Ethanol,Acute and Subchronic ToxicitTimothy SY,Helga BI,Bomai HI,Musa AH Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Maiduguri, Maiduguri, Nigeria.,Department of Human Anatomy, College of Medical Sciences, University of Maiduguri, Maiduguri, Nigeria., Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Maiduguri, Maiduguri, Nigeria., Department of Medical Laboratory Science, College of Medical Sciences, University of Maiduguri, Maiduguri, Nigeria