Procyanidin B2 and a cocoa polyphenolic extract inhibit acrylamide-induced apoptosis in human Caco-2 cells by preventing oxidative stress and activation of JNK pathway

Activity of extracts and isolated compounds Trichilia catigua against clinically relevant candida species

OBJECTIVES

To evaluate the in vitro antifungal activity of extracts and compounds from Trichilia catigua against clinically relevant Candida species, notably Candida glabrata, and investigate possible mechanisms of action using electron microscopy and in silico techniques.

METHODS

Extracts and fractions of T. catigua were obtained through turboextraction and partitioning, while the isolated compounds were previously purified. The ethyl acetate fraction (EAF) was characterized by HPLC. Antifungal activity against C. glabrata was evaluated through MIC tests, synergism was assessed via checkerboard assays, and structural changes were analyzed via electron microscopy. Molecular docking was performed to identify potential targets of action.

RESULTS

The EAF and isolated compounds (cinchonains and procyanidin B2) exhibited significant activity against C. glabrata, with MICs of 9.76 µg/mL (EAF) and 3.9 µg/mL (cinchonains Ia and Ib). Cinchonain Ib combined with epicatechin or procyanidin B2 displayed synergistic effects, particularly with amphotericin B. Microscopy analysis revealed cell membrane damage, and reverse docking analysis suggested that the compounds may target an enzyme essential to the metabolic processes of C. glabrata.

CONCLUSIONS

The findings suggest that compounds isolated from T. catigua hold considerable potential for developing new antifungal agents against Candida species, particularly C. glabrata, with promising safety and synergistic profiles.

Alleviative effects of green-fabricated zinc oxide nanoparticles on acrylamide-induced oxidative and inflammatory reactions in the rat stomach via modulating gastric neuroactive substances and the MiR-27a-5p/ROS/NF-κB axis

Little is known about the effects of acrylamide (AMD) on the stomach. So, this study evaluated the effect of oral AMD exposure (20 mg/kg b.wt) on oxidative status, apoptotic, and inflammatory reactions in rat's stomach for 60 days. To explore novel targets of AMD toxicity, a more detailed molecular and immune-expression study was performed. Besides, the possible protective effect of green synthesized zinc oxide nanoparticles (G-ZNP) (10 mg/kg b.wt) was explored. The results revealed that AMD significantly provoked oxidative and lipid peroxidative damage of the stomach in terms of increased ROS and MDA but reduced SOD, CAT, GSH, and GSH/GSSG. Additionally, the stomachs of AMD-exposed rats showed a significant increment of PGE2 but reduced NO. Histopathologically, AMD induced a significant increase in PAS stain and the immunoexpression of iNOS and NF-κB in the glandular stomach. A significant upregulation of CART, VACHT, EGFR, caspase-3, NOS-1, and miR-27a-5p was evident in the stomach of the AMD group. Yet, G-ZNP oral dosing significantly rescued the AMD-induced oxidative damage, apoptotic reaction, inflammatory effect, and altered miR-27a-5p and gene expressions in the stomach. Conclusively, these findings demonstrated the efficacy of G-ZNP in protecting against the harmful impacts of acrylamide on stomach tissues.

Extracts from Tartary Buckwheat Sprouts Restricts Oxidative Injury Induced by Hydrogen Peroxide in HepG2 by Upregulating the Redox System

Oxidative stress, which results from an overproduction of reactive oxygen species (ROS), can cause damage that may contribute to a range of metabolic disorders. Antioxidants are considered to upregulate the activity of antioxidant enzymes, which are crucial for eliminating excess ROS and safeguarding the body against oxidative stress-induced damage. In the present study, the effect of polyphenol extracts from tartary buckwheat sprouts (TBSE) on the redox system of HepG2-cell-induced oxidative injury by hydrogen peroxide were investigated for evaluating the protective effect and mechanism of tartary buckwheat sprouts (TBS). The results revealed that TBSE that had sprouted for a period of 10 days possessed six predominant phenolic compounds, ranked from the most abundant to the least: chlorogenic acid, syringic acid, caffeic acid, rutin, ferulic acid, and quercetin. TBSE could successfully inhibit H2O2-induced ROS overproduction, restore and balance the mitochondrial membrane potential, while also significantly increasing cellular antioxidant activity (CAA) and the expression of protective enzymes such as SOD, CAT, and GST. More interestingly, treating HepG2 cells with TBSE triggered the translocation of Nrf2 to the nucleus, accompanied by a negative feedback mechanism involving Keap1. Therefore, it regulated the downstream production of antioxidant enzymes, including NQO1 and HO-1. Overall, this finding suggested that TBSE could restore the redox state of H2O2-resistant HepG2 cells, indicating TBSE protected cells from H2O2-induced oxidative stress significantly. Beneficial resistance and effects on redox balance were attributed to activation of Nrf2. Present work revealed the potential health benefits of TBS and provided a test basis for developing functional food of TBS.

Evidence of acrylamide-induced behavioral deficit, mitochondrial dysfunction and cell death in Drosophila melanogaster

Acrylamide (ACR), a ubiquitous compound with diverse route of exposure, has been demonstrated to have detrimental effects on human and animal health. The mechanisms underlying its toxicity is multifaceted and not fully elucidated. This study aims to provide further insight into novel pathways underlying ACR toxicity by leveraging on Drosophila melanogaster as a model organism. The concentrations of acrylamide (25, 50 and 100 mg/kg) and period of exposure (7-days) used in this study was established through a concentration response curve. ACR exposure demonstrably reduced organismal viability, evidenced by decline in survival rate, offspring emergence and deficits in activity, sleep and locomotory behaviors. Using a high-resolution respirometry assay, the role of mitochondria respiratory system in ACR-mediated toxicity in the flies was investigated. Acrylamide caused dysregulation in mitochondrial bioenergetics and respiratory capacity leading to an impaired OXPHOS activity and electron transport, ultimately contributing to the pathological process of ACR-toxicity. Furthermore, ACR exacerbated apoptosis and induced oxidative stress in D. melanogaster. The up-regulation of mRNA transcription of Reaper, Debcl and Dark genes and down-regulation of DIAP1, an ubiquitylation catalyzing enzyme, suggests that ACR promotes apoptosis through disruption of caspase and pro-apoptotic protein ubiquitination and a mitochondria-dependent pathway in Drosophila melanogaster. Conclusively, this study provides valuable insights into the cellular mechanism underlying ACR-mediated toxicity. Additionally, our study reinforces the utility of D. melanogaster as a translational tool for elucidating the complex mechanisms of ACR toxicity.

