Orthosiphon stamineus as a potential antidiabetic drug in maternal hyperglycemia in streptozotocin-induced diabetic rats

Background: Maternal hyperglycemia is associated with increased risk of adverse outcomes for both mother and offspring. Insulin is the standard treatment of hyperglycemia with the aim to reduce risks of complications, however, due to several restrictions, the search for more effective drugs from traditional medicinal plants continues. Methods: The antidiabetic effects of Orthosiphon stamineus (O.stamineus) in non-pregnant and pregnant streptozotocin-induced Sprague Dawley rats were identified. The effect of different concentrations of O. stamineouson insulin level using isolated pancreatic islets in response to low and high concentrations of glucose was identified. Oral glucose tolerance test was performed in both pregnant and non-pregnant rats prior to and after treatment with O. stamineus (0.1 g/100 g of body weight). O. stamineus was given orally daily for 2 weeks in non-pregnant and 10 days in pregnant rats. Results: Oral glucose tolerance test indicated that treatment with O. stamineus in non-pregnant and pregnant rats significantly reduced blood glucose level and stimulated glucose-induced insulin secretion. No mortality was recorded throughout the study and no signs of toxicity during the experimental period including in both mother and foetus. For plasma analysis, the interactions of peptides such as GLP-1 and ghrelin level might contribute to the glucose lowering effect by O. stamineus via stimulation of insulin. The incubation of islets showed that O. stamineussignificantly stimulated insulin release in response to high glucose. Conclusion: O. stamineus could be a potential source of a specific oral hypoglycaemic agent to treat glucose intolerance in pregnancy. (C) 2019 Korea Institute of Oriental Medicine. Publishing services by Elsevier B.V.