Dietary antioxidant intake and the risk of developing Barrett's oesophagus and oesophageal adenocarcinoma

Association between dietary vitamin C intake/blood level and risk of digestive system cancer: a systematic review and meta-analysis of prospective studies

Experimental studies have shown that vitamin C has anti-cancer effects, but previous meta-analyses have indicated that the role of vitamin C in digestive system cancers (DSCs) is controversial. In this study, a systematic review and meta-analysis of the relationship between dietary intake/plasma concentration of vitamin C and the risk of DSC was conducted, evaluating 32 prospective studies with 1 664 498 participants. Dose-response and subgroup analyses were also performed. Systematic literature searches were performed in PubMed, EMBASE and Web of Science databases until 9th September 2023. Vitamin C intake significantly reduced DSCs risk (RR = 0.88, 95% confidence interval (CI) 0.83 to 0.93). The subgroup analyses showed the risks of oral, pharyngeal, and esophageal (OPE) cancers (0.81, 0.72 to 0.93), gastric cancer (0.81, 0.68 to 0.95), and colorectal cancer (0.89, 0.82 to 0.98) were negatively correlated with vitamin C intake, and the effect of vitamin C was different between colon cancer (0.87, 0.77 to 0.97) and rectal cancer (1.00, 0.84 to 1.19). However, plasma vitamin C concentration was only inversely associated with gastric cancer risk (0.74, 0.59 to 0.92). Dose-response analysis revealed that 250 and 65 mg day-1 vitamin C intakes had the strongest protective effect against OPE and gastric cancers respectively. These estimates suggest that vitamin C intake could significantly reduce gastrointestinal cancer incidence, including OPE, gastric, and colon cancers. Plasma vitamin C has a significant reduction effect on the incidence of gastric cancer only, but additional large-scale clinical studies are needed to determine its impact on the incidence of DSCs.

Antioxidant and Anti-Inflammatory Compounds from Edible Plants with Anti-Cancer Activity and Their Potential Use as Drugs

Food is our daily companion, performing numerous beneficial functions for our bodies. Many of them can help to alleviate or prevent ailments and diseases. In this review, an extensive bibliographic search is conducted in various databases to update information on unprocessed foods with anti-inflammatory and antioxidant properties that can aid in treating diseases such as cancer. The current state of knowledge on inflammatory processes involving some interleukins and tumor necrosis factor-alpha (TNF-α) is reviewed. As well as unprocessed foods, which may help reduce inflammation and oxidative stress, both of which are important factors in cancer development. Many studies are still needed to take full advantage of the food products we use daily.

Regulation of wheat bran feruloyl oligosaccharides in the intestinal antioxidative capacity of rats associated with the p38/JNK-Nrf2 signaling pathway and gut microbiota

BACKGROUND

Feruloyl oligosaccharides (FOs), the ferulic acid ester of oligosaccharides, may possess the physiological functions of both ferulic acid and oligosaccharides, including antioxidative activity and gut microbiota modulation capacity. The present study aimed to investigate whether FOs could regulate the intestinal antioxidative capacity of rats by modulating the MAPKs/Nrf2 signaling pathway and gut microbiota. Thirty Wistar rats were randomly divided into five groups. Rats received a standard diet and were gavaged once daily with 0.85% normal saline, 100 mg kg^-1 body weight vitamin C or FOs solution at doses of 20, 40 and 80 mg kg^-1 body weight for 21 days.

RESULTS

FOs strengthened the antioxidative capacity of the jejunum, as indicated by increased in contents of catalase, superoxide dismutase and glutathione peroxidase, as well as glutathione. Moreover, FOs administration upregulated the mRNA expression level of antioxidant-related genes (glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit and heme oxygenase-1) in the jejunum. Increases in phosphorylation levels of Nrf2, p38 and JNK were also observed. Administration with 40 mg kg^-1 FOs altered the structure and composition of the cecal microbiota, which was indicated by the increased the relative abundances of Actinobacteria, Proteobacteria and Acidobacteriota, and the decreased the relative abundances of Firmicutes, Lachnospiraceae_NK4A136_group and Blautia. Furthermore, Spearman correlation analysis revealed that the altered cecal microbiota closely correlated with jejunal antioxidative capacity of rats.

