Exploring the bioactive compounds and biological properties of three Sideritis species (S. lanata, S. rubriflora, S. scardica) from Türkiye

Due to their pharmacological activities, the Sideritis species and herbal teas have attracted great interest. The present work evaluated the chemical profile, antioxidant capacity, and enzyme inhibition effect of Sideritis lanata, S. rubriflora, and S. scardica. The results showed that the methanol extract of S. scardica possessed the highest total phenolic content (66.18 mg GAE/g). The methanol extract of S. rubriflora contained the highest total flavonoid content (100.16 mg RE/g). In the tested extracts, several phenolic compounds were detected, including catechin, chlorogenic acid, benzoic acid, luteolin, hesperidin, and rutin. The main component in the tested extracts was chlorogenic acid. The methanol extract of S. scardica demonstrated the highest DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging (160.20 mg TE/g) and metal chelating activity (34.67 mg EDTAE/g). The methanol extract of S. rubriflora exhibited the most potent reducing power abilities in CUPRAC (Cupric reducing antioxidant capacity) (353.82 mg TE/g), FRAP (ferric reducing antioxidant power) (255.50 mg TE/g) assays. The ethyl acetate and methanol extracts exhibited a significant inhibition against all tested enzymes. The methanol extract of S. lanata had the highest anti-tyrosinase activity (54.18 mg KAE/g). The highest activity against AChE (acetylcholinesterase) (1.03 mg GALAE/g) and BChE (butyrylcholinesterase) (19.63 mg GALAE/g) was provided by the ethyl acetate extract of S. scardica. In α-amylase and α-glucosidase assays, the ethyl acetate and methanol extracts showed higher activity than water extracts in three Sideritis species. The presented results suggest that the tested Sideritis species could be considered as potential sources of bioactive agents for pharmacological, cosmetics, and food applications.