Chemoprevention of colorectal cancer in inflammatory bowel disease

Exploring Chemoprevention in Colorectal Cancer for Patients with Inflammatory Bowel Disease: Mechanisms of Action and Clinical Aspects

Background: Inflammatory bowel diseases (IBDs) have been associated with a higher risk of colorectal cancer (CRC) development and chronic colonic inflammation seems to have a critical role in the pathogenesis of CRC in patients suffering from IBD. In respect to that, surveillance colonoscopy at regular intervals is recommended in patients with colitis. Objective: This review aims to explore the chemopreventive potential of a range of agents, including mesalazine, thiopurines, anti-TNF agents, statins, ursodeoxycholic acid, aspirin, folic acid, and nutraceuticals. Results: These agents target inflammation, oxidative stress, and oncogenic pathways, thereby offering the potential to reduce the risk of CRC in patients with IBD. Anti-TNF agents, such as infliximab and adalimumab, not only reduce colonic inflammation, but also play a protective role against CRC by lessening the carcinogenic effects associated with prolonged inflammatory processes. Furthermore, mesalazine and thiopurines have demonstrated established efficacy, while newer biologics, including interleukin inhibitors, show promising advancements. Although nutraceuticals and dietary interventions require further clinical validation, they offer additional possibilities for non-pharmacological prevention. Conclusion: Despite progress, knowledge gaps persist regarding the long-term safety, optimal dosing, and combined use of these agents. A significant reduction in the incidence of CRC in patients with IBD could be achieved by advancing chemoprevention and personalizing strategies.

Adherence to endoscopic surveillance guidelines for patients with inflammatory bowel disease: An Australian cohort study

BACKGROUND AND AIM

Patients with inflammatory bowel disease have an increased risk of developing colorectal cancer as compared with the general population. Endoscopic surveillance to detect early dysplastic changes is advised by several published clinical guidelines, which provide recommendations as to the timing and performance of surveillance procedures. There is a paucity of data as to adherence with these guidelines in clinical practice.

METHODS

A longitudinal inception cohort study of all new patients diagnosed with inflammatory bowel disease across a service network of Australian hospitals between January 2005 and June 2014, with continuous follow-up in a gastroenterology clinic until December 31, 2022. Patients were included if they warranted surveillance according to the Australian guidelines. Adherence to guidelines and technical and quality measures were reported.

RESULTS

A total of 136 patients were included, and a total of 263 surveillance procedures were performed. Ninety-five patients (70%) had their first surveillance colonoscopy within the correct time interval. Fifty patients (37%) were completely adherent to guidelines with respect to timing of all surveillance procedure. The overall dysplasia detection rate for surveillance procedures was 10%. Chromoendoscopy was only performed in 16% of procedures.

CONCLUSIONS

Adherence to endoscopic surveillance guidelines with regard to timing of procedures and the utilization of chromoendoscopy is poor. Further clinician education, promotion of the surveillance guidelines and incorporation of chromoendoscopy training as part of the national colonoscopy training program may improve adherence to guidelines.

Ultrasonic-assisted extraction of swertisin from sour Jujube seed and comprehensive revelation of its antioxidant activity

As a typical flavonoid glycoside, swertisin mainly exists in sour Jujube seed. In this study, swertisin was extracted by ultrasound-assisted extraction method optimized with Box-Behnken design and response surface methodology. The antioxidant effect of swertisin was determined in vitro and in Caenorhabditis elegans (C. elegans). Furthermore, the potential mechanisms of its antioxidant stress were comprehensively evaluated and explored with network pharmacology and molecular docking technology. The results showed obvious scavenging ability of swertisin on free radical and swertisin (50, 250, and 500 μmol/L) significantly enhanced antioxidative enzymes activity (GST-4, SOD-3, and GSH-P_X ) and reduced the reactive oxygen species and malondialdehyde accumulation in C. elegans, thereby protecting them from oxidative stress (heat stress and hydrogen peroxide). A total of 139 antioxidant targets of swertisin were screened and 70 signal pathways were enriched, including cancer-related pathways, lipid metabolism, liver injury-related pathways, acute lung injury, nervous system diseases, etc. This study provides the basis for further investigation on the antioxidant stress mechanism and contributes to the development of relevant drugs from natural products. PRACTICAL APPLICATIONS: The imbalance between the antioxidant defense system and reactive oxygen species is one of the main causes of neurodegenerative diseases, cardiovascular diseases, cancer, and aging. Therefore, alleviating oxidative stress injury has become a common strategy, which is helpful for the multi-target treatment of related diseases. The flavonoid of sour Jujube seed possesses potential antioxidant activity with multiple food health effects. From this study results, we optimized ultrasound-assisted extraction method for extracting the swertisin from sour Jujube seed and supported the use of C. elegans as an in vivo experimental model. We can recommend that the swertisin as a natural ingredient has a positive effect on antioxidation, which provided a scientific basis for treating related diseases through relevant pharmacological mechanisms and making antiaging functional food formula.

