Enhancing lutein concentration in an indigenous microalgal strain through salinity, light intensity and nutrient concentrations and evaluation of its anticancer potential

The search for new approaches for treating cancer is an urgent need and microalgae have recently shown to be an underestimated source of biocompounds. In this work, the anticancer potential of an indigenous Chlorella-like microalgal strain was investigated by optimizing its lutein content using a Design of Experiment (DoE) approach. Several parameters were assessed such as NaCl, phosphate and nitrate concentration in combination with light intensity. Sodium chloride and nitrate concentrations showed antagonist effects on lutein accumulation. The crude methanolic extracts of the obtained microalgal cultures, containing 2.15 ± 0.12, 1.70 ± 0.17 and of 0.68 ± 0.09 μg mg⁻¹ of lutein, were tested on cancer cell lines, revealing a dosage-dependent antiproliferative effect on melanoma A2058 cells. The extracts' fractions containing lutein exhibited similar effects, likely due to a concerted action of multiple substances, with lutein being one of the main contributors. The described approach, which combined bioprocess optimization and assessment of anticancer proprieties, showed a significant potential in the discovery of new bioactives for pharmaceutics.