Polyphenols: dietary assessment and role in the prevention of cancers

Evaluating the health impact of increased linseed consumption in the Danish population

Consumption of linseeds has been suggested to have beneficial effects on human health. However, toxic constituents of linseed may compromise these benefits. We conducted a quantitative risk-benefit assessment to evaluate the overall health impact of increasing linseed intake up to 45 g/day in the Danish population (15-74 years). We quantified the risks associated with increased cadmium exposure and the benefits associated with increased intake of dietary fibre. Increased intakes of alpha-linoleic acid (ALA) were included in a sensitivity analysis. The overall health impact of different linseed intake scenarios was estimated in terms of Disability-Adjusted Life Years (DALYs). We found that the beneficial effects of linseed due to increased intake of dietary fibre outweighed the adverse health effects due to increased cadmium exposure in all scenarios. Up to 670 DALYs/100,000 individuals could be averted per year by increasing linseed consumption in the Danish population. The estimated beneficial health impact increased further when including ALA in the assessment. Different sources of uncertainty might affect the results, and more research is needed on both the health effects associated with intake of linseed and its constituents, and the bioavailability of ALA and cadmium from linseed to further improve the risk-benefit assessment.

Endoplasmic Reticulum as a Therapeutic Target in Cancer: Is there a Role for Flavonoids?

Flavonoids are classified into subclasses of polyphenols, a multipurpose category of natural compounds which comprises secondary metabolites extracted from vascular plants and are plentiful in the human diet. Although the details of flavonoid mechanisms are still not realized correctly, they are generally regarded as antimicrobial, anti-fungal, anti-inflammatory, anti-oxidative; anti-mutagenic; anti-neoplastic; anti-aging; anti-diabetic, cardio-protective, etc. The anti-cancer properties of flavonoids are evident in functions such as prevention of proliferation, metastasis, invasion, inflammation and activation of cell death. Tumors growth and enlargement expose cells to acidosis, hypoxia, and lack of nutrients which result in endoplasmic reticulum (ER) stress; it triggers the unfolded protein response (UPR), which reclaims homeostasis or activates autophagy. Steady stimulation of ER stress can switch autophagy to apoptosis. The connection between ER stress and cancer, in association with UPR, has been explained. The signals provided by UPR can activate or inhibit anti-apoptotic or apoptotic pathways depending on the period and grade of ER stress. In this review, we will peruse the link between flavonoids and their impact on the endoplasmic reticulum in association with cancer therapy.

Comparative Anticancer Potential of Green Tea Extract and Epigallocatechin-3-gallate on Breast Cancer Spheroids

Despite advances in diagnosis and therapy, breast cancer remains the leading cause of death in many countries. Green tea (GT) has been proposed to play a crucial role in cancer chemoprevention. Although extensive research has been conducted on GT phytochemicals, most experimental studies concentrate mainly on commercial formulations or isolated catechins. This study presents a comparative investigation into the anticancer properties of green tea extract (GTE) and epigallocatechin-3-gallate (EGCG) in a three-dimensional (3D) MCF-7 breast cancer cell culture. MCF-7 spheroids were exposed to GTE or EGCG, and effects on 3D culture formation, growth, cell viability, and migration were examined. GTE inhibits cell migration and the formation of breast cancer spheroids more effectively than EGCG, while inducing more pronounced morphological changes in the spheroids' structure. These findings suggest that the food matrix improves GTE effects on breast cancer spheroids, supporting the hypothesis that a mixture of phytochemicals might enhance its anticancer potential.

Association between Total Dietary Phytochemical Intake and Cardiometabolic Health Outcomes-Results from a 10-Year Follow-Up on a Middle-Aged Cohort Population

Dietary phytochemical intake associations with cardiovascular health and mortality remain unknown. We studied the relations between total dietary phytochemical intake and cardiovascular health outcomes in a middle-aged Swiss population. We analyzed data spanning 2009 to 2021 from a prospective cohort study in Lausanne, Switzerland, including 3721 participants (54.8% women, 57.2 ± 10.3 years) without cardiovascular disease (CVD) history. Dietary intake was assessed using a validated self-reported food frequency questionnaire. The Dietary Phytochemical Index (DPI) and the healthy Dietary Phytochemical Index (hDPI) were calculated as the total energy intake percentage obtained from phytochemical-rich food consumption. The Healthy Plant-Based Diet Index (hPBD) was estimated by scoring healthy plant foods positively and less-healthy plant foods negatively. Indices tertiles and cardiometabolic outcome associations were determined using Cox proportional hazard models. Over 30,217 person-years of follow-up, 262 CVD events, and 178 deaths occurred. Unadjusted analyses found 36%, 33%, and 32% lower CVD risk for the highest hDPI, DPI, and hPBD tertiles, respectively. After adjustment, only the second hDPI tertile showed a 30% lower CVD risk (HR 0.70, 95% CI 0.51-0.95; P for trend 0.362). No other associations emerged. In this middle-aged Swiss cohort, no associations between dietary indices reflecting a phytochemical-rich dietary pattern and incident CVD, all-cause, or CVD mortality were observed.

Association between dietary phytochemical index, cardiometabolic risk factors and metabolic syndrome in Switzerland. The CoLaus study

BACKGROUND AND AIMS

Plant-based diets are associated with reduced cardiometabolic risk factors (CRFs) and lower risk of metabolic syndrome (MetS), probably via phytochemicals acting synergistically. However, dietary phytochemical content estimation is challenging; therefore, the dietary phytochemical index (DPI) was proposed as a practical way to assess total dietary phytochemical content from phytochemical-rich foods (PRFs). We evaluated the association between DPI with CRFs and MetS and its components.

METHODS AND RESULTS

Cross-sectional analysis of 2009-2012 data of Colaus cohort study (Lausanne, Switzerland), including 3879 participants (mean age 57.6 ± 10.4 years, 53.5% women). Dietary intake was assessed via a validated food frequency questionnaire. DPI was calculated as the total energy intake percentage obtained from PRFs consumption and assessed as quartiles. Associations were determined using multivariable linear and logistic regression for CRFs and MetS, respectively. Median DPI value was 25.5 (interquartile range: 17.7-34.6). After multivariable-adjusted analyses, significant inverse associations were observed between the last two highest DPI quartiles and waist circumference (WC), body mass index (BMI), insulin, leptin, and hs-CRP. No significant associations were observed for MetS or its components except for central obesity, as subjects in the highest DPI quartile had lower odds (OR: 0.78; 95% CI: 0.62, 0.97) than those in lowest quartile.

CONCLUSION

A diet high in PRFs assessed via DPI is associated with lower WC, BMI, insulin, leptin, hs-CRP values, and lower odds of central obesity, indicating a potential protective effect of phytochemical intake on these CRFs and highlighting the importance of high PRFs intake in promoting cardiometabolic health.

