Characterization of key compounds and biological screening of Salvia sclareopsis Bornm

Abstract

Research on the phytochemical and biological activities of Salvia sclareopsis Bornm is limited. This study aimed to evaluate the antioxidant properties of a methanol extract and various fractions (water, ethyl acetate, and n-hexane) derived from the aerial parts of S. sclareopsis for their antioxidant properties using DPPH and FRAP assays, as well as their inhibitory effects on enzymes associated with diabetes mellitus, specifically α-glycosidase and α-amylase. Furthermore, the total phenolic content (TPC), total flavonoid content (TFC), and antibacterial activity of the plant extract and its fractions were assessed. The polyphenolic composition of the most effective fraction, (i.e. the water fraction) was analyzed using LC–ESI–MS. The findings revealed that the water fraction exhibited the highest TPC and TFC, measuring 314.24 ± 1.5 mg GAE eq. /g dry extract and 462.62 ± 3.1 mg rutin eq. /g dry extract, respectively. Additionally, this fraction demonstrated significant antioxidant activity in both DPPH (IC₅₀ = 0.0177 mg/ml) and FRAP (0.614 ± 0.010 mM Fe²⁺) assays, outperforming the standard Tolox in the FRAP assay. The water and ethyl acetate fractions also exhibited the most substantial inhibition of α-amylase and α-glucosidase. Analysis of phenolic compounds via LC–ESI–MS identified rosmarinic acid as the predominant phenolic compound in the water fraction, along with the identification of several phenolic compounds from the Salvia genus and Lamiaceae family for the first time in this study. Collectively, these results suggested that the plant extract possesses significant antioxidant and antidiabetic properties.