Systemic treatment with resveratrol reduces the progression of experimental periodontitis and arthritis in rats

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

Resveratrol for preventing medication-related osteonecrosis of the jaws in rats

This study evaluated the effect of resveratrol (RES) on the prevention of medication-related osteonecrosis of the jaws (MRONJ) in ovariectomized (OVX) rats treated with zoledronate (ZOL). Fifty rats were distributed in five groups: SHAM (n = 10): non-ovariectomy + placebo; OVX (n = 10):ovariectomy + placebo; OVX + RES (n = 10):ovariectomy + resveratrol; OVX + ZOL (n = 10):ovariectomy + placebo + zoledronate; and OVX + RES + ZOL (n = 10):ovariectomy + resveratrol + zoledronate. The mandibles left sides were analyzed with micro-CT, histomorphometry, and immunohistochemistry. On the right side, bone markers gene expression was analyzed by qPCR. ZOL increased the percentage of necrotic bone and reduced the neo-formed bone compared to groups not receiving ZOL (p < 0.05). RES impacted the tissue healing pattern in OVX + ZOL + RES, reduced inflammatory cell infiltrate, and improved bone formation in the extraction site. Osteoblasts, alkaline phosphatase (ALP)-, and osteocalcin (OCN)-immunoreactive cells were lower in OVX-ZOL than in SHAM, OVX, and OVX-RES. The OXV-ZOL-RES had fewer osteoblasts and ALP- and OCN-cells than the SHAM and OVX-RES. The tartrate-resistant acid phosphatase (TRAP)-positive cells were reduced in the presence of ZOL (p < 0.05), while the TRAP mRNA levels increased with ZOL treatment, with or without resveratrol, compared with the other groups (p < 0.05). RES alone increased superoxide dismutase levels compared to OVX + ZOL and OVX + ZOL + RES (p < 0.05). In conclusion, resveratrol reduced the tissue impairment severity induced by ZOL; however, it could not prevent the occurrence of MRONJ.

Resveratrol May Reduce the Degree of Periodontitis by Regulating ERK Pathway in Gingival-Derived MSCs

Gingival-derived mesenchymal stem cells (GMSCs) have strong self-renewal, multilineage differentiation, and immunomodulatory properties and are expected to be applied in anti-inflammatory and tissue regeneration. However, achieving the goal of using endogenous stem cells to treat diseases and even regenerate tissues remains a challenge. Resveratrol is a natural compound with multiple biological activities that can regulate stem cell immunomodulation when acting on them. This study found that resveratrol can reduce inflammation in human gingival tissue and upregulate the stemness of GMSCs in human gingiva. In cell experiments, it was found that resveratrol can reduce the expression of TLR4, TNFα, and NFκB and activate ERK/Wnt crosstalk, thereby alleviating inflammation, promoting the proliferation and osteogenic differentiation ability of GMSCs, and enhancing their immunomodulation. These results provide a new theoretical basis for the application of resveratrol to activate endogenous stem cells in the treatment of diseases in the future.

The Anti-Inflammatory and Immunomodulatory Activities of Natural Products to Control Autoimmune Inflammation

Inflammation is an integral part of autoimmune diseases, which are caused by dysregulation of the immune system. This dysregulation involves an imbalance between pro-inflammatory versus anti-inflammatory mediators. These mediators include various cytokines and chemokines; defined subsets of T helper/T regulatory cells, M1/M2 macrophages, activating/tolerogenic dendritic cells, and antibody-producing/regulatory B cells. Despite the availability of many anti-inflammatory/immunomodulatory drugs, the severe adverse reactions associated with their long-term use and often their high costs are impediments in effectively controlling the disease process. Accordingly, suitable alternatives are being sought for these conventional drugs. Natural products offer promising adjuncts/alternatives in this regard. The availability of specific compounds isolated from dietary/medicinal plant extracts have permitted rigorous studies on their disease-modulating activities and the mechanisms involved therein. Here, we describe the basic characteristics, mechanisms of action, and preventive/therapeutic applications of 5 well-characterized natural product compounds (Resveratrol, Curcumin, Boswellic acids, Epigallocatechin-3-gallate, and Triptolide). These compounds have been tested extensively in animal models of autoimmunity as well as in limited clinical trials in patients having the corresponding diseases. We have focused our description on predominantly T cell-mediated diseases, such as rheumatoid arthritis, multiple sclerosis, Type 1 diabetes, ulcerative colitis, and psoriasis.

