Phenolic composition and biological activities of Ornithogalum sigmoideum Freyn & Sint. from Black Sea Region

Ornithogalum sigmoideum Freyn & Sint., locally known as Sakarca, is a wild edible plant that grows naturally in the Eastern Black Sea Region of Türkiye and is traditionally consumed as a seasonal food, typically after cooking in accordance with local preparation practices. In this study, the aerial, flower, and bulb parts of the plant were investigated to characterize their phenolic composition, antioxidant capacity, and antiproliferative properties. Total phenolic content (TPC) and total flavonoid content (TFC) were determined using standard spectrophotometric methods, while individual phenolic constituents, including protocatechuic acid and flavonoids such as chrysin, were identified by HPLC-PDA. Antioxidant activity was assessed by FRAP, CUPRAC, and DPPH assays to evaluate reducing power and radical scavenging capacity. The aerial parts exhibited the highest TPC and TFC values, whereas the flower extract, characterized by relatively higher chrysin content, demonstrated stronger reducing activity in the FRAP and CUPRAC assays together with consistent DPPH scavenging behavior. Antiproliferative activity was assessed in HepG2, DU145, and HT-29 cancer cell lines, with CRL-1790 used as the normal control. The aerial extract produced measurable but limited growth inhibition (49–59%) in cancer cells at the highest tested concentration, while exerting comparatively low effects on normal cells. The flower and bulb extracts showed weaker antiproliferative activity overall. Collectively, these findings indicate that O. sigmoideum possesses noteworthy antioxidant potential and limited antiproliferative effects. Although not a potent cytotoxic agent, its phenolic profile supports its potential relevance as a source of bioactive compounds for functional food and nutraceutical applications.