Intestinal Epithelial Co-Culture Sensitivity to Pro-Inflammatory Stimuli and Polyphenols Is Medium-Independent

The complexification of in vitro models requires the compatibility of cells with the same medium. Since immune cells are the most sensitive to growth conditions, growing intestinal epithelial cells in their usual medium seems to be necessary. This work was aimed at comparing the sensitivity of these epithelial cells to pro-inflammatory stimuli but also to dietary polyphenols in both DMEM and RPMI-1640 media. Co-cultures of Caco-2 and HT29-MTX cells were grown for 21 days in the two media before their stimulation with a cocktail of TNF-α (20 ng/mL), IL-1β (1 ng/mL), and IFN-γ (10 ng/mL) or with LPS (10 ng/mL) from E. coli (O111:B4). The role of catechins (15 µM), a dietary polyphenol, was evaluated after its incubation with the cells before their stimulation for 6 h. The RPMI-1640 medium did not alter the intensity of the inflammatory response observed with the cytokines. By contrast, LPS failed to stimulate the co-culture in inserts regardless of the medium used. Lastly, catechins were unable to prevent the pro-inflammatory response observed with the cytokines in the two media. The preservation of the response of this model of intestinal epithelium in RPMI-1640 medium is promising when considering its complexification to evaluate the complex cellular crosstalk leading to intestinal homeostasis.

Effect of Digested Selected Food Items on Markers of Oxidative Stress and Inflammation in a Caco-2-Based Human Gut Epithelial Model

The human gut epithelium presents a crucial interface between ingested food items and the host. Understanding how different food items influence oxidative stress and inflammation in the gut is of great importance. This study assessed the impact of various digested food items on oxidative stress, inflammation, and DNA/RNA damage in human gut epithelial cells. Differentiated Caco-2 cells were exposed to food items and their combinations (n = 22) selected from a previous study, including sausage, white chocolate, soda, coffee, orange juice, and curcumin. Following stimulation with TNF-α/IFN-1β/LPS and H2O2 for 4 h, the cells were exposed to digested food items or appropriate controls (empty digesta and medium) for a further 16 h. Cell viability, antioxidant capacity (ABTS, FRAP), IL-6, IL-8, F2-isoprostanes, lipid peroxidation (MDA), and DNA/RNA oxidative damage were assessed (3 independent triplicates). The ABTS assay revealed that cells treated with "white chocolate" and "sausage + coffee" exhibited significantly reduced antioxidant capacity compared to stimulated control cells (ABTS = 52.3%, 54.8%, respectively, p < 0.05). Similar results were observed for FRAP (sausage = 34.9%; white chocolate + sausage = 35.1%). IL-6 levels increased in cells treated with "white chocolate + sausage" digesta (by 101%, p < 0.05). Moreover, MDA levels were significantly elevated in cells treated with digested "sausage" or sausage in combination with other food items. DNA/RNA oxidative damage was found to be higher in digesta containing sausage or white chocolate (up to 550%, p < 0.05) compared to stimulated control cells. This investigation provides insights into how different food items may affect gut health and underscores the complex interplay between food components and the epithelium at this critical interface of absorption.

Natural Products as Dietary Agents for the Prevention and Mitigation of Oxidative Damage and Inflammation in the Intestinal Barrier

Food intake is a basic need to sustain life, but foodborne pathogens and food-related xenobiotics are also the main health concerns regarding intestinal barrier homeostasis. With a predominant role in the well-being of the entire human body, intestinal barrier homeostasis is strictly regulated by epithelial and immune cells. These cells are also the main intervenients in oxidative stress and inflammation-related diseases in the intestinal tract, triggered, for example, by genetic/epigenetic factors, food additives, pesticides, drugs, pathogens, and their metabolites. Nevertheless, the human diet can also be seen as a solution for the problem, mainly via the inclusion of functional foods or nutraceuticals that may act as antioxidant/anti-inflammatory agents to prevent and mitigate acute and chronic oxidative damage and inflammation. A literature analysis of recent advances in this topic highlights the significant role of Nrf2 (nuclear factor erythroid 2-related factor 2) and NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells) pathways in these biological processes, with many natural products and phytochemicals targeting endogenous antioxidant systems and cytokine production and balance. In this review, we summarized and discussed studies using in vitro and in vivo models of the intestinal tract used to reproduce oxidative damage and inflammatory events, as well as the role of natural products as modulators of Nrf2 and NK-kB pathways.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

Polysaccharide isolated from wax apple suppresses ethyl carbamate-induced oxidative damage in human hepatocytes

Wax apple (Syzygium samarangense) has received growing research interest for its high nutritional and medicinal value due to its constituents such as polysaccharide, organic acids, flavonoids, minerals, and other substances. In this study, wax apple polysaccharide (WAP) was isolated from this plant and its protective effect against ethyl carbamate (EC)‍-induced oxidative damage was evaluated in human hepatocytes (L02 cells). Firstly, a series of analyses such as high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), gas chromatography/mass spectrometry (GC/MS), and 1H and 13C nuclear magnetic resonance (NMR) were conducted to identify the structure of WAP. Thereafter, in vitro cell experiments were performed to verify the protective effects of WAP against EC-induced cytotoxicity, genotoxicity, and oxidative damage in L02 cells. Our results revealed that WAP is composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose in a molar ratio of 2.20:‍3.94:‍4.45:‍8.56:‍8.86:‍30.82:‍39.78:‍1.48. Using a combination of methylation and NMR spectroscopic analysis, the primary structure of WAP was identified as Araf-(1→, Glcp-(1→, →2)‍-Araf-(1→, →3)‍-Galp-(1→, →3)‍-Araf-‍(1→, and →6)‍-Galp-‍(1→. Cell experiments indicated that WAP exhibited significant protective effects on EC-treated L02 cells via suppressing cytotoxicity and genotoxicity, reducing reactive oxygen species (ROS) and O2•- formation, as well as improving mitochondrial membrane potential (MMP) and glutathione (GSH). In a nutshell, WAP has the potential as an important therapeutic agent or supplement for hepatic oxidative damage. Meanwhile, further studies are needed to prove the above effects in vivo at the biological and clinical levels.

A model study on the site-specificity of (-)-epicatechin-induced reactions in β-lactoglobulin by high-resolution mass spectrometry in combination with bioinformatics

Polyphenol-protein reactions in model solutions of β-lactoglobulin (β-LG) incubated with (-)-epicatechin at 37 °C and 60 °C were monitored by microLC-timsTOF Pro-MS/MS combined with bioinformatics strategies. The addition of (-)-epicatechin to the model solutions resulted in changes in tryptic peptide profiles. Covalent bond formation between (-)-epicatechin o-quinones and β-LG was identified for the residues S27, S30, K60, C66, K69, and C160, with C160 being the predominant binding site. Furthermore, the incubation of β-LG with (-)-epicatechin significantly promoted oxidation, especially for the residues M7 and M24. The reaction of monomeric (-)-epicatechino-quinone at C160 was also identified in the milk chocolate sample. The adaptation of this study by extending the scope of the reaction products offers significant potential for comprehensive food profiling strategies.

