Comparative Study of Antidiabetic and Antioxidant Properties of <i>Viburnum opulus</i> L. and <i>Viburnum lantana</i> L. (Viburnaceae): LC–MS/MS Profiling of Phenolic Compounds

This study aimed to evaluate antidiabetic and antioxidant properties of Viburnum opulus and Viburnum lantana aerial parts methanolic extracts, alongside identification of their bioactive constituents using LC-MS/MS analysis. LC-MS/MS analysis revealed that V. lantana leaves had the highest total polyphenol content (78.955 µg/g dry extract), followed by V. opulus twigs (67.203 µg/g dry extract), with chlorogenic acid being the predominant compound in both species. Antidiabetic potential was assessed through inhibition of α-amylase and α-glucosidase enzymes, while antioxidant activity was determined via ABTS and DPPH radical scavenging assays. In the α-glucosidase inhibition assay, methanolic extracts from leaves, fine branches, and fruits of both species exhibited greater inhibitory activity than the positive control, acarbose, with the leaf extract of V. lantana displaying the strongest inhibition. Regarding antioxidant capacity, V. lantana leaf extracts demonstrated the highest efficacy, outperforming α-tocopherol and Trolox. Notably, in the ABTS radical scavenging assay, V. lantana leaf extracts exhibited superior inhibitory effects compared to α-tocopherol and Trolox.