PHYTOCHEMICAL AND BIOCHEMICAL EVALUATION OF FORMULATED ANTIDIABETIC HERBAL TEA FROM Vitex doniana and Spondias mombin

Abstract

This study formulated and evaluated two antidiabetic herbal tea formulations from the underutilised Nigerian medicinal plants Vitex doniana and Spondias mombin. Formulation F1 was Vitex doniana-dominant, while F2 was Spondias mombin-dominant, with Zingiber officinale and Mentha spicata incorporated as functional adjuncts. The formulations were assessed for phytochemical composition, antioxidant capacity, in-vitro carbohydrate-enzyme inhibitory activity, proximate composition, and antimicrobial activity. The formulations were subsequently evaluated in STZ-induced diabetic Wistar rats at 200, 400 and 600 mg/kg for antidiabetic activity and toxicological effects. Qualitative screening detected alkaloids, carbohydrates, flavonoids, tannins, phenols, steroids and coumarins in both formulations, while saponins, terpenoids and cardiac glycosides were not detected. F1 recorded higher total phenolic, flavonoid and tannin contents, whereas F2 had higher alkaloid content. GC-MS confirmed 9-octadecenamide, (Z)- as the predominant library-matched compound in both formulations. Both formulations demonstrated concentration-dependent antioxidant and α-amylase/α-glucosidase inhibitory activities, with F1 generally showing stronger in-vitro performance. Proximate analysis showed higher crude fibre in F1 and higher protein and carbohydrate contents in F2. Microbial counts were low in both formulations, and both exhibited antimicrobial activity against the test organisms. In vivo, F1 and F2 produced significant (p<0.05) reductions in blood glucose concentration across the treatment period, with improvements also observed in several haematological, liver, kidney and lipid-profile parameters. No observable morbidity, mortality or behavioural abnormalities were recorded, and the treatment groups did not show a statistically demonstrated adverse effect on final body weight relative to the diabetic control. Overall, the findings indicate that both formulations possess promising antidiabetic and antioxidant potential with a generally favourable short-term safety profile, while formulation ratio influenced the magnitude and pattern of the observed biological responses