J Pharm Sci Drug Dev 2020; 2(1): 2-9. Antiplasmodial Activity and Safety Assessment of Methanol Leaf Extract of Detarium microcarpum (Fabaceae) Amira Rahana Abdullahi*, Malami Sani, Umar S Abdussalam, Bichi La Department of Pharmacology and Therapeutics, Bayero University, Kano, Nigeria *Correspondence should be addressed to Abdullahi AR, Department of Pharmacology and Therapeutics, Bayero University, Kano, Nigeria; Email: [email protected] Received :6 May 2020 • Accepted :20 May 2020 ABSTRACT Malaria is an endemic infectious disease that is widespread in the tropical and sub-tropical areas of the world, leading to morbidity and mortality. Detarium microcarpum (Family: Fabaceae) is used traditionally in the treatment of malaria, diabetes, hypertension, pneumonia etc. The aim of this study is to evaluate the antiplasmodial activity and safety profile of methanol leaf extract of Detarium microcarpum. Phytochemical screening and oral median lethal dose (LD50) estimation of the extract were carried out. The antiplasmodial activity was evaluated in mice infected with chloroquine sensitive plasmodium berghei-berghei using curative, suppressive and prophylactic experimental models. Rats were orally administrated the extract of Detarium microcarpum daily for 28 days, biochemical assay and hematological analysis were conducted. Data were analysed using ANOVA followed by Dunnett’s post hoc test. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponins, tannins, triterpenes and glycosides. Oral LD50 of the extract was estimated to be >5000 mg/kg. The extract at all doses tested produced a significant (p<0.001) curative, suppressive and prophylactic effects. The extract also significantly prolonged the survival time of the treated mice up to 19 days compared to the negative control group. The extract revealed some significant change in AST (p<0.01) and ALP (p<0.001) at the highest dose. However, kidney function tests and hematological analysis were not significantly changed in all the treatment groups as compared to the control. The results of this study suggest that the methanol leaf extract of Detarium microcarpum possesses curative, suppressive and prophylactic antiplasmodial activity and relative safety has been observed with the short term use at the doses tested. Keywords: Antiplasmodial, Detarium microcarpum, Plasmodium Berghei-Berghei, Chloroquine, Artesunate. Copyright: © 2020 Abdullahi AR, et al. This is an open access paper distributed under the Creative Commons Attribution License. Journal of Pharmaceutical Sciences and Drug Development is published by Lexis Publisher. INTRODUCTION including artemisinin derivatives has been reported and documented [7,8], causing a major impediment in the fight Malaria is a life threatening parasitic disease transmitted by against malaria and its attendant complications. the bites of female anopheles mosquitoes infected with Plasmodium specie [1]. In humans, Plasmodium falciparum, Remedies from natural plant origin are believe to be harmless Plasmodium vivax, Plasmodium ovale, Plasmodium and have no risk; however some plants are inherently toxic malariae, and Plasmodium knowlesi have been identified to [9] leading to adverse effects. Traditional herbal medicines cause malaria. Clinically, Plasmodium falciparum is the most have been used for the treatment of various ailments for fatal and the primary cause of malaria incidences. Malaria is centuries globally; however the traditional use of any plant an endemic infectious disease that is widespread in tropical for medicinal purposes does not warrant its safety. Therefore and sub-tropical areas of the world [2] leading to morbidity toxicity studies on medicinal plants must be conducted so as and mortality [3,4]. Some population groups are considerably to evaluate and establish their short and long term safety [10], at higher risk of contracting malaria and developing severe for proper validation of their therapeutic use. complications, which include children (below 5 years), Detarium microcarpum is a tree legume that belongs to the pregnant women, sicklers, patients with HIV/AIDS as well as family of Fabacaea, which grows naturally in the drier non-immune immigrants [1]. regions of West and Central Africa. It is known locally as Malaria treatment using medicinal plant extracts has a long taura (Hausa), ofo (Igbo), ogbogbo (Yoruba), gatapo and successful tradition [5]. For example, quinine was (Kanuri), gkungorochi (Nupe), aikperlarimi (Etsako), and isolated from Cinchona (Rubiaceae) and artemisinin from gwogwori (Gwari). Previous scientific work on Detarium Qinghaosu (Asteraceae) [6]. Resistance to various microcarpum revealed that the plant possesses antimicrobial antimalarial drugs (quinolones and antifolate