Dietary intake of lignans and risk of esophageal and gastric adenocarcinoma: a cohort study in Sweden

Polyphenol intake and gastric cancer: A case-control study in the Brazilian Amazon region

BACKGROUND

Polyphenol intake has been associated with a decreased risk of some types of cancer, including gastric cancer (GC). However, few studies address this topic in the Latin American population. In the present study, we evaluated the association between polyphenol intake and the risk of GC in the Brazilian Amazon region.

METHODS

A case-control study was conducted in Belém (Amazon region) from July 2017 to February 2021. A total of 193 GC cases and 194 controls of both sexes, between 18 and 75 years old, were included in the study. Dietary data were collected using a validated food-frequency questionnaire and polyphenol intake identified using the Phenol-Explorer database. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI), with adjustement for potential confounders.

RESULTS

Cases and controls had similar total polyphenol intake (356.4 mg/1000 kcal/d and 331.1 mg/1000 kcal/d, respectively; p = 0.086). After adjusting for potential confounders, high consumption of flavan-3-ols (highest vs. lowest tertile: OR 0.41, 95% CI 0.18-0.94) and hydroxybenzoic acids (highest vs. lowest tertile: OR 0.24, 95% CI 0.10-0.56) was associated with a decreased risk of GC. The opposite was true regarding the intake of flavones (OR 2.46, 95% IC 1.17-5.18) and other polyphenols (OR 2.54, 95% IC 1.16-5.54). When stratifying according to anatomical topography, we observed that the intake of total flavonoids, flavan-3-ols, and flavanones reduced the risk of cardia GC while that of hydroxybenzoic acids reduced the risk of non-cardia GC. In addition, the intake of flavones and other polyphenols was associated with an increased risk of non-cardia GC. According to histologic subtypes, hydroxybenzoic acid intake was associated with a reduced risk of intestinal-type GC (OR 0.21, 95% IC 0.07-0.64), while flavone consumption was associated with an increased risk of diffuse-type GC (OR 2.59, 95% IC 1.05-6.42).

CONCLUSIONS

Our findings suggest that in the Brazilian Amazon region the high intake of flavan-3-ols and hydroxybenzoic acids is associated with a reduced risk of GC, suggesting a potential beneficial role of these compounds against GC.

Interplay between Lignans and Gut Microbiota: Nutritional, Functional and Methodological Aspects

Lignans are non-flavonoid polyphenols present in a wide range of foods frequently consumed in the Western world, such as seeds, vegetables and fruits, and beverages such as coffee, tea and wine. In particular, the human gut microbiota (GM) can convert dietary lignans into biologically active compounds, especially enterolignans (i.e., enterolactone and enterodiol), which play anti-inflammatory and anti-oxidant roles, act as estrogen receptor activators and modulate gene expression and/or enzyme activity. Interestingly, recent evidence documenting those dietary interventions involving foods enriched in lignans have shown beneficial and protective effects on various human pathologies, including colorectal and breast cancer and cardiovascular diseases. However, considering that more factors (e.g., diet, food transit time and intestinal redox state) can modulate the lignans bioactivation by GM, there are usually remarkable inter-individual differences in urine, fecal and blood concentrations of enterolignans; hence, precise and validated analytical methods, especially gas/liquid chromatography coupled to mass spectrometry, are needed for their accurate quantification. Therefore, this review aims to summarize the beneficial roles of enterolignans, their interaction with GM and the new methodological approaches developed for their evaluation in different biological samples, since they could be considered future promising nutraceuticals for the prevention of human chronic disorders.

Dietary Polyphenol Intake and Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Phenolic compound consumption may have a protective effect against gastric cancer (GC). Most GC studies focus on the flavonoids class, but results are conflicting and knowledge gaps remain for other classes and total polyphenol intake. This study aimed to assess the association between polyphenol intake (total, flavonoids, and other classes) and GC.

METHODS

In this systematic review and meta-analysis, the PubMed, Embase, Scopus, LILACS, Web of Science, and OpenGrey databases were searched for studies published up to 20 March 2022. Case-control and cohort studies analyzing the association between polyphenol intake and GC were included. For the meta-analysis, pooled summary estimates were calculated using a random-effects model, and the estimates extracted adjusted for most variables. Subgroup analyses were performed for subclass (e.g., flavonoids and other classes), sex, geographical area, study design, anatomical subtype, histological subtype, family history of GC and fruit and/or vegetable intake. The study was registered with PROSPERO (#CRD42022306014).

