Flavonoid interactions during digestion, absorption, distribution and metabolism: a sequential structure-activity/property relationship-based approach in the study of bioavailability and bioactivity

Biotransformation and metabolite activity analysis of flavonoids from propolis in vivo

Propolis is a natural resinous compound produced by bees, mixed with their saliva and wax, and has a range of biological benefits, including antioxidant and anti-inflammatory effects. This article reviews the in vivo transformation of propolis flavonoids and their potential influence on drug efficacy. Despite propolis is widely used, there is little research on how the active ingredients of propolis change in the body and how they interact with drugs. Future research will focus on these interactions and the metabolic fate of propolis in vivo.

Metabolomic analysis reveals the effect of ultrasonic-microwave pretreatment on flavonoids in tribute Citrus powder

In this study, the ultrasonic-microwave pretreatment was defined as a processing technology in the production of tribute citrus powder, and it could increase the flavonoid compounds in the processing fruit powder. A total of 183 upregulated metabolites and 280 downregulated metabolites were obtained by non-targeted metabolomics, and the differential metabolites was mainly involved in the pathways of flavonoid biosynthesis, flavone and flavonol biosynthesis. A total of 8 flavonoid differential metabolites were obtained including 5 upregulated metabolites (6"-O-acetylglycitin, scutellarin, isosakuranin, rutin, and robinin), and 3 downregulated metabolites (astragalin, luteolin, and (-)-catechin gallate) by flavonoids-targeted metabolomics. The 8 flavonoid differential metabolites participated in the flavonoid biosynthesis pathways, flavone and flavonol biosynthesis pathways, and isoflavonoid biosynthesis pathways. The results provide a reference for further understanding the relationship between food processing and food components, and also lay a basis for the development of food targeted-processing technologies.

The Protective Effect of Flavonoids in the Diet on Autophagy-Related Cardiac Impairment

The compounds known as flavonoids, commonly found in fruits, vegetables, legumes, medicinal herbs, chocolate, and coffee and tea beverages, have been extensively researched for their impact on cardiovascular health. Flavonoids, with their demonstrated potential, have shown promising effects in regulating blood vessel function and apoptotic processes, as well as in improving lipid profiles. While their powerful antioxidant properties were initially thought to be the main reason behind these effects, recent studies have uncovered new insights into the positive effects of flavonoids on cardiovascular health, and researchers have now identified several signaling pathways and mechanisms that also play a role. Of particular interest are the studies that have highlighted the role of autophagy in maintaining the physiological functions of cardiomyocytes and protecting them from harm. Recent publications have linked the dysregulation of autophagic processes with the development of cardiomyopathies, heart failure, and other cardiovascular diseases. This review aims to present the latest, novel findings from preclinical research regarding the potential beneficial effects of flavonoids on various heart conditions associated with altered autophagy processes.

Harnessing the Power of Polyphenols: A New Frontier in Disease Prevention and Therapy

There are a wide variety of phytochemicals collectively known as polyphenols. Their structural diversity results in a broad range of characteristics and biological effects. Polyphenols can be found in a variety of foods and drinks, including fruits, cereals, tea, and coffee. Studies both in vitro and in vivo, as well as clinical trials, have shown that they possess potent antioxidant activities, numerous therapeutic effects, and health advantages. Dietary polyphenols have demonstrated the potential to prevent many health problems, including obesity, atherosclerosis, high blood sugar, diabetes, hypertension, cancer, and neurological diseases. In this paper, the protective effects of polyphenols and the mechanisms behind them are investigated in detail, citing the most recent available literature. This review aims to provide a comprehensive overview of the current knowledge on the role of polyphenols in preventing and managing chronic diseases. The cited publications are derived from in vitro, in vivo, and human-based studies and clinical trials. A more complete understanding of these naturally occurring metabolites will pave the way for the development of novel polyphenol-rich diet and drug development programs. This, in turn, provides further evidence of their health benefits.

Resveratrol-loaded octenyl succinic anhydride modified starch emulsions and hydroxypropyl methylcellulose (HPMC) microparticles: Cytotoxicity and antioxidant bioactivity assessment after in vitro digestion

Hydroxypropyl methylcellulose (HPMC)-based microparticles and modified starch emulsions (OSA-MS) were loaded with resveratrol and characterized regarding their physicochemical and thermal properties. Both delivery systems were subject to an in vitro gastrointestinal digestion to assess the bioaccessibility of resveratrol. In addition, cell-based studies were conducted after in vitro digestion and cytotoxicity and oxidative stress were assessed. HPMC-based microparticles displayed higher average sizes (d) and lower polydispersity index (PDI) (d = 948 nm, PDI < 0.2) when compared to OSA-MS-based emulsions (d = 217 nm, PDI < 0.3). Both proved to protect resveratrol under digestive conditions, leading to an increase in bioaccessibility. Resveratrol-loaded HPMC-microparticles showed a higher bioaccessibility (56.7 %) than resveratrol-loaded emulsions (19.7 %). Digested samples were tested in differentiated co-cultures of Caco-2 and HT29-MTX, aiming at assessing cytotoxicity and oxidative stress, and a lack of cytotoxicity was observed for all samples. Results displayed an increasing antioxidant activity, with 1.6-fold and 1.4-fold increases over the antioxidant activity of free resveratrol, for HPMC-microparticles and OSA-MS nanoemulsions, respectively. Our results offer insight into physiological relevancy due to assessment post-digestion and highlight the protection that the use of micro-nano delivery systems can confer to resveratrol and their potential to be used as functional food ingredients capable of providing antioxidant benefits upon consumption.

Electrophysiology, molecular modelling, and functional analysis of the effects of dietary quercetin and flavonoid analogues on Kir6.1 channels in rat stomach fundus smooth muscle

Flavonoids, ubiquitously distributed in the plant world, are regularly ingested with diets rich in fruit, vegetables, wine, and tea. During digestion, they are partially absorbed in the stomach. The present work aimed to assess the in vitro effects of quercetin and ten structurally related flavonoids on the rat gastric fundus smooth muscle, focussing on ATP-dependent K+ (Kir6.1) channels, which play a central role in the regulation of resting membrane potential, membrane excitability and, consequently, of gastric motility. Whole-cell currents through Kir6.1 channels (IKir6.1) were recorded with the patch-clamp technique and the mechanical activity of gastric fundus smooth muscle strips was studied under isometric conditions. Galangin ≈ tamarixetin > quercetin > kaempferol > isorhamnetin ≈ luteolin ≈ fisetin > (±)-taxifolin inhibited pinacidil-evoked, glibenclamide-sensitive IKir6.1 in a concentration-dependent manner. Morin, rutin, and myricetin were ineffective. The steric hindrance of the molecule and the number and position of hydroxyl groups on the B ring played an important role in the activity of the molecule. Molecular docking simulations revealed a possible binding site for flavonoids in the C-terminal domain of the Kir6.1 channel subunit SUR2B, in a flexible loop formed by residues 251 to 254 of chains C and D. Galangin and tamarixetin, but not rutin relaxed both high K+- and carbachol-induced contraction of fundus strips in a concentration-dependent manner. Furthermore, both flavonoids shifted to the right the concentration-relaxation curves to either pinacidil or L-cysteine constructed in strips pre-contracted by high K+, rutin being ineffective. In conclusion, IKir6.1 inhibition exerted by dietary flavonoids might counterbalance their myorelaxant activity, affect gastric accommodation or, at least, some stages of digestion.

