Combined cereal and pulse flavonoids show enhanced bioavailability by downregulating phase II metabolism and ABC membrane transporter function in Caco-2 model

Predicting patient outcomes with gene-expression biomarkers from colorectal cancer organoids and cell lines

Introduction

Colorectal cancer (CRC) is characterized by an extremely high mortality rate, mainly caused by the high metastatic potential of this type of cancer. To date, chemotherapy remains the backbone of the treatment of metastatic colorectal cancer. Three main chemotherapeutic drugs used for the treatment of metastatic colorectal cancer are 5-fluorouracil, oxaliplatin and irinotecan which is metabolized to an active compound SN-38. The main goal of this study was to find the genes connected to the resistance to the aforementioned drugs and to construct a predictive gene expression-based classifier to separate responders and non-responders.

Methods

In this study, we analyzed gene expression profiles of seven patient-derived CRC organoids and performed correlation analyses between gene expression and IC50 values for the three standard-of-care chemotherapeutic drugs. We also included in the study publicly available datasets of colorectal cancer cell lines, thus combining two different in vitro models relevant to cancer research. Logistic regression was used to build gene expression-based classifiers for metastatic Stage IV and non-metastatic Stage II/III CRC patients. Prognostic performance was evaluated through Kaplan-Meier survival analysis and log-rank tests, while independent prognostic significance was assessed using multivariate Cox proportional hazards modeling.

Results

A small set of genes showed consistent correlation with resistance to chemotherapy across different datasets. While some genes were previously implicated in cancer prognosis and drug response, several were linked to drug resistance for the first time. The resulting gene expression signatures successfully stratified Stage II/III and Stage IV CRC patients, with potential clinical utility for improving treatment outcomes after further validation.

Discussion

This study highlights the advantages of integrating diverse experimental models, such as organoids and cell lines, to identify novel prognostic biomarkers and enhance the understanding of chemotherapy resistance in CRC.

Self-assembled nano delivery system of fenugreek polysaccharides: Effects on curcumin bioavailability and molecular mechanisms

Self-assembly of fenugreek polysaccharides FS60 (a natural macromolecular material) with curcuminoid has been proved to improve curcumin (Cur) water dispersion in preliminary studies. This study further explored the effect of FS60 on Cur bioavailability in vivo to assess the significance of this delivery method. In this study, we optimized the formulation parameters of FS60-curcuminoid aggregates (FC) and studied their effects on Cur pharmacokinetics in rats. Results showed that the optimized aggregates had an encapsulation efficiency (EE) of 88.22 % and hydrodynamic diameter (DH) of 231.48 nm. Additionally, administering FC significantly increased curcumin glucuronide (Cur-O-Glu) levels. The Cmax was 51 times higher and AUC0-12h was 19 times higher than curcuminoid alone. Moreover, FS60 intervention for seven days increased the absorption speed of Cur-O-Glu into the bloodstream. Further mechanistic studies indicated that FS60 promoted Cur ingestion, increased UGT expression, and inhibited enterocyte transporters, allowing large amounts of Cur-O-Glu to enter the bloodstream. Moreover, the gut microbiota modulated by FS60 accelerated the mutual conversion of pentose and gluconate to provide sufficient glucuronic acid for the glucuronidation of Cur in enterocytes. Consequently, the nano delivery system composed by FS60 and curcuminoid facilitated gastrointestinal Cur glucuronidation and Cur-O-Glu absorption.

Studies on absorption mechanism and pharmacokinetic properties of albendazole-bile acid conjugate: In vivo and in vitro

PURPOSE

To improve the oral bioavailability of albendazole (ABZ), a series of albendazole-bile acid conjugates (ABCs) were synthesized. ABC's transmembrane transport mechanism and in vivo pharmacokinetic properties were preliminarily studied.

METHODS

The transmembrane transport mechanism of ABCs was studied using the Caco-2 monolayer cell model and intestinal perfusion model. The concentration of ABCs and ABZ were evaluated using High-Performance Liquid Chromatography (HPLC) and HPLC-Mass Spectrometry (HPLC-MS/MS).

RESULTS

Compared to ABZ, better permeability was observed for different types and concentrations of ABCs using the Caco-2 monolayer cell model, with ABC-C8 showing the highest permeability. The transmembrane transport of ABCs was affected by ASBT inhibitors, indicating an ASBT-mediated active transport mechanism. Additionally, introducing cholic acid resulted in ABZ no longer being a substrate for P-gp, MRP2, and BCRP, effectively reversing ABZ efflux. In vivo unidirectional intestinal perfusion results in rats showed that ABCs altered the absorption site of ABZ from the jejunum to the ileum. The absorption efficiency of ABCs in each intestinal segment was higher than that of ABZ, and the transmembrane transport efficiency decreased with increasing concentrations of ASBT inhibitors. This further confirmed the presence of both passive diffusion and ASBT-mediated active transport mechanisms in the transport of ABCs. The solubility of ABCs in gastric juice and pharmacokinetics in rats showed that ABZ-C4 exhibited enhanced solubility. Moreover, ABCs significantly increased oral bioavailability compared to ABZ, with ABC-C4 showing an approximately 31-fold increase in bioavailability.

CONCLUSION

The transmembrane transport mechanism of ABCs involves a combination of ASBT-mediated active transport and passive diffusion. Moreover, the incorporation of BAs successfully reverses the efflux of ABZ by efflux proteins. Among the synthesized conjugates, ABC-C4 demonstrated superior dissolution behavior both in vitro and in vivo.