Cocoa polyphenols and milk proteins: covalent and non-covalent interactions, chocolate process and effects on potential polyphenol bioaccesibility

In this study, we discussed covalent and non-covalent reactions between cocoa polyphenols and proteins (milk and cocoa) and the possible effects of these reactions on their bioaccessibility, considering environmental and processing conditions. Better insight into these interactions is crucial for understanding the biological effects of polyphenols, developing nutritional strategies, and improving food processing and storage. Protein-polyphenol reactions affect the properties of the final product and can lead to the formation of various precursors at various stages in the manufacturing process, such as fermentation, roasting, alkalization, and conching. Due to the complex composition of the chocolate and the various technological processes, comprehensive food profiling strategies should be applied to analyze protein-polyphenol covalent reactions covering a wide range of potential reaction products. This will help to identify potential effects on the bioaccessibility of bioactive compounds such as low-molecular-weight peptides and polyphenols. To achieve this, databases of potential reaction products and their binding sites can be generated, and the effects of various process conditions on related parameters can be investigated. This would then allow to a deeper insight into mechanisms behind protein-polyphenol interactions in chocolate, and develop strategies to optimize chocolate production for improved nutritional and sensory properties.

Acrylamide in food: Occurrence, metabolism, molecular toxicity mechanism and detoxification by phytochemicals

Acrylamide (ACR) is a common pollutant formed during food thermal processing such as frying, baking and roasting. ACR and its metabolites can cause various negative effects on organisms. To date, there have been some reviews summarizing the formation, absorption, detection and prevention of ACR, but there is no systematic summary on the mechanism of ACR-induced toxicity. In the past five years, the molecular mechanism for ACR-induced toxicity has been further explored and the detoxification of ACR by phytochemicals has been partly achieved. This review summarizes the ACR level in foods and its metabolic pathways, as well as highlights the mechanisms underlying ACR-induced toxicity and ACR detoxification by phytochemicals. It appears that oxidative stress, inflammation, apoptosis, autophagy, biochemical metabolism and gut microbiota disturbance are involved in various ACR-induced toxicities. In addition, the effects and possible action mechanisms of phytochemicals, including polyphenols, quinones, alkaloids, terpenoids, as well as vitamins and their analogs on ACR-induced toxicities are also discussed. This review provides potential therapeutic targets and strategies for addressing various ACR-induced toxicities in the future.

Research Progress of Programmed Cell Death Induced by Acrylamide

Acrylamide exposure through environment pollution and diet is very common in daily life. With the deepening of the study on the toxicity of acrylamide, it has attracted widespread attention for the effects of acrylamide on multiple organs through affecting a variety of programmed cell death. Multiple studies have shown that acrylamide could exert its toxic effect by inducing programmed cell death, but its specific molecular mechanism is still unclear. In this review, the research on the main forms of programmed cell death (apoptosis, autophagy, and programmed necrosis) induced by acrylamide and their possible mechanisms are reviewed. This review may provide basic data for further research of acrylamide and prevention of its toxicity.

Molecular Mechanisms Associated with Protecting IEC-6 Cells from Acrylamide-Induced Tight Junction Damage by Ganoderma atrum Polysaccharide

SCOPE

The previous in vivo studies show Ganoderma atrum polysaccharide (PSG-F₂ ) has a protective effect against the acrylamide (AA)-induced intestinal oxidative damage in rats. Now, this study aims to explore the protective mechanism with IEC-6 cell model.

METHODS AND RESULTS

Based on RNA Sequencing (RNA-Seq), the study screens MAPK signaling pathway as one of the most crucial pathways for pretreatment with PSG-F₂   against AA-induced damage in IEC-6 cells. In total, six key MAPK signaling pathway-related proteins (p-P38/P38, p-ERK/ERK, and p-JNK/JNK), and three tight junction key proteins (Zonula Occludens protein-1, Claudin-1, and Occludin) are detected by Western blot and immunofluorescence, which verify the RNA-Seq data. Moreover, PD98059 interference inhibits critical proteins in the MAPK signaling pathway, thus uncovering the precise molecular mechanisms of MAPK/ERK signaling pathway involve in the protective effects of PSG-F₂ against AA-induced intestinal barrier damage.

CONCLUSION

These findings confirm that PSG-F₂ can be used as a daily dietary supplement to protect the intestinal cells from damage caused by thermal processing hazards AA.

Antioxidative and Antimicrobial Evaluation of Bark Extracts from Common European Trees in Light of Dermal Applications

Plant species have developed effective defense strategies for colonizing diverse habitats and protecting themselves from numerous attacks from a wide range of organisms, including insects, vertebrates, fungi, and bacteria. The bark of trees in particular constitutes a number of components that protect against unwanted intruders. This review focuses on the antioxidative, dermal immunomodulatory, and antimicrobial properties of bark extracts from European common temperate trees in light of various skin pathogens, wound healing, and the maintenance of skin health. The sustainability aspect, achieved by utilizing the bark, which is considered a byproduct in the forest industry, is addressed, as are various extraction methods applied to retrieve extracts from bark.

From Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action

Despite the health benefits associated with the ingestion of the bioactive compounds in cocoa, the high concentrations of polyphenols and methylxanthines in the raw cocoa beans negatively influence the taste, confer the astringency and bitterness, and affect the stability and digestibility of the cocoa products. It is, therefore, necessary to process cocoa beans to develop the characteristic color, taste, and flavor, and reduce the astringency and bitterness, which are desirable in cocoa products. Processing, however, affects the composition and quantities of the bioactive compounds, resulting in the modification of the health-promoting properties of cocoa beans and chocolate. In this advanced review, we sought to better understand the effect of cocoa's transformational process into chocolate on polyphenols and methylxanthine and the mechanism of action of the original flavanols and methylxanthines. More data on the cocoa processing effect on cocoa bioactives are still needed for better understanding the effect of each processing step on the final polyphenolic and methylxanthine composition of chocolate and other cocoa products. Regarding the mechanisms of action, theobromine acts through the modulation of the fatty acid metabolism, mitochondrial function, and energy metabolism pathways, while flavanols mainly act though the protein kinases and antioxidant pathways. Both flavanols and theobromine seem to be involved in the nitric oxide and neurotrophin regulation.

Ferric ions release from iron-binding protein: Interaction between acrylamide and human serum transferrin and the underlying mechanisms of their binding

Acrylamide (ACR) is a surprisingly common chemical due to its widespread use in industry and various other applications. However, its toxicity is a matter of grave concern for public health. Even worse, ACR is frequently detected in numerous fried or baked carbohydrate-rich foods due to the Maillard browning reaction. Herein, this study intends to delineate the underlying molecular mechanisms of Fe ions released from iron-binding protein transferrin (TF) after acrylamide binding by combining multiple methods, including multiple complementary spectroscopic techniques (UV-Vis, fluorescence, and circular dichroism spectroscopy), isothermal titration calorimetry, ICP-MS measurements, and modeling simulations. Results indicated that free Fe was released from TF only under high-dose ACR exposure (>100 μM). Acrylamide binding induced the loosening and unfolding of the backbone and polypeptide chain and destroyed the secondary structure of TF, thereby leading to protein misfolding and denaturation of TF and forming a larger size of TF agglomerates. Of which, H-binding and van der Waals force are the primary driving force during the binding interaction between ACR and TF. Further modeling simulations illustrated that ACR prefers to bind to the hinge region connecting the C-lobe and N-lobe, after that it attaches to the Fe binding sites of this protein, which is the cause of free Fe release from TF. Moreover, ACR interacted with the critical fluorophore residues (Tyr, Trp, and Phe) in the binding pocket, which might explain such a phenomenon of fluorescence sensitization. The two binding sites (Site 2 and Site 3) located around the Fe (III) ions with low-energy conformations are more suitable for ACR binding. Collectively, our study demonstrated that the loss of iron in TF caused by acrylamide-induced structural and conformational changes of transferrin.