Exploring the Transmembrane Behaviors of Dietary Flavonoids under Intestinal Digestive Products of Different Lipids: Insights into the Structure-Activity Relationship In Vitro

This study aimed to investigate the transmembrane transport behavior and structure-activity relationships of various dietary flavonoids in the presence of dietary lipids derived from different sources in vitro. Results revealed that the digestion products of soybean oil (SOED) and lard (LOED) augmented the apparent permeability coefficients of most dietary flavonoids, and SOED exhibited higher transport compared with LOED. The structural properties of flavonoids and the potential interactions between fatty acids in these digestion products and flavonoids may influence the outcomes. 3D quantitative structure-activity relationship analyses revealed that incorporating small-volume groups at position 8 of the A-ring augmented the transmembrane transfer of flavonoids in the LOED system compared with the control group. By contrast, the integration of hydrophobic groups at position 5 of the A-ring and hydrogen bonding acceptor groups at position 6 of the A-ring enhanced the transmembrane transportation of flavonoids in the SOED system. Molecular dynamics simulations revealed that the SOED system may facilitate the interactions with flavonoids to form more stable and compact fatty acid-flavonoid complexes compared to the LOED system. These findings may provide valuable insights into flavonoid absorption to facilitate the development and utilization of functional foods or dietary supplements based on dietary flavonoids.

Transmembrane behaviors and quantitative structure-activity relationship of dietary flavonoids in the presence of intestinal digestive products from different carbohydrate sources based on in vitro and in silico analysis

Bioavailability plays a key role for flavonoids to exert their bioactivities. This study investigated the transmembrane transport behavior and structure-activity of dietary flavonoids. Results showed that the apparent permeability coefficients of some flavonoids could be significantly increased when digestion products from rice flour (RD) or wheat flour (WD) are present (p < 0.05), especially in the WD, potentially due to higher reducing sugar (p < 0.05). 3D-QSAR revealed that the hydrogen bond acceptor groups at positions 5 and 6 of ring A, small-volume groups at position 3', hydrophobic groups at position 4', and large-volume groups at position 5' of ring B increased the transmembrane transport of flavonoids in the WD. A hydrogen bond donor group at position 4' of ring B enhanced the transmembrane transport of flavonoid compounds in the RD. These findings contribute to our comprehensive understanding of flavonoid absorption within the context of intestinal carbohydrate digestion.

Protection against cancer therapy-induced cardiovascular injury by planed-derived polyphenols and nanomaterials

Cancer therapy-induced heart injury is a significant concern for cancer patients undergoing chemotherapy, radiotherapy, immunotherapy, and also targeted molecular therapy. The use of these treatments can lead to oxidative stress and cardiomyocyte damage in the heart, which can result in heart failure and other cardiac complications. Experimental studies have revealed that chemotherapy drugs such as doxorubicin and cyclophosphamide can cause severe side effects such as cardiac fibrosis, electrophysiological remodeling, chronic oxidative stress and inflammation, etc., which may increase risk of cardiac disorders and attacks for patients that underwent chemotherapy. Similar consequences may also be observed for patients that undergo radiotherapy for left breast or lung malignancies. Polyphenols, a group of natural compounds with antioxidant and anti-inflammatory properties, have shown the potential in protecting against cancer therapy-induced heart injury. These compounds have been found to reduce oxidative stress, necrosis and apoptosis in the heart, thereby preserving cardiac function. In recent years, nanoparticles loaded with polyphenols have also provided for the delivery of these compounds and increasing their efficacy in different organs. These nanoparticles can improve the bioavailability and efficacy of polyphenols while minimizing their toxicity. This review article summarizes the current understanding of the protective effects of polyphenols and nanoparticles loaded with polyphenols against cancer therapy-induced heart injury. The article discusses the mechanisms by which polyphenols protect the heart, including antioxidant and anti-inflammation abilities. The article also highlights the potential benefits of using nanoparticles for the delivery of polyphenols.

Polyphenols in Inner Ear Neurobiology, Health and Disease: From Bench to Clinics

There is substantial experimental and clinical interest in providing effective ways to both prevent and slow the onset of hearing loss. Auditory hair cells, which occur along the basilar membrane of the cochlea, often lose functionality due to age-related biological alterations, as well as from exposure to high decibel sounds affecting a diminished/damaged auditory sensitivity. Hearing loss is also seen to take place due to neuronal degeneration before or following hair cell destruction/loss. A strategy is necessary to protect hair cells and XIII cranial/auditory nerve cells prior to injury and throughout aging. Within this context, it was proposed that cochlea neural stem cells may be protected from such aging and environmental/noise insults via the ingestion of protective dietary supplements. Of particular importance is that these studies typically display a hormetic-like biphasic dose-response pattern that prevents the occurrence of auditory cell damage induced by various model chemical toxins, such as cisplatin. Likewise, the hormetic dose-response also enhances the occurrence of cochlear neural cell viability, proliferation, and differentiation. These findings are particularly important since they confirmed a strong dose dependency of the significant beneficial effects (which is biphasic), whilst having a low-dose beneficial response, whereas extensive exposures may become ineffective and/or potentially harmful. According to hormesis, phytochemicals including polyphenols exhibit biphasic dose-response effects activating low-dose antioxidant signaling pathways, resulting in the upregulation of vitagenes, a group of genes involved in preserving cellular homeostasis during stressful conditions. Modulation of the vitagene network through polyphenols increases cellular resilience mechanisms, thus impacting neurological disorder pathophysiology. Here, we aimed to explore polyphenols targeting the NF-E2-related factor 2 (Nrf2) pathway to neuroprotective and therapeutic strategies that can potentially reduce oxidative stress and inflammation, thus preventing auditory hair cell and XIII cranial/auditory nerve cell degeneration. Furthermore, we explored techniques to enhance their bioavailability and efficacy.

Phenolic profile and α-glucosidase inhibitory potential of wampee (Clausena lansium (Lour.) Skeels) peel and pulp: In vitro digestion/in silico evaluations

To investigate the changes in phenolics, flavonoids, and their bio-activities of wampee (Clausena lansium (Lour.) Skeels) during digestion, the peel and pulp were subjected to simulated in vitro digestion, encompassing oral, gastric, small intestine, and large intestine digestion stages. The peel exhibited a total release of 91.93 mg GAE/g DW of phenolics and 61.86 mg RE/g DW of flavonoids, whereas the pulp displayed a release of 27.83 mg GAE/g DW of phenolics and 8.94 mg RE/g DW of flavonoids. Notably, the phenolics and flavonoids were mostly released during the oral digestion stage for peel, while they were mostly released during the small intestine digestion stage for pulp. The results of the targeted flavonoids analysis indicated that rutin and l-epicatechin were the two most widely released compounds in each digestion step. Moreover, myricetin has been identified as the best inhibitor against α-glucosidase, probably because it formed the most H-bonds, 8, with 6 catalytic residues, which was the highest number. Furthermore, the soluble substances released from the peel exhibited significantly higher antioxidant activities and inhibitory activity against α-glucosidase (p < 0.05) compared to those from the pulp. Positive correlations were observed between the total phenolic content or total flavonoid content and the antioxidant activities (r > 0.73 (peel), > 0.61 (pulp)), as well as α-glucosidase inhibitory activity (r <  - 0.48 (peel), < -0.64 (pulp)) of peel and pulp. In conclusion, these findings provide valuable insights into the digestive characteristics and health benefits of both wampee peel and pulp.

Flavonoids as promising anticancer therapeutics: Contemporary research, nanoantioxidant potential, and future scope

Flavonoids are natural polyphenolic compounds considered safe, pleiotropic, and readily available molecules. It is widely distributed in various food products such as fruits and vegetables and beverages such as green tea, wine, and coca-based products. Many studies have reported the anticancer potential of flavonoids against different types of cancers, including solid tumors. The chemopreventive effect of flavonoids is attributed to various mechanisms, including modulation of autophagy, induction of cell cycle arrest, apoptosis, and antioxidant defense. Despite of significant anticancer activity of flavonoids, their clinical translation is limited due to their poor biopharmaceutical attributes (such as low aqueous solubility, limited permeability across the biological membranes (intestinal and blood-brain barrier), and stability issue in biological systems). A nanoparticulate system is an approach that is widely utilized to improve the biopharmaceutical performance and therapeutic efficacy of phytopharmaceuticals. The present review discusses the significant anticancer potential of promising flavonoids in different cancers and the utilization of nanoparticulate systems to improve their nanoantioxidant activity further to enhance the anticancer activity of loaded promising flavonoids. Although, various plant-derived secondary metabolites including flavonoids have been recommended for treating cancer, further vigilant research is warranted to prove their translational values.

