The preventive and therapeutic effects of anthocyanins on colorectal cancer: A comprehensive review based on up-to-date experimental studies

Comparison of the hepatoprotection of intragastric and intravenous cyanidin-3-glucoside administration: focus on the key metabolites and gut microbiota modulation

Liver injury is a life-threatening condition, and the hepatoprotective potential of cyanidin-3-glucoside (C3G) has been previously demonstrated. However, due to the low bioavailability, it has been doubtful that relatively low concentrations of intact C3G in vivo could account for these bioactivities. In this study, the hepatoprotective effects of intragastric and intravenous administration of C3G were investigated in a CCl4 induced liver injury model. Intragastric C3G administration was more effective than intravenous C3G injection in reducing serum damage biomarkers, oxidative stress, and inflammatory responses, indicating that absorption of C3G into the bloodstream does not fully account for its observed benefits in vivo. Furthermore, intragastric C3G administration modulated the gut microbiota structure and increased the contents of five metabolites in the feces and serum with high inter-individual variation, indicating the key role of the interaction between C3G and the gut microbiota. At equivalent doses, the metabolites cyanidin and protocatechuic acid exhibited greater efficacy than C3G in reducing apoptosis and ROS production by activating the Nrf2 pathway in an AAPH-induced oxidative stress model. To achieve the desired health effects via C3G-rich food intake, more attention should be paid to microbially derived catabolites. Screening of specific metabolite-producing strains will help overcome individual differences and enhance the health-promoting effects of C3G.

Αnti-prion effects of anthocyanins

Prion diseases, also known as Transmissible Spongiform Encephalopathies (TSEs), are protein-based neurodegenerative disorders (NDs) affecting humans and animals. They are characterized by the conformational conversion of the normal cellular prion protein, PrPC, into the pathogenic isoform, PrPSc. Prion diseases are invariably fatal and despite ongoing research, no effective prophylactic or therapeutic avenues are currently available. Anthocyanins (ACNs) are unique flavonoid compounds and interest in their use as potential neuroprotective and/or therapeutic agents against NDs, has increased significantly in recent years. Therefore, we investigated the potential anti-oxidant and anti-prion effects of Oenin and Myrtillin, two of the most common anthocyanins, using the most accepted in the field overexpressing PrPScin vitro model and a cell free protein aggregation model. Our results, indicate both anthocyanins as strong anti-oxidant compounds, upregulating the expression of genes involved in the anti-oxidant response, and reducing the levels of Reactive Oxygen Species (ROS), produced due to pathogenic prion infection, through the activation of the Keap1-Nrf2 pathway. Importantly, they showcased remarkable anti-prion potential, as they not only caused the clearance of pathogenic PrPSc aggregates, but also completely inhibited the formation of PrPSc fibrils in the Cerebrospinal Fluid (CSF) of patients with Creutzfeldt-Jakob disease (CJD). Therefore, Oenin and Myrtillin possess pleiotropic effects, suggesting their potential use as promising preventive and/or therapeutic agents in prion diseases and possibly in the spectrum of neurodegenerative proteinopathies.

Causal associations between dietary factors and colorectal cancer risk: a Mendelian randomization study

Background

Previous epidemiological studies have found a link between colorectal cancer (CRC) and human dietary habits. However, the inherent limitations and inevitable confounding factors of the observational studies may lead to the inaccurate and doubtful results. The causality of dietary factors to CRC remains elusive.

Methods

We conducted two-sample Mendelian randomization (MR) analyses utilizing the data sets from the IEU Open GWAS project. The exposure datasets included alcoholic drinks per week, processed meat intake, beef intake, poultry intake, oily fish intake, non-oily fish intake, lamb/mutton intake, pork intake, cheese intake, bread intake, tea intake, coffee intake, cooked vegetable intake, cereal intake, fresh fruit intake, salad/raw vegetable intake, and dried fruit intake. In our MR analyses, the inverse variance weighted (IVW) method was employed as the primary analytical approach. The weighted median, MR-Egger, weighted mode, and simple mode were also applied to quality control. Heterogeneity and pleiotropic analyses were implemented to replenish the accuracy of the results.

Results

MR consequences revealed that alcoholic drinks per week [odds ratio (OR): 1.565, 95% confidence interval (CI): 1.068-2.293, p = 0.022], non-oily fish intake (OR: 0.286; 95% CI: 0.095-0.860; p = 0.026), fresh fruit intake (OR: 0.513; 95% CI: 0.273-0.964; p = 0.038), cereal intake (OR: 0.435; 95% CI: 0.253-0.476; p = 0.003) and dried fruit intake (OR: 0.522; 95% CI: 0.311-0.875; p = 0.014) was causally correlated with the risk of CRC. No other significant relationships were obtained. The sensitivity analyses proposed the absence of heterogeneity or pleiotropy, demonstrating the reliability of the MR results.

