Phytochemical Profiling and Multi‐Target Enzyme Inhibition Potential of Castanea sativa Mill. Leaf Extract: Integrated Experimental and Molecular Docking Studies

ABSTRACT Recent studies on Castanea sativa (C. sativa) leaves have primarily focused on limited phytochemical screening or single‐target biological assays, leaving gaps in the comprehensive evaluation of their bioactive potential. This study aimed to systematically investigate the phytochemical composition, antioxidant capacity, multi‐enzyme inhibitory activity, and molecular interaction profile of the methanolic extract of C. sativa leaves. UPLC‐MS/MS analysis identified ellagic acid, chlorogenic acid, and quinic acid as major constituents, supported by high phenolic (190.556 mg GAE/g) and flavonoid (50.430 mg QE/g) contents. The extract exhibited strong antioxidant properties, particularly in cupric reducing antioxidant capacity (CUPRAC) and 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS • + ) assays, demonstrating activities comparable to those of standard antioxidants. Notably, potent inhibitory effects were observed against carbonic anhydrase (CA) I–II, acetylcholinesterase (AChE) ( IC 50 = 0.0017 µg/mL), and α‐glycosidase ( IC 50 = 0.0063 µg/mL), with AChE inhibition approaching that of tacrine and α‐glycosidase inhibition surpassing acarbose by 2.3‐fold. Molecular docking analyses further revealed specific interactions between major phytochemicals and enzyme active sites, supporting the in vitro findings. These results demonstrate that C. sativa leaves represent a promising, sustainable source of bioactive molecules with strong antioxidant and multi‐target enzyme inhibition potential, suggesting possible applications in the management of oxidative stress‐related conditions, neurodegenerative diseases, and metabolic disorders such as diabetes.