Polyphenols Cause Structure Dependent Effects on the Metabolic Profile of Human Hepatocarcinogenic Cells

SCOPE

Although many beneficial health effects are attributed to polyphenols their influence on the human metabolome has not been elucidated yet. The ubiquitous occurrence of polyphenols in the human diet demands comprehensive knowledge about physiological and toxicological effects of these compounds on human cells.

METHODS AND RESULTS

The human hepatocarcinogenic cell line HepG2 is used to elucidate the effects of 13 polyphenols and three respective phenolic degradation products on the human metabolome using HPLC-MS/MS. To investigate structure-activity-relationships, structurally related examples of polyphenols from different compound classes are selected. The analysis of catechins points toward a relation between the degree of hydroxylation and the extent of metabolic effects particularly on the urea cycle and the pentose phosphate pathway (PPP). A correlation between the modulation of the PPP and the stability of the compounds is demonstrated, which may be caused by reactive oxygen species (ROS). The incubation of flavones and alkenylbenzenes demonstrates reduced activity of methoxylated compounds and no impact of the B-ring position.

CONCLUSION

In general, polyphenols induce a multitude of metabolic effects, for example, on energy metabolism, PPP, and urea cycle. These metabolic alterations may be related to the widely reported bioactivity of these compounds such as the anticarcinogenic effects.

In vitro inhibition of human cytochrome P450 enzymes by licoisoflavone B from Glycyrrhiza uralensis Fisch. ex DC

Glycyrrhiza uralensis Fisch. ex DC, one of the 3 pharmacopeial species of licorice and widely used in dietary supplements, can inhibit certain cytochrome P450 (CYP) enzymes. Thereby, G. uralensis preparations have the potential to cause pharmacokinetic drug interactions when consumed along with prescription medicines. One compound (1.34 mg dry weight) responsible for inhibiting CYP2B6, CYP2C8, and CYP2C9 was isolated using bioactivity-guided fractionation from 250 g dried roots, stolons, and rhizomes. The enzyme kinetics and mechanisms of inhibition were determined using human liver microsomes, recombinant enzymes, and UHPLC-MS/MS-based assays. Identified as licoisoflavone B, this compound displayed reversible inhibition of CYP2C8 with an IC50 value of 7.4 ± 1.1 µM and reversible inhibition of CYP2C9 with an IC50 value of 4.9 ± 0.4 µM. The enzyme kinetics indicated that the mechanism of inhibition was competitive for recombinant CYP2C8, with a Ki value of 7.0 ± 0.7 μM, and mixed-type inhibition for recombinant CYP2C9, with a Ki value of 1.2 ± 0.2 μM. Licoisoflavone B moderately inhibited CYP2B6 through a combination of irreversible and reversible mechanisms with an IC50 value of 16.0 ± 3.9 µM.

Effects of Lyophilized Açaí (Euterpe oleracea) Supplementation on Oxidative Damage and Intestinal Histology in Juvenile Shrimp Penaeus vannamei Reared in Biofloc Systems

The objective of this was to evaluate the ability of bioflocs to assimilate and transfer antioxidant compounds present in açaí Euterpe oleracea to juvenile Penaeus vannamei shrimp grown in a biofloc system. Juvenile shrimp were distributed into four treatment groups (control, 5, 20, and 80 mg açaí L-1), containing 31 shrimps/tank (90 L), and cultivated for 30 days. Every 24 h throughout the experimental period, the respective açaí concentrations were added directly to the cultivation water. The bioflocs and hepatopancreas lost their antioxidant capacity with increasing concentrations of açaí; however, lipid damage was mitigated after treatment with 20 mg of açaí L-1 (p < 0.05). The application of 20 mg açaí L-1 increased the mean height and area of the middle intestinal microvilli (p < 0.05). Mortality and protein and lipid damage in shrimp muscle increased with daily administration of 80 mg açaí L-1 (p < 0.05). It is concluded that the bioflocs were able to assimilate the antioxidants present in açaí and transfer them to the shrimp, and the administration of 20 mg açaí L-1 presented the best performance, demonstrating the possibility of its application in the cultivation of P. vannamei in a biofloc system.

The Effect of a High-Protein Diet Supplemented with Blackthorn Flower Extract on Polyphenol Bioavailability and Antioxidant Status in the Organs of C57BL/6 Mice

The health benefits of polyphenols are based on their bioavailability, which is why a significant portion of research focuses on factors that affect their bioavailability. Previous studies suggest that the intake of polyphenols along with macronutrients in food represents one of the key factors influencing the bioavailability of polyphenols and, consequently, their biological activity in the organism. Since polyphenols in the human diet are mainly consumed in food together with macronutrients, this study investigated the in vivo absorption, metabolism, and distribution of polyphenolic compounds from the water extract of blackthorn flower (Prunus spinosa L.) in combination with a protein-enriched diet in the organs (small intestine, liver, kidney) of C57BL/6 mice. The bioaccumulation of polyphenol molecules, biologically available maximum concentrations of individual groups of polyphenol molecules, and their effect on the oxidative/antioxidative status of organs were also examined. The results of this study indicate increased bioabsorption and bioavailability of flavan-3-ols (EC, EGCG) and reduced absorption kinetics of certain polyphenols from the groups of flavonols, flavones, and phenolic acids in the organs of C57BL/6 mice after intragastric administration of the water extract of blackthorn flower (Prunus spinosa L.) in combination with a diet enriched with whey proteins. Furthermore, subchronic intake of polyphenols from the water extract of blackthorn flower (Prunus spinosa L.) in combination with a diet enriched with whey proteins induces the synthesis of total glutathione (tGSH) in the liver and superoxide dismutase (SOD) in the liver and small intestine. The results of this study suggest potential applications in the development of functional foods aimed at achieving the optimal health status of the organism and the possibility of reducing the risk of oxidative stress-related disease.

Co-Encapsulation of Multiple Polyphenols in Plant-Based Milks: Formulation, Gastrointestinal Stability, and Bioaccessibility

Plant-based milk is particularly suitable for fortification with multiple nutraceuticals because it contains both hydrophobic and hydrophilic domains that can accommodate molecules with different polarities. In this study, we fortified soymilk with three common polyphenols (curcumin, quercetin, and resveratrol) using three pH-driven approaches. We compared the effectiveness of these three different approaches for co-encapsulating polyphenols. The gastrointestinal fate of the polyphenol-fortified soymilks was then studied by passing them through a simulated mouth, stomach, and small intestine, including the stability and bioaccessibility of polyphenols. All three pH-driven approaches were suitable for co-encapsulating multiple polyphenols at a high encapsulation efficiency, especially for the curcumin and resveratrol. The polyphenol-loaded delivery systems exhibited similar changes in particle size, charge, stability, and bioaccessibility as they passed through the mouth, stomach, and intestinal phases. The bioaccessibility of the co-encapsulated polyphenols was much greater than that of crystallized polyphenols dispersed in water. The poor bioaccessibility of the crystallized polyphenols was attributed to their low solubility in water, which made them more difficult to solubilize within mixed micelles. This study underscores the feasibility of pH-driven approaches for encapsulating a variety of polyphenols into the same plant-based delivery system. These fortified plant-based milks may therefore be designed to provide specific health benefits to consumers.

Influence of Soluble Fiber as a Carrier on Antioxidant and Physical Properties of Powders Produced Based on the Spray Drying of Malvae arboreae flos Aqueous Extracts

The objective of this study was to assess the impact of inulin and pectin, wherein pectin replaced inulin with weight ranging from 2% to 8%, as wall materials on various aspects: bioactive component content, antioxidant and anti-inflammatory properties, bioavailability, powder recovery during the drying process, and selected physical characteristics of powders derived from Malvae arboreae flos aqueous extracts obtained through spray drying. Powders containing a soluble fraction of fiber demonstrated a recovery efficiency of over 50% during drying, along with low moisture content, water activity, and hygroscopicity, coupled with high solubility. The incorporation of pectin up to 8% did not significantly alter the color profile of the powders. However, at levels of 4% to 8% pectin, concave distortions and particle morphology cracks became noticeable, along with the potential to form agglomerates (evident when the span index ranged between 5.11 and 14.51). The substitution of inulin with pectin led to higher total contents of flavonoids (from 1.31% to 49.57% before digestion, and from 18.92% to 36.48% after digestion) and anthocyanins (from 45.79% to 78.56% before digestion, and from 65.45% to 521.81% after digestion) compared to samples containing only inulin as a carrier. Bioacceptability values exceeding 100% indicated effective preservation of compounds responsible for ferric-reducing antioxidant power, as well as the inhibition of xanthine oxidase and cyclooxygenase-2 across all samples.