FINDINGS

The search identified 2752 records, of which 19 studies published during the period 1999-2021 including a total of 1,197,857 subjects were eligible. Polyphenol consumption reduced GC risk by 29% (RR = 0.71; 95% CI: 0.62-0.81; I² = 60.5%); while flavonoid intake decreased GC risk by 28% (RR = 0.72; 95% CI: 0.61-0.85; I² = 64.3%), similar to the reduction fort other classes (RR = 0.65; 95% CI: 0.54-0.79; I² = 72.0%). Protective effects against GC were observed in both sexes (male, RR = 0.79; 95% CI: 0.67-0.94, I² = 31.6%; female, RR = 0.65; 95% CI: 0.48-0.87, I² = 49.7%) and for intestinal subtype (RR = 0.65; 95% CI: 0.52-0.82, I² = 0.0%). By continent, polyphenol consumption reduced GC risk in both Europe (RR = 0.67; 95% CI: 0.57-0.79, I² = 44.2%) and Asia (RR = 0.67; 95% CI: 0.51-0.89, I² = 60.7%).

CONCLUSIONS

Dietary polyphenol intake decreased GC risk. The reduction was greatest in females. Most previous studies were carried out in Europe and Asia. Further studies investigating polyphenol consumption and GC in Latin American populations are warranted.

Dietary Assessment Methods to Estimate (Poly)phenol Intake in Epidemiological Studies: A Systematic Review

Nutritional epidemiological studies have frequently reported associations between higher (poly)phenol intake and a decrease in the risk or incidence of noncommunicable diseases. However, the assessment methods that have been used to quantify the intakes of these compounds in large-population samples are highly variable. This systematic review aims to characterize the methods used to assess dietary (poly)phenol intake in observational studies, report the validation status of the methods, and give recommendations on method selection and data reporting. Three databases were searched for publications that have used dietary assessment methods to measure (poly)phenol intake and 549 eligible full texts were identified. Food-frequency questionnaires were found to be the most commonly used tool to assess dietary (poly)phenol intake (73%). Published data from peer-reviewed journals were the major source of (poly)phenol content data (25%). An increasing number of studies used open-access databases such as Phenol-Explorer and USDA databases on flavonoid content since their inception, which accounted for 11% and 23% of the data sources, respectively. Only 16% of the studies reported a method that had been validated for measuring the target (poly)phenols. For future research we recommend: 1) selecting a validated dietary assessment tool according to the target compounds and target period of measurement; 2) applying and combining comprehensive (poly)phenol content databases such as USDA and Phenol-Explorer; 3) detailing the methods used to assess (poly)phenol intake, including dietary assessment method, (poly)phenol content data source; 4) follow the Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut) framework; and 5) complementing dietary intake assessment based on questionnaires with measurement of (poly)phenols in biofluids using appropriate and validated analytical methods.

A network pharmacology perspective for deciphering potential mechanisms of action of Solanum nigrum L. in bladder cancer

BACKGROUND

Solanum nigrum L. decoction has been used as a folklore medicine in China to prevent the postoperative recurrence of bladder cancer (BC). However, there are no previous pharmacological studies on the protective mechanisms of this activity of the plant. Thus, this study aimed to perform a systematic analysis and to predict the potential action mechanisms underlying S. nigrum activity in BC based on network pharmacology.

METHODS

Based on network pharmacology, the active ingredients of S. nigrum and the corresponding targets were identified using the Traditional Chinese Medicines for Systems Pharmacology Database and Analysis Platform database, and BC-related genes were screened using GeneCards and the Online Mendelian Inheritance in Man database. In addition, ingredient-target (I-T) and protein-protein interaction (PPI) networks were constructed using STRING and Cytoscape, Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, and then the pathways directly related to BC were integrated manually to reveal the pharmacological mechanism underlying S. nigrum-medicated therapeutic effects in BC.

RESULTS

Seven active herbal ingredients from 39 components of S. nigrum were identified, which shared 77 common target genes related to BC. I-T network analysis revealed that quercetin was associated with all targets and that NCOA2 was targeted by four ingredients. Besides, interleukin 6 had the highest degree value in the PPI network, indicating a hub role. A subsequent gene enrichment analysis yielded 86 significant GO terms and 89 significant pathways, implying that S. nigrum had therapeutic benefits in BC through multi-pathway effects, including the HIF-1, TNF, P53, MAPK, PI3K/Akt, apoptosis and bladder cancer pathway.

CONCLUSIONS

S. nigrum may mediate pharmacological effects in BC through multi-target and various signaling pathways. Further validation is required experimentally. Network pharmacology approach provides a predicative novel strategy to reveal the holistic mechanism of action of herbs.

