Biological activities and phytochemical investigation of some Sideritis species

One of the most generally used plants for herbal tea is Sideritis L. species (Lamiaceae) which is commonly grown in the Mediterranean region and represented by 46 species and 53 taxa in Türkiye. Sideritis species are widely used in Türkiye due to their antispasmodic, antirheumatic, anti-inflammatory, and diuretic activities. In the present research, the effects against oxidative stress, and enzyme activitiy, as well as chemical compositions of the water and methanol extracts of seven Sideritis species (S. bilgeriana P.H. Davis), S. brevidens P.H. Davis, S. cilicica Boiss. & Balansa, S. erythrantha Boiss. & Heldr., subsp. cedretorum P. H. Davis, S. hololeuca Boiss. & Heldr., S. libanotica Labill. subsp. linearis (Benth.) Bornm., and S. libanotica Labill. subsp. violascens P. H. Davis.). Its main objective was to assess the suppression of five enzymes, tyrosinase, α-glucosidase, α-amylase, acetylcholinesterase (AChE), and butyrylcholinesterase, for the water and methanol extracts of seven different Sideritis species. The extracts were also assessed for antioxidant effects using various spectrophotometric methods involving DPPH,ABTS·+, and iron chelating, as well as the determination of total phenol and flavonoid amounts. As for the phytochemical investigation on Sideritis species, the phenolic compounds of the extracts were determined by LC-MS/MS analysis. Because of the LC-MS/MS analysis, Hierarchical Cluster Analysis was performed on four major components: quinic acid, chlorogenic acid, fumaric acid, and acacetin in the present work. As a result, our research indicates that Sideritis species, particularly S. cilicica, S. erythrantha, and S. libanotica subsp. linearis, deserve to be examined afterwards for their active secondary metabolites, which are thought to be responsible for their potential biological activities. Furthermore, the composition of extracts of Sideritis species was statistically analysed using the principal component.