Resveratrol Ameliorates Fibrosis in Rheumatoid Arthritis-Associated Interstitial Lung Disease via the Autophagy-Lysosome Pathway

Interstitial lung disease associated with rheumatoid arthritis (RA-ILD) can lead to interstitial fibrosis and even lung failure as a complication of rheumatoid arthritis (RA), and there is currently no effective treatment and related basic research. Studies have found that resveratrol (Res) can improve the progression of RA by regulating autophagy, and increasing evidence supports the connection between autophagy and common interstitial lung disease (ILD). We explored changes in autophagy levels in fibrotic lungs in RA-ILD and found that the level of autophagy is enhanced in the early stage but inhibited in the late stage. However, resveratrol treatment improved the level of autophagy and reversed the inhibition of autophagy, and attenuated fibrosis. We created corresponding cell models that exhibited the same phenotypic changes as animal models; under the effect of resveratrol, the level of fibrosis changed accordingly, and the fusion process of lysosomes and autophagosomes in autophagy was liberated from the inhibition state. Resveratrol effects were reversed by the addition of the late autophagy inhibitor chloroquine. These results suggest that resveratrol attenuates pulmonary fibrosis, increases autophagic flux, and modulates the autophagy-lysosome pathway, and particularly it may work by improving the formation of autophagic lysosomes, which may be an effective treatment for induced RA-ILD.

Grape Pomace Polyphenols as a Source of Compounds for Management of Oxidative Stress and Inflammation—A Possible Alternative for Non-Steroidal Anti-Inflammatory Drugs?

Flavonoids, stilbenes, lignans, and phenolic acids, classes of polyphenols found in grape pomace (GP), were investigated as an important alternative source for active substances that could be used in the management of oxidative stress and inflammation. The benefic antioxidant and anti-inflammatory actions of GP are presented in the literature, but they are derived from a large variety of experimental in vitro and in vivo settings. In these in vitro works, the decrease in reactive oxygen species, malondialdehyde, and thiobarbituric acid reactive substances levels and the increase in glutathione levels show the antioxidant effects. The inhibition of nuclear factor kappa B and prostaglandin E2 inflammatory pathways and the decrease of some inflammatory markers such as interleukin-8 (IL-8) demonstrate the anti-inflammatory actions of GP polyphenols. The in vivo studies further confirmed the antioxidant (increase in catalase, superoxide dismutase and glutathione peroxidase levels and a stimulation of endothelial nitric oxide synthase -eNOS gene expression) and anti-inflammatory (inhibition of IL-1𝛼, IL-1β, IL-6, interferon-𝛾, TNF-α and C-reactive protein release) activities. Grape pomace as a whole extract, but also different individual polyphenols that are contained in GP can modulate the endogenous pathway responsible in reducing oxidative stress and chronic inflammation. The present review analyzed the effects of GP in oxidative stress and inflammation, suggesting that it could become a valuable therapeutic candidate capable to reduce the aforementioned pathological processes. Grape pomace extract could become an adjuvant treatment in the attempt to reduce the side effects of the classical anti-inflammatory medication like non-steroidal anti-inflammatory drugs (NSAIDs).

