Protection of lipids from oxidation by epicatechin, trans-resveratrol, and gallic and caffeic acids in intestinal model systems

Resveratrol-Schiff Base Hybrid Compounds with Selective Antibacterial Activity: Synthesis, Biological Activity, and Computational Study

Nowadays, antimicrobial resistance is a serious concern associated with the reduced efficacy of traditional antibiotics and an increased health burden worldwide. In response to this challenge, the scientific community is developing a new generation of antibacterial molecules. Contributing to this effort, and inspired by the resveratrol structure, five new resveratrol-dimers (9a−9e) and one resveratrol-monomer (10a) were synthetized using 2,5-dibromo-1,4-diaminobenzene (8) as the core compound for Schiff base bridge conformation. These compounds were evaluated in vitro against pathogenic clinical isolates of Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus sp., and Listeria monocytogenes. Antibacterial activity measurements of resveratrol-Schiff base derivatives (9a−9e) and their precursors (4−8) showed high selectivity against Listeria monocytogenes, being 2.5 and 13.7 times more potent than chloramphenicol, while resveratrol showed an EC50 > 320 µg/mL on the same model. Moreover, a prospective mechanism of action for these compounds against L. monocytogenes strains was proposed using molecular docking analysis, finding a plausible inhibition of internalin C (InlC), a surface protein relevant in bacteria−host interaction. These results would allow for the future development of new molecules for listeriosis treatment based on compound 8.

Condensed Tannins as Antioxidants in Ruminants-Effectiveness and Action Mechanisms to Improve Animal Antioxidant Status and Oxidative Stability of Products

Condensed tannins (CTs) are widely distributed in plants, and due to their recognized antioxidant activity are considered as possible natural antioxidants for application in ruminant diets. A wide range of CT-rich sources has been tested in ruminant diets, and their effects on animal antioxidant status and oxidative stability of their products are reviewed in the present work. Possible mechanisms underlying the CT antioxidant effects in ruminants are also discussed, and the CT chemical structure is briefly presented. Utilization of CT-rich sources in ruminant feeding can improve the animals' antioxidant status and oxidative stability of their products. However, the results are still inconsistent. Although poorly understood, the evidence suggests that CTs can induce an antioxidant effect in living animals and in their products through direct and indirect mechanisms, which can occur by an integrated and synergic way involving: (i) absorption of CTs with low molecular weight or metabolites, despite CTs' poor bioavailability; (ii) antioxidant action on the gastrointestinal tract; and (iii) interaction with other antioxidant agents. Condensed tannins are alternative dietary antioxidants for ruminants, but further studies should be carried out to elucidate the mechanism underlying the antioxidant activity of each CT source to design effective antioxidant strategies based on the use of CTs in ruminant diets.

Design of an In Vitro Model to Screen the Chemical Reactivity Induced by Polyphenols and Vitamins during Digestion: An Application to Processed Meat

Processed meats’ nutritional quality may be enhanced by bioactive vegetable molecules, by preventing the synthesis of nitrosamines from N-nitrosation, and harmful aldehydes from lipid oxidation, through their reformulation. Both reactions occur during digestion. The precise effect of these molecules during processed meats’ digestion must be deepened to wisely select the most efficient vegetable compounds. The aim of this study was to design an in vitro experimental method, allowing to foresee polyphenols and vitamins’ effects on the chemical reactivity linked to processed meats’ digestion. The method measured the modulation of end products formation (specific nitroso-tryptophan and thiobarbituric acid reactive substances (TBARS)), by differential UV-visible spectrophotometry, according to the presence or not of phenolic compounds (chlorogenic acid, rutin, naringin, naringenin) or vitamins (ascorbic acid and trolox). The reactional medium was supported by an oil in water emulsion mimicking the physico-chemical environment of the gastric compartment. The model was optimized to uphold the reactions in a stable and simplified model featuring processed meat composition. Rutin, chlorogenic acid, naringin, and naringenin significantly inhibited lipid oxidation. N-nitrosation was inhibited by the presence of lipids and ascorbate. This methodology paves the way for an accurate selection of molecules within the framework of processed meat products reformulation.

Effect of feeding pigs with bergamot by-product on fatty acid composition and oxidative stability of meat and salami

This work investigated the effects of feeding ensiled bergamot pulp to pigs on meat and salami quality. Eighteen pigs were assigned to two experimental treatments and fed a cereal-based concentrate diet (control) or the same diet in which ensiled bergamot pulp replaced 15% dry matter of the diet fed (BP). The BP treatment increased α-linolenic acid (+250%; P < 0.05), docosapentaenoic acid (+62%; P < 0.05), docosahexaenoic acid (+43%; P < 0.05) and consequently n-3 PUFA (+15%; P < 0.01) in meat. In salami, the content of α-linolenic acid, total PUFA and n-3 PUFA increased (+320%, +25% and + 258%, respectively) by feeding the BP diet (P < 0.001). The inclusion of bergamot pulp in the diet did not alter the oxidative stability in raw and cooked meat and colour descriptors. In salami, TBARS values were lower after 5 days of storage (P < 0.001) in BP group (1.54 vs 2.96). Finally, dietary supplementation with ensiled bergamot pulp to pigs improved the nutritional value of meat and meat products.