Development of a novel (poly)phenol-rich diet score and its association with urinary (poly)phenol metabolites

Background: Estimating (poly)phenol intake is challenging due to inadequate dietary assessment tools and limited food content data. Currently, a priori diet scores to characterise (poly)phenol-rich diets are lacking. This study aimed to develop a novel (poly)phenol-rich diet score (PPS) and explore its relationship with circulating (poly)phenol metabolites. Methods: A total of 543 healthy free-living participants aged 18-80 years completed a food frequency questionnaire (FFQ) (EPIC-Norfolk) and provided 24 h urine samples. The PPS was developed based on the relative intake (quintiles) of 20 selected (poly)phenol-rich food items abundant in the UK diet, including tea, coffee, red wine, whole grains, chocolate and cocoa products, berries, apples and juice, pears, grapes, plums, citrus fruits and juice, potatoes and carrots, onions, peppers, garlic, green vegetables, pulses, soy and soy products, nuts, and olive oil. Foods included in the PPS were chosen based on their (poly)phenol content, main sources of (poly)phenols, and consumption frequencies in the UK population. Associations between the PPS and urinary phenolic metabolites were investigated using linear models adjusting energy intake and multiple testing (FDR adjusted p < 0.05). Result: The total PPS ranged from 25 to 88, with a mean score of 54. A total of 51 individual urinary metabolites were significantly associated with the PPS, including 39 phenolic acids, 5 flavonoids, 3 lignans, 2 resveratrol and 2 other (poly)phenol metabolites. The total (poly)phenol intake derived from FFQs also showed a positive association with PPS (stdBeta 0.32, 95% CI (0.24, 0.40), p < 0.01). Significant positive associations were observed in 24 of 27 classes and subclasses of estimated (poly)phenol intake and PPS, with stdBeta values ranging from 0.12 (0.04, 0.20) for theaflavins/thearubigins to 0.43 (0.34, 0.51) for flavonols (p < 0.01). Conclusion: High adherence to the PPS diet is associated with (poly)phenol intake and urinary biomarkers, indicating the utility of the PPS to characterise diets rich in (poly)phenols at a population level.

Non-Digestible Carbohydrates: Green Extraction from Food By-Products and Assessment of Their Effect on Microbiota Modulation

The nature and composition of the waste produced by food industrial processing make its abundance and accumulation an environmental problem. Since these by-products may present a high potential for revalorization and may be used to obtain added-value compounds, the main goals of the technological advancements have been targeted at reducing the environmental impact and benefiting from the retrieval of active compounds with technological and health properties. Among the added-value substances, nondigestible carbohydrates have demonstrated promise. In addition to their well-known technological properties, they have been discovered to modify the gut microbiota and enhance immune function, including the stimulation of immune cells and the control of inflammatory reactions. Furthermore, the combination of these compounds with other substances such us phenols could improve their biological effect on different noncommunicable diseases through microbiota modulation. In order to gain insight into the implementation of this combined strategy, a broader focus concerning different aspects is needed. This review is focused on the optimized green and advanced extraction system applied to obtain added-value nondigestible carbohydrates, the combined administration with phenols and their beneficial effects on microbiota modulation intended for health and/or illness prevention, with particular emphasis on noncommunicable diseases. The isolation of nondigestible carbohydrates from by-products as well as in combination with other bioactive substances could provide an affordable and sustainable source of immunomodulatory chemicals.

Combined effect of apigenin and reduced graphene oxide against Enterococcus faecalis biofilms

PURPOSE

Enterococcus faecalis (E. faecalis) is one of the major microorganisms that causes failure of endodontic treatment. This study aimed to investigate the antibacterial activity of apigenin and its synergistic effect with reduced graphene oxide (RGO) in treating E. faecalis biofilms.

METHODS

The antibacterial activities were characterized by viability analysis including colony forming units and confocal laser scanning microscopy (CLSM) analyses. The effect on biofilm biomass was measured using a crystal violet staining method. Live and dead bacteria bio-volumes were determined by CLSM analysis, and the morphology of E. faecalis biofilm after treatment with apigenin and apigenin + RGO was observed by scanning electron microscopy (SEM).

RESULTS

The viability of E. faecalis in biofilms decreased by apigenin treatment in a dose-dependent manner. While apigenin alone did not significantly affect the biofilm biomass, apigenin + RGO reduced the biomass in an apigenin concentration-dependent manner. Likewise, the bio-volume of live bacteria decreased and the bio-volume of dead bacteria increased in apigenin-treated biofilms. According to SEM images, apigenin + RGO-treated samples showed less E. faecalis in biofilms than apigenin-only treated samples.

CONCLUSION

The results suggested that the combined use of apigenin and RGO could be a potential strategy for effective endodontic disinfection.

(Poly)phenol intake, plant-rich dietary patterns and cardiometabolic health: a cross-sectional study

Diet is an important modifiable risk factor for cardiometabolic diseases. Plant foods contain a complex mixture of nutrients and bioactive compounds such as (poly)phenols. Plant-rich dietary patterns have been associated with reduced cardiometabolic risk in epidemiological studies. However, studies have not fully considered (poly)phenols as a mediating factor in the relationship. A cross-sectional analysis was conducted in 525 healthy participants, aged 41.6 ± 18.3 years. Volunteers completed the validated European Prospective Investigation into Diet and Cancer (EPIC) Norfolk Food Frequency Questionnaire (FFQ). We investigated the associations between plant-rich dietary patterns, (poly)phenol intake, and cardiometabolic health. Positive associations were found between (poly)phenols and higher adherence to dietary scores, except for the unhealthy Plant-based Diet Index (uPDI), which was negatively associated with (poly)phenol intake. Correlations were significant for healthy PDI (hPDI), with positive associations with proanthocyanidins (r = 0.39, p < 0.01) and flavonols (r = 0.37, p < 0.01). Among dietary scores, Dietary Approaches to Stop Hypertension (DASH) showed negative associations with diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and non-high-density lipoprotein cholesterol (Non-HDL-C) (stdBeta -0.12 to -0.10, p < 0.05). The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) score was positively associated with flow-mediated dilation (FMD, stdBeta = 0.10, p = 0.02) and negatively associated with the 10-year Atherosclerotic Cardiovascular Disease (ASCVD) risk score (stdBeta = -0.12, p = 0.01). Higher intake of flavonoids, flavan-3-ols, flavan-3-ol monomers, theaflavins, and hydroxybenzoic acids (stdBeta: -0.31 to -0.29, p = 0.02) also showed a negative association with a 10-year ASCVD risk score. Flavanones showed significant associations with cardiometabolic markers such as fasting plasma glucose (FPG) (stdBeta = -0.11, p = 0.04), TC (stdBeta = -0.13, p = 0.03), and the Homeostasis Model Assessment (HOMA) of beta cell function (%B) (stdBeta = 0.18, p = 0.04). Flavanone intake was identified as a potential partial mediator in the negative association between TC and plant-rich dietary scores DASH, Original Mediterranean diet scores (O-MED), PDI, and hPDI (proportion mediated = 0.01% to 0.07%, p < 0.05). Higher (poly)phenol intake, particularly flavanone intake, is associated with higher adherence to plant-rich dietary patterns and favourable biomarkers of cardiometabolic risk indicating (poly)phenols may be mediating factors in the beneficial effects.

Potential Role of Natural Antioxidant Products in Oncological Diseases

Nutrition has a significant effect and a crucial role in disease prevention. Low consumption of fruit and vegetables and a sedentary lifestyle are closely related with the onset and development of many types of cancer. Recently, nutraceuticals have gained much attention in cancer research due to their pleiotropic effects and relatively non-toxic behavior. In fact, although in the past there have been conflicting results on the role of some antioxidant compounds as allies against cancer, numerous recent clinical studies highlight the efficacy of dietary phytochemicals in the prevention and treatment of cancer. However, further investigation is necessary to gain a deeper understanding of the potential anticancer capacities of dietary phytochemicals as well as the mechanisms of their action. Therefore, this review examined the current literature on the key properties of the bioactive components present in the diet, such as carotenoids, polyphenols, and antioxidant compounds, as well as their use in cancer therapy. The review focused on potential chemopreventive properties, evaluating their synergistic effects with anticancer drugs and, consequently, the side effects associated with current cancer treatments.

