Acute and Sub-Acute Oral Toxicity Studies of the Aqueous Extract of Lannea microcarpa Stem Bark on Rats

The aqueous stem bark of Lannea microcarpa is used traditionally for the treatment of swellings, wounds, rheumatism, pains, and infections. Aim: To evaluate the safety of the aqueous extract of the stem bark of Lannea microcarpa. Materials and Methods: Male Sprague-Dawley rats (200-250 g, n=5) received oral administration of 300, 1000 and 3000 mg kg -1 of aqueous extract of Lannea microcarpa and were monitored for 24 hours and 14 consecutive days for acute and sub-acute toxicity effects respectively. Signs of treatmentrelated toxicity such as behavioral changes, mortality and clinical effects were observed and evaluated. Control rats received 1 ml of normal saline. Results: In acute toxicity study, there were no behavioral changes as well as mortality in the LME (300-3000 mg kg -1 , p.o)-treated rats. Similarly, in the subacute studies, LME (300-3000 mg kg -1 , p.o)-treated rats showed no significant differences in the body weight, organ weight, hematological and biochemical parameters that were assessed (P ≤ 0.05). Conclusion: Oral administration of aqueous extract of Lannea microcarpa revealed no signs of toxicity. George Owusu 1, 2 and Meshack Antwi-Adjei 3* 1 Department of Pharmacology, University for Development Studies, Tamale, Ghana 2 Department of Pharmacology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 3 Department of Pharmacology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana. Submission: 23 June 2017 Accepted: 10 July 2017 Published: 25 July 2017 www.ijppr.humanjournals.com Citation: Meshack Antwi-Adjei et al. Ijppr.Human, 2017; Vol. 9 (4): 17-30. 18 INTRODUCTION Traditional medicine has been practiced by man since the advent of a human race. It has a long standing history that while ancient humans were searching for food, they discovered that some plants had the potential of treating both human and animal diseases [1]. Today, every culture has evolved the indigenous system of traditional healing [2]. In addition to providing the potential remedy to many ailments, traditional medicine also serves as a gateway to the discovery of many substances with active therapeutic effects used in the commercial production of drugs [3]. Thus, plants remain the main source of active natural drugs from natural sources and are imperative in traditional medicine for treating numerous diseases [4]. Lannea microcarpa Engl. and Krause (Family Anacardiaceae) is a tropical deciduous tree that grows up to about 15 m tall and 70 cm in diameter. It is located in most regions of West Africa and largely distributed in the dry forest regrowth areas. The leaves usually alternate and imparipinnate up to about 25 cm long with 2-3 pairs of leaflets. The flowers are greenyellowish, unisexual and regular; and the fruits are ellipsoid and glabrous drupes containing a single seed [5]. Most parts of the plant such as the bark and leaves are used traditionally in treating numerous medical disorders including swellings, wounds, blisters, sore throat and rheumatism [5]. The leaves are used to treat diarrhea, gastroenteritis, malaria, bacterial infections, toothaches, swellings, wounds [6,7] and also to manage mouth blisters, sore throat, dysentery and as dressing on boils [8,9]. The fruits are used to treat scurvy, rickets, and cough. The bark and roots are used to treat stomach pain, rheumatism, gonorrhea, diarrhea, chest pain, gastric ulcer, skin and respiratory tract infections [9] and also possess antibacterial and antihypertensive effects [10,11,12]. In Mali, the plant is used traditionally to treat wounds [13]. Isolated and characterized of some phytochemical constituents of the plant [14] and its antioxidant activity [15] have also been reported. We recently reported on the antiinflammatory effect of the aqueous extract of the plant on dextran sulphate-induced edema and xylene-induced pineal edema in murine models [16]. Though the folkloric use of the plant is being established and supported with scientific data, there is no report on its safety in animals or humans. Furthermore, a plant or any herbal formulation containing certain active organic constituents to be identified for traditional medicine, a systematic approach is required for the investigations of safety and efficacy through experimental and clinical discovery [17]. Hence, this study is aimed to evaluate the safety or otherwise of this timetested plant, Lannea microcarpa. www.ijppr.humanjournals.com Citation: Meshack Antwi-Adjei et al. Ijppr.Human, 2017; Vol. 9 (4): 17-30. 19 MATERIALS AND METHODS