Deveci, E.Tel-Çayan, G.Yılmaz Altınok, B.2026-02-102026-02-1020260970-4078https://doi.org/10.1007/s42535-025-01617-zhttps://hdl.handle.net/20.500.13091/13001Cinchona species has been used as the only effective antimalarial drug in traditional medicine since the 17th century, but studies are still limited. This study involved analyzing and identifying chemical compounds by HPLC of Cinchona pubescens Vahl. stem bark extracts, and evaluating their antioxidant activities by DPPH• free radical scavenging, ABTS•+ cation radical scavenging, metal chelating, and phosphomolybdenum reducing assays and cytotoxicity on HT-29, HepG2, HeLa, HEK-293 and THLE-2 cell lines by Alamar blue assay. p-Hydroxybenzoic acid was the compound with the highest concentration among the studied compounds and was found at much higher levels in the methanol extract (40.06 mg/g) than in the water extract (9.29 mg/g). The methanol (IC<inf>50</inf>: 12.04 µg/mL) and water (IC<inf>50</inf>: 18.95 µg/mL) extracts displayed higher ABTS•+ cation radical scavenging activity than α-tocopherol (IC<inf>50</inf>: 38.45 µg/mL). DPPH• free radical scavenging activity of the methanol extract (IC<inf>50</inf>: 14.86 µg/mL) was also determined to be higher than both α-tocopherol (IC<inf>50</inf>: 37.15 µg/mL) and BHA (IC<inf>50</inf>: 19.80 µg/mL). The highest cytotoxic activity was determined in the methanol extract on HT-29 (IC<inf>50</inf>: 69.99 µg/mL), HepG2 (IC<inf>50</inf>: 146.10 µg/mL) and HeLa (IC<inf>50</inf>: 57.99 µg/mL) cell lines. These results reveal that C. pubescens stem bark has potential not only in malaria treatment but also as a source of different drug discovery and development with the chemical compound content defined here. © The Author(s) under exclusive licence to Society for Plant Research 2026.eninfo:eu-repo/semantics/closedAccessAntioxidant ActivityChemical CompoundsCinchona Pubescens Vahl. Stem BarkCytotoxic ActivityHPLCArticle10.1007/s42535-025-01617-z2-s2.0-105028629180