Dietary Flavonoid Intake and Cancer Mortality: A Population-Based Cohort Study

Cancer is a leading cause of death worldwide, posing a huge burden upon society and individuals. The adequate intake of fruit and vegetables is reported to be an effective strategy for primary cancer prevention. Fruits and vegetables are rich in nutrients, such as vitamins and flavonoids, which may reduce the occurrence and progression of cancers. However, the importance of each flavonoid and the sub-classes remains controversial regarding cancer mortality. The population benefiting from increased flavonoid intake has not been determined. An estimation of cancer mortality by flavonoid intake is not established. We explored the association between the intake of flavonoids and cancer mortality amongst 14,029 participants in the National Health and Nutrition Examination Survey. During a median follow-up of 117 months, 405 cancer deaths were confirmed. Being in the second, third, and fourth quartiles of flavonol intake, the cancer mortality was inversely associated with the intake of flavonols (multivariate analysis HR (95% CI] 0.58 [0.36, 0.91], p = 0.02, Q1 vs. Q2; 0.55 [0.31, 0.96], p = 0.04, Q1 vs. Q3; 0.54 [0.30, 0.99], p = 0.05, Q1 vs. Q4, respectively). Potential effects of dietary flavonol intake against cancer death was observed especially in participants aged 50 or above, males, whites, former smokers, people who used to drink or drink alcohol mildly, people without hyperlipidemia, and people with hypertension. Moreover, the dietary intakes of peonidin, naringenin, and catechin were inversely associated with cancer mortality (multivariate HR [95% CI] 0.93 [0.88,0.98], p = 0.01; 0.97 (0.95,1.00), p = 0.03; 0.98 (0.96,1.00), p = 0.05, respectively). Furthermore, a nomogram based on flavonol intake is feasible for assessing cancer mortality for each participant. Taken together, our results could improve personalized nutrition amongst cancer patients.

Baicalein Induces G2/M Cell Cycle Arrest Associated with ROS Generation and CHK2 Activation in Highly Invasive Human Ovarian Cancer Cells

Ovarian cancer is a lethal gynecological cancer because drug resistance often results in treatment failure. The CHK2, a tumor suppressor, is considered to be an important molecular target in ovarian cancer due to its role in DNA repair. Dysfunctional CHK2 impairs DNA damage-induced checkpoints, reduces apoptosis, and confers resistance to chemotherapeutic drugs and radiation therapy in ovarian cancer cells. This provides a basis for finding new effective agents targeting CHK2 upregulation or activation to treat or prevent the progression of advanced ovarian cancer. Here, the results show that baicalein (5,6,7-trihydroxyflavone) treatment inhibits the growth of highly invasive ovarian cancer cells, and that baicalein-induced growth inhibition is mediated by the cell cycle arrest in the G₂/M phase. Baicalein-induced G₂/M phase arrest is associated with an increased reactive oxygen species (ROS) production, DNA damage, and CHK2 upregulation and activation. Thus, baicalein modulates the expression of DNA damage response proteins and G₂/M phase regulatory molecules. Blockade of CHK2 activation by CHK2 inhibitors protects cells from baicalein-mediated G₂/M cell cycle arrest. All the results suggest that baicalein has another novel growth inhibitory effect on highly invasive ovarian cancer cells, which is partly related to G₂/M cell cycle arrest through the ROS-mediated DNA breakage damage and CHK2 activation. Collectively, our findings provide a molecular basis for the potential of baicalein as an adjuvant therapeutic agent in the treatment of metastatic ovarian cancer.

Descriptive analysis of dietary (poly)phenol intake in the subcohort MAX from DCH-NG: "Diet, Cancer and Health-Next Generations cohort"

PURPOSE

(Poly)phenols are bioactive compounds widely distributed in plant-based foods. Currently, limited data exist on the intake distribution of (poly)phenols across meals. This study aimed to estimate dietary intakes of all individual (poly)phenols and total intake per class and subclass by meal event, and to identify their main food sources in the subcohort MAX from the Diet, Cancer and Health-Next Generations cohort (DCH-NG).

METHODS

Dietary data were collected using three web-based 24-h dietary recalls over 1 year. In total, 676 participants completed at least one recall. The dietary data were linked to Phenol-Explorer database using standardized procedures and an in-house software. We categorized foods/drinks into five options of meal events selected by the participant: 'Breakfast', 'Lunch', 'Evening', 'Snack', and 'Drink'.

RESULTS

Adjusted total (poly)phenols mean intake by meal was the highest in the drink event (563 mg/day in men and 423 mg/day in women) and the lowest in the evening event (146 mg/day in men and 137 mg/day in women). The main overall (poly)phenol class contributor was phenolic acids (55.7-79.0%), except for evening and snack events where it was flavonoids (45.5-60%). The most consumed (poly)phenol subclasses were hydroxycinnamic acids and proanthocyanidins. Nonalcoholic beverages (coffee accounted for 66.4%), cocoa products, and cereals were the main food sources of total (poly)phenols.

CONCLUSION

This study provides data on the variability in the intake of classes and subclasses of (poly)phenols and their main food sources by meal event according to lifestyle data, age, and gender in a Danish population.

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.

Quality by Design in optimizing the extraction of (poly)phenolic compounds from Vaccinium myrtillus berries

Quality by Design was adopted for developing an effective extraction procedure of (poly)phenolic compounds from bilberry (Vaccinium myrtillus L.) fruits, using a pooled sample of berries from different regions of Ukraine. Mechanical solvent extraction, microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) were investigated by screening matrices. Extraction time (Time, from 5 to 15 min), organic solvent type (OS type, methanol, ethanol and acetone), organic solvent percentage (OS%, from 50% to 90%), sample/extractant ratio (S/E ratio, from 0.025 to 0.1 g mL^-1), and, only for MAE, extraction temperature (T, from 30 to 60°C), were selected as critical method parameters (CMPs). The spectrophotometric assays total soluble polyphenols (TSP), total monomeric anthocyanins (TMA), and radical scavenging activity (evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), the 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid), and the ferric reducing antioxidant power methods) were chosen as critical method attributes (CMAs). The screening procedure allowed for selecting UAE and methanol, while the other CMPs underwent further optimization through Response Surface Methodology. Target values for TSP, TMA and DPPH were selected and the method operable design region (MODR) was defined by means of Monte-Carlo simulations. The optimized conditions, with the corresponding MODR intervals in bracket, were the following: (i) Time, 17 min (15-23 min); OS%, 56% (44-59%); S/E ratio, 0.030 (0.022-0.034) g mL^-1. Under these experimental conditions, CMAs values of the pooled sample were the following (n = 3): TSP=4433±176 mg (+)-catechin eq/100 g dry weight (d.w.); TMA=3575±194 mg cyanidin-3-glucoside eq/100 g d.w.; DPPH=273±5 μg DPPH inhib./mg d.w. The optimized extraction method was tested for matrix effect (ME%) in the UHPLC-MS/MS analysis of 15 anthocyanins and 20 non-anthocyanins individual (poly)phenols commonly found in bilberries, as well as for luteolin, sinapic acid, and pelargonidin-3-glucoside, absent in this fruit and therefore added to the extracts as surrogate standards for evaluating apparent recovery (AR%). |ME%| was in any case ≤ 23% and AR% of the surrogate standards in the range 91-95%, confirming the very good performances of the optimized extraction method.

Fortification of Durum Wheat Fresh Pasta with Maqui (Aristotelia chilensis) and Its Effects on Technological, Nutritional, Sensory Properties, and Predicted Glycemic Index

Pasta, a staple food worldwide consumed, was fortified with maqui (Aristotelia chilensis) berry powder (MBP) and the effect of MBP inclusion was evaluated concerning technological, nutritional, and sensory properties. Fresh pasta samples were formulated by replacing 0, 7.5, and 15 g 100 g−1 of durum wheat semolina with MBP. The inclusion of MBP did not affect the moisture content, but the water activity decreased in the fortified samples, while pH values decreased with increasing MBP levels in the recipe. The pasta fully cooking time and the swelling index were reduced, while the cooking loss and the firmness increased with increasing MBP levels. In addition, MBP increased the total dietary fiber, ash, and phenol contents, along with the in vitro antioxidant activities. The starch hydrolysis index and the predicted glycemic index of cooked fresh pasta decreased along with the increase of MBP addition. The MPB addition to fresh pasta could represent a valuable strategy for increasing its nutritional value, maintaining pasta’s technological properties without affecting the sensory acceptability.

