EFFICACY OF NATURAL POLYPHENOLIC COMPOUNDS FROM BILBERRY AND BLUEBERRY ON THE METABOLIC ALTERATIONS INDUCED BY STREPTOZOTOCIN IN RATS

Abstract

Chronic hyperglycaemia is associated with dysfunction of various organs. We have previously reported that Vaccinium myrtillus extracts are capable of reducing hyperglycaemia, modulating the secretion of insulin and preventing the development of cataract. The primary objective of this study was to assess the effects of orally administered high polyphenolic content extracts on diabetes-induced complications in rats. After 3 months of treatment with Vaccinium myrtillus and Vaccinium corymbosum extracts, hepatic enzymes, serum creatinine and lipids were measured, and histopathological alterations were evaluated in Wistar rats with streptozotocin-induced diabetes. Histopathological staining revealed that only minor signs of liver impairment were noticed in the Vaccinium myrtillus leaves group, compared with the Vaccinium corymbosum leaves and fruits treated group, where severe fibrosis was noticed. The liver histopathological results are correlated with AST levels. Moreover, some histopathological alterations of the kidneys were observed in the groups treated with V. corymbosum extracts, compared with V. myrtillus treated groups, where only minor modifications were noticed. Extracts with high polyphenolic content from Vaccinium myrtillus are capable of delaying and/or preventing the complications of induced diabetes, like renal and liver impairment.