Antiproliferative potential of Microcystis aeruginosa bioactive compounds against gastrointestinal cancer cells via p53-mediated apoptosis.

Microcystis aeruginosa, a photosynthetic cyanobacterium, produces diverse secondary metabolites with notable anticancer potential. This study evaluated the in vitro effects of its metabolites on two gastrointestinal cancer cell lines, AGS and SW480. Strain identification was confirmed through morphological and molecular analyses, while GC-MS profiling revealed a variety of bioactive fatty acid esters such as E-11-Hexadecenoic acid, ethyl ester, Linoleic acid, ethyl ester, Hexadecadienoic acid, methyl ester, and Palmitic acid ethyl ester. High chlorophyll a content (22.42 ug/g fresh weight (FW)), Total phenolic (9.42 ug/g FW), flavonoid (15.86 ug/g FW), and anthocyanin (6.42 ug/g FW) contents indicated strong photosynthetic activity and metabolic richness. Cytotoxicity assays demonstrated significant antiproliferative effects, with IC50 values of 365-536 and 244-409 µg/mL in AGS and SW480 cells after 24 and 48 h respectively. Western blot analysis further revealed apoptosis-related molecular alterations, including Bax upregulation, Bcl-2 suppression, and activation of p53 in both cell lines.