family) activity [11]; inhibitory activity against hepatitis C virus [12]; 2 J Pharm Sci Drug Dev 2020; 2(1): 2-9. anti-inflammatory and analgesic effects [13]; anti-bacterial Parasite Inoculation activity [14]. In Nigeria, Detarium microcarpum is used A Plasmodium berghei berghei infected mouse (parasitemia traditionally by the Lala tribe of Adamawa to cure malaria and of 34%) was used as a parasite donor and blood sample was jaundice [15] and the Gwaris of the Federal Capital Territory collected retro-orbitally into an EDTA containing bottle. The (FCT) to cure malaria and dysentery [16] but the efficacy has inoculum was prepared by determining the percentage not been scientifically investigated. The rodent malaria parasitemia and erythrocyte count of the donor mouse and parasite model known as plasmodium berghei berghei which further diluting the blood with isotonic saline [21] in such a is chloroquine sensitive is employed to evaluate the in vivo way that 0.2 ml of the blood solution administered antimalarial activity [17,18]. The aim of this study is to intraperitoneally contained approximately 1 × 107 parasitized determine the antiplasmodial activity and safety profile of erythrocytes [22]. methanol leaf extract of Detarium microcarpum. Preliminary Phytochemical Screening MATERIALS AND METHODS Preliminary phytochemical screening was carried out on the Collection and Authentication of Plant Materials leaf extract of Detarium microcarpum to detect the presence of secondary metabolites using established methods [23]. Fresh leaves of Detarium microcarpum were collected from Gwarzo village, Gwarzo LGA, Kano State, Nigeria. The plant Acute Toxicity Study (Determination of Median Lethal Dose was identified and authenticated by Baha’uddeen Said Adam (LD50) of the herbarium unit of Bayero University Kano, Nigeria. A voucher specimen number of (0071) was collected for future Acute oral toxicity of methanol leaf extract of Detarium reference and compared with the already deposited plant microcarpum was evaluated in mice using Lorke’s method specimen. [24]. The study was conducted in two phases; in phase one, nine mice were divided into three groups of three mice each Preparation of Methanol Leaf Extract and were administered with 10, 100 and 1000 mg/kg of the extract orally; they were observed for the first 4 hours, then 24 Fresh leaves were cleaned to remove dust. They were air-dried hours for signs and symptoms of toxicity including death. In under shade at room temperature until the attainment of a phase two, three groups of one mouse each were treated with constant weight and then crushed into fine powder. One 1600, 2900 and 5000 mg/kg orally and were observed for the thousand grams (1000 g) of the powdered material was first 4 hours, then 24 hours for signs and symptoms of toxicity extracted with four liters (4 L) of 70 % v/v methanol using including death. The LD50 was calculated as the geometric cold maceration process for one week with regular shaking. mean of the lowest dose that caused death of the animal (1/1) The liquid methanol extract obtained was filtered using gauze and the highest dose for which the animal survived (0/1). then by Whatman No.1 filter paper and evaporated to dryness o in an oven at a temperature of about 45 C to obtain 14.06% Antiplasmodial Activity Against Established Infection w/w. (Curative Test) Experimental Animals Evaluation of the schizontocidal activity of the extract against established infection was carried out as described by Ryley Adult Swiss albino mice (16-24 g) and Wister rats (170-200 g) and Peters [25]. Adult mice were inoculated with Plasmodium of both sexes were obtained from the Animal House Facility berghei berghei on the first day (D0). 72 hours later (D3), the of the Department of Pharmacology and Therapeutics, Bayero mice were divided randomly into six groups of six mice each. University Kano. They were allowed to acclimatize for one Group I received 10 ml/kg of distilled water (negative week, provided with food and water ad libitum and were control), Group II, III & IV received 250, 500 and 1000 maintained under standard laboratory conditions in mg/kg of the leaf extract respectively, Group V received 10 accordance with the National Academy of Sciences, guides mg/kg of chloroquine and Group VI received 5 mg/kg of for the care and use of Laboratory animals (1996). Ethical artesunate (positive controls) for five consecutive days (D3– approval was obtained from the animal rights committee of D7) orally. Blood was collected from each mouse by tail-bled the College of Health Sciences, Bayero University, Kano on day three (post parasite inoculation) and day seven (post (BUK/CHS/REC/VII/44). treatment) and parasitemia was examined by microscopic examination of