Ononis natrix L. Lowers the Blood Glucose Concentration in Wistar Rats with Streptozotocin-induced Diabetes Mellitus

Background: Practitioners of traditional medicine use the decoction of Ononis natrix L. to treat hyperglycemia. The literature offers no evidence to support the use. Objective: To investigate the effect of the decoction of Ononis natrix L. on the blood glucose concentration in Wistar rats (Rattus norvegicus) with streptozotocin-induced diabetes mellitus. Methods: We obtained 35 Wistar rats from the animal colony of The University of Jordan School of Medicine. We induced diabetes by a single intraperitoneal injection of streptozotocin (60 mg/kg body weight) and 23 rats (66%) survived to allocation. We randomly assigned the rats to one of four groups: negative control (1% Tween 80 in distilled water), positive control (100 mg/kg metformin), high-dose treatment (7.5 mL of the decoction), and low-dose treatment (3.5 mL of the decoction). We administered the doses twice daily by oral gavage for two weeks and measured the tailblood glucose concentration twice daily, once before the first dose and another time after the second dose. We used linear mixed-effects regression to model the change in blood glucose concentration as a function of the experimentation groups, with adjustments for pseudoreplication and temporal variation. Results: The estimated mean change was 1 mmol/L (−30 to 31 mmol/L) for the negative control group, −26 mmol/L (−56 to 5 mmol/L) for the positive control group, −75 mmol/L (−108 to −42) for the low-dose treatment group, and −82 mmol/L (−111 to −53 mmol/L) for the high-dose treatment group. Conclusion: In conclusion, we demonstrate, for the first time, the hypoglycemic effect of Ononis natrix L. in an animal model of diabetes.