[New polyphenolic extracts for oxidative stress treatment in experimental diabetes]

The paper focuses on the extraction and purification by chromatographic and spectral methods of certain natural polyphenolic extracts from Aronia melanocarpa and common elder (Sambuccus nigra) fruit, and also on their effects in hypoinsulinemic diabetes mellitus.

The research was made upon Wistar rats, which were divided into 4 groups: group I--control group; group II--with polyphenols in a dose of 0.034 g/body-kg; group III--with diabetes mellitus, induced by 55 mg/body-kg of streptozotocyne; group IV--to whom was administered a solution of polyphenols, 12 weeks, after the onset of diabetes mellitus.

Glycosylated hemoglobin values are much higher in the diabetic group and they are significantly lower in the group protected by polyphenols. The serous activity of glutathione-peroxidase and superoxide-dismutase has significantly lower values in the diabetic group as compared to the group protected by polyphenols. The serous concentration of malondialdehyde in the diabetic group undergoing polyphenols treatment is lower as compared to the diabetic group, which means a significant decrease of lipid peroxides in the serum. The results demonstrate the hypoglycemic, hypolipemic and antioxidant effects of Aronia melanocarpa and Sambucus nigra extracts in streptozocin-induced diabetes.