Assessment of in vitro antitumoral and antimicrobial activities of marine algae harvested from the eastern Mediterranean sea

Antitumoral activities of five algal extracts obtained from the marine algae Scytosiphon lomentaria, Padina pavonica, Cystoseira mediterranea (Phaeophyceae), Hypnea musciformis and Spyridia filamentosa (Rhodophyta) were assessed against the human breast adenocarcinoma cell line MCF‐7 and the human prostate carcinoma epithelium like cell lines DU 145, LNCaP, PC3 using the cytotoxic assay, in vitro. The crude extract of S. filamentosa showed strong cytotoxic activity against the DU-145 cell line, and it showed less than 10% cell viability after treatment. Antimicrobial activities of the crude extracts of algae (with the exception of H. musciformis) were also tested by disc diffusion assay against three Gram positive and five Gram negative bacterial strains and against the yeast pathogen Candida albicans. Among the extraxts, S. lomentaria extract (prepared with methanol) inhibited highly Gram negative bacterium Salmonella typhimurium growth while C. albicans growth was only inhibited by C. mediterrranea extract.