Epigenetic Activation of Silent Pathways in Endophytic Aspergillus sp. EGP214 Reveals Porphyrin-Derived Antimicrobial Metabolites Targeting DNA Gyrase: In Vitro and In Silico Evaluation.
Endophytic fungi are a reservoir for cryptic metabolites to discover new bioactive compounds through their research on inactive biosynthetic gene clusters. In this study, Aspergillus sp. EGP214 was used to identify Aspergillus sp. EGP214, which they isolated from Hyoscyamus muticus during their study. The expression of cryptic genes needed stimulation through the use of two epigenetic modifiers, which included trichostatin A as a histone deacetylase inhibitor and 5-aza-2'-deoxycytidine as a DNA methyltransferase inhibitor, during fermentation. GC-MS analysis revealed that both treatments significantly altered the metabolic profiles, leading to the production of several unique compounds absent in the control culture. The treated extracts showed improved antimicrobial, antibiofilm, antioxidant, and DNA gyrase inhibitory effects with trichostatin A, treated cultures demonstrating the strongest activity at IC50 = 2.2 μM against DNA Gyrase-B. The induced metabolites demonstrated permanent strong bonds to bacterial DNA gyrase and HDAC enzymes' active sites according to molecular docking and molecular dynamics simulations. The evaluation of ADMET characteristics and toxicity levels showed moderate lipophilicity, together with minimal systemic toxicity but restricted oral bioavailability. The research shows that epigenetic modulation serves as an effective method to activate dormant fungal biosynthetic pathways, which produce valuable secondary compounds with antimicrobial and antioxidant properties.