Hesperetin-7-O-glucoside/β-cyclodextrin Inclusion Complex Induces Acute Vasodilator Effect to Inhibit the Cold Sensation Response during Localized Cold-Stimulate Stress in Healthy Human Subjects: A Randomized, Double-Blind, Crossover, and Placebo-Controlled Study

Hesperetin, a citrus flavonoid, exerts vasodilation and is expected to improve endothelial function and alleviate cold sensation by activating nervous system thermal transduction pathways. In this randomized, double-blind, crossover, and placebo-controlled study, the purpose was to assess the effect of an orally administered highly bioavailable soluble inclusion complex of hesperetine-7-O-glucoside with β-cyclodextrin (HEPT7G/βCD; SunActive® HES/HCD) on cold sensation response during localized cold-stimulated stress in healthy humans. A significant (p ≤ 0.05) dose-dependent increase in skin cutaneous blood flow following relatively small doses of HEPT7G/βCD inclusion complex ingestion was confirmed, which led to a relatively effective recovery of peripheral skin temperature. The time delay of an increase in blood flow during rewarming varied significantly between low- and high-dose HEPT7G/βCD inclusion complex consumption (e.g., 150 mg and 300 mg contain 19.5 mg and 39 mg of HEPT7G, respectively). In conclusion, the substantial alteration in peripheral skin blood flow observed during local cooling stress compared to placebo suggested that deconjugated hesperetin metabolites may have a distinct capacity for thermoregulatory control of human skin blood flow to maintain a constant body temperature during cold stress exposure via cutaneous vasodilation and vasoconstriction systems.

Involvement of Nrf2 Activation and NF-kB Pathway Inhibition in the Antioxidant and Anti-Inflammatory Effects of Hesperetin in Activated BV-2 Microglial Cells

Alzheimer's disease is a progressive neurodegenerative disorder leading to cognitive decline and memory loss. The incidence of this disease continues to increase due to the limited number of novel therapeutics that prevent or slow down its progression. Flavonoids have been investigated for their potential effects on cellular damage triggered by excessive reactive oxygen species (ROS) and neuroinflammatory conditions. This study investigated the effect of the flavonoid hesperetin on LPS-activated murine BV-2 microglial cells. Results show that hesperetin reduced nitric oxide levels and increased catalase, glutathione, and superoxide dismutase levels, suggesting its potential to reduce neuroinflammation and oxidative stress. Moreover, RT-PCR arrays showed that hesperetin modulated multiple genes that regulate oxidative stress. Hesperetin downregulated the mRNA expression of ERCC6, NOS2, and NCF1 and upregulated HMOX1 and GCLC. RT-PCR results showed that hesperetin-induced Nrf2 mRNA and protein expression in LPS-activated BV-2 microglial cells is involved in the transcription of several antioxidant genes, suggesting that hesperetin's antioxidant effects may be exerted via the Keap1/Nrf2 signaling pathway. Furthermore, the data demonstrated that hesperetin reduced the gene expression of PD-L1, which is upregulated as an individual ages and during chronic inflammatory processes, and inhibited the expression of genes associated with NF-kB signaling activation, which is overactivated during chronic inflammation. It was concluded from this investigation that hesperetin may have therapeutic potential to prevent or slow down the progression of neurodegenerative diseases, such as Alzheimer's disease, by reducing chronic oxidative stress and modulating neuroinflammation.

Recent advancement in bioeffect, metabolism, stability, and delivery systems of apigenin, a natural flavonoid compound: challenges and perspectives

Apigenin is a bioflavonoid compound that is widely present in dietary plant foods and possesses biological activities that protect against immune, cardiovascular, and neurodegenerative diseases and cancer. Therefore, apigenin is widely used in food and medicine, and increasing attention has been drawn to developing new delivery systems for apigenin. This review highlights the biological effects, metabolism, stability, and bioactivity of apigenin. In addition, we summarized advancements in the delivery of apigenin, which provides some references for its widespread use in food and medicine. Better stability of apigenin may enhance digestion and absorption and provide health benefits. Constructing delivery systems (such as emulsions, nanostructured lipid carriers, hydrogels, and liposomes) for apigenin is an effective strategy to improve its bioavailability, but more animal and cell experiments are needed to verify these findings. Developing apigenin delivery systems for food commercialization is still challenging, and further research is needed to promote their in-depth development and utilization.

The synergistic ramification of insoluble dietary fiber and associated non-extractable polyphenols on gut microbial population escorting alleviation of lifestyle diseases

Most of the pertinent research which aims at exploring the therapeutic effects of polyphenols usually misapprehends a large fraction of non-extractable polyphenols due to their poor aqueous-organic solvent extractability. These polymeric polyphenols (i.e., proanthocyanins, hydrolysable tannins and phenolic acids) possess a unique property to adhere to the food matrix polysaccharides and protein sowing to their structural complexity with high glycosylation, degree of polymerization, and plenty of hydroxyl groups. Surprisingly resistance to intestinal absorption does not hinder its bioactivity but accelerates its functionality manifolds due to the colonic microbial catabolism in the gastrointestinal tract, thereby protecting the body from local and systemic inflammatory diseases. This review highlights not only the chemistry, digestion, colonic metabolism of non-extractable polyphenols (NEPP) but also summarises the synergistic effect of matrix-bound NEPP exerting local as well as systemic health benefits.

Nanoencapsulation of Phenolic Extracts from Native Potato Clones (Solanum tuberosum spp. andigena) by Spray Drying

Native potato clones grown in Peru contain bioactive compounds beneficial to human health. This study aimed to optimize the spray-drying nanoencapsulation of native potato phenolic extracts utilizing a central composite design and response surface methodology, obtaining the optimal treatment to an inlet temperature of 120 °C and an airflow of 141 L/h in the nano spray dryer B-90, which allowed maximizing the yield of encapsulation, antioxidant capacity (DPPH), encapsulation efficiency (EE), total phenolic compounds, and total flavonoids; on the other hand, it allowed minimizing hygroscopicity, water activity (Aw), and moisture. Instrumental characterization of the nanocapsules was also carried out, observing a gain in lightness, reddening of the color, and spherical nanoparticles of heterogeneous size (133.09-165.13 nm) with a negative ζ potential. Thermal, infrared, and morphological analyses confirmed the encapsulation of the core in the wall materials. Furthermore, an in vitro release study of phenolic compounds in an aqueous solution achieved a maximum value of 9.86 mg GAE/g after 12 h. Finally, the obtained nanocapsules could be used in the food and pharmaceutical industry.

Insights on the Role of Polyphenols in Combating Cancer Drug Resistance

Chemotherapy resistance is still a serious problem in the treatment of most cancers. Many cellular and molecular mechanisms contribute to both inherent and acquired drug resistance. They include the use of unaffected growth-signaling pathways, changes in the tumor microenvironment, and the active transport of medicines out of the cell. The antioxidant capacity of polyphenols and their potential to inhibit the activation of procarcinogens, cancer cell proliferation, metastasis, and angiogenesis, as well as to promote the inhibition or downregulation of active drug efflux transporters, have been linked to a reduced risk of cancer in epidemiological studies. Polyphenols also have the ability to alter immunological responses and inflammatory cascades, as well as trigger apoptosis in cancer cells. The discovery of the relationship between abnormal growth signaling and metabolic dysfunction in cancer cells highlights the importance of further investigating the effects of dietary polyphenols, including their ability to boost the efficacy of chemotherapy and avoid multidrug resistance (MDR). Here, it is summarized what is known regarding the effectiveness of natural polyphenolic compounds in counteracting the resistance that might develop to cancer drugs as a result of a variety of different mechanisms.

