Phytochemical profile, antioxidant, antiproliferative, and enzyme inhibition-docking analyses of Salvia ekimiana Celep & Doğan

S Afr J Bot. 2022 May:146:36-47. doi: 10.1016/j.sajb.2021.09.033. Epub 2021 Oct 9.

Abstract

Salvia ekimiana Celep & Doğan is an endemic species of Turkey. To our knowledge, the number of studies on biological activities and phytochemical profiling of this plant is quite limited. Therefore, this study aimed to analyze its activities and phytochemical content in detail. The qualitative-quantitative compositions were determined via spectrophotometric and chromatographic (LC-MS/MS and HPLC) techniques. 1,1-Diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2'-Azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) radical scavenging and ascorbate-iron (III)-catalyzed phospholipid peroxidation experiments were performed to measure antioxidant capacity. Hyaluronidase, collagenase, and elastase enzyme inhibition tests were determined in vitro using a spectrophotometer. Antiproliferative activity was evaluated in human lung cancer (A549) and human breast cancer (MCF7) cells. The murine fibroblast (L929) cell line was used as a normal control cell. While the subextract rich in phenolic compounds was n-butanol extract, rosmarinic acid was defined as the main secondary metabolite. The highest antioxidant activity observed for the n-butanol subextract included the following: DPPH EC50: 0.08±0.00 mg/mL, TEAC/ABTS: 2.19±0.09 mmol/L Trolox, MDA EC50: 0.42±0.03 mg/mL. The methanolic extract, the ethyl acetate, and n-butanol subextracts displayed significant inhibitory activity on collagenase, while the other subextracts did not show any inhibitory activity on hyaluronidase and elastase. Due to strong interactions with their active sites, molecular docking showed luteolin 7-glucuronide, apigenin 7-glucuronide, and luteolin 5-glucoside had the highest binding affinity with target enzymes. The chloroform subextract showed significant cytotoxicity in all cell lines. These novel results revealed that S. ekimiana has strong antioxidant, collagenase enzyme inhibitory, and cytotoxic potential.

Keywords: Antioxidant; Enzyme inhibition; LC-MS/MS; Molecular docking, Cytotoxicity; Salvia ekimiana.