Induction of beta-glucuronidase activity during dimethylhydrazine carcinogenesis and additive effects of cholic acid and indole

Chang-wei-qing, a Chinese herbal formula, ameliorates colitis-associated tumour development via inhibiting NF-κB and STAT3 signalling pathway

CONTEXT

Chang-wei-qing (CWQ) is a Chinese herbal recipe with clinical efficacy. However, the molecular mechanism underlying its recognized therapeutic benefits against colorectal cancer is still elusive.

OBJECTIVE

To investigate the potential beneficial effects of CWQ in drug-induced colitis-associated cancer (CAC) model and its mechanistic involvements in this disease.

MATERIALS AND METHODS

Colitis-associated cancer model was induced by azoxymethane (AOM) and dextran sulphate sodium (DSS). CWQ was administrated by gavage. Colon length and tumour size were determined after resection. The colitis was systematically scored. The microbiota and population of Faecalibacterium prausnitzii (F. prausnitzii) Hauduroy & Duncan was analysed by quantitative polymerase chain reaction (PCR). β-Glucuronidase, d-lactose and endotoxin were determined with commercially available kits. Pro-inflammatory cytokines were analysed in the colon tissues. Relative protein expressions were determined by Western blotting.

RESULTS

High concentration CWQ significantly restored the colon length, decreased tumour number and size (1.7 ± 0.6 vs. 2.8 ± 0.4 mm, p < 0.01) and reduced colitis score (11.8 ± 2.1 vs. 18.2 ± 2.3, p < 0.01). CWQ also suppressed expansion of F. prausnitzii population (0.029 ± 0.015% vs. 0.052 ± 0.019%, p < 0.01). CWQ greatly inhibited the activity of β-glucuronidase and leakage of d-lactose and endotoxin. Meanwhile, the pro-inflammatory cytokines were remarkably decreased in CAC mice in response to CWQ treatment. We further demonstrated that CWQ inhibited both NF-κB and STAT3 signalling.

CONCLUSIONS

We for the first time demonstrated the antitumour properties of CWQ in vivo via inhibiting NF-κB and STAT3 signalling.

Plantago ovata consumption and colorectal mortality in Spain, 1995-2000

BACKGROUND

Consumption of Plantago ovata may protect against colorectal cancer. To test this hypothesis, an ecological study was performed to determine mortality rates and distribution of colorectal cancer, and the consumption and distribution of P ovata, in different provinces in Spain. The putative association between P ovata consumption and mortality from colorectal cancer was then evaluated.

METHODS

We conducted a comparative ecological study of Spanish provinces, with colorectal cancer mortality as the dependent variable and per capita consumption of P ovata by province and year as the independent variable. Associations were analyzed by calculating Spearman's correlation coefficients and a Poisson multiple regression model.

RESULTS

Consumption of P ovata tended to be inversely correlated with mortality from colorectal cancer. In the Poisson regression analysis this tendency remained and reached statistical significance for the top quintile of P ovata consumption in the adjusted analysis (P = 0.042).

CONCLUSIONS

Our results show an inverse trend between the consumption of P ovata and colorectal cancer mortality. We recommend additional observational studies of individuals, in order to better control confounding factors.

Plantago ovata seeds as dietary fibre supplement: physiological and metabolic effects in rats

In rats, the effects of a 4-week supplementation of a fibre-free elemental diet with 100 or 200 g Plantago ovata seeds/kg was compared with that of the husks and wheat bran. The seeds increased faecal fresh weight up to 100%, faecal dry weight up to 50% and faecal water content up to 50%. The husks, at the high concentration only, were more effective and wheat bran less effective. Length and weight of the small intestine were not greatly affected by the seeds, but both variables increased significantly in the large intestine. The husks had more pronounced effects, especially in the small intestine, and wheat bran almost no effect. Faecal bacterial mass as estimated from the 2,6-diaminopimelic acid output was increased to the greatest extent by the seed-containing diet and by the high concentration of husks, but to a lesser extent by wheat bran. Faecal and caecal protein content was enhanced by the seeds and wheat bran, but to a lesser extent by the husks. Total acetate in caecal contents or faeces was highest on the seeds and husks diet and not elevated by wheat bran. Total faecal bile acid excretion was stimulated and beta-glucuronidase (EC 3.2.1.31) activity reduced by both Plantago ovata preparations, but not by wheat bran. Mucosal digestive enzyme activities were inhibited to different degrees by all dietary fibres in the jejunum, and sometimes activated in the ileum. These results suggest that Plantago ovata seeds are a partly-fermentable dietary fibre supplement which increases stool bulk; metabolic and mucosa-protective effects are also probable.