Sulfated and Glucuronated trans-Resveratrol Metabolites Regulate Chemokines and Sirtuin-1 Expression in U-937 Macrophages

Sirtuins, resveratrol and the intertwining cellular pathways connecting them

Sirtuins are a family of NAD+-dependent deacylases with numerous physiological and pathological implications, which lately became an attractive therapeutic target. Sirtuin-activating compounds (STACs) could be useful in disease prevention and treatment. Despite its bioavailability issues, resveratrol exerts a myriad of beneficial effects, known as the "resveratrol paradox". Modulation of sirtuins' expression and activity may, in fact, underlie many of resveratrol revered actions; however, the cellular pathways affected by modulating the activity of each sirtuin isoform, in different physio-pathological conditions, are not fully known. The purpose of this review was to summarize recent reports concerning the effects of resveratrol on the activity of sirtuins in different experimental settings, focusing on in vitro and in vivo preclinical studies. Most reports concern SIRT1, however recent studies dive into the effects initiated via other isoforms. Numerous cellular signaling pathways were reported to be modulated by resveratrol in a sirtuin-dependent manner (increased phosphorylation of MAPKs, AKT, AMPK, RhoA, BDNF, decreased activation of NLRP3 inflammasome, NF-κB, STAT3, upregulation of SIRT1/SREBP1c pathway, reduced β-amyloid via SIRT1-NF-κB-BACE1 signaling and counteracting mitochondrial damage by deacetylating PGC-1α). Thus, resveratrol may be the ideal candidate in the search for STACs as a tool for preventing and treating inflammatory and neurodegenerative diseases.

Bioaccessibility and transport of lentil hull polyphenols in vitro, and their bioavailability and metabolism in rats

Polyphenol-rich lentil hulls are a valuable by-product. In this study, lentil hulls were subjected to simulated in vitro digestion and caco-2 cell monolayer models to assess the bioaccessibility, transmembrane transport, and a rat model to examine the bioavailability and metabolism in vivo. Polyphenols were increasingly released during the in vitro digestion, and were found to contribute to the increased antioxidant activity. Among the bioaccessible polyphenols, catechin glucoside, kaempferol tetraglucoside, procyanidin dimer and dihydroxybenzoic acid-O-dipentoside were most efficiently transported across the caco-2 membrane, and responsible for promoting intestinal integrity as a result of enhanced expression of tight junction proteins. When ingested by rats, lentil hull polyphenols underwent extensive I and II phase metabolic reactions in vivo, including hydroxylation, methylation, glucuronidation and sulfation. Overall, results of this study showed that lentil hull polyphenols are bioaccessible and bioavailable, and lentil hulls as a by-product can be a valuable ingredient for future functional foods.

Stilbenes, a Versatile Class of Natural Metabolites for Inflammation-An Overview

Stilbenes are polyphenolic allelochemicals synthesized by plants, especially grapes, peanuts, rhubarb, berries, etc., to defend themselves under stressful conditions. They are now exploited in medicine for their antioxidant, anti-proliferative and anti-inflammatory properties. Inflammation is the immune system's response to invading bacteria, toxic chemicals or even nutrient-deprived conditions. It is characterized by the release of cytokines which can wreak havoc on healthy tissues, worsening the disease condition. Stilbenes modulate NF-κB, MAPK and JAK/STAT pathways, and reduce the transcription of inflammatory factors which result in maintenance of homeostatic conditions. Resveratrol, the most studied stilbene, lowers the Michaelis constant of SIRT1, and occupies the substrate binding pocket. Gigantol interferes with the complement system. Besides these, oxyresveratrol, pterostilbene, polydatin, viniferins, etc., are front runners as drug candidates due to their diverse effects from different functional groups that affect bioavailability and molecular interactions. However, they each have different thresholds for toxicity to various cells of the human body, and thus a careful review of their properties must be conducted. In animal models of autoinflammatory diseases, the mode of application of stilbenes is important to their absorption and curative effects, as seen with topical and microemulsion gel methods. This review covers the diversity seen among stilbenes in the plant kingdom and their mechanism of action on the different inflammatory pathways. In detail, macrophages' contribution to inflamed conditions in the liver, the cardiac, connective and neural tissues, in the nephrons, intestine, lungs and in myriad other body cells is explored, along with detailed explanation on how stilbenes alleviate the symptoms specific to body site. A section on the bioavailability of stilbenes is included for understanding the limitations of the natural compounds as directly used drugs due to their rapid metabolism. Current delivery mechanisms include sulphonamides, or using specially designed synthetic drugs. It is hoped that further research may be fueled by this comprehensive work that makes a compelling argument for the exploitation of these compounds in medicine.

