EFFECT OF COFFEA ARABICA ON STREPTOZOTOCIN- INDUCED DIABETES MELLITUS IN WISTAR RATS Ndife NG 1, Olayaki LA 1, Okesina KB 1*, Alagbonsi IA 1,2 1 Department of Physiology, University of Ilorin 2 Department of Physiology, Kogi State University. Abstract Researchers, over the years, have indicated coffee or some of its constituents as having hypoglycaemic effect by different mechanisms. Twenty five albino rats ( g) divided into 5 groups of 5 rats each were used for the study. Group A served as Control, while groups B, C, D and E were the experimental rats induced with diabetes by a single dose of streptozotocin (55mg/kg) intravenously. Group B served as diabetic control; C and D received oral 200mg/kg and 400mg/kg coffea arabica (CA) respectively and E was given 250mg/kg Metformin orally for 21days. Results showed that blood glucose, triglycerides, total cholesterol, LDL and GSK-3 were increased in diabetic group with reduction in insulin and HDL. However, high and low doses of CA reversed these parameters to the level of control and metformin administered group. The results demonstrated that CA exhibited antihyperglycemic and antidyslipidemic effects and this might be partly due to the inhibition of GSK-3. Diabetes mellitus (DM) is a metabolic disorder resulting from a defect in insulin secretion, insulin action, or both. Insulin deficiency in turn leads to chronic hyerglycaemia with disturbances of carbohydrate, fat and protein metabolism. (Lindberg et al., 2004). As the disease progresses tissue or vascular damage ensues leading to severe diabetic complications such as retinopathy, neuropathy, nephropathy, cardiovascular complications and ulceration. Thus, diabetes covers a wide range of heterogeneous diseases. Coffee is one of the most widely consumed beverage. The numerous beneficial health effects of Coffee consumption have received considerable scientific attention (Nawrot et al., 2000; Ranham and Halvorsen, 2005). Evidence obtained through epidemiological studies indicates that consumption of Coffee is associated with a lower risk of Type 2 Diabetes Mellitus (T2DM) (van Dam et al. 2004; Agardh et al. 2004; Bidel et al. 2006). The anti-diabetic effect of Coffea arabica (CA) was investigated in streptozocin induced diabetic rats, with aim of elucidating some of its possible mechanismsof action. Conclusion Coffea arabica may be useful in the management and/or treatment of diabetes associated with hyperglycemia, hyperinsulinemia and hyperlipidemia: reducing the risk of cardiovascular heart diseases and atherosclerosis in diabetes. Coffea arabica also improved glucose tolerance in a dose dependent manner in streptozotocin induced diabetic rats. The anti diabetic effect of Coffea arabica might be due to its antioxidant action with the presence of large quantity of chlorogenic acid. The possible mechanism of action may be through inhibition of the activity of glycogen synthase kinase-3 (GSK-3) thereby increasing insulin secretion and sensitivity and consequently, improving glucose utilization. The High dose (400mg/kg) of Coffee was found to be more potent than Low dose (200mg/kg) of Coffee, the effectiveness of both Doses of Coffee supersedes that of Metformin at 250mg/kg Methodology Twenty five (25) Albino rats (mean weight of 148±25.6g ) Group A Normal control Group B 200mg/kg CA Group C 400mg/kg CA Group D 250mg/kg Metformin Group E Diabetic control The rats, 5 in each group, were acclimatized for one week; their weights and diet were also stabilized. After which diabetes was induced with a single dose streptozotocin (55mg/kg intravenously to four of the five groups) After 21 days The rats were anesthetised by intraperitoneal injection of 0.5mls of ketamin and blood samples was collected by cardiac puncture Laboratory blood glucose, insulin, triglycerides, total cholesterol, LDL and HDL and GSK-3 The results were analysed for statistical significance by t-test and ANOVA using the SPSS (v. 17) statistical program All data were expressed as the mean ± SEM; p values < 0.05 were considered significant. Introduction Results Fig. 1: Blood glucose level before and during treatment References 1.Campos-Florián J, Bardales-Valdivia J, Caruajulca-Guevara L and Cueva-Llanos D (2013). Anti-diabetic effect of Coffea arabica, in alloxan-induced diabetic rats. Emir. J. Food Agric. 25 (10): Lindberg G., Lindblad U., Melander A. (2004). Sulfonylureas for treating type 2 diabetes mellitus. Cochrane Database Systemic Reviews volume Nawrot P, Jordan S, Eastwood J, Rotstein J, Hugenholtz A, Feeley M. (2003). Effects of caffeine on human health. Food Addit Contam; 20(1):1-30 Fig. 2: OGGT at 18 th day of treatment Fig. 3: Serum insulin level Fig. 4: Glycogen Synthase Kinase-3 (GSK-3) (ng/ml ) activity in Gastrocnemius muscle Fig. 5: Glycogen Synthase Kinase-3 (GSK-3) (ng/ml ) activity in Liver GroupsTG (mg/dl)TC (mg/dl)LDL (mg/dl)HDL (mg/dl) NC75.99±1.76 a 82.35±3.42 a 73.10±5.85 a 49.49±2.20 a LDC80.09±1.00 a 86.92±2.70 a 71.41±5.88 a 41.22±5.46 a HDC88.25±1.25 b 81.70±5.18 a 63.35±5.88 a 52.82±8.44 a MET70.14±1.77 c ±6.17 b 68.36±6.01 a 37.11±4.63 a DC166.32±2.80 d ±7.09 c ±6.47 b 18.30±1.74 b Table 1: Serum Lipid Profile Recommendations Further chemical and pharmacological studies should be carried out in order to ascertain the other mechanisms of action of coffea arabica. Regulations as per dosage and administration to cater for patients with other medical conditions should be upheld. This will also help in the tolerance and withdrawal effects associated with coffee intake especially for non-habitual users. PS: NC (Normal control), LDC (Low dose coffee), HDC (High dose coffee), MET (Metformin treated), DC (Diabetic control). Means with the same superscripts are not significantly different