Perceived role of hot food in the pathogenesis of oesophageal cancer: a qualitative study in the Arsi Zone, Oromia, Central Ethiopia

Observational studies in Ethiopia have identified a positive association between hot wheat porridge consumption and oesophageal carcinoma. However, a single dietary intake cannot be a sufficient predictor of cancer among populations that have diverse dietary practices. The present study was carried out to explore the community's perspectives on the role of hot foods in the pathogenesis of oesophageal cancer in Ethiopia. Focus group discussions were conducted from May to August 2019 among purposefully selected 112 participants. Data were collected by using open-ended questions; memo writing, audio recordings and photo pictures. All tape-recorded interviews were transcribed verbatim and inductively coded using Atlas.ti Version 7.0.71 software. Finally, the analysis was performed according to the standard thematic framework analysis techniques. The finding showed that hot foods (porridge, coffee and soup) consumption patterns were perceived as the principal dietary risk of oesophageal cancer. Cooking in unventilated rooms, monotonous cereal-based foods, poor vegetable, and fruit intake, not taking milk with porridge, eating fast, swallowing large bolus of hot porridge and exposure to carcinogens in foods were regarded as predisposing dietary practices to oesophageal carcinoma. Socio-demographic, economic and cultural backgrounds were reported as the underlying risk factors associated with oesophageal cancer. There was a strong perception within the community that oesophageal cancer is linked to several but sequentially interlinked dietary and related practices. Cumulative thermal injuries from the consumptions of hot food could be the immediate dietary risk factors associated with increased risk of oesophageal cancer.

Association between Polyphenol Intake and Gastric Cancer Risk by Anatomic and Histologic Subtypes: MCC-Spain

Several anticancer properties have been largely attributed to phenolics in in vivo and in vitro studies, but epidemiologic evidence is still scarce. Furthermore, some classes have not been studied in relation to gastric cancer (GC). The aim of this study was to assess the relationship between the intake of phenolic acids, stilbenes, and other phenolics and the risk of developing GC and its anatomical and histological subtypes. We used data from a multi-case-control study (MCC-Spain) obtained from different regions of Spain. We included 2700 controls and 329 GC cases. Odds ratios (ORs) were calculated using mixed effects logistic regression considering quartiles of phenolic intake. Our results showed an inverse association between stilbene and lignan intake and GC risk (OR_{Q4 vs. Q1} = 0.47; 95% CI: 0.32–0.69 and OR_{Q4 vs. Q1} = 0.53; 95% CI: 0.36–0.77, respectively). We found no overall association between total phenolic acid and other polyphenol class intake and GC risk. However, hydroxybenzaldehydes (OR_{Q4 vs. Q1} = 0.41; 95% CI: 0.28–0.61), hydroxycoumarins (OR_{Q4 vs. Q1} = 0.49; 95% CI: 0.34–0.71), and tyrosols (OR_{Q4 vs. Q1} = 0.56; 95% CI: 0.39–0.80) were inversely associated with GC risk. No differences were found in the analysis by anatomical or histological subtypes. In conclusion, a diet high in stilbenes, lignans, hydroxybenzaldehydes, hydroxycoumarins, and tyrosols was associated with a lower GC risk. Further prospective studies are needed to confirm our results.

Menopausal hormone therapy treatment options and ovarian cancer risk: A Swedish prospective population-based matched-cohort study

Although menopausal hormone therapy (MHT) seemingly increases the risk of ovarian cancer, evidence is insufficient whether the risk varies between various MHT formulations, regimens and administration modes. With the aim of filling these knowledge gaps, we investigated the effect of different MHT treatment options on the risk of ovarian cancer. This prospective Swedish population-based matched-cohort study included all women ≥40 years having used systemic MHT between 2005 and 2012 (288,950 ever-users), group-level matched (1:3) to 866,546 nonusers. MHT use was ascertained from the Swedish Prescribed Drug Registry and data was linked to several national health data registries. Multivariable conditional logistic regression provided odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for parity, and comorbidities. Current EP-MHT use was associated with a modestly increased risk of ovarian cancer (OR = 1.38, 95% CI 1.18-1.62), while no consistent risk was found among past users (OR = 1.00, 95% CI 0.84-1.18). Current continuous testosterone derived (OR = 1.50, 95% CI 1.15-1.96) regimens increased the risk whereas progesterone derived (OR = 1.48, 95% CI 1.00-2.21) regimens increased the risk marginally. Nonsignificant positive associations were observed for sequential regimens (OR = 1.87, 95% CI 0.70-5.08; OR = 1.54, 95% CI 0.96-2.47, respectively). An inverse relationship was observed for all E-MHT use (OR = 0.25, 95% CI 0.22-0.29), but this association might partly be explained by underreporting of oophorectomies or tubal ligations. Current cutaneous EP-MHT (OR = 1.28, 95% CI 0.81-2.02) suggested a possibly lower risk than oral MHT (OR = 1.48, 95% CI 1.25-1.75). In conclusion EP-MHT, notably continuous regimens, were associated with a modestly increased risk of ovarian cancer. The role of E-MHT requires further clarification.

