Multi-spectroscopic and in silico approaches reveal the α-amylase and α-glucosidase inhibitory mechanism of anacardic acids and their effects on advanced glycation end products

Anacardic acids (AAs) are a class of alkyl phenols widely distributed in the Anacardiaceae family and known for their diverse biological properties. However, their potential against type 2 diabetes mellitus (T2DM) has never been thoroughly investigated. In this study, a fraction isolated from a Pistacia vera shell extract, enriched in AAs, exhibited potent inhibitory activity against α-amylase (α-Amy) and α-glucosidase (α-Glu). Pure (15:0)-AA and (17:1)-AA also acted as strong inhibitors of both enzymes, displaying IC₅₀ values significantly lower than those of the marketed anti-diabetic drug acarbose. Kinetic and molecular docking analyses identified both AAs as competitive α-Amy and α-Glu inhibitors that interact with the catalytic sites via non-covalent interactions. Fluorescence measurements revealed dynamic quenching upon AA-enzyme binding, while FT-IR and dynamic light scattering analyses demonstrated AA-induced conformational rearrangements and increased size distribution.Beyond their hypoglycaemic potential, (15:0)-AA and (17:1)-AA strongly inhibited the formation of pathogenic advanced glycation end products (AGEs). AAs efficiently reduced fluorescent AGE formation in three distinct glycation models and effectively protected human serum albumin (HSA) from glycation-induced structural alterations, including exposure of hydrophobic domains and amyloid aggregation. Notably, AAs retained substantial antiglycation activity after simulated gastrointestinal digestion.Overall, this work provides the first detailed insights into the hypoglycemic and antiglycation properties of AAs, supporting their potential application as multifunctional natural agents for T2DM management.