A:The potential antioxidant and anti-inflammatory effects of catechins polyphenolic compounds in tea and cocoa extracts on STZ diabetic rats

The aim of this study is to investigate the effect of some phenolic compounds such as catechines that heavily present in tea and cocoa extracts against diabetic induction using streptozotocin (STZ) treated rats. Eighty male albino rats were divided into eight groups of ten rats each as follows; normal,  black tea, green tea, cocoa , STZ- diabetic, STZ- diabetic + black tea,  STZ- diabetic + green tea, STZ- diabetic + cocoa. Blood glucose, glycosylated hemoglobin, serum insulin and lipid profile were assessed in all groups. In addition, HOMA-IR and atherogenic index were calculated. Further, inflammatory markers and other metabolic parameters such as endothelial dysfunction and oxidative stress markers were estimated. The data showed that all the used extracts had antioxidant and anti-inflammatory effect against STZ induced diabetes. Although, green tea extract showed the maximum improvement in antioxidants levels and cocoa extract showed the maximum improvement in inflammatory markers. We concluded that tea and cocoa extracts had a protective effect against STZ induced diabetes which attributed to their free radical scavenging antioxidants that reduced both the production and release of inflammatory markers.