Progress in prevention and treatment of gastric cancer with traditional Chinese medicine

Gastric cancer (GC) is one of the most common malignant tumors of the upper digestive tract, threatening the health of Chinese people seriously. It is often diagnosed at the late stage of the disease because of the lack of specific symptoms and signs in the early stage. However, traditional Chinese medicine (TCM) has good effects in the prevention and treatment of GC. This article reviews the etiology, pathogenesis, syndrome differentiation, and classification of GC, as well as the application of TCM in precancerous lesions of GC, preoperative neoadjuvant chemotherapy of GC, postoperative chemotherapy, and prolonging the life span of GC patients.

Naturally Lignan-Rich Foods: A Dietary Tool for Health Promotion?

Dietary guidelines universally advise adherence to plant-based diets. Plant-based foods confer considerable health benefits, partly attributable to their abundant micronutrient (e.g., polyphenol) content. Interest in polyphenols is largely focused on the contribution of their antioxidant activity to the prevention of various disorders, including cardiovascular disease and cancer. Polyphenols are classified into groups, such as stilbenes, flavonoids, phenolic acids, lignans and others. Lignans, which possess a steroid-like chemical structure and are defined as phytoestrogens, are of particular interest to researchers. Traditionally, health benefits attributed to lignans have included a lowered risk of heart disease, menopausal symptoms, osteoporosis and breast cancer. However, the intake of naturally lignan-rich foods varies with the type of diet. Consequently, based on the latest humans' findings and gathered information on lignan-rich foods collected from Phenol Explorer database this review focuses on the potential health benefits attributable to the consumption of different diets containing naturally lignan-rich foods. Current evidence highlight the bioactive properties of lignans as human health-promoting molecules. Thus, dietary intake of lignan-rich foods could be a useful way to bolster the prevention of chronic illness, such as certain types of cancers and cardiovascular disease.

Antifungal Compounds against Candida Infections from Traditional Chinese Medicine

Infections caused by Candida albicans, often refractory and with high morbidity and mortality, cause a heavy burden on the public health while the current antifungal drugs are limited and are associated with toxicity and resistance. Many plant-derived molecules including compounds isolated from traditional Chinese medicine (TCM) are reported to have antifungal activity through different targets such as cell membrane, cell wall, mitochondria, and virulence factors. Here, we review the recent progress in the anti-Candida compounds from TCM, as well as their antifungal mechanisms. Considering the diverse targets and structures, compounds from TCM might be a potential library for antifungal drug development.

The Male Predominance in Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased rapidly during the past 4 decades in many Western populations, including North America and Europe. The established etiological factors for EAC include gastroesophageal reflux and obesity, Helicobacter pylori infection, tobacco smoking, and consumption of fruit and vegetables. There is a marked male predominance of EAC with a male-to-female ratio in incidence of up to 9:1. This review evaluates the available literature on the reasons for the male predominance, particularly an update on epidemiologic evidence from human studies during the past decade. The striking sex difference does not seem to be explained by established risk factors, given that the prevalence of the etiological factors and the strengths of associations between these factors and EAC risk are similar between the sexes. Sex hormonal factors may play a role in the development of EAC; estrogenic exposures may prevent such development, whereas androgens might increase the risk of EAC. However, continuing research efforts are still needed to fully understand the reasons for the male predominance of EAC.

