Total phenolic compounds and antioxidant potential of Salvia nydeggeri Hub.-Mor.: An endemic species of southwestern Türkiye

The genus Salvia constitutes one of the most prominent groups of medicinal and aromatic plants, with documented usage tracing back to antiquity. Salvia nydeggeri is an endemic species distributed in southwestern Türkiye. In this study, the antioxidant activity of this species was investigated. S. nydeggeri was collected from natural populations in Elmalı, Antalya. The samples were extracted using solvents of different polarities (n-hexane, chloroform, ethanol, methanol, and water). Using these extracts, the total phenolic and total flavonoid content, as well as the DPPH antioxidant capacity of S. nydeggeri, were assessed. The total phenolic content was evaluated using the Folin-Ciocalteu reagent with a gallic acid standard curve. The highest phenolic content was found in the water extract (110.489 ± 5.07 mg GAE/g) and the methanol extract (109.74 ± 2.25 mg GAE/g). The total flavonoid content in the extracts was determined using calibration curves for rutin hydrate and quercetin. The highest flavonoid content was found in the methanol extract (151.22 ± 2.64 mg RU/g and 96.00 ± 1.71 mg QE/g) and the chloroform extract (150.32 ± 3.15 mg RU/g and 95.41 ± 2.03 mg QE/g). The antioxidant activity of S. nydeggeri extracts in different solvents was studied using DPPH (1,1-diphenyl-2-picrylhydrazyl). The highest antioxidant capacity was observed in the methanol extract (IC50=12.66 µg/mL) and the water extract (IC50=13.96 µg/mL), while the lowest was in the n-hexane extract (IC50=498.964 µg/mL). This study indicates that S. nydeggeri may be an important potential natural resource for developing pharmaceuticals, cosmetics, and nutraceuticals.