Intestinal absorption mechanism and nutritional synergy promotion strategy of dietary flavonoids: transintestinal epithelial pathway mediated by intestinal transport proteins

Dietary flavonoids exhibit a variety of physiological functions in regulating glucose and lipid metabolism, improving cardiovascular function, and enhancing stress resistance. However, poor intestinal absorption limits their health benefits. Previous studies on improving the absorption efficiency of flavonoids have focused on targeted release, enhanced gastrointestinal stability and prolonged retention time in digestive tract. But less attention has been paid to promoting the uptake and transport of flavonoids by intestinal epithelial cells through modulation of transporter protein-mediated pathways. Interestingly, some dietary nutrients have been found to modulate the expression or function of transporter proteins, thereby synergistically or antagonistically affecting flavonoid absorption. Therefore, this paper proposed an innovative regulatory strategy known as the "intestinal transport protein-mediated pathway" to promote intestinal absorption of dietary flavonoids. The flavonoid absorption mechanism in the intestinal epithelium, mediated by intestinal transport proteins, was summarized. The functional differences between the uptake transporter and efflux transporters during flavonoid trans-intestinal cellular transport were discussed. Finally, from the perspective of nutritional synergy promotion of absorption, the feasibility of promoting flavonoid intestinal absorption by regulating the expression/function of transport proteins through dietary nutrients was emphasized. This review provides a new perspective and developing precise dietary nutrient combinations for efficient dietary flavonoid absorption.

How Do Polyphenol-Rich Foods Prevent Oxidative Stress and Maintain Gut Health?

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, involves chronic inflammatory disorders of the digestive tract. Oxidative stress, associated with increased reactive oxygen species generation, is a major risk factor for IBD pathogenesis. Industrialized lifestyles expose us to a variety of factors that contribute to deteriorating gut health, especially for IBD patients. Many alternative therapeutic strategies have been developed against oxidative stress along with conventional therapy to alleviate IBD pathogenesis. Polyphenol-rich foods have attracted growing interest from scientists due to their antioxidant properties. Polyphenols are natural compounds found in plants, fruits, vegetables, and nuts that exhibit antioxidant properties and protect the body from oxidative damage. This review presents an overview of polyphenol benefits and describes the different types of polyphenols. It also discusses polyphenols' role in inhibiting oxidative stress and fungal growth prevention. Overall, this review highlights how a healthy and balanced diet and avoiding the industrialized lifestyles of our modern society can minimize oxidative stress damage and protect against pathogen infections. It also highlights how polyphenol-rich foods play an important role in protecting against oxidative stress and fungal growth.

Transport and interaction mechanism of four pesticide residues from Chaenomeles speciosa across Caco-2 cells

The presence of multiple pesticide residues in agricultural production highlights the need for studying mixture interaction during transepithelial transport. This study applied the Caco-2 cell model to investigate the interaction of four pesticide residues (carbendazim, epoxiconazole, phoxim, and chlorpyrifos) in Chaenomeles speciosa during transepithelial transport. Results demonstrated that co-treatment with pesticide mixtures generally increased the cumulative transport amount of carbendazim and epoxiconazole by 0.32-1.60 times and 0.32-0.98 times, respectively, compared to individual treatments. Notably, the combination of carbendazim and epoxiconazole displayed a significant synergistic effect. The use of transporter inhibitors and molecular docking analysis provided insights into the interaction mechanism, suggesting that the competitive inhibition of MRP2 and/or BCRP binding via π-bonds contributed to the inhibition of BL-to-AP efflux and a significant increase in AP-to-BL influx of carbendazim and epoxiconazole. The results are of great theoretical significance and practical value for risk assessment of multiple pesticide residues in agricultural products.

Quercetin Enhances the Availability of 5-Heptadecylresorcinol by Inhibiting the Expression of P-gp

5-Heptadecylresorcinol (AR-C17), as the most important active monomer, is found in large quantities in wheat and triticale and plays a variety of health benefits, such as antidiabetic, anti-inflammatory, and antitumor. However, the low bioavailability of AR-C17 due to its low water solubility restricts its application. Moreover, the transport mechanism of AR-C17 is not fully understood. Here, we showed that the transport of AR-C17 in vitro was time- and concentration-dependent, and relatively higher temperature and lower pH obviously promoted the transport of AR-C17. Besides, transporters, especially P-glycoprotein (P-gp), markedly affected the transport of AR-C17 as well. Quercetin, a natural synergist in triticale bran (TB), was confirmed as an inhibitor of P-gp to promote the transport of AR-C17 in this study, and the bioavailability of AR-C17 reached the highest when the concentration ratio of quercetin to AR-C17 was 1:1.

Flavonoids and gastrointestinal health: single molecule for multiple roles

Diet can be considered as one of the pivotal factors in regulating gastrointestinal health, and polyphenols widely distributed in human daily diet. The polyphenols and their metabolites playing a series of beneficial effects in human gastrointestinal tract that can regulate of the gut microbiota, increase intestinal barrier function, repair gastrointestinal mucosa, reduce oxidative stress, inhibit the secretion of inflammatory factors and regulating immune function, and their absorption and biotransformation mainly depend on the activity of intestinal microflora. However, little is known about the two-way interaction between polyphenols and intestinal microbiota. The objective of this review is to highlight the structure optimization and effect of flavonoids on intestinal flora, and discusses the mechanisms of dietary flavonoids regulating intestinal flora. The multiple effects of single molecule of flavonoids, and inter-dependence between the gut microbiota and polyphenol metabolites. Moreover, the protective effects of polyphenols on intestinal barrier function, and effects of interaction between plant polyphenols and macromolecules on gastrointestinal health. This review provided valuable insight that may be useful for better understanding the mechanism of the gastrointestinal health effects of polyphenols, and provide a scientific basis for their application as functional food.