Drug-food Interactions in the Era of Molecular Big Data, Machine Intelligence, and Personalized Health

The drug-food interaction brings forth changes in the clinical effects of drugs. While favourable interactions bring positive clinical outcomes, unfavourable interactions may lead to toxicity. This article reviews the impact of food intake on drug-food interactions, the clinical effects of drugs, and the effect of drug-food in correlation with diet and precision medicine. Emerging areas in drug-food interactions are the food-genome interface (nutrigenomics) and nutrigenetics. Understanding the molecular basis of food ingredients, including genomic sequencing and pharmacological implications of food molecules, helps to reduce the impact of drug-food interactions. Various strategies are being leveraged to alleviate drug-food interactions; measures including patient engagement, digital health, approaches involving machine intelligence, and big data are a few of them. Furthermore, delineating the molecular communications across dietmicrobiome- drug-food-drug interactions in a pharmacomicrobiome framework may also play a vital role in personalized nutrition. Determining nutrient-gene interactions aids in making nutrition deeply personalized and helps mitigate unwanted drug-food interactions, chronic diseases, and adverse events from their onset. Translational bioinformatics approaches could play an essential role in the next generation of drug-food interaction research. In this landscape review, we discuss important tools, databases, and approaches along with key challenges and opportunities in drug-food interaction and its immediate impact on precision medicine.

Dietary exposure to acrylamide and breast cancer risk: results from the NutriNet-Santé cohort

BACKGROUND

Acrylamide is classified as a probable human carcinogen by the International Agency for Research on Cancer but epidemiologic evidence on the carcinogenicity of acrylamide from dietary sources is limited.

OBJECTIVES

This study aimed to investigate the associations between dietary acrylamide and breast cancer risk in the NutriNet-Santé cohort, accounting for menopausal and hormone receptor status.

METHODS

This prospective cohort study included 80,597 French females (mean ± SD age at baseline: 40.8 ± 14 y) during a mean ± SD follow-up of 8.8 ± 2.3 y. Acrylamide intake was evaluated using repeated 24-h dietary records (n ± SD = 5.5 ± 3.0), linked to a comprehensive food composition database. Associations between acrylamide intake and breast cancer risk (overall, premenopausal, and postmenopausal) were assessed by Cox hazard models adjusted for known risk factors (sociodemographic, anthropometric, lifestyle, medical history, and nutritional factors).

RESULTS

The mean ± SD dietary acrylamide intake was 30.1 ± 21.9 µg/d (main contributors: coffee, potato fries and chips, pastries, cakes, bread). During follow-up, 1016 first incident breast cancer cases were diagnosed (431 premenopausal, 585 postmenopausal). A borderline significant positive association was observed between dietary acrylamide exposure and breast cancer risk overall (HR for quartile 4 compared with 1: 1.21; 95% CI: 1.00, 1.47) and a positive association was observed with premenopausal cancer (HRQ4vs.Q1: 1.40; 95% CI: 1.04, 1.88). Restricted cubic spline analyses suggested evidence for nonlinearity of these associations, with higher HRs for intermediate (quartile 2) and high (quartile 4) exposures. Receptor-specific analyses revealed positive associations with estrogen receptor-positive breast cancer (total and premenopausal). Acrylamide intake was not associated with postmenopausal breast cancer.

CONCLUSIONS

Results from this large prospective cohort study suggest a positive association between dietary acrylamide and breast cancer risk, especially in premenopausal females, and provide new insights that support continued mitigation strategies to reduce the content of acrylamide in food.This trial was registered at clinicaltrials.gov as NCT03335644.

Preventive Effect of Cocoa Flavonoids via Suppression of Oxidative Stress-Induced Apoptosis in Auditory Senescent Cells

Presbycusis or Age-related hearing loss (ARHL) is a sensorineural hearing loss that affects communication, leading to depression and social isolation. Currently, there are no effective treatments against ARHL. It is known that cocoa products have high levels of polyphenol content (mainly flavonoids), that are potent anti-inflammatory and antioxidant agents with proven benefits for health. The objective is to determine the protective effect of cocoa at the cellular and molecular levels in Presbycusis. For in vitro study, we used House Ear Institute-Organ of Corti 1 (HEI-OC1), stria vascularis (SV-k1), and organ of Corti (OC-k3) cells (derived from the auditory organ of a transgenic mouse). Each cell line was divided into a control group (CTR) and an H₂O₂ group (induction of senescence by an oxygen radical). Additionally, every group of every cell line was treated with the cocoa polyphenolic extract (CPE), measuring different markers of apoptosis, viability, the activity of antioxidant enzymes, and oxidative/nitrosative stress. The data show an increase of reactive oxidative and nitrogen species (ROS and RNS, respectively) in senescent cells compared to control ones. CPE treatment effectively reduced these high levels and correlated with a significant reduction in apoptosis cells by inhibiting the mitochondrial-apoptotic pathway. Furthermore, in senescence cells, the activity of antioxidant enzymes (Superoxide dismutase, SOD; Catalase, CAT; and Glutathione peroxidase, GPx) was recovered after CPE treatment. Administration of CPE also decreased oxidative DNA damage in the auditory senescent cells. In conclusion, CPE inhibits the activation of senescence-related apoptotic signaling by decreasing oxidative stress in auditory senescent cells.

Catechins protect against acrylamide- and glycidamide-induced cellular toxicity via rescuing cellular apoptosis and DNA damage

Acrylamide (AA) occurs in both various environmental and dietary sources and has raised widespread concern as a probable carcinogen. Glycidamide (GA) is the main genotoxic metabolite through P450 2E1 (CYP2E1). In the present study, we investigate the protective effect of (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin (EC) against AA- and GA-induced hepatotoxicity in HepG2 cells. The results demonstrated that EC and EGCG inhibited AA- and GA-induced cytotoxicity and mitochondria-mediated cellular apoptosis. Moreover, exposure to AA (100 μg/mL) and GA (50 μg/mL) caused cell cycle arrest and DNA damage, while EC and EGCG ranging from 12.5 to 50 μg/mL rescued cell cycle arrest and inhibited DNA damage. Furthermore, EC and EGCG down-regulated pro-apoptotic protein Bax and Caspase 3 after 24 h treatment in HepG2 cells exposed to AA (100 μg/mL) or GA (50 μg/mL). Also, the intervention with EC or EGCG up-regulated DNA repair related protein PARP and down-regulated expression of cleaved-PARP. Besides, EC exerted better protective effect than EGCG against AA- and GA-induced cytotoxicity in HepG2 cells. Altogether, EC and EGCG were effective in protecting AA- and GA-induced hepatotoxicity via rescuing cellular apoptosis and DNA damage, as well as promoting cell cycle progression in HepG2 cells.

