The effect of leaf extract P.harmala on streptozotocin-induced apoptosis in pancreatic tissue of rats

Decreased beta-cell mass has a role in the pathogenesis of human type 2 diabetes and in rodent diabetes models. The study of plant extracts is important as they possibly inhibit the reduction of beta cell mass and the islets of Langerhans. The aim of this study was to determine the effect of leaf extract of P. harmala on streptozotocin-induced apoptosis in rat pancreatic tissue.

In this experimental study that was conducted in 2016, a number of 32 male rats (250±10g) were acquired from the Pasteur Institute of Iran and randomly divided into four groups (n= 8), including control, diabetic, diabetic and experimental treated with P. harmala leaf extract. Diabetic groups were given 60 mg/kg streptozotocin. After confirming the induction of diabetes on the tenth day, methanolic leaf extract (150 mg/kg) was administered by gavage for 28 days for the groups treated with the extract. The extracted content of the P. harmala leaf was then analyzed by HPLC. Subsequently, rats’ serum glucose level was assessed, and the pancreatic tissue was removed. Following H&E and AgNOR staining, the number of beta cells and the diameter of the islets were measured. Finally, the collected data were analyzed by SPSS software.

the results showed that the P. harmala leaf extract is rich in flavonoid compounds. A significant difference was observed in the serum glucose concentrations on days 10, 14, and 28 between the diabetic and control groups (p≤0.001), but there was no meaningful difference between the diabetic group treated with the leaf extract and the diabetic group. The mean islet diameter reduced significantly in the diabetic group relative to the control group (p≤ 0.01), while the difference was insignificant between the diabetic group treated with the leaf extract and the diabetic group. Besides, the experimental groups under treatment did not show any meaningful difference with the control group.

In spite of the fact that the P. harmala leaf extract contains flavonoids and phenolic compounds, unlike previous studies, it could not improve the side effects of streptozotocin in the diabetic group.