Importance of ABC Transporters in the Survival of Parasitic Nematodes and the Prospect for the Development of Novel Control Strategies

ABC transporters, a family of ATP-dependent transmembrane proteins, are responsible for the active transport of a wide range of molecules across cell membranes, including drugs, toxins, and nutrients. Nematodes possess a great diversity of ABC transporters; however, only P-glycoproteins have been well-characterized compared to other classes. The ABC transport proteins have been implicated in developing resistance to various classes of anthelmintic drugs in parasitic nematodes; their role in plant and human parasitic nematodes still needs further investigation. Therefore, ABC transport proteins offer a potential opportunity to develop nematode control strategies. Multidrug resistance inhibitors are becoming more attractive for controlling nematodes due to their potential to increase drug efficacy in two ways: (i) by limiting drug efflux from nematodes, thereby increasing the amount of drug that reaches its target site, and (ii) by reducing drug excretion by host animals, thereby enhancing drug bioavailability. This article reviews the role of ABC transporters in the survival of parasitic nematodes, including the genes involved, their regulation and physiological roles, as well as recent developments in their characterization. It also discusses the association of ABC transporters with anthelmintic resistance and the possibility of targeting them with next-generation inhibitors or nutraceuticals (e.g., polyphenols) to control parasitic infections.

Sodium silicate treatment accelerates biosynthesis and polymerization of suberin polyaliphatics monomers at wounds of muskmelon

Suberin polyaliphatics (SPA) is an important component of healing closing layer at fruit wounds. However, few study is available on the effect of sodium silicon treatment on SPA monomers biosynthesis and polymerization at muskmelon wounds. In this study, sodium silicate enhanced PLA₂ (Phospholipase A₂, PLA₂) expression and enzyme activity, increased oleic acid, linoleic acid, and linolenic acid contents, and degree of fatty acids unsaturation at wounds. Sodium silicate upregulated the expressions of LACS4 (Long chain acyl CoA synthetase, LACS), KCS10 (β-ketoacyl CoA synthase, KCS), CYP86B1 (Cytochrome P450 oxygenase, CYP), FAR3 (Fatty acyl CoA reductase, FAR), GPAT1 (Glycerol-3-phosphate acyltransferase, GPAT) and ABCG6 (ATP-binding cassette transporter), as well as their enzymes activities and ABC content. It is suggested that sodium silicate accelerates the deposition of SPA at muskmelon wounds by increasing the degree of fatty acids unsaturation, and promoting SPA monomers biosynthesis.

ATP-binding cassette efflux transporters and MDR in cancer

Of the many known multidrug resistance (MDR) mechanisms, ATP-binding cassette (ABC) transporters expelling drug molecules out of cells is a major factor limiting the efficacy of present-day anticancer drugs. In this review, we highlights updated information on the structure, function, and regulatory mechanisms of major MDR-related ABC transporters, such as P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), and breast cancer resistance protein (BCRP), and the effect of modulators on their functions. We also provide focused information on different modulators of ABC transporters that could be utilized against the emerging MDR crisis in cancer treatment. Finally, we discuss the importance of ABC transporters as therapeutic targets in light of future strategic planning for translating ABC transporter inhibitors into clinical practice.

Bitter taste signaling in cancer

Pharmacoresistance of cancer cells to many drugs used in chemotherapy remains a major challenge for the treatment of cancer. Multidrug resistance transporters, especially ATP-binding cassette (ABC) transporters, are a major cause of cancer drug resistance since they translocate a broad range of drug compounds across the cell membrane, extruding them out of the cells. The regulation of ABC transporters by bitter taste receptors (TAS2Rs), which might be activated by specific bitter tasting compounds, was described in several types of cells/organs, becoming a potential target for cancer therapy. TAS2Rs expression has been reported in many organs and several types of cancer, like breast, ovarian, prostate, and colorectal cancers, where their activation was shown to be involved in various biological actions (cell survival, apoptosis, molecular transport, among others). Moreover, many TAS2Rs' ligands, such as flavonoids and alkaloids, with well-recognized beneficial properties, including several anticancer effects, have been reported as potential adjuvants in cancer therapies. In this review, we discuss the potential therapeutic role of TAS2Rs and bitter tasting compounds in different types of cancer as a possible way to circumvent chemoresistance.

Targeting Apoptotic Pathway of Cancer Cells with Phytochemicals and Plant-Based Nanomaterials

Apoptosis is the elimination of functionally non-essential, neoplastic, and infected cells via the mitochondrial pathway or death receptor pathway. The process of apoptosis is highly regulated through membrane channels and apoptogenic proteins. Apoptosis maintains cellular balance within the human body through cell cycle progression. Loss of apoptosis control prolongs cancer cell survival and allows the accumulation of mutations that can promote angiogenesis, promote cell proliferation, disrupt differentiation, and increase invasiveness during tumor progression. The apoptotic pathway has been extensively studied as a potential drug target in cancer treatment. However, the off-target activities of drugs and negative implications have been a matter of concern over the years. Phytochemicals (PCs) have been studied for their efficacy in various cancer cell lines individually and synergistically. The development of nanoparticles (NPs) through green synthesis has added a new dimension to the advancement of plant-based nanomaterials for effective cancer treatment. This review provides a detailed insight into the fundamental molecular pathways of programmed cell death and highlights the role of PCs along with the existing drugs and plant-based NPs in treating cancer by targeting its programmed cell death (PCD) network.

