Journal of Ethnopharmacology 127 (2010) 368–372 Contents lists available at ScienceDirect Journal of Ethnopharmacology journal homepage: www.elsevier.com/locate/jethpharm Hypoglycaemic effects of Mammea africana (Guttiferae) in diabetic rats M.-C. Tchamadeu a,c,d , P.D.D. Dzeufiet a , C.C. Kouambou Nouga a , A.G.B. Azebaze b , J. Allard c,d,e , J.-P. Girolami c,d,∗ , I. Tack c,d,e , P. Kamtchouing a , T. Dimo a a Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, P.O. Box 812, Yaounde, Cameroon b Department of Chemistry, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon c INSERM U858, F-31432 Toulouse, Cedex 4, France d University of Toulouse, UPS, Institut de Médecine Moléculaire de Rangueil, IFR31, 31432 Toulouse, Cedex 4, France e University of Toulouse, UPS, Department of Physiology, 133, Route de Narbonne, 31062 Toulouse, France article info Article history: Received 3 August 2009 Received in revised form 22 September 2009 Accepted 22 October 2009 Available online 30 October 2009 Keywords: Diabetes mellitus Streptozotocin Rats Mammea africana Sabine CH2Cl2–MeOH stem bark extract Glycaemia abstract Aim of the study: The stem bark of Mammea africana Sabine (Guttiferae) is used in African rain forest to treat various diseases, including diabetes mellitus. We investigated whether Mammea africana extract induced hypoglycaemic activity in rats. Materials and methods: We tested the effects of acute (5 h) and sub-acute (21 days) oral administrations of the CH 2 Cl 2 –MeOH stem bark extract of Mammea africana (19–300 mg/kg body weight) on blood glucose levels of normal and streptozotocin (STZ)-induced type 1 diabetic rats. The effects were compared with those of glibenclamide. Results: Acute administration reduced blood glucose in the diabetic rats only (33.87%, P < 0.01). Sub-acute treatment for 21 days also reduced blood glucose level in diabetic rats (73.29%, P < 0.01). A reduction or stabilization in total serum protein, triglyceride, cholesterol and alanine amino transferase levels was also observed. No effect was observed on body weight loss but food and water intakes were signifi- cantly reduced (P < 0.01) in diabetic rats. The maximal anti-diabetic effect was obtained with the dose of 75 mg/kg and was more important than that of glibenclamide. Conclusion: It can be concluded that extracts of Mammea africana exhibited a significant anti- hyperglycaemic activity and improved the metabolic alterations in STZ-diabetic rats. These results provide a rationale for the use of Mammea africana to treat diabetes mellitus and hypercholesterolemia. © 2009 Published by Elsevier Ireland Ltd. 1. Introduction Plants have always been used in the African continent where up to 90% of the population in certain countries still relies exclu- sively on plants as a principal source of medicine for the treatment of different diseases (Hostettmann et al., 2000). Using experimen- tal models of diabetic rats, many recent investigations attempted to demonstrate hypoglycaemic and anti-diabetic effects of vari- ous medicinal plants traditionally used for the management of diabetes mellitus (Kamtchouing et al., 1998; Kameswara et al., 2001; Sokeng et al., 2001; Vats et al., 2002). Mammea africana Sabine belongs to the Guttiferae or Clusiaceae family and is found throughout the tropical rain forest of Africa, including Cameroon. It is commonly called: African mammae-aple (English); abricotier d’Afrique (French); Abortzork (Cameroon); Bokoli (RDC). It is ∗ Corresponding author at: INSERM U858, eq 5, BP 84225, 31432 Toulouse, Cedex 4, France. Tel.: +33 5 61 32 26 21. E-mail addresses: Jean-Pierre.Girolami@inserm.fr, girolami@toulouse.inserm.fr (J.-P. Girolami). found in mixed deciduous forests and rather prefers wet envi- ronment and sometimes forms small stands on flood plains. The stem bark of Mammea africana is used as traditional medicine for the treatment of diabetes, fever from various origins, scabies, chlamidiae, and female infertility (Betti, 2002). It has also been reported that the ethanolic stem bark extract of the plant decreased some haematological and biochemical parameters such as alka- line phosphatase (ALP), aspartate amino transferase (ASAT), and alanine amino transferase (ALAT) activities, serum total protein and albumin (Antiab et al., 2006). Reduction of white blood cells counts has been reported in normal rats after 21 days of treat- ment. Phytochemical screening of extracts from Mammea africana stem bark reveals the presence of flavonoids, coumarins, ter- penes, saponins, anthraquinones, cardiac glycosides, tannins and deoxy-sugar, but no alkaloid was found (Games, 1972; Crichton and Waterman, 1978; Ouahouo et al., 2004; Dongmo et al., 2007). However none of these previously published reports on Mammea africana suggested potential anti-diabetic properties. The present investigation was designed to evaluate the anti- diabetic and hypoglycaemic effect of a dichloromethane/methanol (CH 2 Cl 2 –MeOH) extract from stem bark of Mammea africana in 0378-8741/$ – see front matter © 2009 Published by Elsevier Ireland Ltd. doi:10.1016/j.jep.2009.10.029