Oxyresveratrol and Gnetol Glucuronide Metabolites: Chemical Production, Structural Identification, Metabolism by Human and Rat Liver Fractions, and In Vitro Anti-inflammatory Properties

Stilbene metabolites are attracting great interest because many of them exhibit similar or even stronger biological effects than their parent compounds. Furthermore, the metabolized forms are predominant in biological fluids; therefore, their study is highly relevant. After hemisynthesis production, isolation, and structural elucidation, three glucuronide metabolites for oxyresveratrol (ORV) were formed: trans-ORV-4'-O-glucuronide, trans-ORV-3-O-glucuronide, and trans-ORV-2'-O-glucuronide. In addition, two glucuronide metabolites were obtained for gnetol (GN): trans-GN-2'-O-glucuronide and trans-GN-3-O-glucuronide. When the metabolism of ORV and GN is studied in vitro by human and rat hepatic enzymes, four of the five hemisynthesized compounds were identified and quantified. Human enzymes glucuronidated preferably at the C-2' position, whereas rat enzymes do so at the C-3 position. In view of these kinetic findings, rat enzymes have a stronger metabolic capacity than human enzymes. Finally, ORV, GN, and their glucuronide metabolites (mainly at the C-3 position) decreased nitric oxide, reactive oxygen species, interleukin 1β, and tumor necrosis factor α production in lipopolysaccharide-stimulated macrophages.

Gut Microbiota-Derived Resveratrol Metabolites, Dihydroresveratrol and Lunularin, Significantly Contribute to the Biological Activities of Resveratrol

Although resveratrol (RES) is barely detectable in the plasma and tissues upon oral consumption, collective evidence reveals that RES presents various bioactivities in vivo, including anti-inflammation and anti-cancer. This paradox necessitates further research on profiling and characterizing the biotransformation of RES, as its metabolites may contribute profound biological effects. After 4-week oral administration, 11 metabolites of RES were identified and quantified in mice by HPLC-MS/MS, including dihydro-resveratrol (DHR), lunularin (LUN), and conjugates (sulfates and glucuronides) of RES, DHR and LUN. Importantly, DHR, LUN, and their conjugates were much more abundantly distributed in tissues, gastrointestinal tract (GIT), and biological fluids compared to RES and its conjugates. Moreover, we established that DHR and LUN were gut bacteria-derived metabolites of RES, as indicated by their depletion in antibiotic-treated mice. Furthermore, the biological activities of RES, DHR, and LUN were determined at physiologically relevant levels. DHR and LUN exhibited stronger anti-inflammatory and anti-cancer effects than RES at the concentrations found in mouse tissues. In summary, our study profiled the tissue distribution of the metabolites of RES after its oral administration in mice and uncovered the important role of gut microbial metabolites of RES in the biological activities of RES in vivo.

Identification of Interleukin-8-Reducing Lead Compounds Based on SAR Studies on Dihydrochalcone-Related Compounds in Human Gingival Fibroblasts (HGF-1 cells) In Vitro

