Action of Reactive Oxygen Species in the Antifungal Mechanism of Gemini-pyridinium Salts Against Yeast

作者：Shirai Akihiro^*; Ueta Shouko; Maseda Hideaki; Kourai Hiroki; Omasa Takeshi

来源：Biocontrol Science, 2012, 17(2): 77-82.

DOI：10.4265/bio.17.77

• Reactive oxygen species
• Antifungal activity
• Gemini-pyridinium salt
• Yeast

We previously found that the gemini quaternary salt (gemini-QUAT) containing two pyridinium residues per molecule, 3,3%26apos;- (2,7-dioxaoctane)bis(1-decylpyridinium bromide) (3DOBP-4,10), exerted fungicidal activity against Saccharomyces cerevislae and caused respiration inhibition and the cytoplasmic leakage of ATP, magnesium, and potassium ions. Here, we investigated how the gemini-QUAT, 3DOBP-4,10, exerts more powerful antimicrobial activity than the mono-QUAT N-cetylpyridinium chloride (CPC) and examined the association between reactive oxygen species (ROS) and the antimicrobial mechanism. Antifungal assays showed that the activity of 3DOBP-4,10 against two yeasts, S. cerevisiae and Candida albicans, was significantly elevated under aerobic conditions, and largely reduced under anaerobic conditions (nitrogen atmosphere). Adding radical scavengers such as superoxide dismutase, catalase and potassium iodide (KI) also decreased the fungicidal activity of 3DOBP-4,10 but negligibly affected that of CPC. We measured survival under static conditions and found that the rapid fungicidal profile of 3DOBP-4,10 was lost, whereas that of CPC was slightly affected in the presence of KI. Our results suggest that 3DOBP-4,10 exerts powerful antimicrobial activity by penetrating the cell wall and membrane, which then allows oxygen to enter the cells, where it participates in the generation of intracellular ROS. The activity could thus be attributable to a synergic antimicrobial combination of the disruption oil organelle membranes by the QUAT and oxidative stress imposed by ROS.

• 出版日期2012-6