Evaluation of cinnamon extract effects on clbB gene expression and biofilm formation in Escherichia coli strains isolated from colon cancer patients

Abstract

Background: Colon cancer is one of the most common malignancies and the fourth leading cause of cancerrelated mortality in the world. Colibactin, which is synthesized by the pks genomic island of E. coli interfere with the eukaryotic cell cycle. Cinnamon has an antimicrobial effect and considered as a colon cancer-preventing agent. The aim of the study was to evaluate the effects of cinnamon extract and cinnamaldehyde on clbB gene expression and biofilm formation in clinical isolates of E. coli. Methods: Thirty E. coli carrying pks gene were isolated from the colon cancer patients, inflammatory bowel disease and healthy subjects. Antibiotic susceptibility was evaluated by disk diffusion method and the minimum inhibitory concentration of cinnamon essential oil and cinnamaldehyde by microdilution broth method. In vitro biofilm formation of E.coli isolates was monitored using a microtiter plate method. The presence of clbB, clbA and clbQ genes in E.coli isolates were evaluated by PCR. The effect of cinnamaldehyde and cinnamon essential oil on clbB gene expression was evaluated by Real-Time PCR. Results: The highest antibiotic resistance was obtained with 94.4% for ticarcillin-clavulanic acid, azithromycin, amoxicillin, and amikacin. The MIC for all clinical isolates was 32 μl/ml of cinnamon essential oil and the MIC of cinnamaldehyde was between 0.00002 to 0.03 μl/ml. After exposure of isolates to cinnamon extract and cinnamaldehyde, 40 and 13.3% were weakly biofilm producers, respectively. The frequencies of clbB, clbA, and clbQ genes were 23.3, 23.3, and 26.7%, respectively. The expression of clbB gene in the presence of the Sub-MIC concentration of cinnamon essential oil and cinnamaldehyde was decreased in 8 isolates compared to untreated isolates (p-value < 0.05). Conclusions: The antibacterial activity of cinnamaldehyde and cinnamon essential oil allows the use of these herbal compounds for treatment or supplements in infections caused by E. coli and in patients with suspected colorectal cancer.

Oligosaccharides increase the genotoxic effect of colibactin produced by pks+ Escherichia coli strains

“…Our findings add to the efforts in identifying environmental factors that may influence colibactin expression. For example, cinnamon and cinnamaldehyde have been shown to inhibit the expression of the clbB gene among several E. coli isolates from CRC patients [ 43 ]. More recently, a new study identified compounds of tannin and quercetin from medicinal plant extracts of Terminalia catappa , Psidium guajava and Sandoricum koetjape that inhibited the growth and transcription of colibactin genes of colibactin-producing E. coli [ 44 ].…”

Inulin and Galacto-oligosaccharides Increase the Genotoxic Effect of Colibactin Produced by pks+ Escherichia Coli Strains

“…Our ndings add to the efforts in identifying environmental factors that may in uence colibactin expression. For example, cinnamon and cinnamaldehyde have been shown to inhibit the expression of the clbB gene among several E. coli isolates from CRC patients (40). More recently, a new study identi ed compounds of tannin and quercetin from medicinal plant extracts of Terminalia catappa, Psidium guajava and Sandoricum koetjape that inhibited the growth and transcription of colibactin genes of colibactin-producing E. coli (41).…”

Gut Microbiota as Potential Biomarker and/or Therapeutic Target to Improve the Management of Cancer: Focus on Colibactin-Producing Escherichia coli in Colorectal Cancer

“…The addition of natural compounds to the diet could appear to be an innovative alternative to reduce CoPEC activity. Decreased expression of clbB gene in the presence of the Sub-MIC concentrations of cinnamon essential oil and cinnamaldehyde has been observed in CoPEC isolated from CRC compared to untreated isolates [ 146 ]. Extracts of Terminalia catappa , Psidium guajava, and Sandoricum koetjape , as well as their metabolites tannin and quercetin, have been demonstrated to downregulate the expression of several clb genes in a CoPEC strain and protect eukaryotic epithelial cells from infection and DNA damage in vitro [ 147 ].…”