Antidiabetic Effect of Tiger Nut and Coconut Blend in Experimental Type 2 Diabetic Rat Model

ABSTRACT Tiger nut and coconut are chewy and popularly consumed as food either alone, mixed, or paired with other fruits, seeds, and vegetables. In Nigeria, a mixture of tiger nut and coconut is prepared as a refreshing drink called “Kunun aya”, which is usually consumed in the summer. Tiger nut and coconut are locally used to treat diabetes and were separately reported to attenuate hyperglycemia. However, little is known regarding the effect of tiger nut and coconut blend on key diabetes‐related parameters. Therefore, the aim of this study is to investigate the antidiabetic effect and nutritional compositions of the blend. Pilot study showed that blend prepared in the ratio of coconut (3): tiger nut (2) demonstrated the best hypoglycemic activity and was, hence, selected for the study. The blend was then included in the diet (5% and 10%) and fed to fructose‐streptozotocin‐induced type diabetic 2 rat model for 4 weeks. Fasting blood glucose (FBG), serum insulin, homeostatic model assessment insulin resistance (HOMA‐IR), quantitative insulin sensitivity check index (QUICKI), lipid profiles (total cholesterol, triglycerides, HDL‐, and LDL‐cholesterol), pro‐inflammatory markers (tumor necrosis factor‐alpha (TNF‐α), interleukin‐6 (IL‐6)), and antioxidant markers (lipid peroxidation, reduced glutathione (GSH), and the activities of superoxide dismutase (SOD) and catalase) were measured and recorded. All rats were humanely sacrificed 24 hours after last treatment and blood and pancreas were collected. Data were analyzed using a statistical software package (SPSS for Windows, version 24, IBM Corporation, NY, USA) using Tukey's‐HSD multiple range post hoc test. From the results, a diabetic control group showed hyperglycemia, hyperlipidemia, β‐cell failure, and diabetes‐induced inflammation and oxidative stress. Consumption of the blend significantly ( p < 0.05) demonstrated antihyperglycemic, antihyperlipidemic, anti‐inflammatory, ameliorated insulin resistance, improved pancreatic β‐cell failure, and oxidative alterations in the treated groups. The effects were significantly ( p < 0.05) more prominent in the group supplemented with 10% of the mixture comparable to the metformin‐treated group. In conclusion, dietary supplementation with the tiger nut and coconut blend showed antidiabetic action and is, hence, recommended for further study in human volunteers.