Breadstick fortification with red grape pomace: effect on nutritional, technological and sensory properties

BACKGROUND

Grape pomace (GP), a wine-making by-product rich in dietary fiber (DF) and total phenolic compounds (TPC), is a potential functional ingredient in the fortification of baked goods.

RESULTS

In the present study, fortified breadsticks samples were obtained by replacing wheat flour with 0, 5 and 10 g 100 g^-1 of powdered GP (GPP). The GPP inclusion affected the rheological properties of the doughs by increasing the water absorption and tenacity (P) at the same time as reducing the extensibility (L), with a significant increase in the P/L value and a decrease in the swelling index (G) value and deformation energy (W). Textural characteristics of breadsticks were influenced by the GPP addition, showing a reduction in hardness and fracturability as the amount of GPP increased in the recipe. The GPP fortified breadsticks exhibited decreased pH, volume and specific volume values compared to the control. The TPC and the antioxidant capacity increased in GPP fortified breadsticks, whereas the increased amount of DF allowed the products to benefit from the claim 'high fiber content' at the highest level of GPP inclusion. The sensory evaluation revealed that GPP addition increased wine odor, acidity, bitterness, astringency and hardness, and decreased the regularity of alveolation and friability. Finally, the GPP fortified products achieved good sensorial acceptability.

CONCLUSION

GPP improved the nutritional values of fortified breadsticks and changed the rheology of dough and breadsticks' technological properties without affecting sensory acceptability. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Phytochemical-rich vegetable and fruit juice alleviates oral mucositis during concurrent chemoradiotherapy in patients with locally advanced head and neck cancer

Background

Objective

Methods

Results

Conclusion

Section

Taxonomy

•

The blended vegetable and fruit juice (VFJ) was rich in total polyphenols and carotenoids.

•

In head and neck cancer patients, the VFJ was significantly associated with a lower risk of chemoradiotherapy-induced ulcerative oral mucositis.

•

VFJ is healthy, safe, and effective dietary strategy against oral mucositis.

Lipophilic Grape Seed Proanthocyanidin Exerts Anti-Cervical Cancer Effects in HeLa Cells and a HeLa-Derived Xenograft Zebrafish Model

Lipophilic grape seed proanthocyanidin (LGSP) synthesized from GSP and lauric acid exhibits an excellent antioxidant and anti-inflammatory effect. However, its anti-cervical cancer activity is still unknown. In this study, the in vitro anti-cervical cancer activity of LGSP on HeLa cell lines was investigated by MTT assay, flow cytometry and Western blot analysis, and its effect was explored by a HeLa-derived xenograft zebrafish model. LGSP exhibited an excellent anti-proliferative effect on HeLa cells by increasing the level of reactive oxygen species, which further induced cell apoptosis and blocked cell cycle progression in the G2/M phase. LGSP-treated HeLa cells showed a reduction in mitochondrial membrane potential, upregulation of the Bax/Bcl-2 ratio, release of cytochrome c into the cytoplasm, and activation of cleaved caspase-9/3 and cleavage of PARP, thus indicating that LGSP induced apoptosis through the intrinsic mitochondrial/caspase-mediated pathway. In the zebrafish model, LGSP effectively suppressed the growth of a HeLa xenograft tumor. These data suggest that LGSP may be a good candidate for the prevention or treatment of cervical cancer.

Targeting AMPK Signaling by Dietary Polyphenols in Cancer Prevention

Cancer is a serious public health problem in the world and a major disease affecting human health. Dietary polyphenols have shown good potential in the treatment of various cancers. It is worth noting that cancer cells usually exhibit metabolic abnormalities of high glucose intake and inefficient utilization. AMPK is the key molecule in the regulation of energy metabolism and is closely related with obesity and diabetes. Recent studies indicate that AMPK also plays an important role in cancer prevention and regulating cancer-related genes and pathways, and dietary polyphenols can significantly regulate AMPK activity. In this review, the progress of dietary polyphenols preventing carcinogenesis via AMPK pathway is systemically summarized. From the viewpoint of interfering energy metabolism, the anti-cancer effects of dietary polyphenols are explained. AMPK pathway modulated by different dietary polyphenols affects pathways and target genes are summarized. Dietary polyphenols exert anti-cancer effect through the target molecules regulated by AMPK, which broadens the understanding of polyphenols anti-cancer mechanisms and provides value reference for the investigators of the novel field.

Main drivers of (poly)phenol effects on human health: metabolite production and/or gut microbiota-associated metabotypes?

Despite the high human interindividual variability in response to (poly)phenol consumption, the cause-and-effect relationship between some dietary (poly)phenols (flavanols and olive oil phenolics) and health effects (endothelial function and prevention of LDL oxidation, respectively) has been well established. Most of the variables affecting this interindividual variability have been identified (food matrix, gut microbiota, single-nucleotide-polymorphisms, etc.). However, the final drivers for the health effects of (poly)phenol consumption have not been fully identified. At least partially, these drivers could be (i) the (poly)phenols ingested that exert their effect in the gastrointestinal tract, (ii) the bioavailable metabolites that exert their effects systemically and/or (iii) the gut microbial ecology associated with (poly)phenol metabolism (i.e., gut microbiota-associated metabotypes). However, statistical associations between health effects and the occurrence of circulating and/or excreted metabolites, as well as cross-sectional studies that correlate gut microbial ecologies and health, do not prove a causal role unequivocally. We provide a critical overview and perspective on the possible main drivers of the effects of (poly)phenols on human health and suggest possible actions to identify the putative actors responsible for the effects.

Dietary Polyphenols: Promising Adjuvants for Colorectal Cancer Therapies

Simple Summary

Colorectal cancer is a leading cause of death worldwide. Despite the development of novel surgical and therapeutic strategies, 50% of patients relapse after treatment. Therapy failure, due to low efficacy, adverse effects and drug resistance, is thus a major concern. The idea of combining standard therapy with non-toxic bioactive natural compounds is a recent topic in cancer research and aims to increase the efficacy of current antitumor therapies while reducing drug toxicity and adverse effects. In recent years, several studies have explored the capacity of polyphenols, dietary bioactive compounds enriched in fruit and vegetables, to act as adjuvants to improve colorectal cancer therapy. In the present review, we discuss these studies, highlighting the mechanisms underlying the adjuvant effect, and bring out the potential of this novel therapeutic approach as well as the critical issues related to clinical application.

Abstract

Colorectal cancer (CRC) is a major cancer type and a leading cause of death worldwide. Despite advances in therapeutic management, the current medical treatments are not sufficient to control metastatic disease. Treatment-related adverse effects and drug resistance strongly contribute to therapy failure and tumor recurrence. Combination therapy, involving cytotoxic treatments and non-toxic natural compounds, is arousing great interest as a promising more effective and safer alternative. Polyphenols, a heterogeneous group of bioactive dietary compounds mainly found in fruit and vegetables, have received great attention for their capacity to modulate various molecular pathways active in cancer cells and to affect host anticancer response. This review provides a summary of the most recent (i.e., since 2016) preclinical and clinical studies using polyphenols as adjuvants for CRC therapies. These studies highlight the beneficial effects of dietary polyphenols in combination with cytotoxic drugs or irradiation on both therapy outcome and drug resistance. Despite substantial preclinical evidence, data from a few pilot clinical trials are available to date with promising but still inconclusive results. Larger randomized controlled studies and polyphenol formulations with improved bioavailability are needed to translate the research progress into clinical applications and definitively prove the added value of these molecules in CRC management.

