Action of Anastatica hierochuntica plant extract on Islets of Langerhans in normal and diabetic rats

Abstract

The increase in number of diabetic patients motivated scientists to find new methods to control such disease. In the present study, the action of water extract of a common medicinal plant (Anastatica hierochuntica) used in the Arabian Peninsula was studied on normal and Streptozotocin (STZ)-induced diabetic rats. Experimental groups included control rats orally administered distilled water; plant treated group received oral daily dose of the plant extract (12.5 mg/rat) for two weeks; diabetic untreated group intraperitoneally injected with STZ (60 mg/kg); and diabetic-plant treated group included STZ-diabetic rats received the daily oral dose of the plant extract for two weeks. Blood samples were collected for determination of blood glucose level and samples from pancreatic tissues were processed to paraffin blocks for histological and immunohistochemical studies. The diabetogenic effect of STZ was proven by significant elevation of blood glucose in STZ-treated rats. STZ also showed islet cell disintegration and destruction with the presence of hyaline masses and empty spaces invaded with inflammatory cells. However, administration of the plant extract induced a hypoglycemic effect in both normoglycemic and diabetic rats. It also caused significant improvement in tissue injury induced by STZ. Immunohistochemical studies showed intensive reduction of insulin-positive cells in islets of Langerhans after the onset of diabetes, while the plant extract stimulates the appearance of those cells in STZ-diabetic rats. However, glucagon-secreting cells were increased in untreated and plant-treated diabetic rats comparable to control rats. The results indicate the ability of the plant extract to improve the diabetogenic action of STZ.


KEY WORDS: pancreatic islets, diabetes, Streptozotocin, histology, physiology, immunohistochemistry.


Egyptian Journal of Biology Vol.4 2002: 87-94