Targeting gut-brain axis by dietary flavonoids ameliorate aging-related cognition decline: Evidences and mechanisms

Aging-related cognitive impairment, mainly Alzheimer's disease (AD), has been widely studied. However, effective prevention and treatment methods are still lacking. In recent years, researchers have observed beneficial effects of plant-based supplements, such as flavonoids, on cognitive protection. This provides a new clue for the prevention of cognitive dysfunction. Studies have shown that dietary flavonoids have neuroprotective effects, but the mechanism is not clear. In this review, we systematically reviewed the research progress on the effects of dietary flavonoids on gut microbes and their metabolites, and concluded that flavonoids could improve cognitive function through the gut-brain axis. Flavonoids can be absorbed through the intestine, cross the blood-brain barrier, and enter the brain tissue. Flavonoids can inhibit the expression and secretion of inflammatory factors in brain tissue, reduce the damage caused by oxidative stress, clear neural damage proteins and inhibit neuronal apoptosis, thereby ameliorating age-related cognitive disorders. Future work will continue to explore the gut-brain axis and target genes regulated by flavonoids. In addition, clinical research and its mechanisms need to be further explored to provide solutions or advise for patients with cognitive impairment.

Antioxidant Activity, Metabolism, and Bioavailability of Polyphenols in the Diet of Animals

As the world’s population grows, so does the need for more and more animal feed. In 2006, the EU banned the use of antibiotics and other chemicals in order to reduce chemical residues in food consumed by humans. It is well known that oxidative stress and inflammatory processes must be combated to achieve higher productivity. The adverse effects of the use of pharmaceuticals and other synthetic compounds on animal health and product quality and safety have increased interest in phytocompounds. With the use of plant polyphenols in animal nutrition, they are gaining more attention as a supplement to animal feed. Livestock feeding based on a sustainable, environmentally friendly approach (clean, safe, and green agriculture) would also be a win–win for farmers and society. There is an increasing interest in producing healthier products of animal origin with a higher ratio of polyunsaturated fatty acids (PUFAs) to saturated fatty acids by modulating animal nutrition. Secondary plant metabolites (polyphenols) are essential chemical compounds for plant physiology as they are involved in various functions such as growth, pigmentation, and resistance to pathogenic organisms. Polyphenols are exogenous antioxidants that act as one of the first lines of cell defense. Therefore, the discoveries on the intracellular antioxidant activity of polyphenols as a plant supplement have contributed significantly to the improvement of antioxidant activity, as polyphenols prevent oxidative stress damage and eliminate excessively produced free radicals. To achieve animal welfare, reduce stress and the need for medicines, and increase the quality of food of animal origin, the addition of polyphenols to research and breeding can be practised in part with a free-choice approach to animal nutrition.

Bioactive Compounds from Kalanchoe Genus Potentially Useful for the Development of New Drugs

The genus Kalanchoe Adans. (Crassulaceae) is native to Madagascar and comprises 145 species, being naturalized in the tropics and cultivated worldwide. In addition to having ornamental value, several Kalanchoe species are commonly used in popular medicine for the treatment of inflammatory conditions, wounds, gastric ulcers, and other diseases. The great importance of the genus is reflected on its acknowledgment by traditional and alternative health systems and organizations, as well as on the growing number of papers reporting pharmacological properties of extracts and isolated compounds from Kalanchoe. Among these properties, we highlight anti-inflammatory, antitumor, wound healing, antiulcer, and muscle relaxing properties. These activities are attributed mostly to flavonoids and bufadienolides, the main secondary metabolites reported in Kalanchoe extracts. While bufadienolides are generally related to cytotoxic and muscle relaxing activities, flavonoids are commonly reported as anti-inflammatory and wound healing agents. This review provides up to date information and perspectives on bioactive compounds from the Kalanchoe genus that are potentially useful for the development of new drugs. It includes not only a discussion on the advantages of the Kalanchoe species as source of bioactive compounds, but also the gaps, opportunities, and challenges to translate the acquired knowledge into innovation for drug development.

Dietary flavonoids: a novel strategy for the amelioration of cognitive impairment through intestinal microbiota

The chances of people suffering from cognitive impairments increase gradually with age. Diet and lifestyle are closely related to the occurrence and development of cognitive function. Dietary flavonoid supplementation has been shown to be one of the protective factors against cognitive decline. Flavonoids belong to a class of polyphenols that have been proposed for the treatment of cognitive decline. Recent evidence has shown that intestinal flora in the human body can interact with flavonoids. Intestinal microbiota can modify the chemical structure of flavonoids, producing new metabolites, the pharmacological activities of which may be different from those of the parent; meanwhile, flavonoids and their metabolites can, in turn, regulate the composition and structure of intestinal flora. Notably, intestinal flora affect host nervous system activity through the gut-brain axis, ultimately causing changes in cognitive function. This review therefore summarizes the interaction of dietary flavonoids and intestinal flora, and their protective effect against cognitive decline through the gut-brain axis, indicating that dietary flavonoids may ameliorate cognitive impairment through their interaction with intestinal microbiota. © 2022 Society of Chemical Industry.

Does anthocyanins consumption affect weight and body composition? A systematic review and meta-analysis of randomized controlled trials

Background and Aims

Anthocyanins (ACNs) are water-soluble plant pigments belong to flavonoids with beneficial effects on health and disease prevention. Some studies have examined the effect of ACNs on anthropometric and body composition indices, but the findings were inconsistent. This systematic review and meta-analysis aimed to investigate the effect of ACNs and sources rich in anthocyanins on body mass index (BMI), body weight (BW), waist circumference (WC), hip circumference (HC), waist-hip ratio (WHR), percentage of fat mass (PFM) and fat free mass (FFM).

Methods

PubMed, Web of Science, Scopus, and Google Scholar were searched with no limitation until May 2021 to find relevant randomized controlled clinical trials (RCT). The risk of bias was assessed utilizing Cochrane collaboration's tool. Weighted mean differences (WMD) and 95% confidence intervals (CIs) were obtained using a random effects model.

Results

A total of 31 RCTs (with 0.77-640 mg/day of ACNs supplementation for 28-90 days) with 1438 participants were included. No significant effect was found in BMI, WC, HC, WHR, PFM and FFM after ACNs consumption.

Conclusions

The results showed that ACNs did not significantly affect anthropometric and body composition parameters. Further high-quality RCTs are required to validate these findings.

The Role of Propolis as a Natural Product with Potential Gastric Cancer Treatment Properties: A Systematic Review

Gastric cancer is one of the most common, aggressive, and invasive types of malignant neoplasia. It ranks fifth for incidence and fourth for prevalence worldwide. Products of natural origin, such as propolis, have been assessed for use as new complementary therapies to combat cancer. Propolis is a bee product with antiproliferative and anticancer properties. The concentrations and types of secondary metabolites contained in propolis mainly vary according to the geographical region, the season of the year, and the species of bees that make it. The present study is a systematic review of the main articles related to the effects of propolis against gastric cancer published between 2011 and 2021 in the PubMed and Science Direct databases. Of 1305 articles published, only eight studies were selected; among their principal characteristics was the use of in vitro analysis with cell lines from gastric adenocarcinoma and in vivo murine models of the application of propolis treatments. These studies suggest that propolis arrests the cell cycle and inhibits proliferation, prevents the release of oxidizing agents, and promotes apoptosis. In vivo assays showed that propolis decreased the number of tumors by regulating the cell cycle and the expression of proteins related to apoptosis.

