Possible regeneration of the islets of Langerhans in streptozotocin-diabetic rats given Gymnema sylvestre leaf extracts

Two water soluble extracts, GS₃ and GS₄, obtained from the leaves of Gymnema sylvestre, were tested in streptozotocin treated rats for their effects on blood glucose homeostasis and pancreatic endocrine tissue. In the diabetic rats, fasting blood glucose levels returned to normal after 60 days of GS₃ and after 20 days of GS₄ oral administration. Blood collected during the conduct of oral glucose tolerance tests was used to assay for serum insulin. GS₃ and GS₄ therapy led to a rise in serum insulin to levels closer to normal fasting levels. In diabetic rat pancreas, both GS₃ and GS₄ were able to double the islet number and beta cell number. This herbal therapy appears to bring about blood glucose homeostasis through increased serum insulin levels provided by repair/regeneration of the endocrine pancreas.