麻豆淫院

A compound that is abundant in apples and strawberries inhibits the highly pathogenic E. coli O157:H7 biofilms while sparing a beneficial strain of E. coli that also forms biofilms in the human gut, according to a paper in the December 2011 issue of the journal .

Transcriptome analysis revealed that the compound, called phloretin, suppresses toxin and other genes involved in O157:H7 pathology and biofilm formation. And in a rat model of colitis, phloretin, reduced colon inflammation and body weight loss. 鈥淧hloretin has a triple biological activity as an antioxidant compound, a biofilm inhibitor, and an anti-inflammatory agent,鈥� says corresponding author Jintae Lee of Yeungnam University, Gyeongsan, Korea.

E. coli O157:H7 causes hemorrhages in the intestine. To date, no effective therapy for O157:H7 biofilms has been found. Biofilms generally are notoriously resistant to antimicrobial therapy. So in the study, Lee screened a dozen flavonoids, including phloretin, for their ability to inhibit these biofilms. 鈥淲e found that phloretin markedly reduced E. coli O157:H7 biofilm formation on abiotic surface and human colon epithelial cells, while phloretin did not harm commensal E. coli K-12 biofilms,鈥� says Lee. Commensal E. coli can actually fortify the human immune system, he says.

In addition to its anti- E. coli O157:H7 biofilm activity, phloretin 鈥渁ccounts in part for the antioxidant capacity of apples, and it also shows anti-inflammatory activity,鈥� says Lee. 鈥淭his study suggests that phloretin in apples could reduce the risk of E. coli O157:H7 infection and intestinal inflammation.鈥�

鈥淭his study demonstrated for the first time that phloretin, a natural flavonoid, is a nontoxic inhibitor of enterohemorrhagic E. coli O157:H7 biofilms, but does not harm commensal E. coli K-12 biofilms,鈥� Lee writes. 鈥淎lso, importantly, our results confirmed that phloretin shows anti-inflammatory properties in both the in vitro and in vivo inflammatory colitis models.  The effect of phloretin was noticeably more pronounced than that of the conventional [inflammatory bowel disease] drug 5-aminosalicylic acid.鈥