In Vitro Antidiabetic, Antioxidant, and Prebiotic Activities of the Chemical Compounds Isolated from Guizotia abyssinica

India and Ethiopia employ Guizotia abyssinica (niger plant) as a source of edible vegetable oil. Previous studies have documented the niger plant's antioxidant properties and dietary benefits. Here, G. abyssinica extract was obtained and ten known bioactive components (1-10) were isolated. The antioxidant, antidiabetic, and prebiotic properties of whole extract and isolated components of niger and the plant's ability to cooperate symbiotically with probiotic strains were examined. Compound 10, myricetin-3-O-L-rhamnoside, had the highest antioxidant capacity measured in the 2,2-diphenylpicrylhydrazyl (DPPH, 4629.76 ± 6.02 µmol Trolox equivalent/g compound) and ferric-reducing antioxidant power (FRAP, 2667.62 ± 7.5 mol Trolox equivalent/g compound) assays. The lowest α-amylase and glycogen phosphorylase activities and glucose diffusion were obtained with whole G. abyssinica extracts, whereas compounds 8-10 had moderate inhibitory effects. G. abyssinica extract also induced the highest glucose absorption by yeast cells in the presence of 5 mM of glucose. Moreover, Lactobacillus plantarum and L. rhamnosus incubated with β-sitosterol 3-O-D-glucoside (compound 7) showed the highest prebiotic activity score. The levels of L-(+)-lactic acid isomer in the probiotic strains were the highest in presence of the whole extract and decreased progressively in the presence of flavonoid glycosides (compounds 8-10) and β-sitosterol 3-O-D-glucoside. The enzymatic profile of the probiotic strains was unaffected by the niger extract and compounds 7-10. The findings revealed that the biological activities of G. abyssinica extract are mediated by the compounds 1-10, and it may be considered as a promising plant for the treatment of diabetes mellitus.

Digestive and gastroprotective effects of Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae): From traditional uses to preclinical studies

ETHNOPHARMACOLOGICAL RELEVANCE

Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae) is an alpine endemic plant whose aerial parts are harvested by the locals mainly for the digestive properties. Despite its widespread use, few studies have been conducted to date to verify its bioactivity.

AIM OF THE STUDY

The purpose of the work was to meet the tradition confirming with experimental data the popular belief that the consumption of this species offers beneficial effects to the gastrointestinal system.

MATERIALS AND METHODS

Using Soxhlet apparatus, the dried aerial parts of A. erba-rotta subsp. moschata were successively extracted with petroleum ether (PET), dichloromethane (DCM) and methanol (MeOH). The essential oil (EO) was obtained by hydrodistillation using a Clevenger apparatus while infusion (AE) was prepared following the traditional local recipe. Their chemical characterization was performed by various techniques including SPME-GC/MS, GC/MS and HPLC/MS-MS. An in vitro biological screening was carried out. The influence of AE on lipid digestion was monitored by titration of free fatty acids (FFA) during pancreatic lipase activity with the pH-stat method. For all extracts and EO, the anti-Helicobacter pylori activity was assessed by the broth microdilution method, the influence on cell viability was evaluated against NCI-N87, OE21 and Caco-2 cell lines and a preliminary toxicity evaluation was done using Brine Shrimp lethality (BSL) assay. The anti-inflammatory potential was evidenced by interleukin IL-1- induced IL8 expression on Caco-2 cells.

RESULTS

AE increased by 15% the FFA releasing compared to the pancreatic lipase alone. PET, DCM and MeOH extracts as well as AE and EO were considered active against the growth of both antimicrobial susceptible and resistant strains of H. pylori with MIC values starting from 16 μg/mL. PET and DCM (IC₅₀ = 89 μg/mL and 96 μg/mL, respectively, against Caco-2 cell line) extracts showed the high effect on cell viability while the EO reduced in 50% of cell viability at 1.48 μL/mL (NCI-N87 cells), 1.42 μL/mL (OE21 cells), and 3.44 μL/mL (Caco-2 cells) corroborating the BSL results. In different degrees, all extracts and EO inhibited the IL-1β-stimulated IL-8 production in Caco-2 cells.

CONCLUSIONS

The obtained data are encouraging and provide a scientific basis for the traditional use of A. erba-rotta subsp. moschata as a digestive agent although they need to be further corroborated by studies involving the investigation of both the in vivo activities and the role of the compounds detected in the extracts.

Nutritional activities of luteolin in obesity and associated metabolic diseases: an eye on adipose tissues

Obesity is characterized by excessive body fat accumulation and is a high-risk factor for metabolic comorbidities, including type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular disease. In lean individuals, adipose tissue (AT) is not only an important regulatory organ for energy storage and metabolism, but also an indispensable immune and endocrine organ. The sustained energy imbalance induces adipocyte hypotrophy and hyperplasia as well as AT remodeling, accompanied by chronic low-grade inflammation and adipocytes dysfunction in AT, ultimately leading to systemic insulin resistance and ectopic lipid deposition. Luteolin is a natural flavonoid widely distributed in fruits and vegetables and possesses multifold biological activities, such as antioxidant, anticancer, and anti-inflammatory activities. Diet supplementation of this flavonoid has been reported to inhibit AT lipogenesis and inflammation as well as the ectopic lipid deposition, increase AT thermogenesis and systemic energy expenditure, and finally improve obesity and associated metabolic diseases. The purpose of this review is to reveal the nutritional activities of luteolin in obesity and its complications with emphasis on its action on AT energy metabolism, immunoregulation, and endocrine intervention.

Boosting the Bioaccessibility of Dietary Bioactives by Delivery as Protein-Polyphenol Aggregate Particles

Protein-polyphenol aggregate particles concurrently fortify a functional food product with healthy dietary proteins and concentrated polyphenols. However, what impact does ingestion of aggregate particles have on ultimate health relevance of either the polyphenolic molecules in the matrix or the protein molecules? Because human health benefits are contingent on bioavailability after ingestion, the fate of these molecules during transit in the gastrointestinal tract (GIT) will dictate their utility as functional food ingredients. This brief review explores diverse applications of protein-polyphenol particles in the food industry and the bioaccessibility of both bioactive polyphenolic compounds and edible proteins. Evidence to date suggests that complexation of phytoactive polyphenolics effectively enhances their health-relevant impacts, specifically because the phytoactives are protected in the protein matrix during transit in the GIT, allowing intact, non-degraded molecules to reach the colon for catabolism at the gut microbiome level, a prerequisite to realize the health benefits of these active compounds.

Understanding the Gastrointestinal Behavior of the Coffee Pulp Phenolic Compounds under Simulated Conditions

Numerous residues, such as the coffee pulp, are generated throughout coffee processing. This by-product is a source of antioxidant phytochemicals, including phenolic compounds and caffeine. However, the antioxidant properties of the phenolic compounds from the coffee pulp are physiologically limited to their bioaccessibility, bioavailability, and biotransformation occurring during gastrointestinal digestion. Hence, this study explored the phenolic and caffeine profile in the coffee pulp flour (CPF) and extract (CPE), their intestinal bioaccessibility through in vitro digestion, and their potential bioavailability and colonic metabolism using in silico models. The CPE exhibited a higher concentration of phenolic compounds than the CPF, mainly phenolic acids (protocatechuic, chlorogenic, and gallic acids), followed by flavonoids, particularly quercetin derivatives. Caffeine was found in higher concentrations than phenolic compounds. The antioxidant capacity was increased throughout the digestive process. The coffee pulp matrix influenced phytochemicals’ behavior during gastrointestinal digestion. Whereas individual phenolic compounds generally decreased during digestion, caffeine remained stable. Then, phenolic acids and caffeine were highly bioaccessible, while flavonoids were mainly degraded. As a result, caffeine and protocatechuic acid were the main compounds absorbed in the intestine after digestion. Non-absorbed phenolic compounds might undergo colonic biotransformation yielding small and potentially more adsorbable phenolic metabolites. These results contribute to establishing the coffee pulp as an antioxidant food ingredient since it contains bioaccessible and potentially bioavailable phytochemicals with potential health-promoting properties.