A review of the phytochemical, pharmacological, pharmacokinetic, and toxicological evaluation of Quercus Infectoria galls

ETHNOPHARMACOLOGICAL RELEVANCE

Quercus Infectoria galls (QIG) have a long history of use in traditional Chinese medicine and traditional Uyghur medicine for the treatment of diarrhea, hemorrhage, skin disease, and many other human ailments. Medicinal applications of QIG have become increasingly popular in Greece, Asia Minor, Syria, and Iran.

AIM OF THE REVIEW

The present paper reviewed the ethnopharmacology, phytochemistry, analytical methods, biological activities, metabolism, pharmacokinetics, toxicology, and drug interactions of QIG to assess the ethnopharmacological uses, explore its therapeutic potential, and identify future opportunities for research.

MATERIALS AND METHODS

Information on QIG was gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Pubmed, Web of Science, CNKI, and EMBASE) and libraries. Additionally, information was also obtained from local books and PhD and MS dissertations.

RESULTS

QIG has played an important role in traditional Chinese medicine. The main bioactive metabolites of QIG include tannins, phenolic acids, flavonoids, triterpenoids, and steroids. Scientific studies on the QIG extract and its components have shown its wide range of pharmacological activities, such as cholinesterase- and monoamine oxidase-inhibitory, antitumor, anti-hypertension, antidiabetic, antimicrobial, insecticidal, antiparasitic, antioxidant, and anti-inflammatory.

CONCLUSIONS

The ethnopharmacological, phytochemical, pharmacological, and analytical methods of QIG were highlighted in this review, which provides information for future studies and commercial exploration. QIG has a huge potential for pharmaceutical and nutraceutical applications. Moreover, comprehensive toxicity studies of this plant must be conducted to ensure its safety. Additional investigations are recommended to transmute the ethnopharmacological claims of this plant in folklore medicines into scientific rationale-based information. Research on pharmacokinetics studies and potential drug interactions with standard-of-care medications is still limited, which calls for additional studies particularly on humans. Further assessments and clinical trials should be performed before it can be integrated into medicinal practices.

Influence of epicatechin on oxidation-induced physicochemical and digestibility changes in porcine myofibrillar proteins during refrigerated storage

BACKGROUND

The influence of epicatechin (EC) on the physicochemical properties and digestibility changes of porcine myofibrillar protein (MP) under oxidative stress during refrigerated storage was investigated.

RESULTS

The incubation of MP suspensions (20 mg mL^-1 in piperazine-N,N'-bis(2-ethanesulfonic acid) buffer, with 0.6 mol L^-1 sodium chloride, pH 6.25) at 4 °C for 24 h under an iron-catalyzed hydroxyl radical generating system (Fenton reaction) promoted the formation of thiobarbituric acid reactive substances and protein carbonyls, which was attenuated by EC (5, 50, and 100 μmol g^-1 protein). Reduced protein sulfhydryl content, tryptophan fluorescence, protein solubility, as well as increased surface hydrophobicity were found by the co-incubation of EC. Analysis by scanning electron microscopy revealed increased protein aggregation and fragments in oxidized MP, which were further enhanced by the addition of EC. However, the protein digestibility of MP was not affected.

CONCLUSION

EC was demonstrated to be effective in alleviating lipid oxidation and protein carbonylation in MP under oxidative stress. Additionally, the physicochemical and digestibility changes accompanying the incorporation of EC was complicated due to the possible phenol-protein interactions. An in-depth understanding of protein physicochemical and digestibility changes will be helpful in the application of polyphenolic compounds as antioxidants in low-temperature-processed muscle foods. © 2020 Society of Chemical Industry.

Cytotoxic and DNA-Damaging Effects of Aronia melanocarpa, Cornus mas, and Chaenomeles superba Leaf Extracts on the Human Colon Adenocarcinoma Cell Line Caco-2

Aronia melanocarpa, Cornus mas, and Chaenomeles superba leaf extracts contain large amounts of bioactive compounds-mainly polyphenols, which possess many health benefits including anti-cancer properties. Here, we investigate the biological effects of A. melanocarpa, C. mas, and C. superba leaf extracts on the human colon adenocarcinoma cell line Caco-2. The antiproliferative activity of the extracts was measured using the MTT assay. The most cytotoxic extract was C. mas (IC50 = 0.60%). The extracts caused morphological changes in the Caco-2 cells, including partial detachment of cells, necrotic cells, chromatin condensation, cytoplasmic vacuolization, cell nuclei lysis, and nucleus fragmentation. The DNA damage in the Caco-2 cells after exposure to the leaf extracts was measured using the alkaline comet assay. The extracts increased DNA damage in a concentration dependent manner. However, at lower non-cyto- and non-genotoxic (IC0) concentrations the extracts induced DNA repair in Caco-2 cells after exposure to hydrogen peroxide. In conclusion, the results of these studies suggest that A. melanocarpa, C. mas and C. superba leaf extracts can show anticancer activity. However, further research is required on the mechanisms of anti-cancer activity by these extracts, with the application of more advanced and wide-ranging techniques including in vivo experiments.

