Dietary red chilli (Capsicum frutescens L.) is insulinotropic rather than hypoglycemic in type 2 diabetes model of rats

The present study was conducted to clarify whether a low or a high, but tolerable, dietary dose of red chilli (RC) can ameliorate the diabetes related complications in a high-fat (HF) diet-fed streptozotocin (STZ)-induced type 2 diabetes model of rats. Five-week-old male Sprague Dawley rats were fed a HF diet for 2 weeks then randomly divided into four groups namely: normal control (NC), diabetic control (DBC), red chilli low (RCL, 0.5%) and red chilli high (RCH, 2.0%) groups. Diabetes was induced by an intraperitoneal (i.p.) injection of STZ (40 mg/kg BW) in all groups except the NC group. After 4 weeks feeding of experimental diets, the fasting blood glucose concentrations in both RC fed groups were not significantly different. The serum insulin concentration was significantly (p < 0.05) increased in the RCH group compared with the DBC and RCL groups. Blood HbA1c, liver weight, liver glycogen and serum lipids were not influenced by the feeding of RC-containing diets. The data of this study suggest that 2% dietary RC is insulinotropic rather than hypoglycemic at least in this experimental condition.