A multifaceted anti-cancer strategy through apoptosis induction, MMP suppression, and anti-metastatic activity of bioactive pigment–rich lipophilic extracts and their chemical characterization from marine cyanobacteria isolates

Abstract

This study investigated the isolation, chemical characterization, and anti-cancer potential of three cyanobacterial strains: Oscillatoria simplicissima Q1, Oscillatoria acutissima Q2, and Phormidium formosum Q3. Pigment-rich lipophilic extracts were analyzed using GC–MS and FT/IR, revealing the presence of diverse bioactive metabolites, including phytol, squalene, β-sitosterol, and linoleic acid, which are known for their anticancer properties. Biological evaluation demonstrated that all extracts exhibited selective cytotoxic activity against human carcinoma cell lines (A431, A549, and MDA), with high safety toward normal human dermal fibroblast (HSF) cells. The highest activity was observed for the Q3 extract against A549 cells, with an IC₅₀ value of 41.78 μg/mL and a corresponding selectivity index (SI) of 8.16, indicating strong selectivity toward cancer cells. Mechanistically, the observed anticancer activity is attributed to the combined action of key lipophilic metabolites such as phytol (apoptosis induction), β-sitosterol (cell proliferation inhibition), and squalene (oxidative stress modulation), supported by morphological evidence of apoptosis. Furthermore, the extracts significantly inhibited cancer cell migration, with Q3 showing up to 95.34% inhibition after 48 h, and downregulated MMP-2 and MMP-9 gene expression by up to 1.82-fold and 2. 32-fold, respectively. These findings highlight the potential of cyanobacterial pigment-rich lipophilic extracts as promising multi-target anticancer agents.