Background: In order to identify potential activities against periodontal diseases, eighteen dihydrochalcones and structurally related compounds were tested in an established biological in vitro cell model of periodontal inflammation using human gingival fibroblasts (HGF-1 cells). Methods: Subsequently to co-incubation of HGF-1 cells with a bacterial endotoxin (Porphyromonas gingivalis lipopolysaccharide, pgLPS) and each individual dihydrochalcone in a concentration range of 1 µM to 100 µM, gene expression of interleukin-8 (IL-8) was determined by qPCR and cellular interleukin-8 (IL-8) release by ELISA. Results: Structure–activity analysis based on the dihydrochalcone backbone and various substitution patterns at its aromatic ring revealed moieties 2′,4,4′,6′-tetrahydroxy 3-methoxydihydrochalcone (7) to be the most effective anti-inflammatory compound, reducing the pgLPS-induced IL-8 release concentration between 1 µM and 100 µM up to 94%. In general, a 2,4,6-trihydroxy substitution at the A-ring and concomitant vanilloyl (4-hydroxy-3-methoxy) pattern at the B-ring revealed to be preferable for IL-8 release inhibition. Furthermore, the introduction of an electronegative atom in the A,B-linker chain led to an increased anti-inflammatory activity, shown by the potency of 4-hydroxybenzoic acid N-vanillylamide (13). Conclusions: Our data may be feasible to be used for further lead structure designs for the development of potent anti-inflammatory additives in oral care products.

Oxidative stress inhibition by resveratrol in alcohol-dependent mice

OBJECTIVES

Uncontrolled ingestion of alcohol has dramatic consequences on the entire organism that are also associated with the oxidation process induced by alcohol and elevate radical oxygen species. Resveratrol, a nonflavonoid phenol, shows well-documented antioxidant properties. We investigated the potential antioxidant ability of this natural compound in a mouse model of alcohol addiction.

METHODS

We administered (per os) for 60 d 10 mg · kg^-1 · d^-1 of resveratrol in alcoholic adult male mice. Oxidative stress was evaluated by measuring serum-free oxygen radicals defense and free oxygen radical levels. Resveratrol metabolites were measured in the serum of mice that were administered with resveratrol. Finally, the effect of resveratrol on the alcohol-induced alteration of brain-derived neurotrophic factors (BDNF) in the liver was investigated.

RESULTS

Prolonged consumption of resveratrol strongly counteracts serum radical oxygen species formation caused by chronic alcohol intake without effects on natural, free oxygen radical defense. The presence of resveratrol metabolites in the serum only of animals supplemented with resveratrol potentiates the evidence that the antioxidant effect observed is due to the ingestion of the natural compound. Moreover, resveratrol supplementation can counteract alcohol-induced BDNF elevation in the liver, which is the main target of organ alcohol-induced damage.

CONCLUSIONS

The consumption of resveratrol through metabolite formation may play a protective role by decreasing free radical formation and modulating the BDNF involved in hepatic disruption induced by chronic alcohol consumption. Further investigation into the mechanism underlying the protective effect could reinforce the potential use of resveratrol as a dietary supplement to prevent damage associated with chronic alcohol abuse.

Flavonoids Alleviating Insulin Resistance through Inhibition of Inflammatory Signaling

During the past 20 years, many studies have focused on polyphenol compounds for their potential beneficial health effects. Flavonoids represent a large class of phenolic compounds found in fruits, vegetables, nuts, grains, cocoa, tea, and other beverages. Flavonoids have shown antioxidant and anti-inflammatory activities. Given the putative relationship between inflammation and insulin resistance, the consumption of flavonoids or flavonoid-rich foods has been suggested to reduce the risk of diabetes by targeting inflammatory signals. This is the first comprehensive review summarizing the current research progress on the inhibition of inflammation and alleviation of insulin resistance by flavonoids as well as the mechanistic link between these disorders. Laboratory and human studies on the activities of major flavonoids (flavones, isoflavones, flavonols, etc.) are discussed.

Bioactivity of dietary polyphenols: The role of metabolites

A polyphenol-rich diet protects against chronic pathologies by modulating numerous physiological processes, such as cellular redox potential, enzymatic activity, cell proliferation and signaling transduction pathways. However, polyphenols have a low oral bioavailability mainly due to an extensive biotransformation mediated by phase I and phase II reactions in enterocytes and liver but also by gut microbiota. Despite low oral bioavailability, most polyphenols proved significant biological effects which brought into attention the low bioavailability/high bioactivity paradox. In recent years, polyphenol metabolites have attracted great interest as many of them showed similar or higher intrinsic biological effects in comparison to the parent compounds. There is a huge body of literature reporting on the biological functions of polyphenol metabolites generated by phase I and phase II metabolic reactions and gut microbiota-mediated biotransformation. In this respect, the review highlights the pharmacokinetic fate of the major dietary polyphenols (resveratrol, curcumin, quercetin, rutin, genistein, daidzein, ellagitannins, proanthocyanidins) in order to further address the efficacy of biometabolites as compared to parent molecules. The present work strongly supports the contribution of metabolites to the health benefits of polyphenols, thus offering a better perspective in understanding the role played by dietary polyphenols in human health.