Natural Blockers of PD-1/PD-L1 Interaction for the Immunotherapy of Triple-Negative Breast Cancer-Brain Metastasis

The limited treatment options for triple-negative breast cancer with brain metastasis (TNBC-BM) have left the door of further drug development for these patients wide open. Although immunotherapy via monoclonal antibodies has shown some promising results in several cancers including TNBC, it cannot be considered the most effective treatment for brain metastasis. This is due to the protective role of the blood-brain barrier (BBB) which limits the entrance of most drugs, especially the bulky ones such as antibodies, to the brain. For a drug to traverse the BBB via passive diffusion, various physicochemical properties should be considered. Since natural medicine has been a key inspiration for the development of the majority of current medicines, in this paper, we review several naturally-derived molecules which have the potential for immunotherapy via blocking the interaction of programmed cell death protein-1 (PD-1) and its ligand, PD-L1. The mechanism of action, physicochemical properties and pharmacokinetics of these molecules and their theoretical potential to be used for the treatment of TNBC-BM are discussed.

Baking Process Effects and Combined Cowpea Flour and Sorghum Bran on Functional Properties of Gluten-Free Cookies

Gluten-related disorders, including celiac disease and non-celiac gluten sensitivity, are growing worldwide. The only treatment for both disorders is a lifelong gluten-free diet. However, gluten-free foods are generally poorer in nutrients, less healthy, and have a high cost. Sorghum and cowpea are gluten-free grains with high levels of phenolic compounds (PC) and a low cost. Their phenolic profile is structurally different; thus, the blend of both can provide synergistic/complementary health benefits to the final product. This study analyzed the effect of baking process and the blend of cowpea flour (CP) and sorghum bran (SB) on the levels of PC, resistant starch (RS), neutral detergent fiber (NDF), and antioxidant capacity (AC) of gluten-free cookies. Eleven rice or cowpea cookie formulations were made with or without white sorghum bran (WSB) or black sorghum bran (BSB). Baking increased the extractability of PC, AC, and the NDF of almost all formulations. The PC and AC were, respectively, about twice and 3-5 times higher in cookies containing BSB compared to the others. There was a minor effect of WSB on the PC and AC. Although there were losses, the retention of RS of cookies after the baking process was between 49.8 and 92.7%. Sorghum bran has excellent potential for use as a functional ingredient in healthy food production. The combined CP and SB have great potential to improve the nutritional and functional properties of gluten-free products, especially the PC, RS, and NDF contents.

The new exploration of pure total flavonoids extracted from Citrus maxima (Burm.) Merr. as a new therapeutic agent to bring health benefits for people

The peel and fruit of Citrus varieties have been a raw material for some traditional Chinese medicine (TCM). Pure total flavonoids from Citrus maxima (Burm.) Merr. (PTFC), including naringin, hesperidin, narirutin, and neohesperidin, have been attracted increasing attention for their multiple clinical efficacies. Based on existing in vitro and in vivo research, this study systematically reviewed the biological functions of PTFC and its components in preventing or treating liver metabolic diseases, cardiovascular diseases, intestinal barrier dysfunction, as well as malignancies. PTFC and its components are capable of regulating glycolipid metabolism, blocking peroxidation and persistent inflammation, inhibiting tumor progression, protecting the integrity of intestinal barrier and positively regulating intestinal microbiota, while the differences in fruit cultivation system, picking standard, manufacturing methods, delivery system and individual intestinal microecology will have impact on the specific therapeutic effect. Thus, PTFC is a promising drug for the treatment of some chronic diseases, as well as continuous elaborate investigations are necessary to improve its effectiveness and bioavailability.

A review of recent progress in improving the bioavailability of nutraceutical-loaded emulsions after oral intake

Increasing awareness of the health benefits of specific constituents in fruits, vegetables, cereals, and other whole foods has sparked a broader interest in the potential health benefits of nutraceuticals. Many nutraceuticals are hydrophobic substances, which means they must be encapsulated in colloidal delivery systems. Oil-in-water emulsions are one of the most widely used delivery systems for improving the bioavailability and bioactivity of these nutraceuticals. The composition and structure of emulsions can be designed to improve the water dispersibility, physicochemical stability, and bioavailability of the encapsulated nutraceuticals. The nature of the emulsion used influences the interfacial area and properties of the nutraceutical-loaded oil droplets in the gastrointestinal tract, which influences their digestion, as well as the bioaccessibility, metabolism, and absorption of the nutraceuticals. In this article, we review recent in vitro and in vivo studies on the utilization of emulsions to improve the bioavailability of nutraceuticals. The findings from this review should facilitate the design of more efficacious nutraceutical-loaded emulsions with increased bioactivity.

Apigenin in cancer therapy: From mechanism of action to nano-therapeutic agent

Apigenin (APG) is a flavonoid presence in beverages, vegetables, and fruits containing anti-diabetic, anti-oxidant, and anti-viral activities, as well as cancer management properties. There is growing evidence that APG presented extensive anti-cancer effects in several cancer types by modulating various cellular processes, including angiogenesis, apoptosis, metastasis, autophagy, cell cycle, and immune responses, through activation or inhibition of different cell signaling pathways and molecules. By emerging nanotechnology and its advent in the biomedicine field, cancer therapy has been changed based on nanotechnology-based delivery systems. APG nanoformulations have been used to target tumor cells specifically, improve cellular uptake of APG, and overcome limitations of the free form of APG, such as low solubility and poor bioavailability. In this review, the biotherapeutic activity of APG and its mechanisms, both in free form and nanoformulation, toward cancer cells are discussed to shed some light on APG anti-tumor activity in different cancers.

