Cytotoxic Potential of Marine-Derived Fungi Isolated from Sponges and Brown Algae of Mauritius

Marine fungi associated with sponges and brown algae are promising sources of pharmacologically active compounds. This study investigated the cytotoxic potential and metabolomic profiles of fungal strains isolated from the marine environment of Mauritius. Among the twenty extracts screened, the mycelium extracts were more cytotoxic than the broth extracts. Four extracts demonstrated the most potent activity: Aspergillus chevalieri (F2M), Aspergillus ochraceus (F25M) and Biatriospora sp. (F34M, F34B). The algal endophyte Aspergillus chevalieri (F2M) mycelium extract displayed an IC₅₀ of 14.27 ± 1.22 µg/mL after 24 h against HepG2 cells. The sponge-associated fungi Aspergillus ochraceus (F25M) showed promising cytotoxic activities against HepG2 cells (IC₅₀ of 8.775 ± 0.78 µg/mL) after 24 h of treatment, with a selectivity index of 2.27, and had the lowest IC₅₀ (2.49 ± 0.60 µg/mL after 24 h; 7.14 ± 3.14 µg/mL after 48 h) against FLO-1 cells, also reducing tumor spheroid growth and integrity during the first four hours. All four extracts increased the intracellular ROS production, but only the mycelium extract of A. chevalieri (F2M) significantly increased superoxide dismutase (SOD) and catalase (CAT) activity. Metabolomic profiling identified diverse compound classes, including alkaloids, terpenoids, amino acids, anthraquinones and coumarins. The findings revealed that the marine fungi from Mauritius are promising sources of cytotoxic metabolites that require purification and subsequent confirmation and mechanistic studies.