α-Glucosidase and glycation inhibitory activities of Rumex lunaria leaf extract: a promising plant against hyperglycaemia-related damage

Rumex lunaria L. is a Canarian medicinal plant, belonging to Polygonaceae. The potential antidiabetic activity of the methanolic extract of the leaves was investigated. For this purpose, the inhibition of α-glucosidase and albumin glycation by the extract was studied. Further, the anti-radical activity and the phytochemical composition were detected. The reduction of α-glucosidase activity was significant from 3 µg/mL, while the BSA glycation inhibition started from 100 µg/mL. Moreover, the extract exhibited a significant free-radical scavenger activity. Its phytochemical characterization showed the presence of carotenoids, phenolic and flavonoid compounds, whereas anthraquinones were not detected. C-flavonoid glycosides were identified and quercetin-O-hexoside-O-deoxyhexoside was the most detected (22.67 ± 0.02 mg/g). The findings indicate that the methanolic R. lunaria leaf extract has significant anti-α-glucosidase, anti-radical and anti-glycation activities. This research is the first showing the potential antidiabetic activity of R. lunaria.