Toxicity Evaluation of Harungana Madagascariensis Keywords: Harungana Madagascariensis, Acute, Subacute, Toxicity, Biochemistry, Hypericaceae
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Freely Available Online JOURNAL OF ADVANCED PHARMACEUTICAL SCIENCE AND TECHNOLOGY ISSN NO: 2328-0182 Research Article DOI : 10.14302/issn.2328-0182.japst-18-2341 Acute and Subacute Toxicity Evaluation of the Stem Bark Aqueous Extract of Harungana Madagascariensis in Rodents Esther Ngo Lemba Tom1, Nyemb Nyunaї2,*, Kouem Gbaangne Djaouro1, Fabrice Mba Medou2, Florette Diane Nankia1, Théophile Dimo3 1Department of Biological Sciences, Higher Teachers’ Training College, University of Yaoundé I, P.O Box 47, Yaoundé, Cameroon. 2Medical Research Centre, Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O Box 13033, Yaoundé, Cameroon. 3Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, P.O Box 812, Yaoundé, Cameroon. Abstract The present investigation was carried out to evaluate the safety of a stem bark aqueous extract of Harungana madagascariensis Lam. (Hypericaceae) by determining its potential toxicity after acute and subacute administration in rodents. Acute toxicity tests were carried out in mice and the behavior, death and median lethal dose (LD50) were estimated. Subacute toxicity (28 days) studies were conducted in rats with oral daily doses of 200, 400 and 600 mg/kg. Parameters observed at the end of the subacute tests included changes in body and vital organ weights, mortality, hematological, biochemical, hepatic and kidney effects. Harungana madagascariensis extract did not produce any visible toxicity or mortality with oral doses up to 2000 mg/kg within 14 days of single treatment, leading to the conclusion that the LD50 is greater than 2000 mg/kg. In the subacute toxicity tests, neither mortality nor visible signs of lethality was seen in rats. No significant change in the weight of the kidney, liver, heart, lungs spleen, pancreas and testicles was observed. Alanine transaminase (ALT) increased significantly in males at 400 and 600 mg/kg, whereas Aspartate transaminase (AST) decreased at 600 mg/kg in female rats. HDL Cholesterol was reduced at 600 mg/kg in female rats. There was a significant increase in urea concentration in female rats at 400 mg/kg. A significant decrease, both in platelet volume distribution (PVD) at 400 mg/kg in male rats and in red cell volume distribution (RDW) at 200 mg/kg were recorded in female rats respectively, but with no changes in other hematologic parameters. Histological study shows normal structure of liver, kidneys and heart of control and treated rats. Results indicate that oral doses of aqueous stem bark of Harungana madagascariensis are relatively safe in rats; however, assessment of hepatobiliary function should be done during chronic use in humans. Corresponding author: Dr. Nyunaї Nyemb, Medical Research Centre, Institute of Medical Research and Medicinal Plants Studies (IMPM), P.O Box 13033, Yaoundé, Cameroon, Mobile: +237-677816636 Running title: Toxicity evaluation of Harungana madagascariensis Keywords: Harungana madagascariensis, acute, subacute, toxicity, biochemistry, Hypericaceae. Received: Sep 07, 2018 Accepted: Sep 24, 2018 Published: Oct 02, 2018 Editor: Fatma Mady, Minia University Faculty of pharmacy, Egypt. www.openaccesspub.org | JAPST CC-license DOI : 10.14302/issn.2328-0182.japst-18-2341 Vol-1 Issue - 4 Pg. No. - 1 Freely Available Online Introduction isoproterenol-induced myocardial damage in rats. Moreover those authors highlighted the mechanisms of Harungana madagascariensis Lam. ex Poir (HM) the hypotensive action of HM stem bark aqueous extract (known as guttier from Gabon in French) [1] is a in rats [28]. medicinal plant native to Africa. Among the Ewondo tribe in Cameroon, the plant is known as “Atondo”. This Nevertherless, there are few reports about plant, commonly known as 'Haronga', is abundant in possible toxicological actions of HM. Acute and subacute forest and savannah regions [2]. This medicinal plant is toxicity of hydroethanolic extract of HM have been used in Africa and Europe for its antidiabetic and previously studied [29]. There is also a report on its antidiphtheric effects [3]. antityphoidal properties and toxicity evaluation of HM aqueous leaf extract [22]; but no study on the aqueous HM is used for the treatment of diverse human extract of the stem bark, which is the most used, have diseases including anemia, jaundice, bleeding, been reported. gonorrhea, malaria, asthma, liver diseases, diabetes, pancreatic and biliary problems [4, 5]. In Ghana, the The present study has evaluated the acute stem bark is employed in treating skin diseases and as toxicity and 28 days subacute toxicity of aqueous extract dressing material for wounds [6, 7]. The red juice of HM stem bark in mice and rats respectively. obtained from the leaves and stem bark is reputed for Materials and Methods arresting postpartum bleeding in Sierra Leone, while the Plant Materials unopened buds are well known in Liberia for treating Fresh HM stem barks were collected at Essezok, puerperal infection [8]. Mbalmayo (Centre Region, Cameroon) in