RESUMEN
Diabetes mellitus (DM) is characterized by hyperglycemia and alterations in the metabolism of lipids, carbohydrates, and proteins. Due to its hypoglycemic effect Vochysia rufa is frequently used in Uberlandia, Brazil, to treat DM. Despite its popularity, there is little information about its effect on hepatic tissue. Therefore, we evaluated the histoarchitecture, oxidative stress parameters, and polyploidy of liver tissue from streptozotocin- (STZ-) induced diabetic rats treated with aqueous extract of Vochysia rufa (AEV). Histology was determined by fixing the livers, processing, and staining with HE. Oxidative stress was determined by evaluating CAT, GPx, and SOD activity in liver homogenates and hepatic mitochondria fraction and by measuring GST, GSH levels and lipid peroxidation (MDA). Polyploidy was determined by subjecting isolated hepatocyte nuclei to flow cytometry. In the diabetic group, GST activity and GSH rates decreased whereas liver homogenate analysis showed that GPx, SOD activity and MDA increased. AEV treatment restored all parameters to normal levels. The oxidative stress analysis of hepatic mitochondria fraction showed similar results. Lower polyploid cell populations were found in the diabetic rat livers, even after glibenclamide treatment. Thus, AEV treatment efficiently reduced hepatic oxidative stress caused by STZ-induced diabetes and produced no morphological changes in the histological analysis.
RESUMEN
BACKGROUND AND OBJECTIVE: Acarbose is a competitive inhibitor of intestinal alpha-glycosidases that slows the breakdown of sucrose and starch, thereby reducing glucose and fructose absorption. The aim of this study was to evaluate the effect of acarbose treatment on antioxidant parameters and deposition of type I collagen in the parotid glands of diabetic rats. METHODS: Diabetes mellitus was induced by intravenous injection of streptozotocin, and rats were divided into four groups: non-diabetic (NDM), diabetic (DM), diabetic treated with 25mg/kg acarbose (DMA) and non-diabetic treated with acarbose (NDMA). Changes in enzymatic antioxidant systems, such as the activity of SOD and GPx enzymes, were evaluated, and the specific staining pattern of the type I collagen fibres was investigated in the rat parotid glands. RESULTS: The DM group presented high levels of SOD and GPx enzymes, which were reduced by acarbose treatment. Tissue damage, which was indicated by an increased MDA concentration in the parotid glands of rats in the DM group, was also reversed in the DMA group. Moreover, type I collagen fibres from DM rats were more intensely stained than those of NDM rats. Acarbose treatment was effective in decreasing collagen deposition, which was shown by a decrease in staining intensity of approximately 25%. CONCLUSIONS: These results suggest that the diabetic state influences the type I collagen concentration in the parotid glands of rats. In addition, acarbose treatment was helpful in preventing the deposition of such fibres, as well the increase in oxidative stress induced by hyperglycemia.