Anti-Inflammatory Activity of an In Vitro Digested Anthocyanin-Rich Extract on Intestinal Epithelial Cells Exposed to TNF-α

Background: The consumption of foods rich in anthocyanins (ACN) have been associated with beneficial properties in chronic inflammatory disorders such as intestinal bowel diseases (IBD). These effects were attributed not only to a direct antioxidant mechanism but also to the modulation of cell redox-dependent signaling. However, ACN bioavailability is low for their poor stability in the digestive tract, so ACN gastrointestinal digestion should be considered. Methods: To have a more realistic knowledge of the effects of ACN, we performed an in vitro simulated gastrointestinal digestion of an ACN-rich purified and standardized bilberry and blackcurrant extract (BBE), followed by an evaluation of ACN composition modification (HPLC-DAD and pH differential method) and antioxidant activity (FRAP assay). Then, we studied the effects of BBE gastrointestinal extract on Caco-2 exposed to TNF-α. Results: The results confirmed the high instability of ACN in the mild alkaline environment of the small intestine (17% recovery index). However, the digested BBE maintained part of its bioactivity. Additionally, BBE gastrointestinal extract inhibited the TNF-α-induced NF-κB pathway in Caco-2 and activated the Nrf2 pathway. Conclusions: Although ACN stability is affected by gastrointestinal digestion, the anti-inflammatory and antioxidant activity of digested extracts were confirmed; thus, the loss of ACN can probably be counterweighed by their metabolites. Then, ACN introduced by diet or food supplements could represent an approach for IBD prevention.

Development of QSAR model using machine learning and molecular docking study of polyphenol derivatives against obesity as pancreatic lipase inhibitor

In developed countries and developing countries, obesity/overweight is considered a major problem, in fact, it is now recognized as a major metabolic disorder. Additionally, obesity is connected with other metabolic diseases, including cardiovascular disorders, type 2 diabetes, some types of cancer, etc. Therefore, the development of novel drugs/medications for obesity is essential. The best target for treating obesity is Pancreatic Lipase (PL), it breaks 50-70% triglycerides into monoglycerol and free fatty acids.The major aim of this in silico study is to generate a QSAR model by using Multiple Linear Regression (MLR) and to inhibit pancreatic lipase by polyphenol derivatives mainly flavonoids, plant secondary metabolites shows good inhibitory activity against PL, maybe with less unpleasant side effects.In this in silico study, a potent inhibitor was found through calculating drug likness, QSAR (Quantitative structure-activity relationship) and molecular docking. The docking was performed in Maestro 12.0 and the ADME (absorption, distribution, metabolism, and excretion) properties (drug-likeness) of compounds/ligands were predicted by the Qikprop module of Maestro 12.0. The QSAR model was developed to show the relationship between the chemical/structural properties and the compound's biological activity. We have found the best interaction between pancreatic lipase and flavonoids. The best docked compound is Epigallocatechin 3,5,-di-O-gallate with docking score -10.935 kcal/mol .All compounds also show drug-likeness activity.The developed model has satisfied all internal and external validation criteria and has square correlation coefficient (r2) 0.8649, which shows its predictive ability and has good acceptability, predictive ability, and statistical robustness.Communicated by Ramaswamy H. Sarma.

Anti-osteoporosis effects of Anemarrhenae Rhizoma / Phellodendri Chinensis Cortex herb pair and its major active components in diabetic rats and zebrafish

ETHNOPHARMACOLOGICAL RELEVANCE

Anemarrhenae Rhizoma/Phellodendri Chinensis Cortex (AR/PCC) herb pair has been widely used in traditional Chinese medicines for the treatment of diabetic osteoporosis. However, the anti-diabetic osteoporotic active components of AR/PCC remain unclear. This study aimed to explore the major active ingredients in AR/PCC for its protective effects against bone deterioration induced by diabetes.

MATERIALS AND METHODS

The aqueous extracts of AR/PCC with different proportions (AR:PCC = 1:3, 1:2, 1:1, 2:1 and 3:1, w/w) were prepared. Streptozotocin-induced diabetic rats were orally administrated with the AR/PCC extracts. The absorbed phytochemical compounds in serum of diabetic rats were identified by ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry method and their contents in the AR/PCC extracts were determined by high performance liquid chromatography-ultraviolet detector-evaporative light scattering detector method. The absorbed compounds in the extracts were considered as the major potential active components in AR/PCC, and their combination was defined as M-AR/PCC. A component-knockout approach was applied to evaluate the contribution of each compound in M-AR/PCC. The larvae and adults of diabetic zebrafish models were then used to evaluated the anti-diabetic osteoporotic performance of the M-AR/PCC. The real-time reverse transcription polymerase chain reaction technique was applied to study the regulation effects of M-AR/PCC on osteogenesis and osteoclastgensis in diabetic zebrafish models.

RESULTS

The phenotypes of diabetic osteoporosis rats induced by streptozotocin were reversed by the oral administration of AR/PCC extracts with different ratios, as evidenced by the increased bone mineral density, bone volume density, trabecular thickness, trabecular number, and decreased trabecular separation of femoral metaphysis. Seven phytochemical compounds were detected in the serum and their contents in AR/PCC varied dramatically with different proportions, including 1 xanthone glycoside and 6 alkaloids. By using diabetic zebrafish larvae model and compound-knockout strategy, each compound in M-AR/PCC were proved to play an indispensable role in the positive regulatory actions in the bone mass of diabetic zebrafish. Furthermore, the herb pair with a ratio of 1:1 and the related M-AR/PCC showed the best therapeutic effects on diabetic osteoporosis. They showed similar performances on the inhibition of the tartrate-resistant acid phosphatase activity and the promotion of the alkaline phosphatase activity in diabetic adult zebrafish model. The M-AR/PCC treatment could decrease the blood glucose, upregulate the mRNA expression levels of osteoblast-related genes (alp, runx2b and opg) and downregulate the expression of osteoclast-related genes (acp5α, rankl and sost) in streptozotocin-induced zebrafish.

CONCLUSION

AR/PCC herb pair and its major active components possess potent anti-diabetic osteoporotic effect on streptozotocin-induced in vivo models. The combination of the seven active compounds derived from AR/PCC herbal pair could be a potential agent for protection against osteoporosis associated with diabetes.

Flavonoids: Food associations, therapeutic mechanisms, metabolism and nanoformulations

Flavonoids possess an impressive therapeutic potential, thereby imparting them a nutraceutical character. As it becomes increasingly common to consume foods associated with healing properties, it is imperative to understand the associations of different foods with different classes of nutraceutic compounds, and their mechanisms of therapeutic action. At the same time, it is important to address the limitations thereof so that plausible future directions may be drawn. This review summarizes the food associations of flavonoids, and discusses the mechanisms responsible for imparting them their nutraceutic properties, detailing the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway, inhibition of inflammatory signaling pathways such as toll-like receptor (TLR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), cyclooxygenase 2 (COX-2) and lipoxygenase-2 (LOX-2) mediators. Further on, the review explains the mechanism of flavonoids metabolism, reasons for low bioavailability and thereafter recapitulates the role of technological interventions to overcome the limitations, with a particular focus on nanoformulations that utilize the synergy between flavonoids and biocompatible materials used as nanocarriers, as reported in works spanning over a decade. It is the Generally Recognized as Safe (GRAS) classified carriers that will become the basis for developing functional formulations. It is promisingly noteworthy that some flavonoid formulations have been commercialized and mentioned therein. Such commercially viable and safe for consumption technological applications pave way for bringing science to the table, and add value to the innate properties of flavonoids.

Uptake and Transport of Naringenin and Its Antioxidant Effects in Human Intestinal Epithelial Caco-2 Cells

Naringenin, a flavanone, has been reported for a wide range of pharmacological activities. However, there are few reports on the absorption, transport and antioxidant effects of naringenin. The study was to explore the uptake, transport and antioxidant effects of naringenin in vitro. Cell transmembrane resistance, lucifer yellow transmission rate, and alkaline phosphatase activity were used to evaluate the successful construction of cell model. The results showed that the absorption and transport of naringenin by Caco-2 cells were time- and concentration-dependent. Different temperatures (37 and 4°C) had a significant effect on the uptake and transport of naringenin. Verapamil, potent inhibitor of P-glycoprotein, significantly inhibit naringenin transport in Caco-2 cells. The results revealed that naringenin was a moderately absorbed biological macromolecule and can penetrate Caco-2 cells, mainly mediated by the active transport pathway involved in P-glycoprotein. At the same time, naringenin pretreatment could significantly increase the viability of H₂O₂-induced Caco-2 cells. Twenty four differential metabolites were identified based on cellular metabolite analysis, mainly including alanine, aspartate and glutamate metabolism, histidine metabolism, taurine and hypotaurine metabolism, pyruvate metabolism, purine metabolism, arginine biosynthesis, citrate cycle, riboflavin metabolism, and D-glutamine and D-glutamate metabolism. We concluded that the transport of naringenin by Caco-2 cells is mainly involved in active transport mediated by P-glycoprotein and naringenin may play an important role in oxidative stress-induced intestinal diseases.

