The Efficacy of Diavite (prosopis Glandulosa) as Anti-diabetic Treatment in Rat Models of Streptozotocin-induced Type 1 Diabetes and Diet-induced-obese Insulin Resistance

Introduction: Obesity and its associated complications, such as the metabolic syndrome, hypertension and cardiovascular disease, are escalating worldwide. In recognition of this, untested remedies advertised as anti-diabetic agents are flooding the market. Many of these products have limited efficacy, limited tolerability and significant side-effects. One remedy, claiming to have anti-diabetic properties, is Diavite. Diavite, a herbal product, consisting solely of the dried and ground pods of the Prosopis glandulosa tree, which is currently marketed as a food supplement with blood glucose and blood pressure stabilizing properties, as well as having the ability to enhance glucose utilization. It is already freely available from agents as well as sold over the counter at pharmacies. The producers of Diavite are now seeking registration for their product from the Medicines Control Council (MCC) and, therefore, require solid scientific evidence of its effects. Aims: The aims of our study were, on request of the producing company, to determine the efficacy of Diavite (P. glandulosa) as an anti-diabetic agent and possible mechanisms of action of this plant product. Methology: We utilized rat models of streptozotocin (STZ)-induced type 1 diabetes and diet-induced obese (DIO) insulin resistance. Male Wistar rats were rendered (a) type 1 diabetic after a once-off intra-peritoneal injection of STZ at a dose of 40 mg/kg and (b) insulin resistant after being on a high caloric diet (DIO) for 16 weeks. Half the animals of the type 1 diabetes model as well as the insulin resistant model were placed on Diavite treatment (25 mg/kg/day) for a period of 4 – 8 weeks, depending on the model. The STZinduced type 1 diabetic rats were sacrificed and the pancreata harvested for histological analysis. Animals on the DIO diet were sacrificed and (i) intraperitoneal fat weight determined (ii) isolated hearts subjected to ischaemia/reperfusion to determine infarct size and protein expression profiles and (iii) cardiomyocytes prepared to determine insulin sensitivity. At the time of sacrifice blood was collected for blood glucose and serum insulin level