Biomedical and Pharmaceutical Sciences
Natural Products; Mice; Diabetes; Obesity
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Natural product extracts and chemicals isolated from natural products (e.g. plants, berries, seeds) have been commonly used in various types of traditional medicines. In addition, some drugs on the market today have been derived from natural product sources. The purpose of our study was to evaluate two natural products, Rhein and Thymoquinone, for as potential anti-diabetic and anti–obesity agents. According to the Center for Disease Control (CDC), the number of people in the US diagnosed with diabetes has increase from 11.9 million people in the year 2000 to 20.8 million people in the year 2011. Rhein is a natural compound and a major component of Rheum palmatum, or Rhubarb. It has been used in Chinese medicine to treat constipation, gastrointestinal hemorrhage, ulcers as well as metabolic disorders such as diabetes. Thymoquinone (TQ) is a compound found in the plant Nigella sativa and has been documented to exhibit anti-diabetic, anti-obesity, hypotensive and hypo-lipidemic properties in human and animal studies. (Razavi and Hosseinzadeh, 2014). The purpose of our study was to evaluate whether daily administration of Rhein or TQ could improve obesity-induced diabetes in mice. First, male C57BL/6 mice that were 6 weeks of age were fed a low fat diet (10% kcal, LFD) or a high fat diet (60% kCal, HFD) for 12 weeks. Over the twelve-week period, body weight, fasting blood glucose and glucose tolerance were determined to assess whether the high fat diet could induce a diabetic condition. Starting from week 12, mice were administered canola oil vehicle (CO, 5 ml/kg), Rhein (20 mg/kg, 5 ml/kg in CO), or TQ (1 mg/kg, 5 ml/kg) daily. After three weeks of dosing the Rhein and TQ doses were increased to Rhein (50 mg/kg, 2.5 ml/kg) and TQ (10 mg/kg, 2.5 ml/kg). There were six groups of mice in this study, with the following groups: i) LFD + CO, ii) LFD + Rhein, iii) LFD + TQ, iv) HFD + CO, v) HFD + Rhein, vi) HFD + TQ. Body weight and food consumption were measured daily. At periodic points throughout the study, fasting blood glucose (FBG) and glucose tolerance (GTT) were measured in the mice. Overall, in mice administered CO vehicle, HFD feeding increased body weight, FBG and GTT as anticipated. However, the body weights for Rhein and TQ-treated mice fed the LFD or HFD were similar to vehicle-treated controls. In addition, there was no significant improvement in glucose tolerance was observed in mice administered Rhein or TQ. Rhein and TQ did not seem to have effect on body weight, FBG, and GTT, and further studies are needed to determine if the Rhein or TQ has an effect on the mechanisms of obesity and diabetes.