www.ijbcp.com International Journal of Basic and Clinical Pharmacology | November-December 2016 | Vol 5 | Issue 6 Page 2352 IJBCP International Journal of Basic and Clinical Pharmacology Print ISSN: 2319-2003 | Online ISSN: 2279-0780 Original Research Article Pentobarbitone-induced sleeping time and sub-acute toxicity studies of Trichilia monadelpha aqueous extract George Owusu 1,3 , Meshack Antwi-Adjei 2,3 , Isaac T. Henneh 2,3 * INTRODUCTION Trichilia monadelpha (Thonn) JJ De Wilde (fam. Meliaceae) is a medium-sized tree that grows up to 20m high in the tropical rain forest in West Africa. Different parts of the plant are used either alone or in combination with other plants for treatment of many diseases in West Africa. 1 Previously, the inhibitory effects of the aqueous, hydro- ethanol and petroleum ether extracts of the stem bark of the plant in carrageenan-induced paw oedema in 7-day- old chicks and Complete Fruend’s adjuvant-induced arthritis in rats has been reported. 2 Also, the analgesic effect of the hydro-ethanol, petroleum ether and ethyl acetate extracts of the stem bark of the plant has been earlier reported. 3 Again, the antioxidant potential and phytochemical constituents of the stem bark extracts of the plant have been evaluated. 4 Moreover, the plant has been reported to possess antiplasmodial and antitrypanosomal properties. 5 Despite the numerous activities of the plant reported in literature, there is no valid scientific data on its hypno-sedative effects and toxicity profile. ABSTRACT Background: Trichilia monadelpha is used either alone or in combination with other plants to treat many diseases in West Africa. Earlier, the anti- inflammatory, analgesic and anti-parasitic effects of the plant have been investigated to confirm its folkloric use. The current study is aimed at investigating the sub-acute toxicity profile as well as hypno-sedative effect of the Trichilia monadelpha aqueous extract (TAE). Methods: For the pentobarbitone-induced sleeping test, rats (150-200 g, n=5) were pre-treated with TAE (100, 300 and 1000 mg/kg, p.o.) or distilled water (control group) 30 minutes before they were challenged with Pentobarbitone Sodium (50 mg/kg body weight, i.p). Sleeping time of each animal was recorded and analysed. In the sub-acute toxicity test, rats were treated daily either TAE (30, 100 and 1000 mg/kg) or water (control group) for two weeks after which the animals were sacrificed. Blood samples were collected for haematological and biochemical analyses. Specific organs were then removed and weighed immediately. Results: The pentobarbitone-induced sleeping test resulted in a significant and dose-dependent increase in the duration of sleep of the rats. There were however no significant changes in the relative weight of vital organs of the control and TAE treated groups. Similarly, there were no significant differences in haematological and biochemical parameters between control and TAE treated groups. Conclusions: TAE significantly and dose-dependently increased the duration of pentobarbitone-induced sleeping time in rats. TAE showed no significant changes in the relative weight of the vital organs, haematological and biochemical parameters. Keywords: Trichilia monadelpha, Pentobarbitone, Hypno-sedative, Sub-acute toxicity DOI: http://dx.doi.org/10.18203/2319-2003.ijbcp20164088 1 Department of Pharmacology, School of Medicine, University for Development Studies, Tamale, Ghana 2 Department of Pharmacology, School of Medical Science, University for Development Studies, Tamale, Ghana 3 Department of Pharmacology, , Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana Received: 20 September 2016 Accepted: 20 October 2016 *Correspondence to: Mr. Isaac T. Henneh, Email: i.t.henneh@ uccsms.edu.gh Copyright: © the author(s), publisher and licensee Medip Academy. This is an open- access article distributed under the terms of the Creative Commons Attribution Non- Commercial License, which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.