Procyanidin A1 and its digestive products prevent acrylamide-induced intestinal barrier dysfunction via the MAPK-mediated MLCK pathway

Procyanidins can alleviate small-intestine damage induced by acrylamide (ACR). However, little is known about whether procyanidins, after gastrointestinal digestion, can prevent ACR-induced intestinal barrier damage and the possible mechanism. Here, Caco-2 cells were differentiated into an intestinal epithelial cell monolayer membrane, which was stimulated with or without ACR in the presence or absence of procyanidin A₁ (A₁) and its digestive products (D-A₁). Our findings show that both A₁ and D-A₁ significantly increased the transepithelial electrical resistance (TEER) value; decreased FITC-dextran 4 kDa (FITC-4 kDa) permeability, apoptosis and lactic dehydrogenase (LDH) release; and enhanced the expression of claudin-1, occludin and zonula occludens-1 (ZO-1) in ACR-induced Caco-2 cell monolayer membrane. In addition, A₁ and D-A₁ suppressed ACR-induced phosphorylation of mitogen-activated protein kinase (MAPK). Finally, A₁ and D-A₁ inhibited the myosin light chain kinase (MLCK) signaling pathway, thereby maintaining normal intestinal barrier functions, similar to the MLCK inhibitor in ACR-induced Caco-2 cell monolayer membrane. These findings indicate that A₁ can alleviate ACR-induced intestinal barrier dysfunction via inhibiting the MAPK/MLCK signaling pathway, and it still has excellent inhibitory effects after digestion.

Blumea laciniata protected Hep G2 cells and Caenorhabditis elegans against acrylamide-induced toxicity via insulin/IGF-1 signaling pathway

Acrylamide (AC), a proved toxin is mainly used in industrial fields and proved to possess various toxicities. In recent years, AC has been found in starch-containing foods due to Maillard reaction in a high-temperature process. Therefore, how to mitigate the toxic effect of AC is a research spot. Blumea laciniata is a widely used folk medicine in Asia and the extract from B. laciniata (EBL) exhibited a strong protection on cells against oxidative stress. In this work, we used EBL to protect Hep G2 cells and Caenorhabditis elegans against AC toxicity. As the results turned out, EBL increased cell viability under AC stress and notably reduced the cell apoptosis through decreasing the high level of ROS. Moreover, EBL extended the survival time of C. elegans, while EBL failed to prolong the survival time of mutants that were in Insulin signaling pathway. Besides, the expressions of antioxidant enzymes were activated after the worms were treated with EBL and daf-16 gene was activated. Our results indicated that EBL exhibited a protective effect against AC induced toxicity in Hep G2 cells and C. elegans via Insulin/IGF-1 signaling pathway. These outcomes may provide a promising natural drug to alleviate the toxic effect of AC.

In-vitro Investigation of Polyphenol-Rich Date (Phoenix dactylifera L.) Seed Extract Bioactivity

Date seeds are a by-product of the date fruit processing industry with minimal human use; however, they are a rich source of polyphenols with a range of potential biological properties. The current study investigates the cytotoxicity of date seed polyphenols against cancer cell lines, its ability to combat hyperglycemia, its antioxidant potential and its anti-adipogenic effect. The present work aimed to establish the usefulness of date seeds in the food industry as a functional ingredient. The anti-tumour activity of DSE was tested in a panel of cell lines such as MCF-7, MDA-MB-231, Hep-G2, Caco-2, and PC-3 by measuring cell viability and cleaved PARP. Lipid accumulation and effect on the differentiation of 3T3-L1 cells (adipocytes) were tested with date seed extract treatments. The influence of date seed polyphenols on glucose uptake was studied in 3T3-L1 cells and C2C12 cells (muscle cells). The antioxidant activity of the polyphenols from date seed products such as date seed extract (DSE), date seed powder (DSP), and date seeds fortified bread (DSB) was tested following in-vitro digestion to study their stability in the gastrointestinal milieu. DSE treatment resulted in significantly reduced viability in MCF-7 and Hep-G2 cells with 48-h treatments. Glucose uptake increased in the adipocytes with DSE treatments; moreover, it inhibited adipocyte differentiation and lipid accumulation. DSE decreased the expression levels of PPAR-γ, C/EBPα, adiponectin and upregulated GLUT-4, and phospho-AMPK. This study also found that date seed samples retained antioxidant activity in the digestive milieu and concludes that the date seed polyphenols remain active in the digestive milieu and exhibit potential anti-hyperglycemic and anti-adipogenic activity.

The Protective Agents Used against Acrylamide Toxicity: An In Vitro Cell Culture Study-Based Review

Acrylamide is a dangerous electrophile with the potency to react with many biological moieties including proteins, and nucleic acids as well as other macromolecules. Acrylamide was first only known a chemical exposed in working areas as a neurotoxicant, it was later discovered that beyond just being a neurotoxicant exposed in industrial areas, acrylamide is exposed via daily foods as well. As such, several strategies have been sought to be developed to relieve the toxic spectrum of this chemical. The utilization of a protective agent against acrylamide toxicity was one of those strategies. To date, many agents with protective potency have been investigated. Herein, we compiled these agents and their effects shown in in vitro studies. We used the search engines of Web of Knowledge and searched the keywords "acrylamide" and "protect" in the titles along with the keyword "cell" in the topics. Twenty-one directly related articles out of 35 articles were examined. Briefly, all agents used against acrylamide were reported to exhibit protective activity. In most of these reports, 5 mM concentration of acrylamide and 24-hour treatment were the employed dose and duration. Usually, the beneficial agents were pre-treated to the cells. PC12 cells were the most utilized cell line, and the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (NRF2) pathways were the most studied pathways. This study, beside other importance, can be utilized as a guide for how the protective studies against acrylamide were done and which parameters were investigated in in vitro acrylamide studies. In conclusion, taking measures is of utmost importance to prevent or alleviate the toxicity of acrylamide, to which we are daily exposed even in our homes. Therefore, future studies should persist in focusing on mitigating acrylamide toxicity.

