Hyrtios sp.-associated Cladosporium sp. UR3 as a potential source of antiproliferative metabolites.

Background: Sponge-associated microorganisms are promising resources for the production of bioactive compounds with cytotoxic potential. The main goal of our study is to isolate the fungal endophytes from the Red Sea sponge Hyrtios sp. followed by investigating their cytotoxicity against number of cell lines.

Results: The fungal strain UR3 was isolated from the Red Sea sponge using Sabouraud dextrose agar media. It was identified based on partial 18 S rRNA gene and ITS sequence analyses as Cladosporium sp. UR3. The in vitro cytotoxic potential of the ethyl acetate extract of the fungal isolate was evaluated using MTT assay against three cancer cell lines: CACO2, MCF7, and HEPG2. Metabolomics profiling of the obtained ethyl acetate extract using LC-HR-ESI-MS, along with molecular docking and pharmacological network studies for the dereplicated compounds were performed to explore its chemical profile and the possible cytotoxic mechanism of the sponge-associated fungi.

Conclusion: These results highlighted the role of sponge-associated fungi as a fruitful resource for the discovery of cytotoxic metabolites.