Differential growth inhibition of cancer cell lines and antioxidant activity of extracts of red, brown, and green marine algae

As the use of various anticancer drugs is associated with many undesirable side effects, there is an urgent need for the discovery of new, better, and specific anticancer compounds. Antioxidant and antiproliferative activities as well as effects on cell morphology were investigated for methanol (M), chloroform (C), ethyl acetate (E), and aqueous (A) extracts of Caulerpa peltata, Gelidiella acerosa, Padina gymnospora, and Sargassum wightii using 2,2-diphenyl-1-picrylhydrazyl radical-scavenging, ferrous ion chelation, and resazurin-based growth inhibition (in A549, HCT-15, MG-63, and PC-3 cell lines) assays. A general trend was the greater extraction of phenols and flavonoids by chloroform and ethyl acetate, which showed higher activity in many assays. These non-polar C and E extracts showed higher DPPH radical-scavenging and growth inhibitory activities in A549, HCT-15, and PC-3 cells. However, higher ferrous ion chelation (A extracts) and growth inhibition in MG-63 cells (M and A extracts) were seen for the polar extracts. Furthermore, P. gymnospora and C. peltata emerged as promising sources for antiproliferative agents that could be explored for their own activity and as leads for the development of other compounds.