Traceability of polyphenols in cocoa during the postharvest and industrialization processes and their biological antioxidant potential

Noncommunicable diseases, the leading cause of mortality around the world, are responsible for approximately 75% of premature adult deaths (ages 30-69). To tackle this issue, a healthy diet based on functional foods, including cocoa and its derivatives, has been increasingly promoted. The polyphenols present in cocoa have been of interest due to their antioxidant potential and their possible protective role in the context of noncommunicable diseases, such as diabetes and cardiovascular conditions. However, during cocoa postharvest and industrialization, the concentration of these bioactive compounds is reduced, possibly affecting their health-promoting properties. Therefore, this paper reviews in the literature in this field to find the total polyphenol content in cocoa during the postharvest and industrialization processes in order to define concentration ranges as a reference point for future research. In addition, it discusses in vitro and in vivo studies into the biological antioxidant potential of cocoa and its derivatives. This review covers publications in indexed databases from 2010 to 2020, their data were processed and presented here using box plots. As a result, we identified the concentration ranges of polyphenols depending on the type of matrix, treatment and country, as well as their relationship with the main bioactive compounds present in cocoa that are associated with their possible antioxidant biological potential and health-related benefits.

Procyanidin B2 Promotes Intestinal Injury Repair and Attenuates Colitis-Associated Tumorigenesis via Suppression of Oxidative Stress in Mice

Aims: Intact intestinal epithelium is essential to maintain normal intestinal physiological function. Irradiation-induced gastrointestinal syndrome or inflammatory bowel disease occurred when epithelial integrity was impaired. This study aims at exploring the mechanism of procyanidin B2 (PB2) administration to promote intestinal injury repair in mice. Results: PB2 treatment reduces reactive oxygen species (ROS) accumulation and protects the intestine damage from irradiation. Mechanistic studies reveal that PB2 could effectively slow down the degradation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and it significantly triggers Nrf2 into the nucleus, which leads to subsequent antioxidant enzyme expression. However, knockdown of Nrf2 attenuates PB2-induced protection in the intestine. More importantly, PB2 also promotes leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5)-positive intestinal stem cells (Lgr5⁺ ISCs) driven regeneration via enhancing Wnt/β-catenin signaling, which depends on, at least in part, activation of the Nrf2 signal. Evidence from an injury model of intestinal organoids is similar with in vivo results. Correspondingly, results from flow cytometric analysis and luciferase reporter assay reveal that PB2 also inhibits the level of ROS and promotes Lgr5 expression in vitro. Finally, PB2 alleviates the severity of experimental colitis and colitis-associated cancer in a long-term inflammatory model via inhibiting nuclear localization of p65. Innovation: This study, for the first time, reveals a role of PB2 for intestinal regeneration and repair after radiation or dextran sulfate sodium-induced injury in mice. Conclusion: Our results indicate that PB2 can repress oxidative stress via Nrf2/ARE signaling and then promote intestinal injury repair.

Food Contaminants Effects on an In Vitro Model of Human Intestinal Epithelium

Pesticide residues represent an important category of food contaminants. Furthermore, during food processing, some advanced glycation end-products resulting from the Maillard reaction can be formed. They may have adverse health effects, in particular on the digestive tract function, alone and combined. We sought to validate an in vitro model of the human intestinal barrier to mimic the effects of these food contaminants on the epithelium. A co-culture of Caco-2/TC7 cells and HT29-MTX was stimulated for 6 h with chlorpyrifos (300 μM), acrylamide (5 mM), N^ε-Carboxymethyllysine (300 μM) alone or in cocktail with a mix of pro-inflammatory cytokines. The effects of those contaminants on the integrity of the gut barrier and the inflammatory response were analyzed. Since the co-culture responded to inflammatory stimulation, we investigated whether this model could be used to evaluate the effects of food contaminants on the human intestinal epithelium. CPF alone affected tight junctions’ gene expression, without inducing any inflammation or alteration of intestinal permeability. CML and acrylamide decreased mucins gene expression in the intestinal mucosa, but did not affect paracellular intestinal permeability. CML exposure activated the gene expression of MAPK pathways. The co-culture response was stable over time. This cocktail of food contaminants may thus alter the gut barrier function.

Natural Polyphenols as Targeted Modulators in Colon Cancer: Molecular Mechanisms and Applications

Colon cancer commonly develops from long-term chronic inflammation in the intestine and seriously threatens human health. Natural polyphenols have been valued as a crucial regulator of nutrient metabolism and metabolic diseases, owing to their anti-inflammatory and antioxidant functions and the ability to maintain a balance between gut microbes and their hosts. Notably, experimental and clinical evidence has shown that natural polyphenols could act as a targeted modulator to play a key role in the prevention or treatment of colon cancer. Thus, in this review, we summarized recent advances in the possible regulatory mechanism and the potential application of natural polyphenols in colon cancer, which might be regarded as a novel platform for the colon cancer management.

Effect of procyanidins on lipid metabolism and inflammation in rats exposed to alcohol and iron

Background

Lifestyle involving uncontrolled alcohol consumption coupled regularly with red meat and other iron sources has detrimental effects on the liver, which in the long term, results in Alcoholic Liver Disease (ALD). Procyanidin has lately garnered increasing attention and has become the focus of research owing to its antioxidant properties. This study explores the anti-inflammatory effects of procyanidins, in preventing ALD, by analyzing the biological activities of the compound on liver injury caused by excessive alcohol and iron.

Method

Male SPF Wistar rats were placed in 4 groups; the control Group A (basic diet); the model Group B (excess alcohol 8–12 mL/kg/d and iron 1000 mg/kg diet); the low dose procyanidin Group C (model group diet plus 60 mg/kg/d of procyanidin); and the high dose procyanidin Group D (model group diet plus 120 mg/kg/d of procyanidin). Serum biochemical markers for liver damage were measured spectrophotometrically. The NFκB and IκB mRNA expression levels were determined using RT-PCR; the NFκB p65 and IκB protein expression levels were assessed via western blotting, while ELISA was used to detect serum inflammatory factors.

Results

The pathological score of the model Group B, low and high dose procyanidin Groups C and D were 6.58 ± 0.90,4.69 ± 0.70 and 2.00 ± 0.73, respectively (P < 0.05). The results showed that high alcohol and iron contents in the model group led to significant damage of liver structure, increased low-density lipoproteins (LDLs), steatosis, and increased levels of inflammatory cytokines. High amounts of procyanidins led to the preservation of the liver structure, production of high-density lipoproteins, and reduction in serum inflammatory cytokines while also significantly decreasing the expression levels of NFκB p65.

Conclusion

The results prove that procyanidins have hepatoprotective potential and could be effective in reversing histopathology, possibly by alleviating inflammation and improving lipid metabolism.

