Dose-dependent cytotoxic and proliferative effects of Microcystis aeruginosa extract and its fractions on human endothelial cells

Microcystis aeruginosa, which spreads in five continents in the world and reported in drinking water resources in 257 countries, is a dangerous microalgae for human and animal health due to its toxins. The aim of current study was to evaluate the effects of M. aeruginosa extract and its chromatographically separated fractions on human endothelial cells. In this context, crude extract was prepared from M. aeruginosa cultured in BG-11 medium, and it was fractionated by an optimized HPLC method. Algae extract and its six fractions were then analyzed for their cytotoxic effects on ECV304 using MTT assay. The results revealed that algae extract inhibited ECV304 cells by around 72%, a higher percentage than all fractions. The most toxic fraction was the first fraction, which inhibited the cells by 55%. Other fractions, except the third one, were also toxic with 35-40% inhibition percentages. Third fraction and certain doses of some fractions showed proliferative activity on ECV304 cells. These results showed that the activities of the total extract and its fractions in promoting or inhibiting cell proliferation varied depending on not only the content but also the treatment dose.