Endothelial Cells Deconjugate Resveratrol Metabolites to Free Resveratrol: A Possible Role in Tissue Factor Modulation

SCOPE

The antithrombotic effects of resveratrol (RV) and its derivatives remain unknown. The objective is to evaluate the modulatory effects of RV, its glucoside form, piceid, and its biological metabolites (RV-3-O-β-d-glucuronide, RV-4'-O-d-glucuronide, and RV-3-O-sulfate) on tissue factor (TF). Moreover, the endothelial metabolism of RV is assessed.

METHODS AND RESULTS

Human aortic endothelial cells (HAECs) are incubated with trans-piceid, trans-RV, or their biological metabolites and stimulated with tumor necrosis factor-α (TNF-α). TF activity, protein levels, and mRNA expression are determined in cell lysates. Moreover, RV conjugation (phase-II-metabolism) to its sulfated or glucuronidated metabolites and their deconjugation to their parent compound (free RV) are also assessed in cell lysates and culture media. RV decreased TF activity, protein levels, and mRNA expression, whereas piceid and RV metabolites (RVmet) had no effects. RV-3-O-sulfate was the main metabolite generated in the endothelium, while RVmet are deconjugated to free RV. Isomerization of trans-RV and its trans-metabolites to their cis-forms is observed.

CONCLUSIONS

RV exerts antithrombotic effects by modulating TF. RVmet and piceid does not exert this effect. However, the capacity of endothelial cells to deconjugate RVmet to free RV indicates that RVmet function as an endothelial reservoir for RV regeneration, thus, contributing to the antithrombotic effects of RV.

Resveratrol, Metabolic Syndrome, and Gut Microbiota

Resveratrol is a polyphenol which has been shown to have beneficial effects on metabolic syndrome-related alterations in experimental animals, including glucose and lipid homeostasis improvement and a reduction in fat mass, blood pressure, low-grade inflammation, and oxidative stress. Clinical trials have been carried out to address its potential; however, results are still inconclusive. Even though resveratrol is partly metabolized by gut microbiota, the relevance of this “forgotten organ” had not been widely considered. However, in the past few years, data has emerged suggesting that the therapeutic potential of this compound may be due to its interaction with gut microbiota, reporting changes in bacterial composition associated with beneficial metabolic outcomes. Even though data is still scarce and for the most part observational, it is promising nevertheless, suggesting that resveratrol supplementation could be a useful tool for the treatment of metabolic syndrome and its associated conditions.

Resveratrol reduces the inflammatory response in adipose tissue and improves adipose insulin signaling in high-fat diet-fed mice

Background

Obesity-induced glucose metabolism disorder is associated with chronic, low-grade, systemic inflammation and is considered a risk factor for diabetes and metabolic syndrome. Resveratrol (RES), a natural anti-inflammatory compound, is observed to improve glucose tolerance and insulin sensitivity in obese rodents and humans. This study aimed to test the effects of RES administration on insulin signaling and the inflammatory response in visceral white adipose tissue (WAT) caused by a high-fat diet (HFD) in mice.

Methods

A total of 40 wild-type C57BL/6 male mice were divided into four groups (10 in each group): the standard chow diet (STD) group was fed a STD; the HFD group was fed a HFD; and the HFD-RES/L and HFD-RES/H groups were fed a HFD plus RES (200 and 400 mg/kg/day, respectively). The L and H in RES/L and RES/H stand for low and high, respectively. Glucose tolerance, insulin sensitivity, circulating inflammatory biomarkers and lipid profile were determined. Quantitative PCR and Western blot were used to determine the expression of CC-chemokine receptor 2 (CCR2), other inflammation markers, glucose transporter 4 (GLUT4), insulin receptor substrate 1 (IRS-1) and pAkt/Akt and to assess targets of interest involving glucose metabolism and inflammation in visceral WAT.