CONCLUSION

FOs could be used as an antioxidant for gut heath improvement through modulating the p38/JNK-Nrf2 signaling pathway and gut microbiota. © 2022 Society of Chemical Industry.

The Association between Dietary Vitamin C Intake and the Risk of Esophageal Cancer: An Updated Dose-Response Meta-Analysis

Although some epidemiological studies have reported the associations between vitamin C and risk of esophageal cancer, these results are inconsistent. Therefore, we performed an updated meta-analysis to explore the associations between dietary vitamin C intake and risk of esophageal cancer. We used PubMed, Embase, and the Web of Science to screen all published articles, which yielded 18 papers eligible for data extraction (involving 4,126 cases and 36,902 controls), and then pooled the odds ratios (ORs) and corresponding 95% confidence intervals (CIs) using random-effects model. As we detected the associations in highest category and the lowest type of dietary vitamin C intake, we discovered that dietary vitamin C intake was negatively correlated to the risk of esophageal cancer. The analysis of subgroup showed a significant counter proportion between vitamin C and the risk of ESCC and EAC. Moreover, the dose-analysis indicated that if increasing dietary intake of vitamin C of 50 mg/day, esophageal cancer risk dropped down 10% (OR = 0.81, 95%CI: 0.75-0.87). In summary, our study provides a comprehensive and updated epidemiological evidence to elucidate the relationships between dietary vitamin C and reduction of esophageal cancer risk. Nevertheless, we still need larger case-control and cohort studies to confirm these connections.

Relationship Between Dietary Fiber and Vitamin C Intake and Oral Cancer

BACKGROUND

Dietary fiber and vitamin C has been reported to play a possible role in tumorigenesis. However, few studies have estimated their association with oral cancer risk. In this project, we investigated the relationship between dietary fiber and vitamin C and oral cancer risk in adults in Southern China.

METHODS

382 patients newly diagnosed with oral cancer were matched to 382 hospital derived controls by frequency matching in age and sex. Pre-diagnostic consumption of dietary fiber and vitamin C intake were measured through food frequency questionnaire. Association between nutrients intake and oral cancer risk were evaluated by logistic regression. OR value and 95% confidence interval was calculated.

RESULTS

Intake of dietary fiber and vitamin C was significantly lower in oral cancer patients (8.15 g/day) than in control participants (8.88 g/day). Increased dietary fiber or vitamin C intake was linked to a decreased incidence of OC after adjustment of age, marital status, residence, BMI, occupation, education, tobacco smoking, alcohol consumption and family history of cancer Ptrend < 0.001). Compared with the lowest tertile, the adjusted OR of the top tertile of dietary fiber was 0.47 (95 % CI 0.32, 0.68). While the adjusted OR of the highest tertile was 0.60 (95 % CI 0.42, 0.87) compared with the lowest tertile of vitamin C.

CONCLUSIONS

Dietary intake of fiber and vitamin C were lower in oral cancer patients than in control participants. Dietary fiber and vitamin C were inversely related to risk of oral cancer risk.

Zinc Gluconate Induces Potentially Cancer Chemopreventive Activity in Barrett's Esophagus: A Phase 1 Pilot Study

BACKGROUND

Chemopreventive effects of zinc for esophageal cancer have been well documented in animal models. This prospective study explores if a similar, potentially chemopreventive action can be seen in Barrett's esophagus (BE) in humans.

AIMS

To determine if molecular evidence can be obtained potentially indicating zinc's chemopreventive action in Barrett's metaplasia.

METHODS

Patients with a prior BE diagnosis were placed on oral zinc gluconate (14 days of 26.4 mg zinc BID) or a sodium gluconate placebo, prior to their surveillance endoscopy procedure. Biopsies of Barrett's mucosa were then obtained for miRNA and mRNA microarrays, or protein analyses.

RESULTS

Zinc-induced mRNA changes were observed for a large number of transcripts. These included downregulation of transcripts encoding proinflammatory proteins (IL32, IL1β, IL15, IL7R, IL2R, IL15R, IL3R), upregulation of anti-inflammatory mediators (IL1RA), downregulation of transcripts mediating epithelial-to-mesenchymal transition (EMT) (LIF, MYB, LYN, MTA1, SRC, SNAIL1, and TWIST1), and upregulation of transcripts that oppose EMT (BMP7, MTSS1, TRIB3, GRHL1). miRNA arrays showed significant upregulation of seven miRs with tumor suppressor activity (-125b-5P, -132-3P, -548z, -551a, -504, -518, and -34a-5P). Of proteins analyzed by Western blot, increased expression of the pro-apoptotic protein, BAX, and the tight junctional protein, CLAUDIN-7, along with decreased expression of BCL-2 and VEGF-R2 were noteworthy.