Effects of resveratrol/ethanol pretreatment on dentin bonding durability

To determine the effects of resveratrol/ethanol solution on the durability of resin-dentin bonding interfaces. Sixty-four non-caries third molars were randomly divided into four groups (n = 16) after sectioning, and then pretreated with one of the following concentrations of resveratrol/ethanol solutions: 0 (control group), 1, 10 and 20 mg/mL, followed by a universal adhesive and resin composites. All microtensile samples were divided into three subgroups: immediate group, collagenase ageing group and thermocycled group. The microtensile bond strength (MTBS), failure modes, interfacial nanoleakage and in situ zymography were measured, whereas the inhibitory effects of pretreated dentin slices on S. mutans biofilms were determined by confocal laser scanning microscopy and MTT assay. The results indicated that bonding strength was not only influenced by pretreatment factors (P < 0.05) but also ageing factors (P < 0.05). Regardless of collagenase ageing or thermocycling, the 10 mg/mL resveratrol/ethanol pretreatment group presented significantly higher (P < 0.05) MTBS and lower (P < 0.05) expression of nanoleakage than the control group, showed better inhibitory effect of matrix metalloproteinases and S. mutans activity with acceptable cytotoxicity. Meanwhile, cohesive failure in dentin decreased gradually with increasing resveratrol concentration. Therefore, the resveratrol/ethanol solution had the potential to serve as a versatile dentin primer, which can effectively improve dentin bonding durability and prevent secondary caries.

A Global Study by 1H NMR Spectroscopy and SPME-GC/MS of the in Vitro Digestion of Virgin Flaxseed Oil Enriched or not with Mono-, Di- or Tri-Phenolic Derivatives. Antioxidant Efficiency of These Compounds

The effect of enriching virgin flaxseed oil with dodecyl gallate, hydroxytyrosol acetate or gamma-tocopherol on its in vitro digestion is studied by means of proton nuclear magnetic resonance and solid phase microextraction followed by gas chromatography/mass spectrometry. The extent and pattern of the lipolysis reached in each sample is analyzed, as is the bioaccessibility of the main oil components. None of the phenolic compounds provokes inhibition of the lipase activity and all of them reduce the lipid oxidation degree caused by the in vitro digestion and the bioaccessibility of oxidation compounds. The antioxidant efficiency of the three tested phenols is in line with the number of phenolic groups in its molecule, and is dose-dependent. The concentration of some minor oil components such as terpenes, sesquiterpenes, cycloartenol and 24-methylenecycloartenol is not modified by in vitro digestion. Contrarily, gamma-tocopherol shows very low in vitro bioaccessibility, probably due to its antioxidant behavior, although this increases with enrichment of the phenolic compounds. Oxidation is produced during in vitro digestion even in the presence of a high concentration of gamma-tocopherol, which remains bioaccessible after digestion in the enriched samples of this compound.

Can Agro-Industrial By-Products Rich in Polyphenols be Advantageously Used in the Feeding and Nutrition of Dairy Small Ruminants?

Simple Summary

In the Mediterranean area, where dairy sheep and goats are widespread, the use of by-products in the diet of small ruminants is an ancient practice. Today the great availability of industrial by-products produced at the local level (e.g., grape, olive, tomato and myrtle residues), appears to be a promising strategy for reducing competition with human edible foods and the cost of off-farm produced feeds since they are imported worldwide. Moreover, these co-feeds can contribute to reducing the ecological and water footprint associated with crop cultivation. The presence of bioactive compounds, such as polyphenols, confers added value to these materials. Several positive aspects are apparent when such by-products are included in the diets of small dairy ruminants, in particular on ruminal metabolism, animal health, and the quality of derived products.

Abstract

Recently, the interest in industrial by-products produced at the local level in Mediterranean areas, resulting from fruit and vegetable processes, has increased because of their considerable amounts of bioactive compounds, including polyphenols. In this review, we analyze the most recent scientific results concerning the use of agro-industrial by-products, naturally rich in polyphenols (BPRP), in the diets of small dairy ruminants. Effects on milk production, milk and rumen liquor fatty acid profile, metabolic parameters, and methane production are reviewed. The feed intake and digestibility coefficients were generally depressed by BPRP, even though they were not always reflected in the milk yield. The main observed positive effects of BPRP were on quality of the milk’s FA profile, antioxidant activity in milk and blood, a reduction of rumen ammonia, and, consequently, a reduction of milk and blood urea. The expected beneficial effects of dietary polyphenols in small ruminants were not always observed because of their complex and variable matrices. However, owing to the large quantities of these products available at low prices, the use of BPRB in small ruminant nutrition offers a convenient solution to the valorization of residues arising from agricultural activities, reducing feed costs for farmers and conferring added value to dairy products at the local level, in a sustainable way.

Structural Elucidation of Three Novel Kaempferol O-tri-Glycosides that Are Involved in the Defense Response of Hybrid Ornithogalum to Pectobacterium carotovorum

Ornithogalum is an ornamental flowering species that grows from a bulb and is highly susceptible to soft-rot disease caused by Pectobacterium carotovorum (Pc). Interspecific hybridization between O. thyrsoides and O. dubium yielded hybrids with enhanced resistance to that pathogen. The hybrids displayed distinct phenolic-compound profiles with several peaks that were specifically heightened following Pc infection. Three of these compounds were isolated and identified as novel kaempferol O-tri-glycosides. The structures of these compounds were elucidated using reversed phase high-performance liquid chromatography (RP-LC), RP-LC coupled to high-resolution mass spectrometry (RP-LC-MS), and nuclear magnetic resonance (NMR) (1D ¹H and ¹³C, DEPT, HMQC, HMBC, COSY, and NOE), in order to achieve pure and defined compounds data. The new compounds were finally identified as kaempferol 3-O-[4-O-α-l-(3-O-acetic)-rhamnopyranosyl-6-O-β-d-xylopyranosyl]-β-d-glucopyranoside, kaempferol 3-O-[4-O-α-l-(2-O-acetic)-rhamnopyranosyl-6-O-β-d-xylopyranosyl]-β-d-glucopyranoside and kaempferol 3-O-[4-O-α-l-(2,3-O-diacetic)-rhamnopyranosyl-6-O-β-d-xylopyranosyl]-β-d-glucopyranoside.