Results

HFD increased the levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol and proinflammatory cytokines in serum, decreased the high-density lipoprotein cholesterol level in serum, and induced insulin resistance and WAT inflammation in mice. However, RES treatment alleviated insulin resistance, increased the expressions of pAkt, GLUT4 and IRS-1 in WAT, and decreased serum proinflammatory cytokine levels, macrophage infiltration and CCR2 expression in WAT.

Conclusion

Our results indicated that WAT CCR2 may play a vital role in macrophage infiltration and the inflammatory response during the development of insulin resistance in HFD-induced obesity. These data suggested that administration of RES offers protection against abnormal glucose metabolism and inflammatory adaptations in visceral WAT in mice with HFD-induced obesity.

Wine and its metabolic effects. A comprehensive review of clinical trials

The introduction of the term "French Paradox" motivated an extensive and in-depth research into health benefits of moderate wine consumption. The superiority of wine is thought to be attributed to its micro-constituents and consequent effort was made to isolate and identify these bioactive compounds as well as to elucidate the mechanisms of their action. Controlled trials offer more concrete answers to several raised questions than observational studies. Under this perspective, clinical trials have been implemented, mainly in healthy volunteers and rarely in patients, in order to investigate the acute or chronic effect of wine consumption on metabolism and physio-pathological systems, which are mainly associated with cardiovascular diseases. The aim of this review is to update the knowledge about the acute and long term effect of wine consumption on lipid and glucose/insulin metabolism as well as on the inflammatory and haemostatic systems, based on the reported data of controlled clinical trials. In conclusion, the most repeated result of wine consumption is on lipid metabolism, attributed mainly to ethanol, while wine micro-constituents seem to have an important role mainly in haemostatic and inflammatory/endothelial systems.

Therapeutic potential of Bama miniature pig adipose stem cells induced hepatocytes in a mouse model with acute liver failure

The role of mesenchymal stem cells (MSCs) in cellular therapy is well recognized in this work. MSCs have advantages of high proliferation, clone formation, multi-lineage differentiation and immunosuppression. Furthermore, adipose-resident MSCs (ADSCs) are extensively employed due to its advantages of abundant source, low cost and simple operation. Many researchers have emphasized the role of adipose-resident MSCs in the development of therapies for liver injury, but few attentions were paid on the use of induced functional hepatocytes. Therefore, in this work the role of adipose-resident MSCs induced functional hepatocytes was mainly investigated. The function of induced hepatocytes by ELISA and the induction rate was confirmed by flow cytometry and evaluated by experimental observations. The induced hepatocytes were firstly transplanted into CCl₄-caused liver damage ICR mice by tail vein. After transplantation, both liver fibrosis and function could be improved by hepatocytes, which were examined through histology, immunofluorescence staining, serum profile and biochemical parameters levels. The production of cytokines was then compared with normal mice and injury mice to explore the therapeutic mechanisms of hepatocytes. Finally, the secretions of TGF-β1, IL-6 and IL-10 in hepatocytes transplanted mice were determined and found to be higher than that of the normal and injury mice. The hepatocytes derived from ADSCs were proven to have a great significance in the therapeutic efficacy and clinical settings of liver disease animal models.

