In Vitro Anti-Inflammatory and Anti-Diabetic Activities of Methanolic Extract of Sour Plum (Xymenia caffra) Leaves

This study evaluated the in vitro anti-inflammatory and antidiabetic activities of methanolic leaf extracts of Ximenia caffra (sour plum), a medicinal plant widely used in traditional healthcare systems across tropical Africa. Medicinal plants remain an important source of bioactive phytochemicals, and growing interest in phytopharmaceuticals has intensified the search for natural compounds with therapeutic potential. The present investigation aimed to scientifically validate the ethnomedicinal use of X. caffra leaves by assessing their enzyme inhibitory and anti-inflammatory properties. Fresh leaves of X. caffra were collected, authenticated, air-dried, pulverized, and extracted using methanol through maceration. Anti-inflammatory activity was determined using protein denaturation inhibition and membrane stabilization assays, while antidiabetic potential was evaluated through α-amylase and α-glucosidase enzyme inhibition assays. The extract exhibited concentration-dependent biological activities across all experimental models. Anti-inflammatory evaluation showed significant inhibition of protein denaturation and membrane stabilization, with IC₅₀ values of 129.83 µg/mL and 288.11 µg/mL, respectively. Similarly, the extract demonstrated appreciable antidiabetic activity, inhibiting α-amylase and α-glucosidase enzymes with IC₅₀ values of 227.01 µg/mL and 179.35 µg/mL, respectively, indicating stronger inhibition of α-glucosidase. These findings suggest that X. caffra leaves contain bioactive compounds capable of modulating inflammatory responses and carbohydrate-digesting enzymes, thereby supporting their traditional medicinal use. The study highlights the potential of X. caffra as a promising natural source for the development of plant-based anti-inflammatory and antidiabetic therapeutic agents.