Hypoglycemic Effects of Fruits and Vegetables in Hyperglycemic Rats for Prevention of Type-2 Diabetes.

Abstract

An in vivo oral glucose tolerance test (OGTT) was performed on hyperglycemic male Sprague-Dawley rats to assess the effect of fruits and vegetables (1 gㆍ㎏⁻¹ body weight) on blood glucose levels (ΔBGLs) at different time intervals of 0, 5, 15, 30, 60, 90 and 120 min. The areas under glucose curve (ΔAUCs) were calculated at 120 min of OGTT by trapezoid method. Total phenolic content (TPC) and anti-oxidant activity (AOA) of fruits and vegetables were assayed in vitro by Folin Ciocalteu and DPPH (2, 2-diphenyl-1-picrylhydrazyl) methods, respectively. At the end of the experiment the correlations among the parameters TPC, AOA and ΔAUC was estimated by Pearson’s correlations. Among fruit crops, tangerine, plum, grape and pear and among vegetables, blue leaf mustard, cabbage, chicory, broccoli and others exhibited significant hypoglycemic effects by reducing ΔBGLs with significant ΔAUC. The effective ΔAUC ranged from 5548.2 ± 462.1 to 3823.3 ± 282.0 ㎎-minㆍdL⁻¹. The TPC and AOA ranged from 0.063 ± 0.00 to 0.913 ± 0.14 ㎎ㆍg⁻¹ GAE and 01.05 ± 0.08 to 75.46 ± 0.06%, respectively. Overall, six fruits and fifteen vegetables exhibited higher TPC and one fruit and four vegetables exhibited higher AOA. There was a better correlation among TPC, AOA and ΔAUC of fruits and TPC & AOA of vegetables. We report that hypoglycemically significant fruits and vegetables investigated in this study have pharmacological importance which reduced ΔBGLs through insulin like activity and AOA in prevention of type-2 diabetes.