June 2016. The Traditionally, the leaves and stem bark are used identification of the plant was done at the Cameroon for the treatment of anemia, the stem bark is also used National Herbarium, where voucher samples were for nephrosis, malaria and fever [9, 10, 11, 12]; as well deposited under the registration number NO. 4224 HNC. as antimicrobials against different strains of bacteria Preparation of Aqueous Extract of Harungana (Bacillus subtilis, Staphylococcus aureus, Escherichia coli Madagascariensis Stem Bark and Salmonella typhi), thus substantiating its use for gastro-intestinal disorders [13]. In Mola, Kariba district Bark pieces were dried at room temperature and of Zimbabwe, HM is one of the plants used for the powdered with the help of an electrical grinder. One treatment and prevention of malaria [14]. In Ghana, the kilogram of powder was dissolved in 12 L of distilled leaf-sap is prepared as a remedy for amenorrhea and water and boiled for 20 minutes. The resulting decoction heart-troubles [15]. was filtered through Whatman paper NO. 3 and further lyophilized. A crude brown extract powder (HM extract, Nwodo [16] and Kouam et al. [17, 18] have, 98.90g) was obtained, giving a yield of 9.89%. however, examined the effect of crude extracts and isolated compounds from a hexane extract of the stem Experimental Animals bark of HM, for their analgesic, anti-inflammatory, Wistar rats (118-145g) (20 males and 20 alpha-glucosidase inhibition and antioxidant activities females) for subacute toxicity evaluation and female respectively. Many isolated compounds from natural Balb C mice, with body weight between 18 g and 22 g, products have been tested in vitro for anti-malarial were used for the acute toxicity study. All animals for properties and found to exhibit potent activities [19]. the study were bred at the Higher Teachers’ Training Previous studies on this plant involving bark or College ( ENS ) of Yaoundé, Cameroon. They were kept at leaves revealed antihelminthic properties [20], standard laboratory conditions under natural light and antimalarial [21], antityphoidal [22], antidiabetic [23], dark cycles, at constant room temperature (20 ± 5°C) antidiarrhoeal [24], antioxidant [25] and antimicrobial and were given standard food and water ad libitum. This activities [26]. study was approved by the Cameroonian National Ethical Tom et al [27] demonstrated the myocardial Committee (Ref NO. FW-IRB00001954). potency of the aqueous extract of HM stem bark against www.openaccesspub.org | JAPST CC-license DOI : 10.14302/issn.2328-0182.japst-18-2341 Vol-1 Issue - 4 Pg. No. - 2 Freely Available Online Acute Toxicity of the Aqueous Extract of Harungana distribution (RDW), platelet mean volume (PMV) and Madagascariensis in Mice. platelet volume distribution (PVD) were measured with This evaluation was designed following the an automated hematological machine (Cell-DynTM. protocol of OCDE [30]. A total of 6 female mice were Abbot, US). used to evaluate the acute toxicity of the aqueous Blood samples were taken without anticoagulant extract of the bark of HM. Using an oral gavage needle, in dry glass tubes and were immediately centrifuged at the extract solution was first administered at a single 3000 rpm at 4°C for 10 min, then serum for biochemical dose of 2000 mg/kg to three mice previously fasted for examination was removed. Blood Urea Nitrogen (BUN), 12 hours. The behavior of the animals was observed for Glucose, Triglyceride (TG), Total Cholesterol (TC), HDL 30 minutes after which they were fed. If no deaths Cholesterol (HDL), Alanine Transaminase (ALT) and occurred after 48 hours, the same protocol was repeated Aspartate Transaminase (AST) were measured using on the other three female mice. All the six mice were commercial kits obtained from Biotec Diagnostics UK then observed for 14 days. During this period, animal LTD and for Bilirubin the kit provided by Reckon body weight was recorded every 2 days and mice were Diagnostic P. LTD, Vadodara, India was used. sacrificed on day 14 for macroscopic observation of Histopathological Analysis internal organs [30]. On the 28th day, after blood collection for 28 Days Toxicity Evaluation of the Aqueous extract of biological analysis, all the animals were euthanized and Harungana Madagascariensis in Rats. the principal vital organs were removed and This evaluation was done according to Porwal et macroscopically analyzed. After macroscopic analysis, al. [31]. Rats (20 males and 20 females) were divided representative fragments of heart, liver and left kidney into four dose groups (5 animals /dose/sex). The first were subsequently fixed in a 10% solution of buffered group was given 1mL/100g bw distilled water and taken formalin (pH 7.4) and rapped in paraffin. 5 µm sections as the control group. The second, third and fourth were obtained and colored with Hematoxylin - Eosin groups were given a single dose of 200, 400, and 600 (HE) for evaluation under an optical microscope. mg/kg of HM respectively by gavage daily for a period of Statistical Analysis 28 days. The results were reported as mean ± SEM. The Body weight was monitored weekly.