Investigation of phenolic content, antioxidant and α-glucosidase enzyme inhibition activities of Linum mucronatum subsp. Bertol armenum (Bordz.) P.H.Davis

Plants have compounds such as phenols, flavonoids and carotenoids that potentially show high antioxidant activity. Antioxidant defense mechanisms in humans have an important place in the prevention and treatment of oxidative stress-induced diseases. In the study, the leaf and flower parts of Linum mucronatum subsp. armenum were extracted using five solvents of different polarity. The antioxidant activities of these extracts were measured using six antioxidant activity determination methods (DPPH radical scavenging, Iron (III) Reducing/Antioxidant Power (FRAP), Copper (II) Reducing Antioxidant Activity (CUPRAC), ABTS radical scavenging, Total Phenolic Content and Total Flavonoid Content). While, ethanol extract of leaf part of the plant for the DPPH, FRAP and CUPRAC tests showed the highest antioxidant activity, the methanol extract showed the highest activity for the flower part. The highest activity values for ABTS test was measured in acetone extract in both flower (SC50=0.287 mg/ml) and leaf (SC50=0.163 mg/ml). Lowest activity values for all tests were determined in hexane extracts. Phenolic compounds of the plant were analyzed using LC-MS/MS. These phenolics are protecatechuic acid, caffeic acid, vanillin, p-coumaric acid, salicylic acid, p-OH benzoic acid, rutin, quercetin and kaempferol. The leaf and flower parts showed α-glucosidase enzyme inhibition effect. It was determined that the leaf part of the plant (IC50=4.533 mg/ml) showed higher enzyme inhibition than the flower (IC50=6.096 mg/ml). As a result, it was determined that the subspecies, which has a natural distribution in Gümüşhane, showed biological activity. The results obtained will contribute to the studies on the biological activity of the plant.