Herb–drug interaction study between Aloe vera and glimepiride in normal and diabetic rats

Abstract

Background Herb–drug interaction study, which is the newest area of research, can affect the modern practice of medicine. Aim The present study was designed to explore the herb–drug interaction of Aloe vera gel, an herbal drug used in herbal formulation for hypoglycemic activity, with glimepiride in normal and diabetic rats. Materials and methods Lethal dose 50% studies for the aqueous extract of A. vera were carried out in albino mice up to the dose level of 2000 mg/kg by following ‘up and down method’ of Organization for Economic and Cooperation Development guidelines no. 425 of Committee for the Purpose of Control and Supervision of Experiments on Animals. Overall, 1/5th, 1/10th, and 1/20th doses of the maximum dose tested for lethal dose 50% of the aqueous extract were selected for the experimental study. A. vera (100, 200, and 400 mg/kg, postoperatively) and glimepiride ½ therapeutic dose (TD), 1 TD, and 2 TD (0.036, 0.072, and 0.144 mg/200 g, postoperatively) were administered orally alone as single doses and as well as concomitantly in normal and streptozotocin-induced diabetic rats. Results After the treatment in all the groups, serum glucose levels were determined, and the serum insulin levels were estimated only in the diabetic rats using chemiluminescence assay method. Both A. vera and glimepiride on their own when administered alone showed hypoglycemic effect in normal rats. The hypoglycemic effect observed with combination of A. vera and glimepiride was significantly more compared with either of the drugs given alone. A. vera also augmented the hypoglycemic effect of glimepiride in streptozotocin-induced diabetic rats. Conclusion Administration of A. vera with glimepiride increased the serum insulin levels. It has been concluded that A. vera augmented hypoglycemic effect of glimepiride. There was a herb–drug interaction that necessitates dose readjustment of glimepiride and monitoring of glucose levels to avoid hypoglycemic condition.