title: An aqueous extract of Yunnan Baiyao inhibits the quorum-sensing-related virulence of Pseudomonas aeruginosa.
abstract: Yunnan Baiyao is a famous Chinese medicine that has long been directly applied to wounds to reduce bleeding, pain, and swelling without causing infection. However, little is known about its ability to prevent infection. The present study aimed to assess in vitro the anti-virulence activity of an aqueous extract of Yunnan Baiyao (YBX) using Pseudomonas aeruginosa as a pathogenic model. We found that a sub-MIC (2.5 mg/ml) of YBX can efficiently interfere with the quorum-sensing (QS) signaling circuit. Real-time polymerase chain reaction analysis showed that a sub-MIC of YBX down-regulated the transcriptions of lasR, lasI, rhlR, and rhlI, which resulted in global attenuation of QS-regulated virulence activities, such as biofilm formation, and secretion of LasA protease, LasB elastase and pyocyanin. Further, YBX reduced the motility of P. aeruginosa related to QS, and impaired the formation of biofilms. These results suggest that YBX may possess global inhibitory activity against the virulence of P. aeruginosa and that YBX may also exhibit antimicrobial activity in vivo. The present study suggests that Yunnan Baiyao represents a potential source for isolating novel, safe, and efficacious antimicrobial agents.
authors.affiliation: Department of Microbiology and Immunology, Guangdong Medical College, Zhanjiang 524023, P. R. China.
authors.forename: Zu-Guo
authors.initials: ZG
authors.lastname: Zhao
authors.forename: Shuang-Shuang
authors.initials: SS
authors.lastname: Yan
authors.forename: Yun-Mei
authors.initials: YM
authors.lastname: Yu
authors.forename: Na
authors.initials: N
authors.lastname: Mi
authors.forename: La-Xi
authors.initials: LX
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Li
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Jun-Fa
authors.initials: JF
authors.lastname: Xu
authors.forename: Wei-Qing
authors.initials: WQ
authors.lastname: Yang
authors.forename: Guo-Ming
authors.initials: GM
authors.lastname: Li
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects; D002681:China; D015536:Down-Regulation / Q000187:drug effects*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D053038:Quorum Sensing / Q000187:drug effects*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004365:Drugs, Chinese Herbal; D014157:Transcription Factors; D037521:Virulence Factors; C530960:yunnan baiyao