No increased risk of flare in ulcerative colitis patients in corticosteroid-free remission after stopping 5-aminosalicylic acid: A territory-wide population-based study

BACKGROUND AND AIM

Whether 5-aminosalicylic acid (ASA) can be stopped in patients with stable ulcerative colitis (UC) remains unclear. We aimed to examine whether 5-ASA can be safely withdrawn in UC patients who have been in corticosteroid-free clinical remission for ≥ 1 year.

METHODS

This is a retrospective cohort study using territory-wide healthcare database in Hong Kong. Primary outcome was development of UC flare, defined as new corticosteroid use or UC-related hospitalizations within 5 years. UC patients on oral 5-ASA ≥ 2 g daily for ≥ 1 year with C-reactive protein (CRP) < 10 mg/dL and no 5-ASA dosage escalation, UC-related hospitalization or corticosteroid use in the past year were included. Patients on biological agents were excluded. Patients were classified as "stopping" if 5-ASA was withdrawn for ≥ 90 days within follow-up period. We performed multivariable Cox regression models adjusting for demographics, blood parameters and immunosuppressants used. Adjusted hazard ratio (aHR) with 95% confidence interval (CI) was reported comparing stopping and continuous-use groups.

RESULTS

A total of 1408 patients were included with a median follow-up duration of 41.8 months (interquartile range [IQR]: 17.2-60.0 months). Stopping 5-ASA was not associated with an increased risk of UC flare (aHR 0.91; 95% CI 0.64-1.31; P = 0.620). A higher CRP levels at the time of stopping 5-ASA (aHR 1.15; 95% CI: 1.01-1.30; P = 0.037) were associated with increased risk of flare.

CONCLUSION

Stopping 5-ASA in UC patients in corticosteroid-free remission for ≥ 1 year was not associated with increased risk of flare. Future prospective trials should evaluate the role of stopping 5-ASA in stable UC patients.

hucMSC-Derived Exosomes Alleviate the Deterioration of Colitis via the miR-146a/SUMO1 Axis

Human umbilical cord mesenchymal stem cell-derived exosome (hucMSC-Ex) plays an important role in tissue repair and immunomodulation, leading to the mitigation of inflammatory bowel disease. However, the preventive function of hucMSC-Ex in the onset and progression of colitis-associated colon cancer (CAC) is poorly understood. In the current study, dextran sodium sulfate/azoxymethane-induced colitis mouse model was established, and the mice disease activity index, body weight, colon length, tumor counts, survival curve, tissue H&E/immunohistochemistry, and cytokines expression were analyzed to evaluate the effects of hucMSC-Ex on CAC. In addition, miR-146a mimics were transfected into colonic epithelial cells (fetal human cells) to evaluate their role in the hucMSC-Ex-mediated regulation of SUMO1. The results showed that hucMSC-Ex inhibits the expression of SUMO1 to reduce the process of CAC progression. Further analysis indicated that miR-146a targets and inhibits SUMO1 expression and its binding to β-catenin. In conclusion, our findings showed that hucMSC-Ex is effective in alleviating the deterioration of colitis via the miR-146a-mediated inhibition of SUMO1, which is crucial in this disease process.

Melatonin Attenuates Dextran Sodium Sulfate Induced Colitis in Obese Mice

Epidemiological studies have indicated that obesity is an independent risk factor for colitis and that a high-fat diet (HFD) increases the deterioration of colitis-related indicators in mice. Melatonin has multiple anti-inflammatory effects, including inhibiting tumor growth and regulating immune defense. However, the mechanism of its activity in ameliorating obesity-promoted colitis is still unclear. This study explored the possibility that melatonin has beneficial functions in HFD-induced dextran sodium sulfate (DSS)-induced colitis in mice. Here, we revealed that HFD-promoted obesity accelerated DSS-induced colitis, while melatonin intervention improved colitis. Melatonin significantly alleviated inflammation by increasing anti-inflammatory cytokine release and reducing the levels of proinflammatory cytokines in HFD- and DSS-treated mice. Furthermore, melatonin expressed antioxidant activities and reversed intestinal barrier integrity, resulting in improved colitis in DSS-treated obese mice. We also found that melatonin could reduce the ability of inflammatory cells to utilize fatty acids and decrease the growth-promoting effect of lipids by inhibiting autophagy. Taken together, our study indicates that the inhibitory effect of melatonin on autophagy weakens the lipid-mediated prosurvival advantage, which suggests that melatonin-targeted autophagy may provide an opportunity to prevent colitis in obese individuals.

