Metabolomic profiling and biological evaluations of Spongia irregularis-associated actinomycetes supported by multivariate statistical analysis

Aim
Metabolomic analysis using LC–HRESIMS of 12 extracts of Spongia irregularis-associated actinomycetes for dereplication purposes in addition to evaluation of cytotoxic and antiviral activities of the extracts.

Methods and results
In this study, three actinomycetes belonging to the genera Micromonospora, Streptomyces, and Rhodococcus were recovered from the marine sponge Spongia irregularis. Applying the OSMAC approach, each strain was fermented on four different media, resulting in 12 extracts. All extracts were subjected to metabolomic analysis using LC–HRESIMS for dereplication purposes. Multivariate data statistical analysis was carried out for the differentiation between extracts. Additionally, the cytotoxic and anti-hepatitis C virus (anti-HCV) potentials of extracts were evaluated. Most of extracts showed strong to moderate cytotoxicity effects against HepG-2, CACO-2, and MCF-7 cell lines with a general IC50 range of 2.8–8.9 µg/ml. Moreover, the extracts of Micromonospora sp. UR44 using ISP2 and OLIGO media and Streptomyces sp. UR32 using ISP2 medium exhibited anti-HCV activity with IC50 of 4.5 ± 0.22, 3.8 ± 0.18, and 5.7 ± 0.15 µM, respectively.

Conclusion
Metabolomic analysis of 12 extracts of S. irregularis-associated actinomycetes led to the identification of a large number of secondary metabolites. Morever, investigation of cytotoxic and antiviral activities of the extracts revealed that only three extracts exhibited antiviral activity and seven extracts exhibited cytotoxic activity.