6'"-p-Coumaroylspinosin protects PC12 neuronal cells from acrylamide-induced oxidative stress and apoptosis

6'"-p-coumaroylspinosin (P-CS) is a flavonoid isolated from Ziziphi Spinosae Semen (ZSS), whereas, the antioxidative activity has not been reported. Oxidative stress is believed to be one of the main causes of neurodegenerative disorders. In this study, the antioxidative effect of P-CS on PC12 cells was determined. The cells were treated with acrylamide (AA) in the absence or presence of P-CS, and cell apoptosis was analyzed. Interestingly, P-CS pretreatment of the cells could significantly prevent AA-induced cell death, glutathione (GSH) contents decrease, and reactive oxygen species (ROS) overproduction. Further investigation of the molecular mechanism underlying the effect of P-CS on cell apoptosis revealed that P-CS was able to suppress the expression of Bax and Bim induced by AA and inhibit the JNKs pathway. Our findings support a role of P-CS in preventing neuronal cell apoptosis induced by AA, suggesting its therapeutic potential for the treatment of neurodegenerative disorders as a medicinal supplement. PRACTICAL APPLICATIONS: Oxidative stress is believed to cause damage in subcellular organelles, nucleic acids, and alteration in protein aggregation as well as disruption of the signaling cascades associated with aging and apoptosis. A small molecule, non-poisonous natural antioxidant is needed to protect the brain from oxidative stress. Compared with western medicine, natural products carry less risk of adverse effects and are not too expensive, especially for the third-world countries. Furthermore, ZSS could be used to produce or prepare antioxidants, such as P-CS, which has been reported significant anti-oxidative activity in this study.

Cocoa Flavanols Protect Human Endothelial Cells from Oxidative Stress

Oxidative stress may cause functional disorders of vascular endothelia which can lead to endothelial apoptosis and thus alter the function and structure of the vascular tissues. Plant antioxidants protect the endothelium against oxidative stress and then become an effective option to treat vascular diseases. Cocoa flavanols have been proven to protect against oxidative stress in cell culture and animal models. In addition, epidemiological and interventional studies strongly suggest that cocoa consumption has numerous beneficial effects on cardiovascular health. The objective of this study was to test the chemo-protective effect of realistic concentrations of a cocoa phenolic extract and its main monomeric flavanol epicatechin on cultured human endothelial cells submitted to an oxidative challenge. Both products efficiently restrained stress-induced reactive oxygen species and biomarkers of oxidative stress such as carbonyl groups and malondialdehyde, and recovered depleted glutathione, antioxidant defences and cell viability. Our results demonstrate for the first time that a polyphenolic extract from cocoa and its main flavonoid protect human endothelial cells against an oxidative insult by modulating oxygen radical generation and antioxidant enzyme and non-enzyme defences.

Acrylamide Induced Toxicity and the Propensity of Phytochemicals in Amelioration: A Review

Acrylamide is widely found in baked and fried foods, produced in large amount in industries and is a prime component in toxicity. This review highlights various toxicities that are induced due to acrylamide, its proposed mode of action including oxidative stress cascades and ameliorative mechanisms using phytochemicals. Acrylamide formation, the mechanism of toxicity and the studies on the role of oxidative stress and mitochondrial dysfunctions are elaborated in this paper. The various types of toxicities caused by Acrylamide and the modulation studies using phytochemicals that are carried out on various type of toxicity like neurotoxicity, hepatotoxicity, cardiotoxicity, immune system, and skeletal system, as well as embryos have been explored. Lacunae of studies include the need to explore methods for reducing the formation of acrylamide in food while cooking and also better modulators for alleviating the toxicity and associated dysfunctions along with identifying its molecular mechanisms.

Role of Oxidative Stress, MAPKinase and Apoptosis Pathways in the Protective Effects of Thymoquinone Against Acrylamide-Induced Central Nervous System Toxicity in Rat

The present study evaluated biochemical endpoints characterizing acrylamide (ACR) neurotoxicity in the cortex of rats, following the possible neuroprotective activity of thymoquinone (TQ), an active constituent of Nigella sativa. ACR (50 mg/kg, intraperitoneal [i.p.]) concurrently with TQ (2.5, 5 and 10 mg/kg, i.p.) for 11 days were administered to rats. As positive control, vitamin E was used. After 11 days of injections, narrow beam test (NBT) was performed. The levels of reduced glutathione (GSH) and malondialdehyde (MDA) were measured and Western blotting was done for mitogen-activated protein kinases (MAPKinases) and apoptosis pathways proteins in the rats' cortex. Additionally, Evans blue assay was done to evaluate the integrity of blood brain barrier (BBB). Administration of ACR significantly induced gait abnormalities. A significant decrease and increase in the levels of GSH and MDA was observed in the cortex of ACR-treated rats, respectively. The elevation in the levels of caspases 3 and 9, glial fibrillary acidic protein (GFAP) content, and Bax/Bcl-2, P-P38/P38 and P-JNK/JNK ratios accompanied by reduction in myelin basic protein (MBP) content and P-ERK/ERK ratio were noticed in the ACR group. TQ (5 mg/kg) improved gait abnormalities, and restored these changes. ACR affected the integrity of BBB while TQ was able to maintain the integrity of this barrier. TQ reversed the alterations in the protein contents of MAP kinase and apoptosis signaling pathways as well as MBP and GFAP contents, induced by ACR. It protected against ACR-mediated neurotoxicity, partly through its antioxidant and antiapoptotic properties.

Procyanidin B2 Suppresses Lipopolysaccharides-Induced Inflammation and Apoptosis in Human Type II Alveolar Epithelial Cells and Lung Fibroblasts

Acute lung injury (ALI) is characterized by acute lung inflammation and apoptosis of alveolar epithelial cells (AECs) with a high morbidity and mortality. Procyanidin B2 (PCB2) is a naturally occurring flavonoid with anti-inflammatory activity. Our previous study demonstrated that PCB2 inhibited NLRP3 inflammasome signaling and ameliorated paraquat-induced ALI in rat, indicating the protective role of PCB2. As lipopolysaccharide (LPS) induced acute cell injury and dysfunction, we continued to evaluate the protective effects of PCB2 using LPS-treated human AECs and lung fibroblasts (LFs) model. We tested the effects of PCB2 on cell permeability, viability, apoptosis, nuclear factor-kappaB (NF-κB) activation, NLRP3 inflammasome activation, and proinflammatory cytokines production in LPS-treated human AECs and LFs. PCB2 prevented LPS-induced cell apoptosis, and increased the cell viability in LPS-treated human AECs and LFs. PCB2 inhibited LPS-induced Bax and active caspase-3 expression, and promoted Bcl-2 expression. PCB2 prevented LPS-induced tumor necrosis factor-α, interleukin-1β expression, NF-κB activation, and NLRP3 inflammasome activation. PCB2 suppressed LPS-induced inflammation and apoptosis in human AECs and LFs by inhibiting NF-κB and NLRP3 inflammasome.