Whole-cell-dependent biosynthesis of sulfo-conjugate using human sulfotransferase expressing budding yeast

Cytosolic sulfotransferases (SULTs), one of the predominant phase II drug metabolizing enzymes (DME), play important roles in metabolism of xeno- and endobiotics to generate their sulfo-conjugates. These sulfo-conjugates often have biological activities but are difficult to study, because even though only small amounts are required to evaluate their efficacy and safety, chemical or biological synthesis of sulfo-conjugatesis is often challenging. Previously, we constructed a DME expression system for cytochrome P450 and UGT, using yeast cells, and successfully produced xenobiotic metabolites in a whole-cell-dependent manner. In this study, we developed a yeast expression system for human SULTs, including SULT1A1, 1A3, 1B1, 1C4, 1E1, and 2A1, in Saccharomyces cerevisiae and examined its sulfo-conjugate productivity. The recombinant yeast cells expressing each of the SULTs successfully produced several hundred milligram per liter of xeno- or endobioticsulfo-conjugates within 6 h. This whole-cell-dependent biosynthesis enabled us to produce sulfo-conjugates without the use of 3'-phosphoadenosine-5'-phosphosulfate, an expensive cofactor. Additionally, the production of regiospecific sulfo-conjugates of several polyphenols was possible with this method, making this novel yeast expression system a powerful tool for uncovering the metabolic pathways and biological actions of sulfo-conjugates.

A simple LC-MS/MS method facilitated by salting-out assisted liquid-liquid extraction to simultaneously determine trans-resveratrol and its glucuronide and sulfate conjugates in rat plasma and its application to pharmacokinetic assay

A simple LC-MS/MS method facilitated by salting-out assisted liquid-liquid extraction (SALLE) was applied to simultaneously investigate the pharmacokinetics of trans-resveratrol (Res) and its major glucuronide and sulfate conjugates in rat plasma. Acetonitrile-methanol (80:20, v/v) and ammonium acetate (10 mol L^-1 ) were used as extractant and salting-out reagent to locate the target analytes in the supernatant after the aqueous and organic phase stratification, then the analytes were determined via gradient elution by LC-MS/MS in negative mode in a single run. The analytical method was validated with good selectivity, acceptable accuracy (>85%) and low variation of precision (<15%). SALLE showed better extraction efficiency of target glucuronide and sulfate conjugates (>80%). The method was successfully applied to determine Res and its four conjugated metabolites in rat after Res administration (intragastric, 50 mg kg^-1 ; intravenous, 10 mg kg^-1 ). The systemic exposures to Res conjugates were much higher than those to Res (AUC_0-t , i.v., 7.43 μm h; p.o., 8.31 μm h); Res-3-O-β-d-glucuronide was the major metabolite (AUC_0-t , i.v., 66.1 μm h; p.o., 333.4 μm h). The bioavailability of Res was estimated to be ~22.4%. The reproducible SALLE method simplified the sample preparation, drastically improved the accuracy of the concomitant assay and gave full consideration of extraction recovery to each target analyte in bio-samples.

Distribution of trans-resveratrol and its metabolites after acute or sustained administration in mouse heart, brain, and liver

SCOPE

Trans-resveratrol is widely studied for its potentially beneficial effects on numerous disorders. It is rapidly metabolized and its metabolites can exhibit biological activity. The present study aimed to investigate whether acute or sustained trans-resveratrol administration impacted on the distribution of trans-resveratrol and its metabolites in brain, heart, and liver.

METHODS AND RESULTS

We used ultra-HPLC quadrupole-TOF (UHPLC-Q-TOF) in a full-scan mode to identify and assess large numbers of resveratrol metabolites. For acute intake, mice were overfed with a single dose of trans-resveratrol (150 mg/kg) and organs were collected after 30 and 60 min. For sustained intake, trans-resveratrol was given in the chow (0.04% w/w corresponding to 40 mg/kg/day), and plasma and the organs were collected after 3 months of this resveratrol diet. We found that trans-resveratrol-3-O-glucuronide and resveratrol-3-sulfate were the main metabolites found after acute intake, and free trans-resveratrol (in the brain and heart) and dihydroresveratrol derivatives were found after sustained administration CONCLUSIONS: Our results show notable differences between acute and sustained administration of trans-resveratrol and distribution of trans-resveratrol and its metabolites in mouse heart, brain, and liver. The results suggest a strategy for development of galenic forms of resveratrol.