Attenuation of allergic responses following treatment with resveratrol in anaphylactic models and IgE-mediated mast cells

Resveratrol exists widely in plant species and has a variety of anti-oxidant, anti-inflammatory, and immunomodulatory properties. However, there have been few reports regarding its anti-food allergic activity. In this study, we demonstrated that resveratrol (isolated from Abies georgei) could decrease the release of β-hexosaminidase and histamine in rat basophilic leukemia-2H3 cells. Resveratrol was not only found to suppress the development of diarrhea, up-regulate the rectal temperature of ovalbumin-allergic mice, and decrease the serum level of specific immunoglobulin E, mouse mast cell protease-1 and histamine, but also found to decrease the population of dendritic cells, B cells and mast cells of ovalbumin -allergic mice in the spleen or mesenteric lymph node. Furthermore, resveratrol inhibited the release of β-hexosaminidase and histamine in bone marrow-derived cells and alleviated mast cell-mediated passive cutaneous anaphylaxis reactions. These findings indicated that resveratrol isolated from Abies georgei might have the potential to alleviate food hypersensitivity or allergic disease.

Reduced sirtuin 1/adenosine monophosphate-activated protein kinase in amyotrophic lateral sclerosis patient-derived mesenchymal stem cells can be restored by resveratrol

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neuron system. Our previous study has shown that bone marrow-mesenchymal stem cells (BM-MSCs) from ALS patients have functional limitations in releasing neurotrophic factors and exhibit the senescence phenotype. In this study, we examined sirtuin 1/adenosine monophosphate-activated protein kinase (SIRT1/AMPK) activities and identified significant decreases in the ALS-MSCs compared with normal healthy control originated BM-MSCs. This decline was restored by pretreatment with resveratrol (RSV), measured using quantitative polymerase chain reaction, NAD/NADH assay, and immunoblot analysis. Neuroprogenitor markers were increased in RSV-treated ALS-MSCs (RSV/ALS-MSCs). The differentiated ALS-MSCs (ALS-dMSCs) exhibited a cell body and dendritic shape similar to neurons. RSV/ALS-MSCs showed significantly increased differentiation rate as compared with the untreated ALS-dMSCs. The neurite numbers and lengths were also significantly increased. This was confirmed with immunoblot analysis using neuron specific markers such as nestin, NF-M, Tuj-1, and Map-2 in RSV/ALS-dMSCs. Thus, this study shows that ALS-MSCs showed down-regulation of AMPK/SIRT1 signalling, which was recovered by treatment with RSV. This data suggest that RSV can be one of the candidate agents for improving therapeutic efficacy of ALS patients' originated MSCs.

Effects of corn replacement by sorghum in diets on performance, nutrient utilization, blood parameters, antioxidant status, and meat colour stability in lambs

The aim of this research was to compare growth performance, nutrient utilization, rumen fermentation, blood parameters, antioxidant status, and meat colour stability of lambs fed diets that partially or completely substituted corn with sorghum. Twenty-four male German merino weaned lambs (16.19 ± 2.05 kg body weight) were divided into four treatments in a completely randomized design. The diets for four treatments contained 450 g kg−1 of ground corn (C), 300 + 150 g kg−1 of ground corn and sorghum (CSM1), 150 + 300 g kg−1 of ground corn and sorghum (CSM2) and 450 g kg−1 ground sorghum (S); all diets consisted of 70% concentrated feed and 30% Leymus chinensis hay. The lambs were fed the experimental diets for 56 d. Inclusion of sorghum tended to increase average daily weight gain and total gain (P = 0.06), and lower feed conversion ratio (P = 0.10). Significant increase in nitrogen (N) intake and fecal N excretion was observed after substitution of corn with sorghum, and the apparent digestibility of crude protein was significantly reduced. Concentrations of ammonia N in rumen fluid were affected by treatment (P = 0.01) and an interaction (P < 0.01) between treatment and sampling time. No significant effects were found on blood parameters among treatments. Replacement of corn with sorghum significantly decreased b* (yellowness) values of meat during storage. Sorghum instead of corn is feasible in lamb diets, and it has positive effects on the lamb growth and meat quality.

Ion Channels Induced by Antimicrobial Agents in Model Lipid Membranes are Modulated by Plant Polyphenols Through Surrounding Lipid Media

The potential therapeutic applications of plant polyphenols in various neurological, cardiovascular, metabolic and malignant disorders determine the relevance of studying the molecular mechanisms of their action on the cell membranes. Here, the quantitative changes in the physical parameters of model bilayer lipid membranes upon the adsorption of plant polyphenols were evaluated. It was shown that butein and naringenin significantly decreased the intrinsic dipole potential of cholesterol-free and cholesterol-enriched membranes. Cardamonin, 4'-hydroxychalcone, licochalcone A and liquiritigenin demonstrated the average efficiency, while resveratrol did not characterized by the ability to modulate the bilayer electrostatics. At the same time, the tested polyphenols affected melting of phospholipids with saturated acyl chains. The effects were attributed to the lipid disordering and a promotion of the positive curvature stress. According to DSC data and results of measurements of the threshold voltages that cause bilayer breakdown licochalcone A is the most effective agent. Furthermore, the role of the polyphenol induced changes in the electric and elastic properties of lipid host in the regulation of reconstituted ion channels was examined. The ability of the tested polyphenols to decrease the conductance of single ion channels produced by the antifungal cyclic lipopeptide syringomycin E was in agreement with their effects on the dipole potential of the lipid bilayers. The greatest effect of licochalcone A on the steady-state membrane conductance induced by the antifungal polyene macrolide antibiotic nystatin correlated with its greatest efficacy to induce the positive curvature stress. We also found that butein and naringenin bind specifically to a single pore formed by α-hemolysin from Staphylococcus aureus.

