Biological Activities of Chinese Propolis and Brazilian Propolis on Streptozotocin-Induced Type 1 Diabetes Mellitus in Rats

Figure 4

ROS as a common upstream event of diabetes. ROS are believed to be an underlying mechanism of diabetes. Hyperglycemia induced oxidative stress by stimulating mitochondrial pathway, NAD(P)H oxidase and xanthine oxidase, and subsequently activated various pathways including PKC pathway, hexosamine pathway, polyol pathway, production of AGE and so on. In addition, hyperglycemia disregulated the expression of reactive nitrogen species (RNS) which reacts with superoxide forming peroxynitrite, a highly reactive oxidant. In this experiment, Chinese and Brazilian propolis were certificated to inhibit the increase of MDA and improve the antioxidase activity in STZ-damaged rats. In addition, Brazilian propolis decreased serum NOS level, which suggested that the improvement of propolis on diabetes may partially be attributed to the inhibition of oxidative stress.