Comparative Effect of Carbimazole, Citrus sinensis, Glycine Max and Levothyroxine on Blood Glucose Levels and Body Weight Changes

Aims: The role of thyroid hormones as important mediator of glucose metabolism and body weight dynamics had long been established. This study was therefore designed to evaluate the effect of standard thyro-active drugs in comparison to crude nutritional extracts, on blood glucose level and body weight changes.
Methodology: Albino wistar rats weighing between 100 - 150g were randomly assigned to seven groups of seven rats each. Group 1 served as control, while groups 2-7 were orally administered Fresh orange juice(FOJ) (1500mg/kg), Fresh soybean(FSB) (0.01mg/kg), levothyroxine (LVT) (0.01mg/kg), carbimazole (Carb) (0.01mg/kg), FSB+LVT and FOJ+Carb respectively once daily for twenty eight days. Weekly weight records were taken and the difference calculated as weight changes. The animals were sacrificed and blood samples collected by cardiac puncture. Serum was obtained by standard procedure and used for blood glucose estimation.
Results: Separate treatment with both FOJ and FSB significantly (P<0.05) increased the blood glucose levels and body weight compared to control. Levothyroxine significantly (P<0.05) increased the blood glucose levels but significantly (P<0.05) decreased the body weight compared to the FOJ treated group. Carbimazole significantly (P<0.05) decreased the blood glucose levels compared to the control, FOJ and FSB treated groups. FSB+LVT treatment significantly (P<0.05) decreased the blood glucose levels compared to the LVT group and also significantly (P<0.05) decreased the body weight compared to the control, FOJ and FSB groups. FOJ+Carbimazole combination treatment significantly (P<0.05) decreased the blood glucose levels compared to LVT treatment and also significantly (P<0.05) decreased the body weight compared to the FOJ and FSB groups. FOJ significantly reduced T4 and T3 levels compared to control. FOJ, Carb and FOJ+Carb significantly (p<0.05) reduced T4 level compared to control.
Conclusion: The acclaimed antithyroid activity of FOJ and FSB did not appear to directly correlate with that of carbimazole, a standard antithyroid drug, considering their effect on blood glucose level and body weight changes. However their combination treatment with Carb and LVT respectively, showed similar pattern with carbimazole.