Preventive effects of royal jelly against anaphylactic response in a murine model of cow's milk allergy

CONTEXT

Royal jelly (RJ) has long been used to promote human health.

OBJECTIVE

The current study investigated the preventive effects of RJ against the development of a systemic and intestinal immune response in mice allergic to cow's milk proteins.

MATERIALS AND METHODS

Balb/c mice treated orally for seven days with RJ at doses of 0.5, 1 and 1.5 g/kg were sensitized intraperitoneally with β-lactoglobulin (β-Lg). Serum IgG and IgE anti-β-Lg were determined by an enzyme-linked immunosorbent assay (ELISA). Plasma histamine levels, symptom scores and body temperature were determined after in vivo challenge to β-Lg. Jejunums were used for assessment of local anaphylactic responses by an ex vivo study in Ussing chambers and morphologic changes by histological analysis.

RESULTS

RJ significantly decreased serum IgG (31.15-43.78%) and IgE (64.28-66.6%) anti-β-Lg and effectively reduced plasma histamine level (66.62-67.36%) (p < 0.001) at all the doses tested. Additionally, no clinical symptoms or body temperature drops were observed in RJ-pretreated mice. Interestingly, RJ significantly reduced (p < 0.001) intestinal dysfunction by abolishing the secretory response (70.73-72.23%) induced by sensitization and prevented length aberrations of jejunal villi by 44.32-59.01% (p < 0.001).

DISCUSSION AND CONCLUSIONS

We speculate that using RJ may help prevent systemic and anaphylactic response in allergic mice. These effects may be related to its inhibitory effects on the degranulation of mast cells.

Resveratrol (3,5,4'-trihydroxystilbene) and its properties in oral diseases

Health promotion strategies and lifestyle changes are important in disease prevention. Oral health has received a large amount of attention previously as it is a fundamental component of general health and it contributes to the quality of life. Therefore, the study of associations between diet, health and the presence of bioactive compounds in food is receiving a substantial amount of attention. In the present review the effects and targets of a natural polyohenolic stilbenoid compound; resveratrol (3,5,4'-trihydroxystilbene; RSV) is assessed, and the future prospects for RSV in promoting oral health are considered. RSV is a phytoalexin, synthesized by a wide range of plants and abundantly extracted in grape skin, it has been purported to exert a multiplicity of anti-inflammatory, anti-viral, anti-microbial, estrogenic, anticancer, cardioprotective, neuroprotective and immunomodulatory functions. In this review, following an introduction documenting the biochemistry of RSV and RSV glucosides, the bioavailability and pharmacokinetics of RSV are described. Considering its multiple properties, the present review has focused on the potential benefits of RSV as an antioxidant and chemopreventive agent.

Interactions between CYP3A4 and Dietary Polyphenols

The human cytochrome P450 enzymes (P450s) catalyze oxidative reactions of a broad spectrum of substrates and play a critical role in the metabolism of xenobiotics, such as drugs and dietary compounds. CYP3A4 is known to be the main enzyme involved in the metabolism of drugs and most other xenobiotics. Dietary compounds, of which polyphenolics are the most studied, have been shown to interact with CYP3A4 and alter its expression and activity. Traditionally, the liver was considered the prime site of CYP3A-mediated first-pass metabolic extraction, but in vitro and in vivo studies now suggest that the small intestine can be of equal or even greater importance for the metabolism of polyphenolics and drugs. Recent studies have pointed to the role of gut microbiota in the metabolic fate of polyphenolics in human, suggesting their involvement in the complex interactions between dietary polyphenols and CYP3A4. Last but not least, all the above suggests that coadministration of drugs and foods that are rich in polyphenols is expected to stimulate undesirable clinical consequences. This review focuses on interactions between dietary polyphenols and CYP3A4 as they relate to structural considerations, food-drug interactions, and potential negative consequences of interactions between CYP3A4 and polyphenols.

Effect of royal jelly on formalin induced-inflammation in rat hind paw

BACKGROUND

Royal Jelly (RJ), a food item secreted by worker honeybees, is a mixture that contains protein, glucose, lipid, vitamins, and minerals; it is widely used as a commercial medical product. Previous studies have shown that RJ has a number of physiological effects, such as anti-inflammatory, antitumor, antiallergic and antioxidant activities.

OBJECTIVES

In the present study, the anti-inflammatory properties of RJ were investigated in formalin-induced rat paw edema.

MATERIALS AND METHODS

In this study, 30 male Wistar albino rats were divided into five equal groups (n = 6) as follows: test groups received different doses (25, 50 and 100 mg/kg, ip) of RJ and a negative control group received normal saline (5 mL/kg) and a positive control group received aspirin (300 mg/kg, i.p). Edema was induced on the right hind paw of the rat by a subplantar injection of 100 µL of formalin (2.5%) after 30 minutes. Paw edema was measured in the rats received the drugs, saline and aspirin before and after the formalin injection during 5 hours, using a plethysmometer.

