Mechanisms of toxic effect of streptozotocin on ß-cells in the islets of langerhans.

Administration of streptozotocin caused selective damage to endocrine ß-cells in rat pancreatic islets, which was related to activation of apoptosis. The cytotoxic effect of streptozotocin was associated not only with DMA damage due to dysfunction of the antioxidant defense system, but also with activation of the caspase cascade and TNF-related apoptosis-inducing ligand.

[Antidiabetic effect of Gymnema sylvestre-based medicinal complex].

The paper deals with the study of the antidiabetic mechanism of action of the medicine "Diabeta". The agent has been found to have a central effect (pancreatotropic one associated with insulin secretion stimulation) and a peripheral one (extrapancreatic effect associated with intestinal carbohydrate malabsorption).

[Structural alterations in pancreatic islets in streptozotocin-induced diabetic rats treated with of bioactive additive on the basis of Gymnema sylvestre].

The structural alterations in pancreatic islets in streptozotocin-induced diabetic rats were studied after the administration of Gymnema sylvestre extract or its composition. Diabetes mellitus was modeled by daily injection of streptozotocin (20 mg/kg for 5 days) and single injection of 0.2 ml of complete Freund's adjuvant, Only the animals with the blood glucose level exceeding 15 mmol/l were included in the experiment. B- and A-endocrinocytes were demonstrated using immunocytochemistry. The proportions of the area of the pancreatic islets, occupied by B- and A-endocrinocytes, as well as the volume fraction of the pancreatic islets within the pancreas, were determined. In the model of streptozotocin-induced diabetes, the part of the total islet area occupied by B-endocrinocytes, was diminished in the pancreatic islets located in all the zones of the gland. Prophylactic administration of Gymnema sylvestre extract or its composition tended to restore the area occupied by B-endocrinocytes in the pancreatic islets. These results indicate the equal potency of the composition and extract of Gymnema sylvestre to induce the regeneration of B-endocrinocytes.

[Hemorheological activity of Gymnemy sylvestre extracts in streptozotocin-induced diabetes].

Extracts of Gymnemy sylvestre (GS) exhibit hemorheological activity. The most pronounced effect was observed for GL extract in 25 wt % concentration, which (i) induced a decrease in the viscosity of blood and washed erythrocyte suspensions in the entire range of shear rates by a factor of 1,3 (ii) reduced the degree of deformability of red blood cells, (iii) increased the degree of osmotic resistance of erythrocytes by 21.3%, (iv) increased the intensity of fluorescence of DSM+ probe in erythrocyte suspensions by a factor of 1.5, and (v) decreased the degree of anisotropy, thus generally improving the viscoelastic properties of the erythrocyte membrane and preventing the thrombocyte aggregation. In this respect, the GS extract activity exceeded that of Tanakan.

Study of antidiabetic activity of a new ultralow-dose antibody preparation on the model of streptozotocin diabetes in rats.

Antidiabetic activity of a new ultralow-dose preparation of antibodies to insulin receptor beta-subunit was revealed on the model of streptozotocin diabetes in rats: treatment with this preparation in a daily dose of 2.5 ml/kg (for 50 days through a gastric tube) normalized blood glucose level, restored glucose tolerance in the oral glucose test and body weight gain, and improved animal survival. By its hypoglycemic activity and effect on glucose tolerance the preparation was not inferior to classical drugs for the treatment of types 1 and 2 diabetes mellitus insulin (12 U/kg) and glybenclamide (8 mg/kg).