Polarity-Guided Extraction of Crithmum maritimum L.: Phenolic Profiling, Selective Anticancer Activity in AR42J and HT-29 Cells, and Antimicrobial Effects

Crithmum maritimum L. (sea fennel) (C. maritimum) is a halophyte plant rich in phenolic compounds, flavonoids, essential oils, and other secondary metabolites. Despite its traditional medicinal use, no study has comprehensively compared multiple solvent extracts of C. maritimum across diverse cancer and non-cancerous cell lines, leaving its solvent-dependent cytotoxic potential and selectivity largely uncharacterized. Therefore, this study aimed to investigate the biochemical composition of different extracts of C. maritimum (obtained using ethanol, ethyl acetate, and distilled water) and the cytotoxic effects of these extracts on pancreatic cancer (AR42J) and colon cancer (HT-29) cell lines, compared to a healthy cell line (ARPE19). Additionally, we determined the extracts’ antimicrobial activity against various bacteria and a fungal species. Ethanol yielded the richest and most diverse phenolic profile in C. maritimum, while ethyl acetate extracted moderate levels, and the aqueous extract contained only minor amounts, demonstrating that solvent polarity strongly influences the recovery of bioactive phenolic compounds. Ethanol extracts showed the strongest and most consistent cytotoxicity across normal and cancer cells, while ethyl acetate extracts exhibited high and selective activity on cancer cells. Water extract demonstrated selective cytotoxic effects during prolonged incubations. The extracts displayed solvent-dependent antimicrobial activity, with ethanol and ethyl acetate fractions showing potent inhibition, particularly against Yersinia pseudotuberculosis, Candida albicans, and Staphylococcus aureus. In contrast, the water extract showed no activity. Overall, the findings indicate that C. maritimum contains bioactive constituents with selective cytotoxicity against cancer cells and microorganisms, depending on the extraction solvent, supporting its potential as a source of natural anticancer and antimicrobial agents.