RESULTS

The results showed that RJ has a dose-dependent anti-inflammatory effect and the highest anti-inflammatory effect was observed in the doses of 50 and 100 mg/kg.

CONCLUSIONS

Royal jelly has potent anti-inflammatory effects compared to aspirin and it could be used in the treatment of inflammation. However, further studies are required to determine the active components in RJ responsible for this effect and its mechanism of action.

Polyphenols protect the epithelial barrier function of Caco-2 cells exposed to indomethacin through the modulation of occludin and zonula occludens-1 expression

The aim of this study was to determine the protective effect of quercetin, epigallocatechingallate, resveratrol, and rutin against the disruption of epithelial integrity induced by indomethacin in Caco-2 cell monolayers. Indomethacin decreased the transepithelial electrical resistance and increased the permeability of the monolayers to fluorescein-dextran. These alterations were abolished by all the tested polyphenols but rutin, with quercetin being the most efficient. The protective effect of quercetin was associated with its capacity to inhibit the redistribution of ZO-1 protein induced in the tight junction by indomethacin or rotenone, a mitochondrial complex-I inhibitor, and to prevent the decrease of ZO-1 and occludin expression induced by indomethacin. The fact that the antioxidant polyphenols assayed in this study differ in their protective capacity against the epithelial damage induced by indomethacin suggests that this damage is due to the ability of this agent to induce not only oxidative stress but also mitochondrial dysfunction.

The efficacy of topical royal jelly on healing of diabetic foot ulcers: a double-blind placebo-controlled clinical trial

Foot ulcers are major sources of morbidity in individuals with diabetes mellitus. As royal jelly (RJ, a worker honey bee product) contains enzymatic, antibacterial and vasodilative properties, it can potentially help in healing of diabetic foot ulcers (DFUs). This study aimed to evaluate the efficacy of topical RJ on healing of DFUs. Diabetic patients with foot ulcers who were referred to us at Khorshid Hospital, Isfahan, Iran, were managed by offloading, infection control, vascular improvement and debridement (if required). Then, all ulcers were randomly selected to receive either 5% sterile topical RJ or placebo on their total surface area. Patients were followed for 3 months or until complete healing. Twenty-five patients (6 females and 19 males) and a total of 64 ulcers were included and randomly allocated to case or control group (32 per group). Four ulcers were excluded and 60 ulcers included in the final analysis. Healing parameters including depth, length and width reduction rate, duration of complete healing and incidence of complete healing did not show any significant difference (P = 0·69, 0·95, 0·7, 0·74 and 0·6, respectively) between groups. We did not observe any side effect of topical RJ application. This study could not confirm any significant superiority of 5% topical RJ over placebo for the treatment of DFUs.

Dietary quebracho tannins are not absorbed, but increase the antioxidant capacity of liver and plasma in sheep

A total of sixteen lambs were divided into two groups and fed two different diets. Of these, eight lambs were fed a control diet (C) and eight lambs were fed the C diet supplemented with quebracho tannins (C+T). The objective of the present study was to assess whether dietary quebracho tannins can improve the antioxidant capacity of lamb liver and plasma and if such improvement is due to a direct transfer of phenolic compounds or their metabolites, to the animal tissues. Feed, liver and plasma samples were purified by solid-phase extraction (SPE) and analysed by liquid chromatography–MS for phenolic compounds. Profisitinidin compounds were identified in the C+T diet. However, no phenolic compounds were found in lamb tissues. The liver and the plasma from lambs fed the C+T diet displayed a greater antioxidant capacity than tissues from lambs fed the C diet, but only when samples were not purified with SPE. Profisetinidin tannins from quebracho seem not to be degraded or absorbed in the gastrointestinal tract. However, they induced antioxidant effects in animal tissues.

The effect of royal jelly on CD3(+), CD5(+), CD45(+) T-cell and CD68(+) cell distribution in the colon of rats with acetic acid-induced colitis

BACKGROUND

Traditional medicines and health supplements have historically been used to treat many illnesses but most of them have not been evaluated objectively to prove their efficacy. We have been investigating the effects of royal jelly (RJ) supplements on acetic acid-induced colitis on the distribution of CD3(+), CD5(+), CD45(+) T-cell and CD68(+) cells in rats.

METHODS

The rats were divided into four equal groups: control group, royal jelly-treated (RJ - 150mgkg(-1) body weight), acetic acid-treated (colitis) and acetic acid-treated (colitis)+royal jelly (CRJ - 150mgkg(-1) body weight). Colitis was induced by intracolonic instillation of 4% acetic acid; the control group received physiological saline (10mLkg(-1)). Colon samples were obtained under deep anaesthesia from animals in four groups. Tissues were fixed in 10% formalin neutral buffer solution for 24h and embedded in paraffin.

RESULTS

The proliferative response of CD3(+) and CD45(+) T cells stimulated with colitis was affected by colitis treated with RJ. No differences were found in CD5(+) T cells and CD68(+) macrophages in the colitis treated with RJ.

CONCLUSIONS

This study has shown that RJ has anti-inflammatory and cell regeneration effect in the colon of rats with acetic acid induced colitis.

