Hyperglycemic and Hypocholesterolemic Effect of Monosodium Glutamate in Wistar Rats

Background: The use of seasonings to enhance the flavor of food has been on the increase in recent times. Different types of seasonings are produced daily and the constituents of these flavor-enhancers are unknown to ignorant consumers. They only want to eat food with good taste without consideration of the effect of these additives on their health. These seasonings contain monosodium glutamate (MSG) which really spiced the food.

Aim: This study sought to investigate the effect of MSG on blood sugar and cholesterol.

Place and Duration: This research was carried out at the Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, Abia State University, Uturu, Nigeria in 2011.

Methods: Forty Wistar rats were used for this study. Fifteen of the rats were used for acute toxicity test (LD50) and twenty-five for the experiment. The 25 Wistar rats were divided into five groups of 5 rats each. Animals in groups A, B, C, and D were respectively administered 500 mg/kg, 750 mg/kg, 1000 mg/kg and 1,250 mg/kg of MSG thoroughly mixed with standard feed for eight weeks. Animals in group E received equal amount of feeds without MSG added. This group served as the control group. At the end of 8 weeks, animals were fasted overnight and anaesthetized using diethyl ether. Blood samples were collected by cardiac puncture into plain test tubes and allowed to clot. The clotted blood was centrifuged at 4000 rpm for 10 minutes in a centrifuge. Serum was collected and analyzed immediately (for glucose) and the remaining refrigerated for further analysis (cholesterol) using standard methods.

Results: The LD50 was taken to be 500 mg/kg, which is the median of 200 mg/kg which did not kill any of the animals and 800 mg/kg that killed all its animals. MSG was observed to increase blood glucose but decreased cholesterol when compared with control animals.

Conclusion: The elevation of blood sugar by MSG is an indication that it can induce diabetes.