Antimicrobial, Cytotoxic, and α-Glucosidase Inhibitory Potentials Using the One Strain Many Compounds Technique for Red Sea Soft Corals Associated Fungi’ Secondary Metabolites and Chemical Composition Correlations

Abstract

Aspergillus unguis SPMD-EGY (A. unguis) and Aspergillus sp. 2C1-EGY (Aspergillus sp.) were isolated from the soft corals Sinularia and Lobophyton sp in the Hurghada coast, Red Sea, Egypt. One strain many compounds (OSMAC) was applied to trigger fungal silent biosynthetic genes. The results revealed that the A. unguis static filtrate extracts (St F) of all tested media exhibited the highest antimicrobial activity (inhibition zones 18.5-30.5 mm) against S. aureus, P. aeruginosa, and C. albicans. The A. unguis shake cell extracts of media A and C exhibited the highest α-glucosidase inhibitory activity (Sh Cell, 78 and 82 %). A high degree of acetylcholinesterase enzyme inhibition was obtained from A. unguis (Sh F, 61-66 %) shake filtrate extracts. The A. unguis extracts (A St F and D St Cell) demonstrated the highest cytotoxic activity against cancer cells, namely, HepG2, MCF-7, and HCT-116 (%I: 62-95; IC50: 7.9-90.8 µg/mL). The A. unguis extracts (A St F&D St F) exhibited high cytotoxic activities against HCT116 cancer spheroids compared with cisplatin (42.2 % and 51 %, respectively, vs 32.6 % for cisplatin). The biological activities of the extracts were due to the presence of various secondary metabolites detected by GC/MS analysis. Further pharmacological studies may lead to the isolation of new antitumor compounds besides the prospective antimicrobial and α-glucosidase inhibition capacity of the active extracts.