Differential protective effects of quercetin, resveratrol, rutin and epigallocatechin gallate against mitochondrial dysfunction induced by indomethacin in Caco-2 cells

The beneficial effects of dietary polyphenols on health are due not only to their antioxidant properties but also to their antibacterial, anti-inflammatory and/or anti-tumoral activities. It has recently been proposed that protection of mitochondrial function (which is altered in several diseases such as Alzheimer, Parkinson, obesity and diabetes) by these compounds, may be important in explaining the beneficial effects of polyphenols on health. The aim of this study was to evaluate the protective effects of dietary polyphenols quercetin, rutin, resveratrol and epigallocatechin gallate against the alterations of mitochondrial function induced by indomethacin (INDO) in intestinal epithelial Caco-2 cells, and to address the mechanism involved in such damaging effect by INDO, which generates oxidative stress. INDO concentration dependently decreases cellular ATP levels and mitochondrial membrane potential in Caco-2 cells after 20min of incubation. INDO also inhibits the activity of mitochondrial complex I and causes accumulation of NADH; leading to overproduction of mitochondrial O(2)()(-), since it is prevented by pyruvate. Quercetin (0.01mg/ml), resveratrol (0.1mg/ml) and rutin (1mg/ml) protected Caco-2 cells against INDO-induced mitochondrial dysfunction, while no protection was observed with epigallocatechin gallate. Quercetin was the most efficient in protecting against mitochondrial dysfunction; this could be due to its ability to enter cells and accumulate in mitochondria. Additionally its structural similarity with rotenone could favor its binding to the ubiquinone site of complex I, protecting it from inhibitors such as INDO or rotenone. These findings suggest a possible new protective role for dietary polyphenols for mitochondria, complementary of their antioxidant property. This new role might expand the preventive and/or therapeutic use of PPs in conditions involving mitochondrial dysfunction and associated with increased oxidative stress at the cellular or tissue levels.

Effect of royal jelly on experimental colitis Induced by acetic acid and alteration of mast cell distribution in the colon of rats

This study investigated the effects of royal jelly (RJ) on acetic acid-induced colitis in rats. Twenty adult female Wistar albino rats were divided into four treatment groups of 5 animals each, including a control group (Group I); Group II was treated orally with RJ (150 mg kg(-1) body weight); Group III had acetic acid-induced colitis; and Group IV had acetic acid-induced colitis treated orally with RJ (150 mg kg(-1) body weight) for 4 weeks. Colitis was induced by intracolonic instillation of 4% acetic acid; the control group received physiological saline (10 mL kg(-1)). Colon samples were obtained under deep anaesthesia from animals in all groups. Tissues were fixed in 10% formalin neutral buffer solution for 24 h and embedded in paraffin. Six-micrometre-thick sections were stained with Mallory’s triple stain and toluidine blue in 1% aqueous solution at pH 1.0 for 5 min (for Mast Cells). RJ was shown to protect the colonic mucosa against the injurious effect of acetic acid. Colitis (colonic damage) was confirmed histomorphometrically as significant increases in the number of mast cells (MC) and colonic erosions in rats with acetic acid-induced colitis. The RJ treatment significantly decreased the number of MC and reduced the area of colonic erosion in the colon of RJ-treated rats compared with rats with untreated colitis. The results suggest that oral treatment with RJ could be used to treat colitis.

Effects of resveratrol on membrane biophysical properties: relevance for its pharmacological effects

The current study gathers a range of spectrophotometric and spectrofluorimetric techniques to systematically monitor the effects of resveratrol (trans-3,5,4'-trihydrostilbene) on the biophysical properties of membrane model systems consisting of unilamellar liposomes of phosphatidylcholine (DPPC) with the ultimate goal of relating these effects with some of the well documented pharmacological properties of this compound, and clarifying some controversial results reported on the literature. Physiological conditions have been pursued, such as a buffered pH control with adjusted ionic strength similar to the blood plasma conditions (pH 7.4, I=0.1M) and the study at different membrane physical states (gel phase and fluid phase) for the assessment of resveratrol-membrane: aqueous partition coefficient by derivative spectroscopy. Results obtained by fluorescence quenching and anisotropy studies indicate that resveratrol has a membrane fluidizing effect and is able to permeate the membrane even in the gel phase. These results mirror the well described antioxidant effect of resveratrol, since antioxidants have to reach peroxidised rigid membranes and increase membrane fluidity in order to interact more efficiently with lipid radicals in the disordered lipid bilayer. Location of resveratrol pointed also to a membrane distribution that is favourable for scavenging the lipid radicals and was elucidated using probes positioned at different membrane depths suggesting that this compound penetrates into the acyl membrane region but also positions its polar hydroxyl group near the headgroup region of the membrane.

Functional properties of honey, propolis, and royal jelly

Honey, propolis, and royal jelly, products originating in the beehive, are attractive ingredients for healthy foods. Honey has been used since ancient times as part of traditional medicine. Several aspects of this use indicate that it also has functions such as antibacterial, antioxidant, antitumor, anti-inflamatory, antibrowning, and antiviral. Propolis is a resinous substance produced by honeybees. This substance has been used in folk medicine since ancient times, due to its many biological properties to possess, such as antitumor, antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory effects, among others. Royal jelly has been demonstrated to possess numerous functional properties such as antibacterial activity, anti-inflammatory activity, vasodilative and hypotensive activities, disinfectant action, antioxidant activity, antihypercholesterolemic activity, and antitumor activity. Biological activities of honey, propolis, and royal jelly are mainly attributed to the phenolic compounds such as flavonoids. Flavonoids have been reported to exhibit a wide range of biological activities, including antibacterial, antiviral, anti-inflammatory, antiallergic, and vasodilatory actions. In addition, flavonoids inhibit lipid peroxidation, platelet aggregation, capillary permeability and fragility, and the activity of enzyme systems including cyclo-oxygenase and lipoxygenase.

