Investigation of total phenolic and flavonoid content of Salvia willeana (Holmboe) Hedge, an endemic plant of Cyprus, and screening of its antioxidant and cholinesterase inhibitory properties

Abstract

Salvia willeana (Holmboe) Hedge is an endemic plant of Cyprus island. There have been limited number of studies on the plant, beside some analytical studies on its chemical content. This study aimed to investigate total phenolic and flavonoid content of the plant concomitant to some pharmacological activity screening studies including antioxidant and cholinesterase inhibition. Following obtaining different organic solvent and aqueous extracts of the dried aerial parts of the plant, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric-reducing antioxidant power (FRAP), iron-chelation capacity assays, and modified Ellman's method were employed for screening antioxidant and cholinesterase inhibition studies. S. willeana extracts displayed low to moderate activities in cholinesterase inhibition assays. The ethyl acetate extracts of the leaves and the methanol extracts of the stem part of the plant displayed the highest acetylcholinesterase inhibitory potential (i.e., 28.95 +/- 0.035%, and 24.01 +/- 0.007%, respectively), while the highest butyrylcholinesterase inhibitory potential was obtained in aqueous extracts of the stem at 0.5 mg/mL (i.e., 29.10 +/- 0.005%). The methanol extracts of the leaves and flower of the plant provided the highest antioxidant activity in DPPH radical scavenging activity (67.94 +/- 0.003%, and 45.07 +/- 0.001%, respectively) at 0.5 mg/mL concentration. Ferrous iron chelating activity of the extracts were found weak in general. The plant was found rich in terms of its flavonoid and phenolic contents as shown in the ethyl acetate and methanol extracts of the leaves (i.e., 547.55 +/- 3.12 mg/g, and 300.24 +/- 1.23 mg/g extract, respectively).