关键词: 桂皮醛, 卡泊芬净, 烟曲霉菌, 抗菌活性, 细胞壁, 细胞膜, 电镜

Abstract:

Objective To study the antifungal activity of cinnamaldehyde against Aspergillus and its effect on the cell wall of Aspergillus fumigatus. To provide a basis for the development of new targeted antifungal drugs. Methods The MICs were determined by dilution on Sabouraud (4% dextrose, 1% peptone, 2% agar) dilution. Aspergillus fumigatus were prepared into 1×10⁸ CFU/mL 0.1% cinnamaldehyde and caspofungin Tween 80 (4% dextrose, 1% peptone) liquid, incubated at 37℃ for 48 h and centrifuged film, transmission electron microscopy, fluconazole as a control. Results MICs of cinnam aldehyde, caspofungin, fluconazole against Aspergillus were as followed:Aspergillus fumigatus 0.019 5 μg/mL, 0.039 1 μg/mL, >32 μg/mL; Aspergillus flavus 0.039 1 μg/mL, 0.039 1 μg/mL, >32 μg/mL. Electron microscopy showed that after 0.1% cinnamaldehyde and caspofungin acting for 48 h, the outer cell wall of Aspergillus fumigatus dissolved, the nuclei and organelles dissolved disappeared, but the cell membrane remained intact. Effect of 0.1% caspofungin on Aspergillus fumigatus cell wall and cell membrane. 0.1% fluconazole has no effect on cell wall and cell membrane of Aspergillus fumigatus. Conclusion Cinnamaldehyde and caspofungin have strong antifungal activity against Aspergillus fumigatus, but cinnamaldehyde is superior to caspofungin. Both cinnamaldehyde and caspofungin act on the cell wall of Aspergillus fumigatus without affecting the cell membrane. Fluconazole has no effect on the cell wall and cell membrane of Aspergillus fumigatus. Therefore, cinnamaldehyde will be an effective drug targeted for the treatment of Aspergillus infections.

Key words: cinnamaldehyde, caspofungin, Aspergillus fumigatus, antifungal activity, cell wall, electron microscopy