Using Theory To Extend the Scope of Azobenzene Drugs in Chemotherapy: Novel Combinations for a Specific Delivery

Gut microorganisms metabolize azobenzene compounds (Ph¹ -N=N-Ph² ) into free aniline products (Ph¹ -NH₂ +H₂ N-Ph² ), a process that has been largely investigated to reduce dyes residues in the textile industry. However, the action of bacterial core enzymes such as azoreductases (AzoR) might also help to deliver prodrugs that become active when they reach the colonic region, a mechanism with potential applications for the treatment of inflammatory bowel disease (IBD) and colorectal cancer. So far, three azo-bonded prodrugs of 5-aminosalicylic acid (5-ASA), for example, sulfasalazine, olsalazine and balsalazide, have been used for colon-targeted delivery. The present contribution describes the first rational design of a novel azobenzene prodrug thanks to a computational approach, with a focus on linking 5-ASA to another approved anti-inflammatory drug. The resulting prodrugs were assessed for their degradation upon AzoR action. Replacing the original carriers by irsogladine is found to improve action.

3'-Hydroxypterostilbene Potently Alleviates Obesity Exacerbated Colitis in Mice

Epidemiological surveys show that obesity and the western diet increase the risk of colitis. Studies have also confirmed that the high-fat-diet (HFD) promoted the deterioration of colitis-related indicators in mice. Compared with stilbenoids, the results showed that 3'-hydroxypterostilbene (HPSB) was found to be the most effective inhibitor for the antiadipogenesis and anti-inflammation. However, its role in ameliorating obesity-promoted colitis is still unknown. We intend to investigate the protective effect and related molecular mechanisms of HPSB on HFD promoted dextran sodium sulfate (DSS)-induced colitis in mice. The results indicate that colitis in the HFD+DSS group tends to be more apparent in the DSS-only group, while feeding 0.025% of HPSB at different stages can improve the colitis induced by HFD+DSS. HPSB significantly reduced the levels of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) induced by HFD+DSS in mice. Furthermore, the Western blotting revealed that the administration of HPSB significantly downregulated cyclooxygenase-2 (COX-2), plasmalemma vesicle-associated protein-1 (PV-1), and phospho-signal transducer and activator of transcription 3 (p-STAT3) expressions in HFD+DSS treated mice. Presented results reveal that HPSB is a novel functional agent capable of preventing HFD exacerbated colitis.

Peripheral monocyte counts predict the clinical outcome for patients with colorectal cancer: a systematic review and meta-analysis

Monocytes originating from bone marrow play a key role in the inflammatory response. Divergent findings regarding the prognostic value of inflammatory factors like absolute monocyte count (AMC) in colorectal cancer (CRC) exist in the current literature. Thus, we sought to perform a systemic meta-analysis to comprehensively estimate whether the peripheral AMC affects the clinical outcome of CRC patients. A comprehensive literature search was performed in PubMed, Web of Science and EMBASE last updated to 23 December 2018, to identify studies reporting the prognostic value of AMC in patients with CRC. Hazard ratios and corresponding 95% confidence intervals (CIs) or P values were used as the effect size estimates for clinical outcomes including overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS) and progression-free survival (PFS) with the random-effect inverse variance weighted method. The potential heterogeneity was assessed with Q test and I statistics. Subgroup analyses with respect to some clinicopathological parameters were conducted. A total of 16 clinical studies comprising 3826 patients were included for analysis. Pooled analyses revealed that CRC patients with elevated AMC were significantly associated with worse OS (hazard ratio = 1.708, 95% CI: 1.480-1.971, P < 0.001), DFS (hazard ratio = 1.817, 95% CI: 1.289-2.560, P = 0.001), CSS (hazard ratio = 1.551, 95% CI: 1.187-2.027, P = 0.001) and PFS (hazard ratio = 1.487, 95% CI: 1.259-1.756, P < 0.001). In addition, subgroup analyses provided more information and demonstrated the prognostic effect of elevated preoperative AMC in patients with CRC. There were no significant heterogeneity and publication bias. In conclusion, elevated AMC seems to be served as an unfavorable and robust predicative indicator in CRC patients.

Statin Exposure Is Not Associated with Reduced Prevalence of Colorectal Neoplasia in Patients with Inflammatory Bowel Disease

Background/Aims

Statins have been postulated to lower the risk of colorectal neoplasia. No studies have examined any possible chemopreventive effect of statins in patients with inflammatory bowel disease (IBD) undergoing colorectal cancer (CRC) surveillance. This study examined the association of statin exposure with dysplasia and CRC in patients with IBD undergoing dysplasia surveillance colonoscopies.