TMEA, a Polyphenol in Sanguisorba officinalis, Promotes Thrombocytopoiesis by Upregulating PI3K/Akt Signaling

Thrombocytopenia is closely linked with hemorrhagic diseases, for which induction of thrombopoiesis shows promise as an effective treatment. Polyphenols widely exist in plants and manifest antioxidation and antitumour activities. In this study, we investigated the thrombopoietic effect and mechanism of 3,3′,4′-trimethylellagic acid (TMEA, a polyphenol in Sanguisorba officinalis L.) using in silico prediction and experimental validation. A KEGG analysis indicated that PI3K/Akt signalling functioned as a crucial pathway. Furthermore, the virtual molecular docking results showed high-affinity binding (a docking score of 6.65) between TMEA and mTOR, suggesting that TMEA might target the mTOR protein to modulate signalling activity. After isolation of TMEA, in vitro and in vivo validation revealed that this compound could promote megakaryocyte differentiation/maturation and platelet formation. In addition, it enhanced the phosphorylation of PI3K, Akt, mTOR, and P70S6K and increased the expression of GATA-1 and NF-E2, which confirmed the mechanism prediction. In conclusion, our findings are the first to demonstrate that TMEA may provide a novel therapeutic strategy that relies on the PI3K/Akt/mTOR pathway to facilitate megakaryocyte differentiation and platelet production.

Food frequency questionnaire is a valid assessment tool of quercetin and kaempferol intake in Iranian breast cancer patients according to plasma biomarkers

In epidemiological and clinical studies, the most common nutritional tool to assess dietary flavonol intake is the food frequency questionnaire (FFQ), which needs to contain a detailed list of plant-based foods and be previously validated. Our study aimed to assess the accuracy of dietary flavonol (quercetin, kaempferol, and isorhamnetin) intake from a food frequency questionnaire (FFQ) compared to fasting plasma flavonol concentrations, as biomarkers of exposure, in breast cancer patients. In a consecutive case series, newly diagnosed patients with breast cancer (n = 140) were recruited at Nour-Nejat Hospital, Tabriz, Iran. Flavonol intake was assessed using a validated FFQ. Plasma flavonol concentrations were measured using high-performance liquid chromatography-ultraviolet detection. The accuracy of dietary status was evaluated using a receiver operating characteristic (ROC) and area under the ROC curve (AUC). Dietary status was shown in dichotomous using ROC-cutoff point. The plasma concentrations of quercetin were moderately correlated with dietary intake of quercetin (Spearman's correlation coefficient (r_s) = 0.188, P < .05; r_partial= 0.330, P < .01) and plasma concentrations of isorhamnetin (r_s = 0.337, P < .001). A linear correlation between dietary levels and plasma concentrations of kaempferol was attained (r_partial = 0.240, P < .05). Using a ROC-cutoff of 61.9 nmol/L for plasma quercetin (test reference), we were able to differentiate between lower and higher consumers of quercetin with an AUC_{ROC-based reference} =0.65 (P < .01, sensitivity = 61.8%, and specificity = 60.0%). Using a plasma kaempferol concentration of 60.1 nmol/L (ROC-cutoff), it was possible to detect significant differences between higher and lower intakes of kaempferol (AUC_{ROC-based reference} = 0.64, P < .05). The correlations and diagnostic performance with plasma concentrations could present a significant accuracy rate (validity), which seems acceptable for a nutritional questionnaire (FFQ) to assess intakes intake levels of quercetin and kaempferol. An improvement in the accuracy of the flavonol exposure can provide more precise relationship with health outcomes, which may increase their clinical significance.

Flavonoid-Based Cancer Therapy: An Updated Review

As cancers are one of the most important causes of human morbidity and mortality worldwide, researchers try to discover novel compounds and therapeutic approaches to decrease survival of cancer cells, angiogenesis, proliferation and metastasis. In the last decade, use of special phytochemical compounds and flavonoids was reported to be an interesting and hopeful tactic in the field of cancer therapy. Flavonoids are natural polyphenols found in plant, fruits, vegetables, teas and medicinal herbs. Based on reports, over 10,000 flavonoids have been detected and categorized into several subclasses, including flavonols, anthocyanins, flavanones, flavones, isoflavones and chalcones. It seems that the anticancer effect of flavonoids is mainly due to their antioxidant and anti inflammatory activities and their potential to modulate molecular targets and signaling pathways involved in cell survival, proliferation, differentiation, migration, angiogenesis and hormone activities. The main aim of this review is to evaluate the relationship between flavonoids consumption and cancer risk, and discuss the anti-cancer effects of these natural compounds in human cancer cells. Hence, we tried to collect and revise important recent in vivo and in vitro researches about the most effective flavonoids and their main mechanisms of action in various types of cancer cells.

Technological, nutritional, and sensory properties of durum wheat fresh pasta fortified with Moringa oleifera L. leaf powder

BACKGROUND

Pasta is a staple food that is consumed worldwide and is an excellent product for the addition of ingredients rich in bioactive compounds. The fortification of pasta with such compounds could represent a healthy choice for consumers.

RESULTS

In this study, fresh pasta was formulated by replacing durum wheat semolina with 0, 5, 10, and 15 g 100 g^-1 of dried Moringa oleifera leaf powder (MOLP), rich in fibers, minerals, and antioxidant compounds. Increasing levels of MOLP influenced the technological and nutritional properties of wheat-based fresh pasta. Moringa oleifera reduced the optimum cooking time, the swelling index and firmness, while increasing the cooking loss and adhesiveness. From a nutritional viewpoint, the inclusion of MOLP enhanced the phenol content, the antioxidant activity, and the mineral content of fresh pasta. The products obtained had good sensorial acceptability and can make several nutritional claims due to MOLP richness minerals.

CONCLUSIONS

The fortification of fresh pasta with MOLP could represent a valuable strategy to increase the nutritional value of the product, preserving pasta technological properties without affecting sensory acceptability. © 2020 Society of Chemical Industry.

Current methodologies to refine bioavailability, delivery, and therapeutic efficacy of plant flavonoids in cancer treatment

Over the last two decades, several advancements have been made to improve the therapeutic efficacy of plant flavonoids, especially in cancer treatment. Factors such as low bioavailability, poor flavonoid stability and solubility, ineffective targeted delivery, and chemo-resistance hinder the application of flavonoids in anti-cancer therapy. Many anti-cancer compounds failed in the clinical trials because of unexpected altered clearance of flavonoids, poor absorption after administration, low efficacy, and/or adverse effects. Hence, the current research strategies are focused on improving the therapeutic efficacy of plant flavonoids, especially by enhancing their bioavailability through combination therapy, engineering gut microbiota, regulating flavonoids interaction with adenosine triphosphate binding cassette efflux transporters, and efficient delivery using nanocrystal and encapsulation technologies. This review aims to discuss different methodologies with examples from reported dietary flavonoids that showed an enhanced anti-cancer efficacy in both in vitro and in vivo models. Further, the review discusses the recent progress in biochemical modifications of flavonoids to improve bioavailability, solubility, and therapeutic efficacy.

Total urinary polyphenols and longitudinal changes of bone properties. The InCHIANTI study

The aim of this study was to evaluate the association of levels of urinary total polyphenols considered as a proxy measure of polyphenol intake, with longitudinal changes of bone properties, in the InCHIANTI study. Dietary intake of polyphenols appears to be associated with future accelerated deterioration of bone health.

