Oral delivery of insulin with Desmodium gangeticum root aqueous extract protects rat hearts against ischemia reperfusion injury in streptozotocin induced diabetic rats

Abstract

Objective To evaluate the effect of insulin administered via oral route with the help of aqueous extract of Desmodium gangeticum (DG) root in rendering cardio protection against ischemia reperfusion injury in diabetic rats. Methods Diabetes mellitus was induced in rats by the β-cell toxin, streptozotocin (STZ, 60 mg/kg). Isolated rat (IR) heart was used to investigate the effect of insulin mixed DG pretreatment on ischemia reperfusion injury. Mitochondrial respiratory enzymes and microsomal enzymes were used to assess the metabolic recovery of myocardium. Cardiac marker enzymes were used to find the functional recovery, which were compared with that of the STZ treated IR rats. Results Compared with IR control group, rat treated with insulin mixed DG showed a significant functional and metabolic recovery of myocardium from the insult of ischemia reperfusion. Even though orally administered insulin mixed DG displayed a slow but prolonged hypoglycemic effect, the cardio protection it provided was more significant than when it was given intra peritoneal. Furthermore the above result indicates that insulin mixed DG can overcome the barriers in the gastrointestinal tract and be absorbed. Conclusions The above results indicate the efficacy of insulin mixed DG in protecting the heart from ischemia reperfusion induced injury in diabetic rats. Furthermore the study gives additional information that herbal extracts can be used to transport insulin across the membrane and found to be a feasible approach for developing the oral delivery of insulin, as well as other peptide drugs.