Transport and Interactions of Co-incubated Bi-functional Flavonoids through Inhibiting the Function of P-Glycoprotein (P-gp) Using KB/Multidrug-Resistant (MDR) Cells and Rat Everted Gut Sacs

This study aims to evaluate the interaction of flavonoid-flavonoid by inhibiting the function of P-glycoprotein (P-gp). The cellular uptake of seven substrates and eleven co-incubated inhibitors was measured in KB/MDR cells. The effect of galangin or morin on the absorption of silibinin or wogonin was carried out in the rat everted gut sacs. Docking was performed to evaluate the interactions between inhibitors and P-gp. Most substrates were greatly enhanced by at least five co-incubated inhibitors. Conversely, the increased uptake of substrates coincided with a decrease or without affecting the uptake of inhibitors, implying a competitive/non-competitive inhibition on P-gp. The enhancement effect by galangin or morin on the transport of silibinin or wogonin was verified in everted gut sacs. Docking explained the inhibition of flavonoids on P-gp by competitively binding to the ATP site. These results provide a strategy for increasing the absorption of flavonoids by co-administration.

The influence of rhein on the absorption of rehmaionoside D: In vivo, in situ, in vitro, and in silico studies

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese Medicine, Rehmannia glutinosa (Gaertn.) DC., as the principle herb of ShengDiHuang Decotion (SDHD), has the effect of cooling blood and hemostasis, and tonifying the yin and kidney. Rheum L., as adjuvant herbs, assist Rehmannia glutinosa (Gaertn.) DC. to promote blood circulation to remove blood stasis.

AIM OF STUDY

To study the mechanism of Rhein (RH) involved in the promotion of Rehmannioside D (RD) absorption by pharmacokinetic studies, single-pass intestinal perfusion, Caco-2 cell models, molecular docking technique and western blotting.

MATERIALS AND METHODS

Initially, the intestinal absorption of RD in the presence or absence of RH was conducted through pharmacokinetic studies. Thereafter, the intestinal absorption of RD and RH was studied using the single-pass intestinal perfusion and Caco-2 cell models. Finally, using molecular docking technique and western blotting.

RESULTS

We found that the promotion of RD absorption by RH was mediated by breast cancer resistance and multidrug resistance-associated protein 2, thereby affecting the permeability of the intestinal epithelium. Additionally, RH and RD can competitively bind to breast cancer resistance and multidrug resistance-associated protein 2, and that RH inhibits the expression of breast cancer resistance and multidrug resistance-associated protein 2 in the ileum to promote the intestinal absorption of RD.

CONCLUSION

This study reveals the mechanisms associated with the RH-mediated promotion of RD absorption and provides a basis for further exploring the synergistic effect of Rehmannia glutinosa (Gaertn.) DC and rhubarb.

The role of dietary flavonoids for modulation of ATP binding cassette transporter mediated multidrug resistance

Flavonoids are widely existing compounds with enormous pharmacological effects from food and medicine. However, the low bioavailability in intestinal absorption and metabolism limits their clinical application. Intestinal efflux ABC (ATP binding cassette) transporters, including P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs), act as "pumping doors" to regulate the efflux of flavonoids from intestinal epithelial cells into the intestinal cavity or the systemic circulation. The present review describes the critical effect of ABC transporters involved in the efflux of flavonoids which depend on its efflux direction. And the role of flavonoids for modulation of intestinal ABC transporters was emphasized and several examples were given. We summarized that the resistance effect of flavonoid-mediated multidrug on ABC transporters may influence the bioavailability of drugs, bioactive ingredients and/or toxic compounds upon dietary uptake. Meanwhile, flavonoids functionalized as reversing agents of the ABC transporter may be an important mechanism for unexpected food-drug, food-toxin or food-food interactions. The overview also indicates that elucidation of the action and mechanism of the intestinal metabolic enzymes-efflux transporters coupling will lay a foundation for improving the bioavailability of flavonoids <i>in vivo</i> and increasing their clinical efficacy.

Repurposing Natural Dietary Flavonoids in the Modulation of Cancer Tumorigenesis: Decrypting the Molecular Targets of Naringenin, Hesperetin and Myricetin

In the past few years flavonoids have been gaining more attention regarding their (still un) exploited anticancer properties. Flavonoids are natural compounds present in fruits, vegetables, and seeds, meaning that they are already present in the daily life of every person, with a described broad-spectrum of pharmacological activities, including anticancer, anti-inflammatory and antioxidant. In the present review we discuss the anticancer activity of three important flavonoids - myricetin (MYR) (flavanol group), hesperetin (HESP) and naringenin (NAR) (flavanone group). Although some mechanisms underlying their activities remain still unclear, they can act as potential inhibitors of key tumorigenic signaling pathways, such as PI3K/Akt/mTOR, p38 MAPK and NF-κB. Simultaneously, they can reset the levels of pro-apoptotic proteins that belong to the Bcl-2 and caspase family and decrease the intracellular levels of ROS and pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6. Together with their synergetic effect they have the potential to become key elements in the prevention and/or treatment of several types of cancer, with the major improvement to the patient life quality, due to their non-existent toxicity.