Methods

A cohort of patients with IBD undergoing colonoscopic surveillance for dysplasia and CRC at a single academic medical center were studied. The inclusion criteria were IBD involving the colon for 8 years (or any colitis duration if associated with primary sclerosing cholangitis [PSC]) and at least two colonoscopic surveillance exams. The exclusion criteria were CRC or high-grade dysplasia (HGD) prior to or at enrollment, prior colectomy, or limited (<30%) colonic disease. The primary outcome was the frequency of dysplasia and/or CRC in statin-exposed versus nonexposed patients.

Results

A total of 642 patients met the inclusion criteria (57 statin-exposed and 585 nonexposed). The statin-exposed group had a longer IBD duration, longer follow-up period, and more colonoscopies but lower inflammatory scores, less frequent PSC and less use of thiopurines and biologics. There were no differences in low-grade dysplasia, HGD, or CRC development during the follow-up period between the statin-exposed and nonexposed groups (21.1%, 5.3%, 1.8% vs 19.2%, 2.9%, 2.9%, respectively). Propensity score analysis did not alter the overall findings.

Conclusions

In IBD patients undergoing surveillance colonoscopies, statin use was not associated with reduced dysplasia or CRC rates. The role of statins as chemopreventive agents in IBD remains controversial.

The inhibitory effect of Filipendula ulmaria (L.) Maxim. on colorectal carcinogenesis induced in rats by methylnitrosourea

ETHNOPHARMACOLOGICAL RELEVANCE

Meadowsweet (Filipendula ulmaria (L.) Maxim.) is a medicinal plant with a variety of therapeutic properties, traditionally used in various diseases including treatment and prevention of tumors. The aim of this study was to present an ethnomedicinal justification that a meadowsweet decoction is able to inhibit colorectal carcinogenesis induced by the methylnitrosourea (MNU) in rats.

MATERIALS AND METHODS

The chemical composition of meadowsweet extracts was studied by traditional methods. In animal experiments adult outbred female rats received four intrarectal instillations of MNU, one per week, at dose 4 mg in 0.5 ml saline (the total dose of MNU during the 4-week exposure was 16 mg/rat). After carcinogenic exposure one group (MNU) of rats continued to receive standard feed and tap water throughout life. In another group (MNU+meadowsweet), rats were given daily a decoction of the meadowsweet instead of drinking water and standard feed.

RESULTS

Meadowsweet extracts showed a sufficiently high content of flavonoids and tannins and also some individual phenolic compounds and salicylic acid. In rats after administration of MNU the overall incidence of tumors was 91% with tumor multiplicity of 3.5. The majority of rats (86%) developed multiple tumors of large intestine (most often adenocarcinomas:88 from 107; index of multiplicity - 2.0). In rats from the group MNU+meadowsweet there was a statistically significant decrease of the overall tumor incidence and multiplicity-by 1.4 and 2.9 times, respectively, and the incidence and multiplicity of colon tumors - by 2.0 and 2.8 times, respectively; the incidence and multiplicity of malignant tumors of other localizations was also reduced-by 2.2 and 3.0 times, respectively.

CONCLUSIONS

Meadowsweet extract is an effective inhibitor of colorectal carcinogenesis in experiment, that provides support for the traditional use of this plant in the oncology.

Effects of compound K, an enteric microbiome metabolite of ginseng, in the treatment of inflammation associated colon cancer

Ginsenoside Rb1, a major component of different ginseng species, can be bioconverted into compound K by gut microbiota, and the latter possess much stronger cancer chemopreventive potential. However, while the initiation and progression of colorectal cancer is closely associated with gut inflammation, to date, the effects of compound K on inflammation-linked cancer chemoprevention have not been reported. In the present study, liquid chromatography quadrupole time-of-flight mass spectrometry analysis was applied to evaluate the biotransformation of Rb1 in American ginseng by human enteric microflora. The in vitro inhibitory effects of Rb1 and compound K were compared using the HCT-116 and HT-19 human colorectal cancer cell lines by a MTS assay. Cell cycle and cell apoptosis were assayed using flow cytometry. Using ELISA, the anti-inflammatory effects of Rb1 and compound K were compared for their inhibition of interleukin-8 secretion in HT-29 cells, induced by lipopolysaccharide. The results revealed that compound K is the major intestinal microbiome metabolite of Rb1. When compared with Rb1, compound K had significantly stronger anti-proliferative effects in HCT-116 and HT-29 cell lines (P<0.01). Compound K significantly arrested HCT-116 and HT-29 cells in the G1 phase, and induced cell apoptosis (P<0.01). By contrast, Rb1 did not markedly influence the cell cycle or apoptosis. Furthermore, compound K exerted significant anti-inflammatory effects even at low concentrations (P<0.05), while Rb1 did not have any distinct effects. The data obtained from the present study demonstrated that compound K, an intestinal microbiome metabolite of Rb1, may have a potential clinical value in the prevention of inflammatory-associated colorectal cancer.