Witch hazel (Hamamelis virginiana) fractions and the importance of gallate moieties--electron transfer capacities in their antitumoral properties

Witch hazel (Hamamelis virginia) extracts are used in traditional medicine. They are particularly rich in gallate esters included in proanthocyanidins, hydrolyzable tannins (galloylated sugars), and methyl gallate. This study examines the response of human colon cancer cells to treatment with fractions obtained from a witch hazel polyphenolic extract. The results are compared with those obtained previously with homologous fractions from grape (less galloylated) and pine (nongalloylated). Witch hazel fractions were the most efficient in inhibiting cell proliferation in HT29 and HCT116 human colon cancer cell lines, which clearly shows that the more galloylated the fractions, the more effective they were at inhibiting proliferation of colon cancer cells. Witch hazel fractions were, in addition, more potent in arresting the cell cycle at the S phase and inducing apoptosis; they also induced a significant percentage of necrosis. Interestingly, the apoptosis and cell cycle arrest effects induced were proportional to their galloylation. Moreover, witch hazel fractions with a high degree of galloylation were also the most effective as scavengers of both hydroxyl and superoxide radicals and in protecting against DNA damage triggered by the hydroxyl radical system. These findings provide a better understanding of the structure-bioactivity relationships of polyphenolics, which should be of assistance in choosing an appropriate source and preparing a rational design for formulations of plant polyphenols in nutritional supplements.

Nutritive and antioxidative potential of fresh and stored pomegranate industrial byproduct as a novel beef cattle feed

Pomegranate peel is a nutritive-rich byproduct whose amounts are extensively growing due to the exponential increase in the production of pomegranate juice and "ready to eat" arils. Pomegranate peel is a rich source for antioxidants and thus may serve in the prevention of cattle diseases and in the improvement of beef products, making it an attractive component in beef cattle diets. The present study aims to evaluate the effect of commonly used storage practices on the nutritive and antioxidative properties of pomegranate peel. In general, storage conditions preserved most antioxidant capacity. Ensiling ambivalently affected the nutritive values of the peel and promoted increased levels of antioxidative components. In addition to polyphenols, nonphenolic components, such as alpha- and gamma-tocopherols, contributed to the total antioxidative capacity, and several minerals found in the peel added to its nutritional value. Dietary supplementation with fresh peels promoted significant increases in feed intake and alpha-tocopherol concentration in the plasma, with positive tendency toward increased weight gain of bull calves. All in all, the nutritive value and the antioxidant capacity of pomegranate peel turn it into a favorable health-promoting constituent of feedlot beef cattle diet.

Fast and simple method for the simultaneous evaluation of the capacity and efficiency of food antioxidants in trapping peroxyl radicals in an intestinal model system

A simple oxygraphic method, for which the theoretical and experimental bases have been recently revised, has been successfully applied to evaluate the peroxyl radical chain-breaking characteristics of some typical food antioxidants in micelle systems, among which is a system that reproduces conditions present in the upper part of the digestive tract, where the absorption and digestion of lipids occur. This method permits one to obtain from a single experimental run the peroxyl radical trapping capacity (PRTC, that is, the number of moles of peroxyl radicals trapped by a given amount of food), the peroxyl radical trapping efficiency (PRTE, that is, the reciprocal of the amount of food that reduces to half the steady-state concentration of peroxyl radicals), and the half-life of the antioxidant ( t(1/2)) when only a small fraction of peroxyl radicals reacts with the antioxidants present in foods. Examples of application of the method to various types of foodstuffs have been reported, assessing the general validity of the method in the simple and fast evaluation of the above-reported fundamental antioxidant characteristics of foods.

(-)-Catechin in cocoa and chocolate: occurrence and analysis of an atypical flavan-3-ol enantiomer

Cocoa contains high levels of different flavonoids. In the present study, the enantioseparation of catechin and epicatechin in cocoa and cocoa products by chiral capillary electrophoresis (CCE) was performed. A baseline separation of the catechin and epicatechin enantiomers was achieved by using 0.1 mol x L(-1) borate buffer (pH 8.5) with 12 mmol x L(-1) (2-hydroxypropyl)-gamma-cyclodextrin as chiral selector, a fused-silica capillary with 50 cm effective length (75 microm I.D.), +18 kV applied voltage, a temperature of 20 degrees C and direct UV detection at 280 nm. To avoid comigration or coelution of other similar substances, the flavan-3-ols were isolated and purified using polyamide-solid-phase-extraction and LC-MS analysis. As expected, we found (-)-epicatechin and (+)-catechin in unfermented, dried, unroasted cocoa beans. In contrast, roasted cocoa beans and cocoa products additionally contained the atypical flavan-3-ol (-)-catechin. This is generally formed during the manufacturing process by an epimerization which converts (-)-epicatechin to its epimer (-)-catechin. High temperatures during the cocoa bean roasting process and particularly the alkalization of the cocoa powder are the main factors inducing the epimerization reaction. In addition to the analysis of cocoa and cocoa products, peak ratios were calculated for a better differentiation of the cocoa products.