Effects of Carvacrol on Aortic Damage in a Streptozotocin-Induced Type 1 Diabetic Rat Model

Diabetes mellitus (DM) is associated with vascular complications that increase morbidity and mortality. Natural antioxidants play a vital role in reducing diabetes-related damage. This study investigated the protective effects of the phenolic monoterpene carvacrol (CAR) against diabetic complications. Thirty-two male Wistar Albino rats (4 months, 250–300 g) were divided into four groups: control, DM, DM + DMSO, and DM + CAR. Type 1 diabetes was induced via intraperitoneal injection of 50 mg/kg streptozotocin (STZ). The DM + CAR group received 20 mg/kg CAR daily for four weeks. Body weight and blood glucose levels were regularly monitored. At the end of the study, aortic tissues were examined using hematoxylin–eosin (H&E), Verhoeff–Van Gieson, and immunohistochemical staining, while cardiac tissues were analyzed with H&E and Masson’s trichrome. Serum levels of ischemia-modified albumin (IMA), cholesterol (CHOL), triglycerides (TG), and high-density lipoprotein (HDL) were measured. In the DM group, IMA and CHOL levels were increased (<i>p</i> = 0.0208 and <i>p</i> = 0.0207, respectively), apoptosis was elevated (caspase-3 expression, <i>p</i> = 0.0001), and marked tissue damage was observed. In contrast, in the DM + CAR group, IMA levels (<i>p</i> = 0.0228) and caspase-3 expression (<i>p</i> = 0.0457) were reduced, and notable improvements were detected in vascular and cardiac tissues. These results suggest that CAR protects against diabetic complications by modulating oxidative stress, inhibiting apoptosis, and preventing tissue injury.