Chemical characterization and antioxidant potential of Arthrospira sp., Thalassiosira sp., and Raphidonema sp.

Microalgae are emerging as valuable sources of bioactive compounds. This study evaluates hexane extracts from Thalassiosira sp. and Raphidonema sp., and Arthrospira sp., for their bioactive potential. Saturated fatty acids predominated in Arthrospira sp. and Thalassiosira sp. while Raphidonema was rich in polyunsaturated fatty acids. Carotenoids, such as carotenes and xanthophylls, were abundant in Arthrospira sp., while Thalassiosira sp. contained chlorophylls and fucoxanthin derivatives, and Raphidonema sp. showed high levels of chlorophylls and xanthophylls. Antioxidant assays revealed up to 70 % radical scavenging activity, 60 % iron chelation, and up to 67 (μM) ferric-reducing power. Dose-dependent protective effects were observed in Schizosaccharomyces pombe and HepG2 cells, with viability improvements up to 50 %, indicating their potential as antioxidant-rich ingredients for functional foods, promoting health and disease prevention. This study enhances our understanding of Thalassiosira sp. and Raphidonema sp. while underscoring the promising applications of microalgae extracts in functional foods.