Dracocephalum subcapitatum Alleviates Hyperglycemia, Dyslipidemia, Oxidative Stress, and Organ Injury in STZ-Induced Diabetic Rats: a Dose-Response Study

Background and objectives: Dracocephalum subcapitatum is a plant indigenous to northeastern Iran with some traditional applications and limited pharmacological data. Since antidiabetic activities have been reported for several species of Dracocephalum genus, this study aimed to explore the effects of the hydroalcoholic extract of D. subcapitatum in an animal model of diabetes mellitus. Methods: Extraction was prepared through the maceration technique, and the total phenolics content was determined using the Folin-Ciocalteu method. Male Wistar rats were divided into five groups (n=8). Hyperglycemia was induced by a single dose of streptozotocin (60 mg/kg, i.p.). In the treatment groups, diabetic animals orally received the extract (50, 100, and 200 mg/kg) or glibenclamide (10 mg/kg) for 21 days. The glucose and insulin tolerance tests, and biochemical evaluations of fasting blood glucose, HbA1c, cholesterol, triglycerides, ALT, AST, ALP, creatinine, BUN, malondialdehyde, and total plasma antioxidant levels were performed. The rat's liver, kidneys, and pancreas were examined histologically. Results: The total phenolics content was 70.2±1.8 mg gallic acid equivalent/g of the extract. Dracocephalum subcapitatum extract, especially at higher doses, effectively lowered serum blood glucose, HbA1c, triglycerides, creatinine, and MDA levels, as well as the activities of ALT and ALP enzymes (p<0.001), without a positive effect on AST levels in diabetic rats. It also improved blood sugar regulation and insulin resistance, enhanced the total antioxidant capacity of plasma (p<0.001), and reversed tissue toxicities. Conclusions: This study suggests that D. subcapitatum has antihyperglycemic, triglyceride-lowering, antioxidant, and tissue-protective activities in diabetes caused by streptozotocin.