Applied Medical Research DOI: 10.5455/amr.20160320075556 www.scopemed.org 6 AMR ● 2016 ● Vol 2 ● Issue 1 Anti-hyperglycemic efect of Canarium schwenfurthii fruit oil on wistar rats Idu MacDonald 1 , Ovuakporie-Uvo Oghale 1 , Seriki Cecilia Olajesu 2 ABSTRACT Aim: The effect of oil got from the fruit pulp of Canarium schweinfurthii on normal and STZ-induced diabetic rats was evaluated. Methodology: Twenty four rats were divided into six groups of four each. Group 1 (normal rats) received 5 ml of distilled water, group 2 diabetic rats received STZ + 5 ml / kg b.w glibenclamide; groups 3,4 and 5 STZ-induced diabetic rats received 5 ml, 10 ml and 20 ml per b.w of C.s oil respectively while group 6 STZ-induced diabetic rats received no treatment. All treatments were orally administered using an oral-gastric tube for two weeks. Changes in blood glucose concentration were compared to positive (STZ + glibenclamide) and negative (STZ only) controls. Results: The oil showed positive effect against STZ-induced diabetic rats after 2 hrs at all dose levels tested. Daily administration of 10 ml / b.w of C.s oil showed similar activities as the reference drug (glibenclamide) and glucose reduction compared to STZ only. At 20 ml / b.w daily administration of C.s oil, mortality was observed. Conclusion: In conclusion, Canarium schweinfurthii fruit oil may be considered as a remedy for diabetes mellitus when administered at low doses (10 ml / bw and below) for long-term use. Further research is recommended. KEY WORDS: Canarium schweinfurthii oil; STZ-induced diabetes; Glibenclamide. Original Research INTRODUCTION Plants have been used from ancient times for the treatment of various diseases of man [1]. In Ayurveda, a number of medicinal plants have been used for the treatment of diabetes [2]. About 880 plants are believed to possess hypoglycemic activity and nearly 343 plants have been reported in scientific papers [3]. The pharmacological treatment of disease began long ago with the use of herbs [4]. Plants not only possess hypoglycemic property but also reduce cholesterol; triglyceride and alkaline phosphatase levels while it increases total protein content [5]. Ascorbic acid and α-tocopherol cause reduction in glycosylated haemoglobin concentration which is an indicator of diabetes mellitus and its concentration increases linearly with the duration of the disorder [6]. Diabetes mellitus is the most common type of chronic metabolic disorder characterized by hyperglycemia. It may be due to relative or absolute deficiency of insulin action on blood sugar [7]. According to World Health Organization (WHO), in 2000, there were 171 million persons in the world with diabetes and this is projected to increase to 366 million by 2030. Canarium schweinfurthii Engl (Burseraceae) is a large forest tree characterized by a straight and cylindrical bole exceeding 50 m; thick bark on young tree fairly smooth, reddish to light brown slash with turpentine-like odour, exuding a heavy, sticky oleoresin yellowish in colour; pinnate leaves (up to 15- 65 cm long); 8-12 pairs of leaflets, mostly opposite, oblong, cordate at base, 5-20 cm long and 3-6 cm broad. Its creamy white flowers are unisexual about 1 cm; the fruit is a small drupe, bluish-purple, glabrous, 3-4 cm long and 1-2 cm thick containing a hard spindle-shaped, trigonous stone that eventually splits releasing 3 seeds [8]. The decoction of C. schweinfurthii tree bark is used against colic in Ivory Coast, cough and chest pains in Sierra Leone, venereal diseases in Cameroon and to mature abscesses, treat dysentery in Nigeria. In Angola, it constitutes one of the ingredients of the insecticidal powders and perfumes [9]. Koudou et al [10] have reported that C. schweinfurthii possesses anti- malaria and anti- diarrhea activities. The analgesic effect of resin essential oil of C. schweinfurthii oil has also been reported [10]. C. schweinfurthii have also been implicated to have a measure of anti-sickling [11] and anti-diabetic [12-14] activities. This research is aimed at testing the anti-hyperglycemic effect of Canarium schwenfurthii fruit oil on STZ-induced diabetic wistar rats. MATERIALS AND METHODS Collection and Preparation of Canarium schweinfurthii oil: Fresh Canarium schweinfurthii fruits were collected from a farmland in Vom village of Jos, Plateau state, Nigeria. The fruits were positively identified at the Department of Biological Sciences, University of Abuja, FCT Abuja. Fruits were sorted, damaged and rotten ones were discarded. The fruits were washed and extracted following methods described by Olawale [15]. Induction of Diabetes: The experimental animals were fastened overnight and the diabetes was induced by a single intraperitoneal injection of streptozotocin (Zayo-Sigma (ZSA) Ltd, Jos, Nigeria), dissolved in a freshly prepared 1 Department of Plant Biology and Bio- technology, University of Benin, PMB 1154, Benin City, Edo State, Nigeria. 2 Department of Biological Sciences, University of Abuja, PMB 127, FCT, Abuja, Nigeria. Address for correspondence: MacDonald Idu, Department of Plant Biology and Biotechnology. University of Benin, PMB 1154. Benin City. Nigeria. mcdonald@uniben.edu Received: January 13, 2016 Accepted: March 8, 2016 Published: March 22, 2016