Luteolin decreases the attachment, invasion and cytotoxicity of UPEC in bladder epithelial cells and inhibits UPEC biofilm formation

• Published in: Food and chemical toxicology Vol. 72; pp. 204 - 211
• Main Authors: SHEN, Xiao-Fei, REN, Lai-Bin, TIAN, Han-Wen, WANG, Xiao-Ying, LIU, Xiao-Kang, JINGYU LI, NING HUANG, YAN TENG, SHUANG ZHENG, YANG, Xiao-Long, GUO, Xiao-Juan, WANG, Xin-Yuan, SHA, Kai-Hui, NA LI, XU, Guang-Ya
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 01.10.2014
• Subjects: Adhesins, Escherichia coli - genetics; Adhesins, Escherichia coli - metabolism; Anti-Bacterial Agents - pharmacology; Biofilms - drug effects; Biological and medical sciences; Cell Line; Down-Regulation; Epithelial Cells - drug effects; Epithelial Cells - microbiology; Escherichia coli; Escherichia coli Infections - drug therapy; Fimbriae Proteins - genetics; Fimbriae Proteins - metabolism; Food toxicology; Humans; Luteolin - pharmacology; Medical sciences; Microbial Sensitivity Tests; Polyphenols - pharmacology; Toxicology; Urinary Bladder - cytology; Urinary Bladder - drug effects; Urinary Bladder - microbiology; Urinary Tract Infections - drug therapy; Uropathogenic Escherichia coli - drug effects; Uropathogenic Escherichia coli - growth & development; Flavones; Biofilm formation; Escherichia coli; Cytotoxicity; Urinary tract; Antioxidant; Flavonoid; In vitro; Invasion; Attachment and invasion; Micronutrient; Infection; Uropathogenic Escherichia coli; Polyphenol; Urinary tract infection; Decrease; Urinary bladder; Phenols; Bacteria; Epithelial cell; Proanthocyanidin; Luteolin; Enterobacteriaceae
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2014.07.019

Urinary tract infection (UTI), primarily caused by uropathogenic Escherichia coli (UPEC), is one of the most common infectious diseases worldwide. Emerging antibiotic resistance requires novel treatment strategies. Luteolin, a dietary polyphenolic flavonoid, has been confirmed as a potential antimicrobial agent. Here, we evaluated the sub-MICs of luteolin for potential properties to modulate the UPEC infection. We found that luteolin significantly decreased the attachment and invasion of UPEC J96 or CFT073 in human bladder epithelial cell lines T24. Meanwhile, obvious decreased expression of type 1 fimbriae adhesin fimH gene, lower bacterial surface hydrophobicity and swimming motility, were observed in luteolin-pretreated UPEC. Furthermore, luteolin could attenuate UPEC-induced cytotoxicity in T24 cells, which manifested as decreased activity of lactate dehydrogenase (LDH). Simultaneously, the inhibition of luteolin on UPEC-induced cytotoxicity was confirmed by ethidium bromide/acridine orange staining. Finally, the luteolin-pretreated UPEC showed a lower ability of biofilm formation. Collectively, these results indicated that luteolin decreased the attachment and invasion of UPEC in bladder epithelial cells, attenuated UPEC-induced cytotoxicity and biofilm formation via down-regulating the expression of adhesin fimH gene, reducing the bacterial surface hydrophobicity and motility.