Glucose‐Lowering Properties of a Tea Formulation Containing Citrullus lanatus Peel, Ananas comosus Peel, and Mentha spicata L. Leaf Extracts in Dexamethasone‐Induced Insulin‐Resistant Wistar Rats

Abstract

ABSTRACT This study investigated the glucose‐lowering properties of a tea blend combining Citrullus lanatus , Ananas comosus , and Mentha spicata . To achieve this, we initially characterized the raw materials and subsequently developed a mixture design, resulting in 11 distinct tea formulations. Physicochemical analyses of the various tea formulations enabled the development of mathematical models describing the relationships between the characteristics and raw material quantities. Using Design Expert 13 software, optimization was performed to maximize antioxidant content, facilitated by a specification sheet. After microbiological analysis, the optimal tea formulation was administered to male Wistar rats at doses of 300 and 500 mg/kg body weight during hypoglycemia, oral glucose tolerance, and insulin resistance tests induced by dexamethasone. Upon completion of the 10‐day experiment, the diabetic animals were euthanized, and biochemical parameters were evaluated. The optimized antioxidant‐rich tea formulation contained flavonoids (813.986 mg/mL), tannins (0.056 mg/mL), polyphenols (2019.35 mg/mL), and vitamin C (0.735 mg/mL) and exhibited high antioxidant activity (128.86 mg/mL). Additionally, it met the required microbiological standards. The rat experiment indicated that both tea doses significantly ( p < 0.05) improved glycemic control, comparable to the reference drug group. Additionally, the tea doses resulted in significant reductions in total cholesterol, triglycerides, and LDL cholesterol, as well as an increase in HDL cholesterol. Furthermore, the activity of intracellular enzymes ASAT and ALAT, as well as serum concentrations of urea, creatinine, and albumin, decreased significantly in response to the tea's action. The 500 mg/kg dose showed the highest efficacy, suggesting that it could be a potential alternative treatment for diabetic patients.