Effects of Ethyl Acetate Extracts from the Polycephalomyces nipponicus Isolate Cod-MK1201 (Ascomycetes) against Human Pathogenic Bacteria and a Breast Cancer Cell Line

This study aimed to identify a suitable organic solvent for extracting bioactive compounds from Polycephalomyces nipponicus and to evaluate the antibacterial and anticancer activities of the extracts obtained. Only extracts obtained with ethyl acetate exhibited antibacterial activity, so ethyl acetate was chosen for large-scale extraction. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Gram-positive and Gram-negative human pathogenic bacteria of the 3 ethyl acetate-derived extracts-ethyl acetate extract from P. nipponicus (PN-ME), ethyl acetate extract after defatting (PN-ME*), and ethyl acetate extract after refluxation (PN-ME')-were determined. PN-ME' exhibited the most potent activity, inhibiting 12 of the 18 test bacteria, especially Bacillus cereus ATCC 11778 and Vibrio cholera (O1) DMST 9700, with low MIC and MBC values. PN-ME* showed greater inhibitory activity than PN-ME. The effects of the extracts on bacterial cell morphology were also determined. After 120 minutes of treatment with PN-ME* or PN-ME', B. cereus ATCC 11778 exhibited an abnormal rod-shaped cell structure, with some cells elongated to multiple times their original size and others appearing collapsed. V cholera (O1) DMST 9700 cells showed shrinkage and the formed subsurface cavities. PN-ME* and PN-ME' also inhibited the growth of MCF-7 breast cancer cells. In conclusion, the fungal isolate P. nipponicus Cod-MK1201 represents a source of antibacterial and anti-breast cancer compounds.