Neuroprotective Effects and Therapeutic Potential of the Citrus Flavonoid Hesperetin in Neurodegenerative Diseases

Neurodegenerative disorders affect more than fifty million Americans each year and represent serious health threats as the population ages. Neuroinflammation and oxidative stress are critical in the onset, progression, and pathogenesis of neurodegenerative diseases such as Alzheimer’s (AD), Parkinson’s (PD), and amyotrophic lateral sclerosis (ALS). A wide range of natural compounds has been investigated because of their antioxidant, anti-inflammatory, and neuroprotective properties. The citrus flavonoid hesperetin (HPT), an aglycone of hesperidin found in oranges, mandarins, and lemons, has been extensively reported to exert neuroprotective effects in experimental models of neurogenerative diseases. This review has compiled multiple studies on HPT in both in vivo and in vitro models to study neurodegeneration. We focused on the modulatory effects of hesperetin on the release of cellular anti-inflammatory and antioxidative stress mediators. Additionally, this review discusses the hesperetin effect in maintaining the levels of microRNA (miRNA) and modulating autophagy as it relates to hesperetin’s protective mechanisms against neurodegeneration. Moreover, this review is focused on providing experimental data for hesperetin’s potential as a neuroprotective compound and discusses reported evidence that HPT crosses the blood–brain barrier. In summary, this review shows the evidence available in the literature to indicate the efficacy of hesperetin in delaying the onset of neurodegenerative diseases.

A Molecular Insight into the Role of Antioxidants in Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) defines fat accumulation in the liver, and it is commonly associated with metabolic syndromes like diabetes and obesity. Progressive NAFLD leads to nonalcoholic steatohepatitis (NASH) and ultimately causes cirrhosis and hepatocellular carcinoma, and NASH is currently a frequent cause of liver transplantation. Oxidative stress is often contributed to the progression of NAFLD, and hence, antioxidants such as silymarin, silybin, or silibinin, pentoxifylline, resveratrol, and vitamins A, C, and E are used in clinical trials against NAFLD. Silymarin induces the peroxisome proliferator-activated receptor α (PPARα), a fatty acid sensor, which promotes the transcription of genes that are required for the enzymes involved in lipid oxidation in hepatocytes. Silybin inhibits sterol regulatory element-binding protein 1 and carbohydrate response element-binding protein to downregulate the expression of genes responsible for de novo lipogenesis by activating AMP-activated protein kinase phosphorylation. Pentoxifylline inhibits TNF-α expression and endoplasmic reticulum stress-mediated inflammatory nuclear factor kappa B (NF-κB) activation. Thus, it prevents NAFLD to NASH progression. Resveratrol inhibits methylation at Nrf-2 promoters and NF-κB activity via SIRT1 activation in NAFLD conditions. However, clinically, resveratrol has not shown promising beneficial effects. Vitamin C is beneficial in NAFLD patients. Vitamin E is not effectively regressing hepatic fibrosis. Hence, its combination with antifibrotic agents is used as an adjuvant to produce a synergistic antifibrotic effect. However, to date, none of these antioxidants have been used as a definite therapeutic agent in NAFLD patients. Further, these antioxidants should be studied in NAFLD patients with larger populations and multiple endpoints in the future.

Intestinal Glucuronidation, Prior to Hepatic Glucuronidation, Plays an Important Role in the Low Circulating Levels of Calycosin

Calycosin is a dietary flavonoid with favorable activities, which seems to be inconsistent with its low circulating levels in vivo. To address this issue, we developed a strategy to understand calycosin distribution by integrating qualitative and quantitative analyses of calycosin and its metabolites in portal vein plasma, the liver, and systemic plasma after oral administration to rats. Consequently, 21 metabolites were characterized in total, including the first report of a reductive biotransformation and 14 new metabolites. Compared with the low levels of calycosin, calycosin glucuronides were predominant in circulation, and both the hepatic and intestinal regions contributed to the high exposure of these calycosin glucuronides. However, intestinal glucuronidation, prior to hepatic glucuronidation, plays a key role in the low circulating levels of calycosin.

Nutrition Benefits and Considerations for Whole Foods Plant-Based Eating Patterns

Whole foods plant-based approaches to eating place an emphasis on the intake of fruits, vegetables, whole grains, and legumes and have many health benefits. While there are key nutrients and phytochemicals that can contribute to the purported health benefits, practitioners and patients should also be advised of key nutrients for which intake may be compromised when following this dietary pattern. With careful planning and utility of dietary supplements, individuals can achieve optimal intake of calcium, iron, vitamin D, omega 3 fatty acid-docosahexaenoic acid (DHA), and vitamin B12 and experience the health benefits of a dietary fiber and a host of phytochemicals. This article presents the health benefits of these food substances and approaches for overcoming nutrients of concern when following whole food plant-based eating patterns.

Bioaccessibility, gut microbial metabolism and intestinal transport of phenolics from 100% Concord grape juice and whole grapes are similar in a simulated digestion and fecal fermentation model

Phenolic rich 100% grape juice has been associated with many health benefits, but its place in dietary guidance is controversial relative to whole fruit. Direct comparisons of phenolic profiles and bioavailability between these food forms are needed. Phenolic bioaccessibility and metabolism from Concord (CG) and Niagara (NG) grapes and corresponding 100% juices were investigated using an in vitro digestion coupled with anaerobic gut fermentation model. Intestinal transport of resulting bioaccessible phenolics and microbial metabolites was estimated using a Caco-2 cell model. Total bioaccessible phenolics from both upper and lower digestion were similar (P > 0.05) between NG (400.9 ± 26.3 μmol per 100 g) and NGJ (349.5 ± 8.3 μmol per 100 g) and significantly different (P < 0.05) between CG (417.2 ± 24.4 μmol per 100 g) and CGJ (294.3 ± 45.4 μmol per 100 g) total cellular transport of phenolics was similar (P > 0.05) between whole grapes (89.4 ± 5.3 μmol per 100 g for CG, and 71.8 ± 2.4 μmol per 100 g for NG) and 100% juices (88.0 ± 5.6 μmol per 100 g for CGJ, and 85.3 ± 9.4 μmol per 100 g for NGJ). Differences were observed between the location of phenolic metabolism, bioaccessibility and subsequent cellular transport of individual phenolics between grapes and juice matrices. Specifically, greater amounts of phenolics were transported from grape juices than whole grapes from the upper tract. However, cumulative bioaccessibility and transport from upper and lower GI digestion/fermentation together indicates that the absorbable phenolics from 100% grape juice is similar to that of whole grapes, suggesting that phenolic-mediated health benefits from consumption of whole fruit and juice may be similar.

Flavonoids in Treatment of Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive systemic disease, which changes the function and structure of the kidneys irreversibly over months or years. The final common pathological manifestation of chronic kidney disease is renal fibrosis and is characterized by glomerulosclerosis, tubular atrophy, and interstitial fibrosis. In recent years, numerous studies have reported the therapeutic benefits of natural products against modern diseases. Substantial attention has been focused on the biological role of polyphenols, in particular flavonoids, presenting broadly in plants and diets, referring to thousands of plant compounds with a common basic structure. Evidence-based pharmacological data have shown that flavonoids play an important role in preventing and managing CKD and renal fibrosis. These compounds can prevent renal dysfunction and improve renal function by blocking or suppressing deleterious pathways such as oxidative stress and inflammation. In this review, we summarize the function and beneficial properties of common flavonoids for the treatment of CKD and the relative risk factors of CKD.