Dietary habits and esophageal cancer

Cancer of the esophagus is an underestimated, poorly understood, and changing disease. Its overall 5-year survival is less than 20%, even in the United States, which is largely a function of a delay in diagnosis until its more advanced stages. Additionally, the epidemiologic complexities of esophageal cancer are vast, rendering screening and prevention limited at best. First, the prevalence of esophageal cancer is unevenly distributed throughout the world. Second, the two histological forms (squamous cell and adenocarcinoma) vary in terms of their geographic prevalence and associated risk factors. Third, some populations appear at particular risk for esophageal cancer. And fourth, the incidence of esophageal cancer is in continuous flux among groups. Despite the varied prevalence and risks among populations, some factors have emerged as consistent associations while others are only now becoming more fully recognized. The most prominent, scientifically supported, and long-regarded risk factors for esophageal cancer are tobacco, alcohol, and reflux esophagitis. Inasmuch as the above are regarded as important risk factors for esophageal cancer, they are not the sole contributors. Dietary habits, nutrition, local customs, and the environment may be contributory. Along these lines, vitamins, minerals, fruits, vegetables, meats, fats, salted foods, nitrogen compounds, carcinogens, mycotoxins, and even the temperature of what we consume are increasingly regarded as potential etiologies for this deadly although potentially preventable disease. The goal of this review is to shed light on the less known role of nutrition and dietary habits in esophageal cancer.

Metabolism of secoisolariciresinol-diglycoside the dietary precursor to the intestinally derived lignan enterolactone in humans

Secoisolariciresinol-diglycoside (SDG), a natural dietary lignan of flaxseeds now available in dietary supplements, is converted by intestinal bacteria to the mammalian lignans enterodiol and enterolactone. High levels of these lignans in blood and urine are associated with reduced risk of many chronic diseases. Our objective was to determine the bioavailability and pharmacokinetics of SDG in purified flaxseed extracts under dose-ranging and steady-state conditions, and to examine whether differences in secoisolariciresinol-diglycoside purity influence bioavailability. Pharmacokinetic studies were performed on healthy postmenopausal women after oral intake of 25, 50, 75, 86 and 172 mg of secoisolariciresinol-diglycoside. Extracts differing in secoisolariciresinol-diglycoside purity were compared, and steady-state lignan concentrations measured after daily intake for one week. Blood and urine samples were collected at timed intervals and secoisolariciresinol, enterodiol and enterolactone concentrations measured by mass spectrometry. Secoisolariciresinol-diglycoside was efficiently hydrolyzed and converted to secoisolariciresinol. Serum concentrations increased rapidly after oral intake, peaking after 5-7 h and disappearing with a plasma elimination half-life of 4.8 h. Maximum serum concentrations of the biologically active metabolites, enterodiol and enterolactone were attained after 12-24 h and 24-36 h, respectively, and the half-lives were 9.4 h and 13.2 h. Linear dose-responses were observed and secoisolariciresinol bioavailability correlated (r(2) = 0.835) with cumulative lignan excretion. There were no significant differences in the pharmacokinetics of extracts differing in purity, and steady-state serum lignan concentrations were obtained after one-week of daily dosing. In conclusion, this study defines the pharmacokinetics of secoisolariciresinol-diglycoside and shows it is first hydrolyzed and then metabolized in a time-dependent sequence to secoisolariciresinol, enterodiol and ultimately enterolactone, and these metabolites are efficiently absorbed.

Expression of KLF6 in gastric carcinoma and premalignant gastric lesions

AIM: To detect the expression of the krüppel-like factor 6 (KLF6) in human gastric carcinoma and premalignant gastric lesions to investigate its role in the occurrence and development of gastric cancer.

METHODS: Fresh frozen gastric carcinoma tissues and matched tumor-adjacent normal gastric mucosa tissues were collected from 32 patients with gastric carcinoma. RT-PCR was used to analyze the expression level of KLF6 mRNA in these tissue samples. Meanwhile, the expression of KLF6 protein was detected by immunohistochemistry in 111 formalin-fixed paraffin-embedded samples, including 20 cases of normal gastric mucosa, 45 cases of intestinal metaplasia, 16 cases of dysplasia, and 30 cases of gastric carcinoma. The association of KLF6 expression with clinicopathological characteristics was analyzed.

RESULTS: The positive rate of KLF6 protein expression in normal gastric mucosa was significantly different from those in type Ⅲ intestinal metaplasia, dysplasia and gastric carcinoma (χ² = 6.033, 3.889, 11.092, P = 0.014, 0.049, 0.001). The positive rate of KLF6 expression in gastric carcinoma was associated with tumor differentiation and size (P = 0.009, 0.010). There was no significant difference in the expression of KLF6 mRNA between normal gastric mucosa and gastric carcinoma (P = 0.357).

CONCLUSION: Abnormal expression of KLF6 is closely related to type Ⅲ intestinal metaplasia, dysplasia, and gastric carcinoma. Detection of KLF6 expression may have certain value in the surveillance of premalignant lesions and the discovery of early gastric carcinoma.