Anti-diabetic and antioxidant effects of virgin coconut oil in alloxan induced diabetic male Sprague Dawley rats

Abstract

Oxidative stress has been discovered to be involved in the progression of diabetes mellitus. The antioxidant properties of virgin coconut oil (VCO) among other functions might have a beneficial effect in ameliorating the disease. This study was aimed to determine the glycemic and antioxidant effects of VCO in alloxan induced diabetic rats. 24 male Sprague-Dawley rats were divided into 4 groups as follows: control (C), diabetes untreated (DUT), diabetes treated with 7.5 ml/kg VCO (DT 7.5 ) and diabetes treated with 10 ml/kg VCO (DT 10 ). Alloxan (100 mg/kg b.w I.P) was used to induce diabetes and VCO was administered orally once daily for 4 weeks. Fasting blood glucose level was measured on Day 0 (72 hours post alloxan injection) and after 4 weeks. Glucose tolerance test was conducted on the 4th week as well as the determination of serum insulin and liver antioxidant parameters using standard biochemical methods. Values are means ± S.E.M., compared by ANOVA and Tukey’s post hoc test. The results show that VCO significantly reduced the fasting blood glucose level in DT 7.5 rats (132.4 ± 6.911) and DT 10 rats (131.6 ± 12.2) are compared with DUT rats (320.4 ± 22.99) and improved the oral glucose tolerance. Serum insulin was increased in DT 10 rats. GSH activities significantly increased p < 0.05 in DT 10 rats (0.39 ± 0.022) when compared to DUT rats (0.032 ± 0.004). CAT activities also significantly increased p < 0.05 in DT 7.5 (17.63 ± 0.61) and DT 10 rats (30.88 ± 0.97) when compared to DUT rats (10.98 ± 0.6). SOD activities significantly increased p < 0.05 in DT 7.5 (2.634 ± 0.04) and DT 10 rats (2.258 ± 0.32) when compared to DUT rats (1.366 ± 0.05) while MDA significantly reduced p < 0.05 in DT 7.5 (49.16 ± 0.51) and DT 10 (33.64 ± 0.42) rats when compared to DUT rats (99.93 ± 4.79). This study revealed that VCO has a hypoglycemic action, enhances insulin secretion and also ameliorates oxidative stress induced in type I (alloxan-induced diabetic) male rats.