The prevention of colon carcinogenesis in rats by dietary cellulose is greater than the promotive effect of dietary lard as assessed by repeated endoscopic observation

National and subnational incidence, mortality and associated factors of colorectal cancer in China: A systematic analysis and modelling study

Background

Due to their known variation by geography and economic development, we aimed to evaluate the incidence and mortality of colorectal cancer (CRC) in China over the past decades and identify factors associated with CRC among the Chinese population to provide targeted information on disease prevention.

Methods

We conducted a systemic review and meta-analysis of epidemiolocal studies on the incidence, mortality, and associated factors of CRC among the Chinese population, extracting and synthesising data from eligible studies retrieved from seven global and Chinese databases. We pooled age-standardised incidence rates (ASIRs) and mortality rates (ASMRs) for each province, subregion, and the whole of China, and applied a joinpoint regression model and annual per cent changes (APCs) to estimate the trends of CRC incidence and mortality. We conducted random-effects meta-analyses to assess the effect estimates of identified associated risk factors.

Results

We included 493 articles; 271 provided data on CRC incidence or mortality, and 222 on associated risk factors. Overall, the ASIR of CRC in China increased from 2.75 to 19.39 (per 100 000 person-years) between 1972 and 2019 with a slowed-down growth rate (APC1 = 5.75, APC2 = 0.42), while the ASMR of CRC decreased from 12.00 to 7.95 (per 100 000 person-years) between 1974 and 2020 with a slight downward trend (APC = -0.89). We analysed 62 risk factors with synthesized data; 16 belonging to the categories of anthropometrics factors, lifestyle factors, dietary factors, personal histories and mental health conditions were graded to be associated with CRC risk among the Chinese population in the meta-analysis limited to the high-quality studies.

Conclusions

We found substantial variation of CRC burden across regions and provinces of China and identified several associated risk factors for CRC, which could help to guide the formulation of targeted disease prevention and control strategies.

Registration

PROSPERO: CRD42022346558.

Analysis of polar lipids in the serum from rats fed shiitake by liquid chromatography-mass spectrometry/mass spectrometry

Consumption of a shiitake mushroom diet has been reported to have effects on serum phospholipids. However, much less is known about the effect on serum polar lipids including lysophospholipids and free fatty acids. In the present study, the effects of a shiitake diet were evaluated on the basis of identification and quantification of individual polar lipid components in rat serum using liquid chromatography-mass spectrometry/mass spectrometry. By comparison with standards and published data, 50 lysophospholipids and 32 free fatty acids were identified, and the concentrations of 27 polar lipids in rat serum were determined. Shiitake diets decreased the levels of all individual polar lipid components in the serum of male rat. The total level of serum polar lipids in males fed 4% shiitake diets (1365.71 mol/L) was significantly lower than that of the control (2270.26 mol/L). However, shiitake diets did not significantly affect the levels of serum polar lipids in female rats.

Combined treatment of Caco-2 cells with butyrate and mesalazine inhibits cell proliferation and reduces Survivin protein level

There is epidemiological evidence, that mesalazine can inhibit colon cancer development by affecting proliferation and apoptosis. Several studies suggest that supplementary intake of butyrate may yield to improved efficacy of mesalazine. However, the underlying molecular mechanisms of such interaction remain unknown. This study addressed the combinatory effect of both substances on the growth of Caco-2 cells. Challenging of cells with mesalazine and butyrate provoked a time-dependent decrease in both cell counts and proliferation. Co-treatment with the substances could further intensify these effects. The growth-inhibitory action of mesalazine and butyrate was accompanied by a significant increase in caspase-3 activity, cleavage of PARP and caspase-8, while decreasing the expression of Xiap and Survivin simultaneously. Co-incubation of both substances exaggerated effects on all examined apoptosis-regulatory proteins except for Xiap. Our data demonstrate that co-treatment of mesalazine and butyrate evoked additive effects on inhibition of cell growth and induction of apoptosis in Caco-2 cells.

Effects of Dietary Angelica keiskei on Serum and Liver Lipid Profiles, and Body Fat Accumulations in Rats

Angelica keiskei (Ashitaba) is a perennial plant belonging to the Umbelliferae family. Recently, much attention has been focused on Ashitaba products as a so-called health food for the breakdown of cellulite among various physiological benefits of Ashitaba. The current study was carried out to investigate the physiological efficacy of dietary Ashitaba on serum and liver lipid profiles and body fat accumulation in rats. Rats were fed a high-fat diet with various amounts of Ashitaba for 28 d. Perirenal adipose tissue weights of rats fed the x 10 (170 mg/100 g BW) Ashitaba diet were significantly higher (p < 0.05) than those of the control group. Serum triacylglycerol concentrations of rats fed the x 100 (1,700 mg/100 g BW) Ashitaba diet were significantly higher (p < 0.05) than those of the x 1 (17 mg/100 g BW) group. Fecal weights and bile acid excretions of rats fed the x 10 or x 100 Ashitaba diet were significantly higher (p < 0.05) than those of the control group. However, there were no significant differences in the body weight gain, epididymal adipose tissue weight, serum cholesterol or liver lipid concentrations or other biochemical profiles in the serum. Furthermore, even the excessive ingestion of Ashitaba had no significant pathological impact on the liver or kidney. These results indicate that the large intake of Ashitaba products may supply dietary fiber and thus improve gastrointestinal condition through the increased excretion of feces containing high level of bile acids, although even excessive intake of Ashitaba for a short period of 28 d did not show any impact on the decrease in body fat or modification of lipid profiles in this study.

PPARgamma is a key target of butyrate-induced caspase-3 activation in the colorectal cancer cell line Caco-2

BACKGROUND

Butyrate, a potent histone deacetylase inhibitor, belongs to a promising new class of antineoplastic agents with the capacity to induce apoptosis of cancer cells. However, the underlying mechanisms of action have yet not been elucidated.

AIM

To further investigate the molecular events involved in butyrate-induced caspase-3 activation in Caco-2 wild-type, empty-vector and dominant-negative PPARgamma mutant cells along the signalling pathway. In this context, the involvement and up-regulation of PPARgamma was examined.

RESULTS

Stimulation of cells with butyrate resulted in increased expression of PPARgamma mRNA, protein, and activity as well as phospho-p38 MAPK protein expression and caspase-3 activity. Arsenite, a direct stimulator of p38 MAPK, also led to an increased PPARgamma expression, thereby mimicking the effects of butyrate. In contrast, butyrate-mediated up-regulation of PPARgamma was counteracted by co-incubation with the p38 MAPK inhibitor SB203580. Treatment of cells with butyrate resulted in both increased caspase-8 and -9 activity and reduced expression of XIAP and survivin. However, butyrate-mediated effects on these apoptosis-regulatory proteins leading to caspase-3 activation were almost completely abolished in Caco-2 dominant-negative PPARgamma mutant cells.

CONCLUSIONS

Our data clearly unveil PPARgamma as a key target in the butyrate-induced signalling cascade leading to apoptosis via caspase-3 in Caco-2 cells.