Conclusion

This study indicated that alcoholic drinks were associated with an increased risk of CRC, while non-oily fish intake, fresh fruit intake, cereal intake, and dried fruit were associated with a decreased risk of CRC. This study also indicated that other dietary factors included in this research were not associated with CRC. The current study is the first to establish the link between comprehensive diet-related factors and CRC at the genetic level, offering novel clues for interpreting the genetic etiology of CRC and replenishing new perspectives for the clinical practice of gastrointestinal disease prevention.

Hawthorn Proanthocyanidin Extract Inhibits Colorectal Carcinoma Metastasis by Targeting the Epithelial-Mesenchymal Transition Process and Wnt/β-Catenin Signaling Pathway

Colorectal carcinoma (CRC) is a major global health concern, with cancer metastasis being the main cause of patient mortality, and current CRC treatments are challenged by drug resistance. Although natural compounds, especially in foods like hawthorn proanthocyanidin extract (HPOE), have good anticancer activity, their effects on CRC metastasis remain unknown. Therefore, our objective was to investigate the impact and potential mechanisms of HPOE on the movement and infiltration of cells in the HCT116 CRC cells. Firstly, scratch-healing experiments confirmed the anti-migratory and anti-invasive capabilities of HPOE. Then, network pharmacology identified 16 possible targets, including MMP-9. Subsequently, RT-qPCR and Western blotting experiments confirmed that HPOE downregulated epithelial-mesenchymal transition-related factors (N-cadherin and MMP-9) and inhibited Wnt/β-catenin pathway activation. Finally, these results were experimentally validated using the Wnt pathway activator Licl and inhibitor XAV939. It was confirmed that HPOE had a certain inhibitory effect on the activation of the Wnt signaling pathway caused by the activator Licl and could enhance the inhibitory effect of the inhibitor XAV939. Our findings provide a basis for developing functional foods or dietary supplements, especially positioning HPOE as a functional food raw material for adjuvant treatment of CRC, given its ability to inhibit metastasis through the Wnt/β-catenin pathway.

Association between Dietary Anthocyanidins and Biliary Cancer Risk in 98,458 Participants: Results from a Prospective Study

BACKGROUND

Previous studies have suggested anthocyanidins or anthocyanidin-rich foods and extracts exhibit protective effects against various cancers. However, the relationship between dietary anthocyanidins and the risk of biliary cancer remains uncertain.

METHODS

This study used data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to investigate the relationship between total anthocyanidins intake and biliary cancer incidence. Cox regression analysis was conducted to estimate HRs and corresponding 95% confidence intervals (CI) for the incidence of biliary cancer, with adjustments made for confounding factors. A restricted cubic spline model was employed to examine the dose-response relationship. In addition, subgroup and sensitivity analyses were conducted to evaluate potential interactions and test the model's robustness.

RESULTS

During 8.9 years and 872,645.3 person-years of follow-up, 95 cases of biliary cancer were observed. The incidence rate of biliary cancer in this study was 11 cases per 100,000 person-years. Using the fully adjusted Cox regression model, the inverse association was observed between total anthocyanidins intake and the risk of biliary cancer (HR Q4 vs..Q1: 0.52; 95% CI: 0.29-0.91; Ptrend = 0.043). This association remained significant in sensitivity analyses. A linear dose-response relationship (Pnonlinearity = 0.118) and potential interaction with drinking status (Pinteraction = 0.033) were identified.

CONCLUSIONS

This study provides evidence of an inverse association between total anthocyanidins intake and biliary cancer incidence.

IMPACT

Our study found a total anthocyanidin-rich diet was associated with a reduced risk of biliary cancer in Americans ages 55 to 74 years.

The structure of anthocyanins and the copigmentation by common micromolecular copigments: A review

Under natural physiological conditions, anthocyanins can keep bright and stable color for a long time due to the relatively stable acid-base environment of plant vacuoles and the copigmentation from various copigment substances, such as polyphenols, nucleotides, metallic ions and other substances. Therefore, the copigmentation caused by copigments is considered an effective way to stabilize anthocyanins against adverse environmental conditions. This is attributed to the covalent and noncovalent interactions between colored forms of anthocyanins (flavylium ions and quinoidal bases) and colorless or pale yellow organic molecules (copigments). These interactions are usually manifested in both hyperchromic effect and bathochromic shifts. In addition to making anthocyanins more stable, the copigmentation also could make an important contribution to the diversification of their tone. Based on the molecular structure of anthocyanins, this review focuses on the interaction mode of auxochrome groups or copigments with anthocyanins and their effects on the chemical and color stability of anthocyanins.