Guzel, Mehmet AliKolac, TurgayMenevse, Irem NurDundar, MuhammedZengin, RukiyeGuzel, AbdussamatUgur, Yilmaz2026-04-042026-04-0420262045-2322https://doi.org/10.1038/s41598-026-36793-8https://hdl.handle.net/11616/109319Hypericum perforatum L. (St. John's wort) is a medicinal plant known for its diverse secondary metabolites and pharmacological potential. This study provides a comprehensive evaluation of the phytochemical composition and bioactivities of methanolic extracts from wild H. perforatum. LC-MS/MS analysis identified 36 compounds, including phenolic acids (chlorogenic acid, protocatechuic acid) and flavonoids (rutin, isoquercitrin, quercetin), with the first-time detection of genkwanin, vicenin-2, schaftoside, and afzelin, to the best of our knowledge. The extract demonstrated significant antioxidant activity, with a total phenolic content of 203.04 mg GAE/g DW and strong radical scavenging activity in DPPH (544.78 mg TE/g DW) and ABTS (312.15 mg TE/g DW) assays. In vitro assays showed marked cytotoxicity across multiple cancer cell lines, with IC50 values as low as 3.57 & micro;g/mL in A549 cells, indicating stronger activity compared to cisplatin. Flow cytometric analysis revealed substantial apoptosis induction (up to 53.67% in A549 cells) and G0/G1 cell cycle arrest (76.37% in A549). The extract also exhibited moderate antibacterial activity against E. coli and S. aureus, but no activity against P. aeruginosa or Candida species. These results position H. perforatum as a rich source of bioactive compounds with antioxidant, anticancer, and antimicrobial potential, and suggest further research into its therapeutic applications.eninfo:eu-repo/semantics/openAccessAntioxidant activityApoptosisCell cycle arrestCytotoxicityHypericum perforatumLC-MS/MSPhytochemical compositionArticle1614159317710.1038/s41598-026-36793-82-s2.0-105030019397N/AWOS:001691505300006Q10009-0004-3497-83970000-0002-9040-4249