Effects of Selected Medicinal Plants on Enzymatic Targets Related to Diabetes Mellitus and Obesity

Diabetes mellitus is an increasingly prevalent global health issue, with obesity being a major contributing factor to its rise. Consequently, the discovery of novel therapeutic agents for the treatment of diabetes and obesity is of critical importance. In this context, 14 medicinal plants were evaluated in vitro for their inhibitory effects on α-amylase, α-glucosidase, and pancreatic lipase that involved in carbohydrate and lipid metabolism. Additionally, the total phenolic and flavonoid contents, along with antioxidant activities of the extracts, were assessed. Alhagi maurorum methanol extract exhibited strong α-glucosidase (IC₅₀ 45.16 µg/mL) and moderate pancreatic lipase inhibitory activity (46.47%). Moderate α-amylase inhibitory activity was observed only in the methanol extracts of Crocus ancyrensis and Scabiosa rotata (38.54% and 28.79%, respectively). Extracts of Tilia tomentosa, Thymus praecox, and Berberis crataegina, which contained high levels of total phenolics and flavonoids, also demonstrated notable antioxidant activity. Quantitative analysis of chlorogenic acid, rutin, quercetin-3-O-glucoside, and hesperidin was carried out using RP-HPLC on the methanol extract of A. maurorum, which showed the most significant α-glucosidase and lipase inhibition. On the basis of these findings, it can be concluded that activity-guided fractionation of A. maurorum methanol extract may lead to the identification of novel compounds with antidiabetic potential.