INTRODUCTION

Polyphenols, micronutrients ingested through plant-based foods, have antioxidant and anti-inflammatory properties and may contribute to osteoporosis prevention. We evaluated associations of high levels of urinary total polyphenols (UTP), a proxy measure of polyphenol intake, with longitudinal changes of bone properties in a representative cohort of free-living participants of the InCHIANTI study.

METHODS

The InCHIANTI study enrolled representative samples from the registry list of two towns in Tuscany, Italy. Baseline data were collected in 1998 and follow-up visits in 2001 and 2004. Of the 1453 participants enrolled, 956 consented to donate a 24-h urine sample used to assess UTP, had dietary assessment, a physical examination, and underwent a quantitative computerized tomography (pQCT) of the tibia. From pQCT images, we estimated markers of bone mass (BM), diaphyseal design (DD), and material quality (MQ). Mixed models were used to study the relationship between baseline tertiles of UTP with changes of the bone characteristics over the follow-up.

RESULTS

At baseline, higher levels of UTP were positively correlated with markers of BM, DD, and MQ. Compared with lower tertile of UTP, participants in the intermediate and highest tertiles had higher cortical bone area, cortical mineral content, and cortical thickness. However, participants in the intermediate and highest UTP tertiles experienced accelerated deterioration of these same parameters over the follow-up compared with those in the lowest UTP tertile.

CONCLUSIONS

Dietary intake of polyphenols estimated by UTP and dietary questionnaire was associated with long-term accelerated deterioration of bone health. Our study does not support the recommendation of increasing polyphenol intake for osteoporosis prevention.

Blood polyphenol concentrations and differentiated thyroid carcinoma in women from the European Prospective Investigation into Cancer and Nutrition (EPIC) study

BACKGROUND

Polyphenols are natural compounds with anticarcinogenic properties in cellular and animal models, but epidemiological evidence determining the associations of these compounds with thyroid cancer (TC) is lacking.

OBJECTIVES

The aim of this study was to evaluate the relations between blood concentrations of 36 polyphenols and TC risk in EPIC (the European Prospective Investigation into Cancer and Nutrition).

METHODS

A nested case-control study was conducted on 273 female cases (210 papillary, 45 follicular, and 18 not otherwise specified TC tumors) and 512 strictly matched controls. Blood polyphenol concentrations were analyzed by HPLC coupled to tandem MS after enzymatic hydrolysis.

RESULTS

Using multivariable-adjusted conditional logistic regression models, caffeic acid (ORlog2: 0.55; 95% CI: 0.33, 0.93) and its dehydrogenated metabolite, 3,4-dihydroxyphenylpropionic acid (ORlog2: 0.84; 95% CI: 0.71, 0.99), were inversely associated with differentiated TC risk. Similar results were observed for papillary TC, but not for follicular TC. Ferulic acid was also inversely associated only with papillary TC (ORlog2: 0.68; 95% CI: 0.51, 0.91). However, none of these relations was significant after Bonferroni correction for multiple testing. No association was observed for any of the remaining polyphenols with total differentiated, papillary, or follicular TC.

CONCLUSIONS

Blood polyphenol concentrations were mostly not associated with differentiated TC risk in women, although our study raises the possibility that high blood concentrations of caffeic, 3,4-dihydroxyphenylpropionic, and ferulic acids may be related to a lower papillary TC risk.

Wheat Bread Fortification by Grape Pomace Powder: Nutritional, Technological, Antioxidant, and Sensory Properties

Grape pomace powder (GPP), a by-product from the winemaking process, was used to substitute flour for wheat bread fortification within 0, 5, and 10 g/100 g. Rheological properties of control and fortified doughs, along with physicochemical and nutritional characteristics, antioxidant activity, and the sensory analysis of the obtained bread were considered. The GPP addition influenced the doughs' rheological properties by generating more tenacious and less extensible products. Concerning bread, pH values and volume of fortified products decreased as the GPP inclusion level increased in the recipe. Total phenolic compounds and the antioxidant capacity of bread samples, evaluated by FRAP (ferric reducing ability of plasma) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) assays, increased with GPP addition. Moreover, the GPP inclusion level raised the total dietary fiber content of bread. Regarding sensory evaluation, GPP fortification had a major impact on the acidity, the global flavor, the astringency, and the wine smell of bread samples without affecting the overall bread acceptability. The current results suggest that GPP could be an attractive ingredient used to obtain fortified bread, as it is a source of fiber and polyphenols with potentially positive effects on human health.

Pine Bark Phenolic Extracts, Current Uses, and Potential Food Applications: A Review

PURPOSE

To summarize the main findings from research on food uses of Pine Bark Phenolic Extracts (PBPE), their origin, methods of extraction, composition, health effects, and incorporation into food products.

METHODS

A narrative review of all the relevant papers known to the authors was conducted.

RESULTS

PBPE are mainly extracted from the bark Pinus pinaster. They are generally rich in procyanidins and their effects on health in the form of nutritional supplements include effect on some forms of cancer, on diabetes, on eye and skin health. Their method of extraction influences greatly their composition and yield, and commercially suitable methods are still to be developed. Incorporation into food products raises challenges related to bioavailability and subsequent bioactivity and sensory properties of the final products.

CONCLUSION

PBPE represent an opportunity for the development of functional foods with phenolic-rich bioactive compounds.

Interaction between Polyphenolic Antioxidants and Saccharomyces cerevisiae Cells Defective in Heavy Metal Transport across the Plasma Membrane

Natural polyphenols are compounds with important biological implications which include antioxidant and metal-chelating characteristics relevant for their antimicrobial, antitumor, or antiaging potential. The mechanisms linking polyphenols and heavy metals in their concerted actions on cells are not completely elucidated. In this study, we used the model eukaryotic microorganism Saccharomyces cerevisiae to detect the action of widely prevalent natural polyphenols on yeast cells defective in the main components involved in essential heavy metal transport across the plasma membrane. We found that caffeic and gallic acids interfered with Zn accumulation, causing delays in cell growth that were alleviated by Zn supplementation. The flavones morin and quercetin interfered with both Mn and Zn accumulation, which resulted in growth improvement, but supplemental Mn and especially Zn turned the initially benefic action of morin and quercetin into potential toxicity. Our results imply that caution is needed when administering food supplements or nutraceuticals which contain both natural polyphenols and essential elements, especially zinc.

Mediterranean diet and breast cancer risk: a narrative review

Breast cancer is the second most frequent type of cancer worldwide and the most commonly occurring malignancy in women, and its incidence is increasing in most developed and developing countries. There is growing evidence that lifestyle factors, in particular diet may be associated with higher breast cancer risk. Some evidence exists regarding the benefit of Mediterranean diet on reduced risk of breast cancer in premenopausal and postmenopausal women. The protective effect of the Mediterranean diet against the risk of breast cancer, is primarily due to principal foods of this nutritional pattern. The principal components of the Mediterranean diet, such as fruits and vegetables, olive oil, fish and red wine have important antioxidants properties due to their high content of substances like polyphenols, flavonoids, carotenoids and fibers, along with a favorable fatty acid profile, that in turn could reduce the risk of breast cancer. Considering the severity of breast cancer and the increasing incidence in the world, there is an increasing interest in promoting prevention strategies in order to reduce the incidence. The aim of this paper is to provide a general overview of the current evidence on the relationship between breast cancer and Mediterranean diet, in premenopausal and postmenopausal women, and to emphasize the potential role of Mediterranean Diet as an effective tool in primary prevention. The possible molecular mechanisms underlying this association will be also pointed out.

