LC–ESI–MS/MS targeted phenolic profiling, antioxidant, anticholinesterase and cytotoxic activities of ethyl acetate and <i>n</i> -butanol fractions of <i>Hypericum pubescens</i> Boiss

Abstract

This study reports a targeted phenolic profiling of the ethyl acetate (EAFHP) and <i>n</i>-butanol (BFHP) fractions of <i>Hypericum pubescens</i> Boiss. A validated LC-ESI-MS/MS method, limited to simple phenolic acids and flavonoids rather than a comprehensive profiling of all phytochemical classes present in the specie, allowed the identification and quantification of 26 and 16 compounds in EAFHP and BFHP, respectively. Quercitrin, isoquercitrin and chlorogenic acid were the major compounds of both fractions whereas epicatechin, gentisic acid and quercetin were mainly found in EAFHP. The EAFHP (IC₅₀:3.13 ± 0.12 µg/mL) and the BFHP (IC₅₀:5.22 ± 0.74 µg/mL) exhibited strong antioxidant activity in the DPPH assay. Additionally, EAFHP (IC₅₀:16.10 ± 0.51 µg/mL) and BFHP (IC₅₀:24.36 ± 0.22 µg/mL) exhibited a higher BChE inhibitory effect than galantamine (IC₅₀:46.48 ± 0.18 µg/mL). Cytotoxic test of both fractions, evaluated against four cancer cell lines (colorectal Caco-2, ovarian SKOV-3, glioblastoma T98G), as well as normal fibroblasts (L929), indicated that neither cancerous normal cells exhibited significant cytotoxic responses.