Bioavailability, Absorption, and Metabolism of Pelargonidin-Based Anthocyanins Using Sprague-Dawley Rats and Caco-2 Cell Monolayers

The present study is aimed to clarify the absorption and metabolism properties of pelargonidin-based anthocyanins. Results showed that pelargonidin-3-O-rutinoside (Pg3R) was absorbed in its intact form after oral administration and reached a maximum plasma concentration of 175.38 ± 55.95 nM at 60 min. Three main metabolites were identified in plasma, including Pg3R-monoglucuronide (m/z 755.2046), Pg3R-hydroxylated (m/z 595.1644), and Pg3R-demethylated (m/z 565.1569) metabolites. The plasma concentration of the Pg3R-demethylated metabolite (57.04 ± 23.15 nM) was much higher than that of other two metabolites, indicating that demethylation was the main metabolic pathway for Pg3R, while the glucuronide conjugate was detected as the dominant metabolic form of pelargonidin-3-O-glucoside (Pg3G). The bioavailability of Pg3R (1.13%) was fourfold higher than that of Pg3G (0.28%), demonstrating that anthocyanins linked to the rutinoside may exhibit higher bioavailability than that of glucoside. In vitro transport study unveiled that passive diffusion and active efflux were involved in the absorption of Pg3R and Pg3G.

Binding and antiplatelet activity of quercetin, rutin, diosmetin, and diosmin flavonoids

Platelets exert an essential role in vascular inflammation and thrombosis. Flavonoids are natural compounds employed for the clinical management of vascular disorders preventing capillary permeability, working as phlebotonics and improving the blood rheology, although their mechanism of action remains partially unknown. The effects of quercetin, rutin, diosmetin and diosmin were investigated in platelet activation utilizing blood from healthy and non-treated volunteers. The arrangement of the different activation states of platelets and GPIIb/IIIa receptor occupation was computed by flow cytometry working with calcium ionophore as pro-aggregant to provoke platelet activation and aggregation. The flavonoids studied demonstrated relevant antiplatelet activity through the blocked of GPIIb/IIIa receptors, the suppression of the platelet activation, as well as the pro-aggregate effect of calcium ionophore. Therefore, whichever of the active ingredients examined could be beneficious in the prevention of cardiovascular disease and this article also contributes to elucidate a new mechanism of action for these drugs.

Changes in extractable phenolic profile during natural fermentation of wheat, sorghum and teff

Whole grain polyphenols are associated with structure-specific bioactive properties. However, the phenolic profile of grain ingredients can be significantly altered by processes like fermentation. This study investigated how polyphenol profiles in different cereal grains respond to microbial metabolism during sourdough fermentation. Whole grain wheat (white and red), sorghum (white and lemon-yellow), and teff (white and brown) flours were subjected to natural sourdough fermentation for 48-96 h, and phenolic profiles and their metabolites monitored using UPLC-tandem quadrupole MS. Flavonoid O-glycosides (dominant in sorghum) were rapidly metabolized (66% reduction in 48 h) to release aglycones (2.5 fold increase). O-Glycoside groups in mixed O/C-glycosides (dominant in teff) were selectively hydrolyzed, but more slowly (11-32% reduction in 48 h) than homo-O-glycosides, suggesting steric hindrance from the C-glycoside groups. Flavonoid C-glycosides (dominant in wheat) and aglycones (white sorghum) were generally stable to microbial degradation. Extractable phenolic acids and their esters (most abundant in white sorghum) were extensively degraded (80% reduction in 48 h) with few metabolites detected at the end of fermentation. Thus, extractable phenolics in sorghum were generally most extensively metabolized, whereas those in wheat were the least impacted by sourdough fermentation. New microbial metabolites, putatively identified as O-methylcatechol-vinyl-isoflavans, were detected in all fermented samples, with levels increasing with fermentation time. Based on structure, these compounds were likely derived from cell wall C-C linked diferulic acid metabolism. As expected, Folin reactive phenols and antioxidant capacity increased in fermented samples, but the extent was distinctly smaller in sorghums (1.3-1.9 fold) vs teff (2.4-3.2 fold) and wheat (2.0-6.1 fold), likely due to higher presence of easily metabolizable phenolics in sorghum. The phenolic profile of a cereal grain affects the products of microbial metabolism during fermentation, and may thus alter phenolic-dependent bioactive properties associated with a specific grain.

Does Oral Apigenin Have Real Potential for a Therapeutic Effect in the Context of Human Gastrointestinal and Other Cancers?

Apigenin (4′, 5, 7-trihydroxyflavone) is a plant flavone that has been found to have various actions against cancer cells. We evaluated available evidence to determine whether it is feasible for apigenin to have such effects in human patients.

Apigenin taken orally is systemically absorbed and recirculated by enterohepatic and local intestinal pathways. Its bioavailability is in the region of 30%. Once absorbed from the oral route it reaches maximal circulating concentration (C_max) after a time (T_max) of 0.5–2.5h, with an elimination half-life (T¹/₂) averaging 2.52 ± 0.56h.

Using a circulating concentration for efficacy of 1–5μmol/L as the target, we evaluated data from both human and rodent pharmacokinetic studies to determine if a therapeutic concentration would be feasible. We find that oral intake of dietary materials would require heroic ingestion amounts and is not feasible. However, use of supplements of semi-purified apigenin in capsule form could reach target blood levels using amounts that are within the range currently acceptable for other supplements and medications. Modified formulations or parenteral injection are suitable but may not be necessary.

Further work with direct studies of pharmacokinetics and clinical outcomes are necessary to fully evaluate whether apigenin will contribute to a useful clinical strategy, but given emerging evidence that it may interact beneficially with chemotherapeutic drugs, this is worthy of emphasis. In addition, more effective access to intestinal tissues from the oral route raises the possibility that apigenin may be of particular relevance to gastrointestinal disorders including colorectal cancer.

