American Journal of Pharmacology and Toxicology 4 (3):94-97, 2009 ISSN 1557-4962 © 2009 Science Publications Corresponding Author: D.O. Edem, Department of Biochemistry, University of Uyo, PMB 1017, Uyo, Akwa Ibom State, Nigeria 94 Biochemical Changes in Wistar Rats on Oral Doses of Mistletoe (Loranthus micranthus) D.O. Edem and I.F. Usoh Department of Biochemistry, University of Uyo, PMB 1017, Uyo, Akwa Ibom State, Nigeria Abstract: Problem statement: To evaluate the effects of the water extract of the leaves of mistletoe (Loranthus micranthus) (traditionally used antidiabetic and antihypertensive) in male albino Wistar rats. Approach: The animals were divided into 4 groups (n = 6). Water extract of L. micranthus leaves was administered in graded doses of 0, 275, 551 and 827 mg kg -1 body weight (wt) of experimental animals for 21days. Blood samples were collected by cardiac puncture. The serum harvested was analyzed for some biochemical parameters, using assay kits. Results: There were no significant changes (p>0.05) in the levels of cholesterol, bilirubin, glucose, protein, urea, alkaline phosphatase and Aspartate Transaminase (AST). Alanine Transaminase (ALT) activities of the groups rats given 551 and 827 mg kg -1 body weight extracts (15.96 and 14.24 U L -1 respectively) showed significant decreases (p<0.05) when compared with the control (24.96 U L -1 ) and the group fed 275 mg kg -1 body weight of extract (16.19U L -1 ). Computed ALT/AST showed decreases in the test groups (0.77-0.78) when compared with the control (1.04). Conclusion: The results suggested no adverse biochemical changes being associated with the use of the extract or absence of hepatocellular damage at the investigated concentrations. Thus the use of the plant in the treatment and management of diabetes and hypertension should be encouraged. Key words: Mistletoe, Loranthus micranthus, leaf extract, biochemical parameters INTRODUCTION The tropical rain forest of West Africa is endowed with enormous natural resources, mainly medicinal plants. Medicinal plants form the basis of medical treatment in many developing countries [1-4] . It is to this class that the African mistletoe (Loranthus micranthus Linn.) (family-Loranthaceae) belongs. Mistletoe is a semi-parasitic evergreen plant found growing on a host of evergreen and deciduous trees all year round, around the branches of the tree. It is an obligate parasite, obtaining part of its food from the host plant. It depends on its host for minerals and water only, but photosynthesizes its carbohydrate by means of its green leathery, oblong leaves [5] . In Nigeria and some other parts of Africa, mistletoe has been used traditionally as antihypertensive and antidiabetic [6-9] . There have been reports on the phytochemical and antimicrobial properties of African mistletoe Loranthus micranthus [9] . However, information is scanty on the effects of the plant on biochemical parameters in experimental animals and on the possible risks associated with consumption of mistletoe extracts. The present study was designed to determine the biochemical changes associated with oral consumption of aqueous extracts of the leaves of the African mistletoe. MATERIALS AND METHODS Collection of plant materials and preparation of crude extract: Mistletoe plants obtained from host pear trees (Persea americana), were collected from 8 different locations of Ikot Essien Oku Village in Etinan Local Government Area of Akwa Ibom State, Nigeria. The plant was authenticated at the Department of Botany, University of Uyo, Akwa Ibom State of Nigeria. The leaves from the mistletoe plants were dried to constant weight in an oven (Stuart Scientific, UK) at 52°C for 24 h. They were ground into smooth powder (which passed through a 30-mesh sieve) and stored in air container at 4°C until when required. One hundred grams (100 g) of the powdered material were brewed in 750 mL of boiled tap water and allowed to stand for at least 30 min. The decoction was then filtered (through a plug of cotton wool) and stored in a clean bottle to be administered to rats. Twenty mL aliquots of the decoction were evaporated