A High Polyphenol Diet Improves Psychological Well-Being: The Polyphenol Intervention Trial (PPhIT)

Mental ill health is currently one of the leading causes of disease burden worldwide. A growing body of data has emerged supporting the role of diet, especially polyphenols, which have anxiolytic and antidepressant-like properties. The aim of the present study was to assess the effect of a high polyphenol diet (HPD) compared to a low polyphenol diet (LPD) on aspects of psychological well-being in the Polyphenol Intervention Trial (PPhIT). Ninety-nine mildly hypertensive participants aged 40-65 years were enrolled in a four-week LPD washout period and then randomised to either an LPD or an HPD for eight weeks. Both at baseline and the end of intervention, participants' lifestyle and psychological well-being were assessed. The participants in the HPD group reported a decrease in depressive symptoms, as assessed by the Beck Depression Inventory-II, and an improvement in physical component and mental health component scores as assessed with 36-Item Short Form Survey. No differences in anxiety, stress, self-esteem or body image perception were observed. In summary, the study findings suggest that the adoption of a polyphenol-rich diet could potentially lead to beneficial effects including a reduction in depressive symptoms and improvements in general mental health status and physical health in hypertensive participants.

Dietary Phenolics against Breast Cancer. A Critical Evidence-Based Review and Future Perspectives

Breast cancer (BC) is the most common malignancy and the leading cause of cancer-related death in adult women worldwide. Over 85% of BC cases are non-hereditary, caused by modifiable extrinsic factors related to lifestyle, including dietary habits, which play a crucial role in cancer prevention. Although many epidemiological and observational studies have inversely correlated the fruit and vegetable consumption with the BC incidence, the involvement of their phenolic content in this correlation remains contradictory. During decades, wrong approaches that did not consider the bioavailability, metabolism, and breast tissue distribution of dietary phenolics persist behind the large currently existing gap between preclinical and clinical research. In the present review, we provide comprehensive preclinical and clinical evidence according to physiologically relevant in vitro and in vivo studies. Some dietary phenolics such as resveratrol (RSV), quercetin, isoflavones, epigallocatechin gallate (EGCG), lignans, and curcumin are gaining attention for their chemopreventive properties in preclinical research. However, the clinical evidence of dietary phenolics as BC chemopreventive compounds is still inconclusive. Therefore, the only way to validate promising preclinical results is to conduct clinical trials in BC patients. In this regard, future perspectives on dietary phenolics and BC research are also critically discussed.

Phenolic Composition, Antioxidant and Anticancer Potentials of Extracts from Rosa banksiae Ait. Flowers

Rosa banksiae Ait. (R. banksiae) is a traditional Chinese folk medicine and an ornamental plant. Most previous studies have focused on cultivation and utilization while there are few research papers on the pharmacological activity of R. banksiae. This study aimed to get a better understanding of R. banksiae by extracting polyphenols with fractionated extraction technology. The results showed that ethyl acetate phase (EAP) contained the most polyphenols, while water phase (WP) had the least. HPLC analysis indicated that rutin and luteolin-4'-O-glucoside existed in the EAP and butanol phase (BP), but quercetin was only detected in the EAP. Six phenolic compositions were not detected in WB. The antioxidant and anti-tumor abilities of the EAP and BP were excellent. The results revealed that R. banksiae possessed a great antioxidant capacity and was rich in polyphenols, thus indicating R. banksiae was suitable for being a natural antioxidant and an abundant source of polyphenols.

Correlations between urinary concentrations and dietary intakes of flavonols in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

PURPOSE

In this study, we aimed to study the correlation between acute and habitual intakes of flavonols, their main food sources and their 24-h urinary concentrations in an European population.

METHODS

A 24-h dietary recall (24-HDR) and 24-h urine samples were collected on the same day from a convenience subsample of 475 men and women from four countries (France, Italy, Greece and Germany) of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. A standardized 24-HDR software and a country/centre-specific validated dietary questionnaire (DQ) were used to collect acute and habitual dietary data, respectively. The intake of dietary flavonols was estimated using the Phenol-Explorer database. Urinary flavonols (quercetin, isorhamnetin, and kaempferol) were analysed using tandem mass spectrometry with a previous enzymatic hydrolysis.

RESULTS

Weak partial Spearman correlations between both dietary acute and habitual intake and urinary concentrations of quercetin (both Rpartial ~ 0.3) and total flavonols (both Rpartial ~ 0.2) were observed. No significant correlations were found for kaempferol and isorhamentin. Regarding flavonol-rich foods, weak correlations were found between urinary concentrations of quercetin and total flavonols and the acute intake of onions and garlics, fruits, tea, and herbal tea (all Rpartial ~ 0.2). For habitual intake, statistically significant correlations were only found between urinary quercetin concentration and herbal tea (Rpartial = 0.345) and between urinary total flavonol concentration and tea, and herbal tea consumption (Rpartial ~ 0.2).

CONCLUSIONS

Our results suggest that urinary quercetin level can be used as potential concentration biomarkers of both acute and habitual quercetin intake, while urinary concentrations of flavonols are unlikely to be useful biomarkers of individual flavonol-rich foods.

Effect of Grape Pomace Addition on the Technological, Sensory, and Nutritional Properties of Durum Wheat Pasta

In this study, fortified pasta was prepared by replacing semolina with 0, 5, and 10 g/100 g of grape pomace (GP), a food industry by-product, rich in fiber and phenols. GP inclusion in pasta significantly reduced its optimum cooking time and the swelling index, while also increasing the cooking loss (p < 0.05). Furthermore, pasta firmness and adhesiveness were enhanced by the GP addition, as well as the total phenol content and the antioxidant activity, evaluated through ABTS and FRAP assays (p < 0.05). From a nutritional point of view, increasing amounts of GP resulted in a significative decrease in the rapidly digestible starch and an increase in the slowly digestible starch, while the predicted in vitro glycemic index was also reduced (p < 0.05). Sensory analysis showed that fortified spaghetti had good overall acceptability, and the results suggest that GP-fortified pasta could represent a healthy product with good technological and sensory properties.

Green tea (Camellia sinensis) for the prevention of cancer

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects.

OBJECTIVES

To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes.

SEARCH METHODS

We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies.

SELECTION CRITERIA

We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type.

MAIN RESULTS

In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies.

AUTHORS' CONCLUSIONS

Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

The Influence of Polyphenol Compounds on Human Gastrointestinal Tract Microbiota

Polyphenols form a diverse group of compounds containing at least two hydroxyl groups in their chemical structure. Because of the common presence in plant kingdom, polyphenols are considered a significant component of food and an important group of compounds with antioxidant properties. The absorption of polyphenols present in food depends mostly on the activity of intestinal microflora. However, little is known about the processes and interactions responsible for such phenomenon in guts ecosystem. There are only few available publications that examine the effect on polyphenols on intestinal microbiota. Therefore, this work will focus on describing the relationship between polyphenol compounds present in food and bacteria colonizing the intestines, their mechanism, and impact on human’s health.

Incomplete Hydrolysis of Curcumin Conjugates by β-Glucuronidase: Detection of Complex Conjugates in Plasma

SCOPE

The diphenol curcumin from turmeric is rapidly metabolized into phase II conjugates following oral administration, resulting in negligible plasma concentration of the free compound, which is considered the bioactive form. Total plasma concentration of curcumin is often quantified after treatment with β-glucuronidase to hydrolyze curcumin-glucuronide, the most abundant conjugate in vivo. The efficiency of enzymatic hydrolysis has not been tested.