Phenolic profile of jujube fruit subjected to gut microbiota fermentation and its antioxidant potential against ethyl carbamate-induced oxidative damage

OBJECTIVES

To evaluate the composition of bioactive substances and the antioxidant effects of jujube fruit under gut microbiota fermentation (GMF), and the inhibitory effect on cytotoxicity caused by ethyl carbamate (EC).

METHODS

Changes in the contents of flavonoids, polyphenols, total sugars, and reducing sugars of jujube fruit after GMF (0, 2, 6, 12, 24, and 48 h) were determined. The oxidation resistance of fermented jujube fruits (from 0 to 48 h fermentation) was evaluated using in vitro 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Inhibitory effects of 48 h-fermented jujube fruit at various concentrations (0.25, 0.50, 1.00, and 2.00 mg/mL) on EC-treated toxicity and DNA damage of Caco-2 cells were estimated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and nuclear staining assays, respectively. Effects of different concentrations of jujube fruit on EC-treated Caco-2 cells' intracellular reactive oxygen species (ROS), glutathione (GSH) levels, and mitochondrial membrane potential (MMP) were also evaluated.

RESULTS

Jujube fruit has rich bioactive components after GMF and shows strong antioxidant capacity. Fermented jujube fruit can inhibit the cytotoxicity and DNA damage of Caco-2 cells caused by EC and reduce intracellular ROS generation, as well as restoring GSH and MMP.

CONCLUSIONS

Fermented jujube fruit extracts produced by GMF still contain biologically active substances which retain biological activity and antioxidation capabilities.

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.

Characterization of Formononetin Sulfonation in SULT1A3 Overexpressing HKE293 Cells: Involvement of Multidrug Resistance-Associated Protein 4 in Excretion of Sulfate

Formononetin is one of the main active compounds of traditional Chinese herbal medicine Astragalus membranaceus. However, disposition of formononetin via sulfonation pathway remains undefined. Here, expression-activity correlation was performed to identify the contributing of SULT1A3 to formononetin metabolism. Then the sulfonation of formononetin and excretion of its sulfate were investigated in SULT1A3 overexpressing human embryonic kidney 293 cells (or HKE-SULT1A3 cells) with significant expression of breast cancer resistance protein (BCRP) and multidrug resistance-associated protein 4 (MRP4). As a result, formononetin sulfonation was significantly correlated with SULT1A3 protein levels (r = 0.728; p < 0.05) in a bank of individual human intestine S9 fractions (n = 9). HEK-SULT1A3 cells catalyzed formononetin formation of a monosulfate metabolite. Sulfate formation of formononetin in HEK-SULT1A3 cell lysate followed the Michaelis-Menten kinetics (V_max = 13.94 pmol/min/mg and K_m = 6.17 μM). Reduced activity of MRP4 by MK-571 caused significant decrease in the excretion rate (79.1%–94.6%) and efflux clearance (85.3%–98.0%) of formononetin sulfate, whereas the BCRP specific inhibitor Ko143 had no effect. Furthermore, silencing of MRP4 led to obvious decrease in sulfate excretion rates (>32.8%) and efflux clearance (>50.6%). It was worth noting that the fraction of dose metabolized (f_met), an indicator of the extent of drug sulfonation, was also decreased (maximal 26.7%) with the knockdown of MRP4. In conclusion, SULT1A3 was of great significance in determining sulfonation of formononetin. HEK-SULT1A3 cells catalyzed formononetin formation of a monosulfate. MRP4 mainly contributed to cellular excretion of formononetin sulfate and further mediated the intracellular sulfonation of formononetin.

Evaluation of the nutritional quality of cereal bars made with pulse flours using desirability functions

The development of nutritious, low-cost snacks has become increasingly important due to consumer demand for healthier diets. In this study, sensory and physical-chemical parameters and mineral compositions (P, Ca, Na, K, Mg, Fe, Zn, Al, Cu, Mn, Ni and Ba) of cereal bars were evaluated. The bars were made with flours of Lablab purpureus L. Sweet (mangalo), Vigna unguiculata L. Walp (cowpea) or Cajanus cajan L. Huth (pigeon pea) and the desirability function was used to attain the best formulation for maximising the content of protein, fibre, ashes and essential elements. Sensory analysis revealed satisfactory acceptability. Acidity did not change significantly (p > 0.05), and water activity values ​​did not exceed 0.557 over 90 days, indicating stability. Principal component analysis revealed no significant differences when comparing the mineral content between the bars. The desirability function indicated that the cowpea-based bar had a higher nutritional quality, with a protein content of 4.91 ± 0.25 g 100 g^-1, P content of 187.7 ± 3.6 mg 100 g^-1, Mg content of 87.37 ± 1.19 mg 100 g^-1 and Mn content of 2020 ± 130 µg 100 g^-1, than the other bars. The overall sensory evaluation also yielded a high score for the cowpea-based bar (overall quality equal to 6.23 ± 1.10). Therefore, pulse flours could be potential nutritional ingredients for making snacks, and in particular, cereal bars containing them could be a viable product alternative for small rural cooperatives.

