Antibacterial activity of curcumin via apoptosis-like response in Escherichia coli

作者：Yun Dae Gyu; Lee Dong Gun^*

来源：Applied Microbiology and Biotechnology, 2016, 100(12): 5505-5514.

DOI：10.1007/s00253-016-7415-x

• Apoptosis-like response
• Curcumin
• Escherichia coli
• RecA

Curcumin, a naturally occurring phenolic compound, has been shown to exhibit antimicrobial activity against Candida albicans, Escherichia coli, Pseudomonas aeruginosa, etc., but the mechanism remains unclear. The present study was designed to investigate the novel antibacterial mechanism of curcumin that shows an apoptosis-like response in E. coli. We found that curcumin induces membrane damage at relatively high concentrations, but there was no effect at the minimum inhibitory concentration (MIC). At the MIC, curcumin-treated cells displayed various apoptotic markers such as reactive oxygen species (ROS) accumulation, membrane depolarization, and Ca2+ influx. Expression of RecA protein, which mediates a bacterial apoptosis-like response, was also increased by curcumin. In order to evaluate the influence of RecA on the appearance of other apoptotic markers, phosphatidylserine (PS) exposure and DNA fragmentation were examined and compared with a RecA deletion strain (Delta RecA). These markers were detected in E. coli wild-type cells, but not in Delta RecA cells. In conclusion, our data demonstrate that curcumin induces an apoptosis-like response in E. coli that involves RecA.

• 出版日期2016-6