Transcriptional profiling of Salmonella enterica serovar Enteritidis exposed to ethanolic extract of organic cranberry pomace.

Non-typhoidal Salmonella enterica serovars continue to be an important food safety issue worldwide. Cranberry (Vaccinium macrocarpon Ait) fruits possess antimicrobial properties due to their various acids and phenolic compounds; however, the underlying mechanism of actions is poorly understood. We evaluated the effects of cranberry extracts on the growth rate of Salmonella enterica serovars Typhimurium, Enteritidis and Heidelberg and on the transcriptomic profile of Salmonella Enteritidis to gain insight into phenotypic and transcriptional changes induced by cranberry extracts on this pathogen. An ethanolic extract from cranberry pomaces (KCOH) and two of its sub-fractions, anthocyanins (CRFa20) and non-anthocyanin polyphenols (CRFp85), were used. The minimum inhibitory (MICs) and bactericidal (MBCs) concentrations of these fractions against tested pathogens were obtained using the broth micro-dilution method according to the Clinical Laboratory Standard Institute's guidelines. Transcriptional profiles of S. Enteritidis grown in cation-adjusted Mueller-Hinton broth supplemented with or without 2 or 4 mg/ml of KCOH were compared by RNASeq to reveal gene modulations serving as markers for biological activity. The MIC and MBC values of KCOH were 8 and 16 mg/mL, respectively, against all tested S. enterica isolates. The MIC value was 4 mg/mL for both CRFa20 and CRFp85 sub-fractions, and a reduced MBC value was obtained for CRFp85 (4 mg/ml). Treatment of S. Enteritidis with KCOH revealed a concentration-dependent transcriptional signature. Compared to the control, 2 mg/ml of KCOH exposure resulted in 89 differentially expressed genes (DEGs), of which 53 and 36 were downregulated and upregulated, respectively. The upregulated genes included those involved in citrate metabolism, enterobactin synthesis and transport, and virulence. Exposure to 4 mg/ml KCOH led to the modulated expression of 376 genes, of which 233 were downregulated and 143 upregulated, which is 4.2 times more DEGs than from exposure to 2 mg/ml KCOH. The downregulated genes were related to flagellar motility, Salmonella Pathogenicity Island-1 (SPI-1), cell wall/membrane biogenesis, and transcription. Moreover, genes involved in energy production and conversion, carbohydrate transport and metabolism, and coenzyme transport and metabolism were upregulated during exposure to 4 mg/ml KCOH. Overall, 57 genes were differentially expressed (48 downregulated and 9 upregulated) in response to both concentrations. Both concentrations of KCOH downregulated expression of hilA, which is a major SPI-1 transcriptional regulator. This study provides information on the response of Salmonella exposed to cranberry extracts, which could be used in the control of this important foodborne pathogen.

Effects of cyanidin 3-0-glucoside on cardiac structure and function in an animal model of myocardial infarction.

Cyanidin 3-0-glucoside (CG) is a polyphenol with potential health benefits. In this study, we investigated, for the first time, the cardioprotective effects of CG in an animal model of myocardial infarction (MI), a major cause of death worldwide. Sham and MI rats were administered CG (10 mg kg-1 day-1) daily for one week prior to surgery, and 8 weeks post-surgery. Echocardiography was performed to assess cardiac structure and function at 4 and 8 weeks. At 4 weeks, MI rats had significantly lower body mass when compared to control rats, and CG administration significantly prevented this decrease. Four-week MI rats also showed significantly increased left ventricle dilation, end systolic and end diastolic volumes in comparison to controls, and CG significantly prevented these adverse changes. Ejection fraction was significantly lower in 4-week MI rats in comparison to controls, and CG had no effect on this parameter. At 8 weeks, body mass was significantly lower in MI rats when compared to control rats, and CG significantly prevented this decrease. At 8 weeks, MI rats showed a significant increase in left ventricle dilation and isovolumic relaxation time, while ejection fraction was significantly lower when compared to controls; these parameters were not altered by CG treatment. Eight-week MI rats had significantly higher level of oxidative stress in heart tissue in comparison to controls, and CG administration did not prevent this increase. In conclusion, administration of CG was able to significantly preserve body mass in both 4 and 8 weeks MI rats, as well as significantly prevent cardiac dilation in 4 weeks MI rats. However, CG was unable to sustain this cardioprotection, as cardiac structure and function were not significantly improved in 8 weeks MI rats.

NMR characterization of novel pyranoanthocyanins derived from the pulp of Panax quinquefolius L. (North American ginseng).

Three major pigments (one natural and two derived) were determined to be present in the berry pulp of Panax quinquefolius L. (North American ginseng). The first was a simple anthocyanin (pelargonidin 3-O-lathyroside) along with two novel pyranoanthocyanins, structurally similar to those recently discovered in Staghorn sumac. The three anthocyanins were structurally characterized using NMR (1 H, gCOSY, gHSQC, gHMBC, TOCSY, ROESY, and 13 C DEPTq135) and High Resolution MS. All three anthocyanins had the disaccharide lathyrose (2-O-(ß-D-xylopyranosyl)-ß-D-galactopyranoside) attached at the 3-O position. In the tradition of naming novel anthocyanin aglycones based on botanical origin, the new pyranoanthocyanin aglycones have been given the common names Panaxidin A (pelaragonidin-4-vinylcatechol) and Panaxidin B (pelargonidin-4-vinylphenol). Copyright © 2015 Her Majesty the Queen in Right of Canada Magnetic Resonance in Chemistry © 2015 John Wiley & Sons, Ltd.

Evaluation of antioxidant activities and chemical characterisation of staghorn sumac fruit (Rhus hirta L.).

Staghorn sumac (Rhus hirta L.) is a native tree in Eastern Canada whose fruit has been used by aboriginal peoples to treat various illnesses, and has recently been found to be a good source of antioxidants. However, the phytochemical composition of R. hirta is not known. In this study, we used Four highly accepted assays and confirmed its FRAP, ORAC, ß-CLAMS and PCL values to be 79.95 µmol AAE/g DW, 1544 µmol TE/g DW, RAA 129% and 4513 µmol TE/g DW, respectively. The antioxidant activities correlated positively to the total polyphenols content, which was higher in the ethanolic extract (81.6 mg GAE/ g DW) compared to the water extract (46.3mg GAE/g DW), suggesting polyphenols play an important role. Quantitative data from UHPLC and qualitative studies using HPLC-DAD-MS showed that in addition to commonly found phenolic acids, flavonoids and anthocyanins, R. hirta fruit contained a novel group of unique anthocyanins with aglycones (anthocyanidins) at 449, 419 and 433 Da. Further studies on the identification and their health beneficial effects are being conducted.