Evaluation of the Phytochemical Profiling, Tyrosinase Inhibitory Activity, and Antioxidant Potential of Various Extracts of Acacia Concinna (Willd.) DC.

The legume Acacia concinna (Willd.) DC. (Fabaceae) is eaten as a food and used for medicinal purposes. This study evaluated the phytochemical profile, total phenolic content and antioxidant and tyrosinase inhibitory activities of leaf, bark, and heartwood extracts of A. concinna using different extraction solvents. Crude extracts were prepared by reflux extraction with dichloromethane, ethanol, and deionized water. The dichloromethane extracts of bark and heartwood provided the highest total phenolic content as determined by the Folin-Ciocalteu reaction. Antioxidant activities were assessed using the DPPH and ABTS assays, with the bark ethanolic extract (BE) giving the highest antioxidant activities at IC50 values of 3.0 ± 0.03 and 5.0 ± 0.01 µg/mL, respectively. The BE antioxidant capacity was similar to ascorbic acid. Tyrosinase inhibitory activity was determined using an in vitro enzymatic spectroscopic model. Highest tyrosinase inhibitory activity was recorded in the heartwood ethanolic extract (HE) with IC50 value 0.7634 ± 0.01 mg/mL. GC-MS analysis revealed long-chain fatty acids as the major phytochemicals in BE and HE. BE had excellent antioxidant abilities, whereas HE showed potential tyrosinase inhibitory activity. Long-chain fatty acids and lupeol were the principal phytoconstituents of BE and HE as important bioactive components in A. concinna extracts. HIGHLIGHTS The bark extracts have the highest total phenolic content and antioxidant activities in comparison to those of heartwood and leaf extracts. The heartwood extracts have the highest tyrosinase inhibitory activity. 9-octadecanoic acid ethyl ester, hexadecanoic acid and lupeol were the principal phytoconstituents of BE and HE as important bioactive components in the concinna extracts. GRAPHICAL ABSTRACT