Sorghum Grain: From Genotype, Nutrition, and Phenolic Profile to Its Health Benefits and Food Applications

Globally, sorghum is one of the most important but least utilized staple crops. Sorghum grain is a rich source of nutrients and health-beneficial phenolic compounds. The phenolic profile of sorghum is exceptionally unique and more abundant and diverse than other common cereal grains. The phenolic compounds in sorghum are mainly composed of phenolic acids, 3-deoxyanthocyanidins, and condensed tannins. Studies have shown that sorghum phenolic compounds have potent antioxidant activity in vitro, and consumption of sorghum whole grain may improve gut health and reduce the risks of chronic diseases. Recently, sorghum grain has been used to develop functional foods and beverages, and as an ingredient incorporated into other foods. Moreover, the phenolic compounds, 3-deoxyanthocyanidins, and condensed tannins can be isolated and used as promising natural multifunctional additives in broad food applications. The objective of this review is to provide a comprehensive understanding of nutrition and phenolic compounds derived from sorghum and their related health effects, and demonstrate the potential for incorporation of sorghum in food systems as a functional component and food additive to improve food quality, safety, and health functions.

Transepithelial transport mechanisms of 7,8-dihydroxyflavone, a small molecular TrkB receptor agonist, in human intestinal Caco-2 cells

7,8-Dihydroxyflavone (7,8-DHF), as a high-affinity TrkB receptor agonist, has been extensively explored in many human disorders involving brain-derived neurotrophic factor (BDNF) such as Alzheimer's disease, Parkinson's disease, depression, and obesity. However, to date, the transepithelial transport mechanisms of 7,8-DHF in the intestines remain unclear. The aim of our work was to quantify and to characterize in vitro transport of naturally occurring 7,8-DHF distinguished by its physicochemical and pharmacological properties. We discussed the transport mechanisms of 7,8-DHF using the Caco-2 cell model to determine the bi-directional permeability with different environmental factors (time, concentration, pH, metabolic inhibitors etc.). The influx and efflux characteristics of 7,8-DHF were also clarified. 7,8-DHF was poorly transported across Caco-2 cell monolayers by mainly passive diffusion via a transcellular pathway and not a paracellular pathway. The transport of 7,8-DHF was time and concentration-dependent in both the apical (AP) to basolateral (BL) side and the reverse direction. Interestingly, decreasing the pH from 7.4 to 6.0 markedly enhanced 7,8-DHF transport. It is noteworthy that 7,8-DHF transport was strongly inhibited by metabolic inhibitors and was highly dependent on temperature. The efflux ratio (ER) values at different concentrations were all above 1.5, indicating the existence of the efflux transporter. We found that breast cancer resistance protein (BCRP) was not involved in 7,8-DHF secretion and that the transport mechanism of 7,8-DHF was passive transport with an active efflux mediated by P-glycoprotein (P-gp) and multidrug resistance associated proteins (MRPs), particularly MRP 2. Moreover, the use of various influx transporter inhibitors in Caco-2 cells showed that organic cation transporters (OCTs) and organic anion-transporting polypeptides (OATPs) participated in 7,8-DHF transport. Taken together, the elucidated transport characteristics of 7,8-DHF provide useful information for designing novel and efficient delivery systems and avoiding food-food or food-drug interactions.

Anti-inflammatory effects of flavonoids

Inflammation plays a key role in diseases such as diabetes, asthma, cardiovascular diseases and cancer. Diet can influence different stages of inflammation and can have an important impact on several inflammatory diseases. Increasing scientific evidence has shown that polyphenolic compounds, such as flavonoids, which are found in fruits, vegetables, legumes, or cocoa, can have anti-inflammatory properties. Recent studies have demonstrated that flavonoids can inhibit regulatory enzymes or transcription factors important for controlling mediators involved in inflammation. Flavonoids are also known as potent antioxidants with the potential to attenuate tissue damage or fibrosis. Consequently, numerous studies in vitro and in animal models have found that flavonoids have the potential to inhibit the onset and development of inflammatory diseases. In the present review, we focused in flavonoids, the most abundant polyphenols in the diet, to give an overview of the most recent scientific knowledge about their impact on different inflammatory diseases.

Antioxidant and Photoprotective Activity of Apigenin and its Potassium Salt Derivative in Human Keratinocytes and Absorption in Caco-2 Cell Monolayers

Ultraviolet (UV) radiation, especially types A (UVA) and B (UVB), is one of the main causes of skin disorders, including photoaging and skin cancer. Ultraviolent radiation causes oxidative stress, inflammation, p53 induction, DNA damage, mutagenesis, and oxidation of various molecules such as lipids and proteins. In recent decades, the use of polyphenols as molecules with an antioxidant and anti-inflammatory capacity has increased. However, some of these compounds are poorly soluble, and information regarding their absorption and bioavailability is scarce. The main objective of this study was to compare the intestinal absorption and biological activity of apigenin and its more soluble potassium salt (apigenin-K) in terms of antioxidant and photoprotective capacity. Photoprotective effects against UVA and UVB radiation were studied in human keratinocytes, and antioxidant capacity was determined by different methods, including trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. Finally, the intestinal absorption of both apigenins was determined using an in vitro Caco-2 cell model. Apigenin showed a slightly higher antioxidant capacity in antioxidant activity assays when compared with apigenin-K. However, no significant differences were obtained for their photoprotective capacities against UVA or UVB. Results indicated that both apigenins protected cell viability in approximately 50% at 5 J/m² of UVA and 90% at 500 J/m² of UVB radiation. Regarding intestinal absorption, both apigenins showed similar apparent permeabilities (P_app), 1.81 × 10^-5 cm/s and 1.78 × 10^-5 cm/s, respectively. Taken together, these results suggest that both apigenins may be interesting candidates for the development of oral (nutraceutical) and topical photoprotective ingredients against UVA and UVB-induced skin damage, but the increased water solubility of apigenin-K makes it the best candidate for further development.