METHODS AND RESULTS

Using liquid chromatography-mass spectrometry (LC-MS) analyses the efficiency of β-glucuronidase and sulfatase from Helix pomatia is compared to hydrolyze curcumin conjugates in human and mouse plasma after oral administration of turmeric. Both β-glucuronidase and sulfatase completely hydrolyze curcumin-glucuronide. Unexpectedly, β-glucuronidase hydrolysis is incomplete, affording a large amount of curcumin-sulfate, whereas sulfatase hydrolyzed both glucuronide and sulfate conjugates. With sulfatase, the concentration of free curcumin is doubled in human and increased in mouse plasma compared to β-glucuronidase treatment. Incomplete hydrolysis by β-glucuronidase suggests the presence of mixed glucuronide-sulfate conjugates. LC-MS based searches detect diglucuronide, disulfate, and mixed sulfate-glucuronide and sulfate-diglucuronide conjugates in plasma that likely contribute to the increase of free curcumin upon sulfatase treatment.

CONCLUSION

β-Glucuronidase incompletely hydrolyzes complex sulfate-containing conjugates that appear to be major metabolites, resulting in an underestimation of the total plasma concentration of curcumin.

Phenolic Acid Subclasses, Individual Compounds, and Breast Cancer Risk in a Mediterranean Cohort: The SUN Project

BACKGROUND

Biological and epidemiological evidence supports an inverse association of phenolic acids with obesity-related chronic diseases. However, no previous study has prospectively evaluated the relationship between subclasses and individual compounds of phenolic acids and the risk of postmenopausal breast cancer, one of the most important and prevalent obesity-related cancer sites.

OBJECTIVE

This study examined associations between subclasses of phenolic acids, including hydroxycinnamic and hydroxybenzoic acids intake, and risk of breast cancer.

DESIGN

The Seguimiento Universidad de Navarra (SUN) Project is a dynamic, permanently open prospective cohort which started in 1999.

PARTICIPANTS/SETTING

Participants were 10,812 middle-aged women. All of them were university graduates.

MAIN OUTCOME MEASURES

Usual diet was assessed at baseline and after 10 years of follow-up with a 136-item food frequency questionnaire. Phenolic acid intake was calculated by matching food consumption with the Phenol-Explorer database on phenolic acids content of each reported food item.

STATISTICAL ANALYSIS PERFORMED

Participants were classified according to tertiles of subclasses or individual compounds of phenolic acids. Cox regression models were fitted to estimate multivariable-adjusted hazard ratios and 95% CIs for breast cancer incidence.

RESULTS

Over an average of 11.8 years of follow-up, 101 incident cases of breast cancer were confirmed. After multivariable adjustment, an inverse association between hydroxycinnamic acids intake and breast cancer was observed (hazard ratio third tertile vs first tertile 0.37, 95% CI 0.16 to 0.85; P for trend=0.029) among postmenopausal women. Specifically, chlorogenic acids (3-, 4-, and 5- caffeoylquinic acids) showed the strongest inverse association (hazard ratio third tertile vs first tertile 0.33, 95% CI 0.14 to 0.78; P for trend=0.012).

CONCLUSIONS

A higher intake of hydroxycinnamic acids, especially from chlorogenic acids-present in coffee, fruits, and vegetables-was associated with a lower incidence of breast cancer among postmenopausal women. Future observational studies are needed to corroborate these results.

Artichoke Polyphenols Sensitize Human Breast Cancer Cells to Chemotherapeutic Drugs via a ROS-Mediated Downregulation of Flap Endonuclease 1

Combined treatment of several natural polyphenols and chemotherapeutic agents is more effective comparing to the drug alone in inhibiting cancer cell growth. Polyphenolic artichoke extracts (AEs) have been shown to have anticancer properties by triggering apoptosis or reactive oxygen species- (ROS-) mediated senescence when used at high or low doses, respectively. Our aim was to explore the chemosensitizing potential of AEs in order to enhance the efficacy of conventional chemotherapy in breast cancer cells. We employed breast cancer cell lines to assess the potential synergistic effect of a combined treatment of AEs/paclitaxel (PTX) or AEs/adriamycin (ADR) and to determine the underlying mechanisms correlated to this potential therapeutic approach. Our data shows that AEs/PTX reduced cell proliferation by increasing DNA damage response (DDR) mediated by Flap endonuclease 1 (FEN1) downregulation that results into enhanced breast cancer cell sensitivity to chemotherapeutic drugs. We demonstrated that ROS/Nrf2 and p-ERK pathways are two molecular mechanisms involved in the synergistic effect of AEs plus PTX treatment. To highlight the role of ROS herein, we report that the addition of antioxidant N-acetylcysteine (NAC) significantly decreased the antiproliferative effect of the combined treatment. A combined therapy could be able to reduce the dose of chemotherapeutic drugs, minimizing toxicity and side effects. Our results suggest the use of artichoke polyphenols as ROS-mediated sensitizers of chemotherapy paving the way for innovative and promising natural compound-based therapeutic strategies in oncology.

Phellinus gilvus‑derived protocatechualdehyde induces G0/G1 phase arrest and apoptosis in murine B16‑F10 cells

Protocatechualdehyde (PCA) is considered to be the main phenolic component of Phellinus gilvus responsible for its anticancer properties. Previous studies have demonstrated that PCA can have an anticancer effect on multiple cancer types, but little is known about the effect of PCA on melanoma cells. The present study investigated the inhibitory abilities and potential anticancer mechanisms of PCA on B16-F10 cells using MTT assay. Cell apoptosis and cell cycle were assessed by flow cytometry using Annexin V-FITC and propidium iodide staining. Whole-transcriptome analysis was used to investigate the effects of PCA on gene expression. PCA significantly decreased cell viability, induced cell cycle arrest at G0/G1 phase and promoted apoptosis of B16-F10 cells, suggesting that PCA could have anticancer effects against melanoma cells. Whole-transcriptome analysis indicated that PCA treatment upregulated genes involved in histone modification and decreased the transcription of genes involved in DNA repair and replication. Kyoto Encyclopedia of Genes and Genomes analysis showed that PCA treatment enhanced the complement and coagulation cascades, and the p53 signaling pathway. The present results indicated that PCA could act as an antitumor agent in melanoma cells, which may provide experimental support for the development of novel therapies to treat melanoma.

Effects of flavonoids on tongue squamous cell carcinoma

Squamous cell carcinoma (SCC) of the tongue is associated with tobacco use, alcohol abuse, and human papillomavirus (HPV) infections. While clinical outcomes have recently improved for HPV-positive patients in general, 50% of patients suffering from tongue cancer die within 5 years of being diagnosed. Flavonoids are secondary plant metabolites with a wide range of biological activities including antioxidant, anti-inflammatory, and anticancer activities. Flavonoids have generated high interest as therapeutic agents owing to their low toxicity and their effects on a large variety of cancer cell types. In this literature review, we evaluate the actions of flavonoids on SCC of the tongue demonstrated in both in vivo and in vitro models.

Flavonoids as anticancer therapies: A systematic review of clinical trials

Flavonoids have been proposed as potential chemotherapeutic agents because they are toxic against cancer cells but not harmful to healthy cells. This systematic review analyzed flavonoid effectiveness in human cancer chemotherapy. Overall, 22 phase II and 1 phase III clinical trials (PubMed, Scopus, and Web of Science) that used flavonoids as a single agent or combined with other therapeutics against hematopoietic/lymphoid or solid cancer published by January 2019 were selected for analysis. Flavopiridol was the most commonly used flavonoid (at a dose of 50-mg/m² IV) for all tumor types. Aside from the relatively low rate of complete response (CR) or partial response (PR) with any administration protocol, flavonoids showed higher positive outcomes for hematopoietic and lymphoid tissues (140 patients with CR and 88 with PR among 615 patients in 11 trials) than for solid tumors (4 patients with CR and 21 with PR among 525 patients in 12 trials). However, because of the high variety in administration schedule, more studies are needed to further understand how flavonoids can promote positive outcomes for cancer patients.