Antioxidant capacity, total phenolic content, and in vitro cytotoxic and oxidative effects of the methanol extract of Dunaliella sp. against breast cancer cells

Microalgae are rich sources of essential biomolecules, including proteins, pigments, and a diverse array of secondary metabolites such as carotenoids, polyphenols, sterols, polyunsaturated fatty acids, and polysaccharides, which they secrete at various growth stages. Owing to this property, microalgae are gaining significant research interest as natural product producers with cell-protective potential and minimal or no side effects compared to synthetic drugs. This study explores the potential of the methanol extract of Dunaliella sp. (mD) as an in vitro therapeutic agent for breast cancer. The antioxidant activity and total phenolic content of mD were assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Folin-Ciocalteu methods. Additionally, its cytotoxic and oxidative effects were evaluated in vitro. mD exhibited a radical scavenging activity (RSA) of 40.27, 1.8% below the expected value, and a total phenolic content of 25.4 mg GAE/g dry extract. The MTT cell viability assay further indicated that this microalgal extract has cytotoxic potential against breast cancer cells. The IC50 values were 768 and 728 µg/mL for MCF-7 and MDA-MB-231 cells, respectively. While the use of H2O2 alone led to an increase in ROS production in the cells, treatment with mD reduced ROS production. According to the current study, mD could be an interesting candidate for the synthesis of drugs and nutraceuticals for the treatment of breast cancer.