Tissue Distribution of trans-Resveratrol and Its Metabolites after Oral Administration in Human Eyes

Purpose. This study was performed to measure the concentration of trans-resveratrol and its three metabolites in human eyes. Methods. The patients who underwent pars plana vitrectomy for rhegmatogenous retinal detachment were included. The participants were orally given trans-resveratrol-based supplement (Longevinex®). A suitable amount of conjunctiva, aqueous humor, and vitreous humor were obtained during the operation. High-performance liquid chromatography (HPLC) with mass spectrometry (LC/MS/MS) was used to detect the concentration of trans-resveratrol and its three metabolites in the various samples. Results. The average concentration of resveratrol in the conjunctiva was 17.19 ± 15.32 nmol/g (mean ± SD). The concentration of resveratrol in the aqueous humor was close to the limit of detection, but its metabolites could be quantified. The concentrations of resveratrol metabolites in the aqueous humor can be detected. In the vitreous humor, the average concentration of resveratrol-3-O-sulfate was 62.95 ± 41.97 nmol/L. The sulfate conjugations of resveratrol were recovered in the conjunctiva, aqueous humor, and vitreous humor. Conclusions. Resveratrol and its three metabolites can be detected in the ocular tissues after oral administration. Although the concentration of parent resveratrol was low in the eyes, its metabolites could be detected and may have a role in the treatment of ocular diseases.

Members of the Oral Microbiota Are Associated with IL-8 Release by Gingival Epithelial Cells in Healthy Individuals

The triggers for the onset of oral diseases are still poorly understood. The aim of this study was to characterize the oral bacterial community in healthy humans and its association with nutrition, oral hygiene habits, and the release of the inflammatory marker IL-8 from gingival epithelial cells (GECs) with and without stimulation by bacterial endotoxins to identify possible indicator operational taxonomic units (OTUs) associated with inflammatory marker status. GECs from 21 healthy participants (13 females, 8 males) were incubated with or without addition of bacterial lipopolysaccharides (LPSs), and the oral microbiota was profiled using 16S rRNA gene-targeted sequencing. The basal IL-8 release after 6 h was between 9.9 and 98.2 pg/ml, and bacterial communities were characteristic for healthy oral microbiota. The composition of the oral microbiota was associated with basal IL-8 levels, the intake of meat, tea, white wine, sweets and the use of chewing gum, as well as flossing habits, allergies, gender and body mass index. Additionally, eight OTUs were associated with high basal levels of IL-8 and GEC response to LPS, with high basal levels of IL-8, and 1 with low basal levels of IL8. The identification of indicator bacteria in healthy subjects with high levels of IL-8 release is of importance as they may be promising early warning indicators for the possible onset of oral diseases.

Lactobacillus plantarum NCU116 Attenuates Cyclophosphamide-Induced Immunosuppression and Regulates Th17/Treg Cell Immune Responses in Mice

The balance of T helper cells 17 (Th17)/regulatory T cells (Treg) plays a key role in maintaining a normal immune response. It is well-known that cyclophosphamide (CTX) applied at high dose often damages the immune system by inhibiting immune cell proliferation. In this study, the immunomodulating effects of Lactobacillus plantarum NCU116 in CTX-induced immunosuppression mice were investigated. Results showed that the levels of cytokines interleukin (IL)-17 and IL-21 were significantly increased after 10 days of treatment with a high dose of NCU116 (46.92 ± 4.28 and 119.92 ± 10.89, respectively) compared with the model group (36.20 ± 2.63, 61.00 ± 6.92, respectively), and the levels of cytokines IL-23 and TGF-β3 of the three NCU116 treatment groups were significantly higher than that of the model group (90.48 ± 6.33 and 140.45 ± 14.30, respectively) (p < 0.05) and close to 62 and 69% of the normal group's level (140.98 ± 14.74 and 266.95 ± 23.11, respectively) at 10 days. The bacterium was also found to increase the expression levels of Th17 immune response and Treg immune response specific transcription factors RORγt and Foxp3. In addition, the bacterium significantly increased the number of CD4(+)T cells and dendrtic cells (DCs) and up-regulated mRNA expression of Toll-like receptors (TLRs). These findings demonstrated that NCU116 has the potential ability to enhance intestinal mucosa immunity and regulate the Th17/Treg balance, which may be attributed to the TLR pathway in DCs.