Catechin and Procyanidin B2 Modulate the Expression of Tight Junction Proteins but Do Not Protect from Inflammation-Induced Changes in Permeability in Human Intestinal Cell Monolayers

The possibility of counteracting inflammation-related barrier defects with dietary compounds such as (poly)phenols has raised much interest, but information is still scarce. We have investigated here if (+)-catechin (CAT) and procyanidin B₂ (PB₂), two main dietary polyphenols, protect the barrier function of intestinal cells undergoing inflammatory stress. The cell model adopted consisted of co-cultured Caco-2 and HT29-MTX cells, while inflammatory conditions were mimicked through the incubation of epithelial cells with the conditioned medium of activated macrophages (MCM). The epithelial barrier function was monitored through trans-epithelial electrical resistance (TEER), and ROS production was assessed with dichlorofluorescein, while the expression of tight-junctional proteins and signal transduction pathways were evaluated with Western blot. The results indicated that MCM produced significant oxidative stress, the activation of NF-κB and MAPK pathways, a decrease in occludin and ZO-1 expression, and an increase in claudin-7 (CL-7) expression, while TEER was markedly lowered. Neither CAT nor PB₂ prevented oxidative stress, transduction pathways activation, ZO-1 suppression, or TEER decrease. However, PB₂ prevented the decrease in occludin expression and both polyphenols produced a huge increase in CL-7 abundance. It is concluded that, under the conditions adopted, CAT and PB₂ do not prevent inflammation-dependent impairment of the epithelial barrier function of intestinal cell monolayers. However, the two compounds modify the expression of tight-junctional proteins and, in particular, markedly increase the expression of CL-7. These insights add to a better understanding of the potential biological activity of these major dietary flavan-3-ols at intestinal level.

Viburnum opulus Fruit Phenolic Compounds as Cytoprotective Agents Able to Decrease Free Fatty Acids and Glucose Uptake by Caco-2 Cells

In recent years, there has been increasing interest in studying food-originated phytocompounds with beneficial influences for humans. Amongst the most active natural substances are polyphenols, for which high content has been identified in the Viburnum opulus berry, and which are unused in Western Europe. Due to its strong antioxidant activity we explored the potential of V. opulus as a preventive agent against diet-related chronic diseases, such as obesity and type 2 diabetes. Among the causes of these ailments is oxidative stress, as well as impaired glucose and free fatty acids (FFA) uptake. Thus, the purpose of this study was to determine biological activity of V. opulus phenolic extracts as cytoprotective agents able to decrease induced oxidative stress, lower lipid accumulation and attenuate glucose and FFA uptake by Caco-2 cells via GLUT2 and CD36/FAT transporters. To determine the source of the most biologically active phenolic compounds, we obtained four phenolic compounds extracts as crude juice, phenolics isolated from juice and two preparations of phenolics obtained with different extraction agents from fruit pomace. Among the studied extracts, the phenolic rich fraction obtained from fruit juice revealed the strongest activity to decrease uptake of glucose, FFA and accumulation of lipid droplets in Caco-2 cells without affecting their viability (IC₀ 50 μg/mL). Observed uptake attenuation was followed by decrease of the CD36/FAT gene expression, without influence on the GLUT2 and PPARα levels. We suspect that V. opulus phenolics were able to modulate the cellular membrane dynamic, although that hypothesis requires further, more detailed studies. Extracts revealed strong chemo-preventive activity against oxidative stress induced chemically by tert-butylhydroperoxide (t-BOOH), as well as against DNA damage through the induction of DNA repair after cell exposition to methylnitronitrosoguanidine (MNNG) and H₂O₂. Our findings suggest Viburnum opulus fruit as a dietary source of phytocompounds, which could be considered as a tailored design food supplement components for the prevention and treatment of postprandial elevation of glucose and fatty acids through delaying the rate of glucose and fatty acid absorption by intestinal cells.

Bioaccessibility of polyphenols and antioxidant properties of the white grape by simulated digestion and Caco-2 cell assays: Comparative study with its winemaking product

The primary objective of this study was to assess the changes on phenolic composition and AC (antioxidant capacity) of white grape and its winemaking product, during in vitro gastrointestinal (GI) digestion. Phenolic compounds were evaluated by HPLC-MS/MS. The AC was measured by in vitro (FRAP, ABTS and DPPH) and cellular (Caco-2 cells) assays. Digestion had a reducing effect on phenolic content, being only 31% and 67% of native polyphenols from grapes and wines, respectively, potentially bioaccessible. At same polyphenol concentration, cellular AC of nondigested and digested foods was the same, indicating that changes in phenolic profile did not modify the bioactivity. Phenolic acids, in addition to quercetin, were the most resistant polyphenols to digestion, and would be the most relevant to explain the biological activity of digested foods. Results indicate that the changes occurred in the native phenolic profile of foods as a consequence of GI digestion, do not modify the bioactivity of white grapes and wines.

Polyphenols: Immunomodulatory and Therapeutic Implication in Colorectal Cancer

Polyphenolic compounds, widely present in fruits, vegetables, and cereals, have potential benefits for human health and are protective agents against the development of chronic/degenerative diseases including cancer. More recently these bioactive molecules have been gaining great interest as anti-inflammatory and immunomodulatory agents, mainly in neoplasia where the pro-inflammatory context might promote carcinogenesis. Colorectal cancer (CRC) is considered a major public healthy issue, a leading cause of cancer mortality and morbidity worldwide. Epidemiological, pre-clinical and clinical investigations have consistently highlighted important relationships between large bowel inflammation, gut microbiota (GM), and colon carcinogenesis. Many experimental studies and clinical evidence suggest that polyphenols have a relevant role in CRC chemoprevention, exhibit cytotoxic capability vs. CRC cells and induce increased sensitization to chemo/radiotherapies. These effects are most likely related to the immunomodulatory properties of polyphenols able to modulate cytokine and chemokine production and activation of immune cells. In this review we summarize recent advancements on immunomodulatory activities of polyphenols and their ability to counteract the inflammatory tumor microenvironment. We focus on potential role of natural polyphenols in increasing the cell sensitivity to colon cancer therapies, highlighting the polyphenol-based combined treatments as innovative immunomodulatory strategies to inhibit the growth of CRC.

Achacha (Garcinia humilis) Rind Improves Cardiovascular Function in Rats with Diet-Induced Metabolic Syndrome

Garcinia humilis is a fruit known as achachairú. It is native to South American countries such as Bolivia, Peru, and Brazil, but it is also cultivated as achacha in northern Australia. The aim of this study was to determine the phytochemicals in achacha rind and pulp and to investigate these components as potential treatments for the symptoms of metabolic syndrome. Both rind and pulp contain procyanidins and citric acid rather than hydroxycitric acid. Male Wistar rats (8⁻9 weeks old) were fed with either high-carbohydrate, high-fat, or corn starch diets for 16 weeks. Intervention groups were fed with either diet supplemented with 1.5% G. humilis rind powder or 2.0% G. humilis pulp for the last 8 weeks of the protocol. Rats fed a high-carbohydrate, high-fat diet exhibited hypertension, dyslipidemia, central obesity, impaired glucose tolerance, and non-alcoholic fatty liver disease. G. humilis rind decreased systolic blood pressure, diastolic stiffness, left ventricular inflammatory cell infiltration, and collagen deposition in high-carbohydrate, high-fat diet-fed rats. However, there was no change in glucose tolerance, body weight, or body composition. Therefore, G. humilis rind, usually a food by-product, but not the edible pulp, showed potential cardioprotection with minimal metabolic changes in a rat model of diet-induced metabolic syndrome.