CONCLUSIONS

When these mRNA, miRNA, and protein molecular data are considered collectively, a cancer chemopreventive action by zinc in Barrett's metaplasia may be possible for this precancerous esophageal tissue. These results and the extensive prior animal model studies argue for a future prospective clinical trial for this safe, easily-administered, and inexpensive micronutrient, that could determine if a chemopreventive action truly exists.

Urinary exposure of N-nitrosamines and associated risk of esophageal cancer in a high incidence area in China

Esophageal cancer (EC) is a deadly malignancy worldwide with a high incidence and exhibits unevenly geographic prevalence, which suggests that environmental factors are deeply involved in the development of EC. Although the carcinogenesis of nitrosamines in the esophagus has been identified by tremendous toxicological data, the role of nitrosamines in the genesis of human EC has so far proved inconclusive largely due to a lack of convincing evidences. In this study, urinary nitrosamines in population controls and cases with esophageal precancerous lesions, including reflux esophagitis (RE) accompanying with basal cell hyperplasia (BCH) and dysplasia (DYS), and esophageal squamous cell carcinoma (ESCC) were detected by a SPE-LC-MS/MS method and the associated risk was evaluated. Higher excretion concentrations of N-nitrosomethylethylamine (NMEA) in the RE/BCH patients, NMEA and N-nitrosodibutylamine (NDBA) in the DYS patients, and NMEA, NDBA, N-nitrosopyrrolidine (NPyr) and N-nitrosomorpholine (NMor) in the ESCC patients were observed compared with the controls (p < .05). And with the progression of esophageal lesion, the exposure complexity increased in terms of the categories of nitrosamines. Furthermore, the observed positive associations between the hazardous exposure of NMEA, NDBA and NPyr and the increased risk of ESCC, and between NMEA and NDBA and RE/BCH were established. These findings provided direct evidence to support the hypothesis that exposure to nitrosamines are involved in the carcinogenesis of esophageal epithelia in this high incidence area from the perspective of endogenous exposure assessment. However, discoveries in this study need to be confirmed by systematic researches in the future. And the dose-response relationships, the reference ranges or cutoff values to predict the risks of nitrosamines exposure also need to be defined.

Lonicera caerulea L. Polyphenols Alleviate Oxidative Stress-Induced Intestinal Environment Imbalance and Lipopolysaccharide-Induced Liver Injury in HFD-Fed Rats by Regulating the Nrf2/HO-1/NQO1 and MAPK Pathways

SCOPE

This study investigates the modulatory effects of Lonicera caerulea L. polyphenols (LCPs) on the intestinal environment and lipopolysaccharide (LPS)-induced liver injury via the nuclear factor erythroid-2-related factor 2/heme oxygenase-1 (HO-1)/NQO1 and mitogen-activated protein kinase (MAPK) pathways in a rat model of oxidative stress damage (OSD).

METHODS AND RESULTS

To examine the prebiotic properties of LCP, a model of high-fat-diet-induced OSD is established using Sprague Dawley rats. In the colon, treatment with LCP for 8 weeks ameliorates enhanced intestinal permeability (glucagon-like peptide-2 content and occludin protein increase, whereas claudin-2 protein decreases), intestinal inflammation (levels of pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin-6, cyclooxygenase-2, and nuclear factor kappa-B p65 (NF-κB p65), decrease), and intestinal OSD (through regulation of the Nrf2/HO-1/NQO1 pathway). Moreover, LCP alleviates LPS-induced liver injury by suppressing the nuclear translocation of NF-κB p65 and activation of the MAPK signaling pathway. Additionally, Bacilli, Lactobacillales, Lactobacillaceae, Lactobacillus, Akkermansia, Actinobacteria, Proteobacteria, Rothia, and Blautia are found to be the key intestinal microbial taxa related to intestinal OSD and LPS-induced liver injury in rats.

CONCLUSION

LCP treatment potentially modulates the intestinal environment and alleviates liver injury by suppressing oxidative-stress-related pathways and altering the composition of the intestinal microbiota.