Mitochondrial Dysfunction and Oxidative Stress in Rheumatoid Arthritis

Control of excessive mitochondrial oxidative stress could provide new targets for both preventive and therapeutic interventions in the treatment of chronic inflammation or any pathology that develops under an inflammatory scenario, such as rheumatoid arthritis (RA). Increasing evidence has demonstrated the role of mitochondrial alterations in autoimmune diseases mainly due to the interplay between metabolism and innate immunity, but also in the modulation of inflammatory response of resident cells, such as synoviocytes. Thus, mitochondrial dysfunction derived from several danger signals could activate tricarboxylic acid (TCA) disruption, thereby favoring a vicious cycle of oxidative/mitochondrial stress. Mitochondrial dysfunction can act through modulating innate immunity via redox-sensitive inflammatory pathways or direct activation of the inflammasome. Besides, mitochondria also have a central role in regulating cell death, which is deeply altered in RA. Additionally, multiple evidence suggests that pathological processes in RA can be shaped by epigenetic mechanisms and that in turn, mitochondria are involved in epigenetic regulation. Finally, we will discuss about the involvement of some dietary components in the onset and progression of RA.

Neutrophils Orchestrate the Periodontal Pocket

The subgingival biofilm attached to tooth surfaces triggers and maintains periodontitis. Previously, late-onset periodontitis has been considered a consequence of dysbiosis and a resultant polymicrobial disruption of host homeostasis. However, a multitude of studies did not show "healthy" oral microbiota pattern, but a high diversity depending on culture, diets, regional differences, age, social state etc. These findings relativise the aetiological role of the dysbiosis in periodontitis. Furthermore, many late-onset periodontitis traits cannot be explained by dysbiosis; e.g. age-relatedness, attenuation by anti-ageing therapy, neutrophil hyper-responsiveness, and microbiota shifting by dysregulated immunity, yet point to the crucial role of dysregulated immunity and neutrophils in particular. Furthermore, patients with neutropenia and neutrophil defects inevitably develop early-onset periodontitis. Intra-gingivally injecting lipopolysaccharide (LPS) alone causes an exaggerated neutrophil response sufficient to precipitate experimental periodontitis. Vice versa to the surplus of LPS, the increased neutrophil responsiveness characteristic for late-onset periodontitis can effectuate gingiva damage likewise. The exaggerated neutrophil extracellular trap (NET) response in late-onset periodontitis is blameable for damage of gingival barrier, its penetration by bacteria and pathogen-associated molecular patterns (PAMPs) as well as stimulation of Th17 cells, resulting in further neutrophil activation. This identifies the dysregulated immunity as the main contributor to periodontal disease.

The pharmacological assessment of resveratrol on preclinical models of rheumatoid arthritis through a systematic review and meta-analysis

Resveratrol/RES (3,5,4'-trihydroxy-trans-stilbene) is a natural compound found in many food items and red wine, which exhibits pleiotropic biological effects. Several preclinical studies evaluating the efficacy of RES in animal models of rheumatoid arthritis (RA) have been conducted, but the diversity of the experimental conditions and of their outcomes preclude definitive conclusions about RES's efficacy. We, therefore, performed a meta-analysis to assess its efficacy in mitigating experimental RA. We searched three databases until January 2021 and used the random-effects model for drawing inferences. Eighteen studies involving 544 animals were used in this study. Pooled analysis showed that experimental RA causes paw swelling (Hedge's g = 9.823, p = 0.000), increases polyarthritis score and arthritis index, and RES administration reduces paw volume (Hedge's g = -2.550, p = 0.000), polyarthritis score, and arthritis index besides amelioration in the histopathological score and cartilage loss. RA is accompanied by increased oxidative stress due to high malondialdehyde (MDA) level (p < 0.001) and low superoxide dismutase (SOD) activity (p = 0.002), and RES reduced MDA level (p < 0.001) and increased SOD activity (p < 0.001). Experimental RA exhibited an increase in pro-inflammatory cytokines viz. tumor necrosis factor (TNF)-α (p < 0.001), interleukin (IL)-6 (p = 0.002), and IL-1 (p < 0.001); however, insufficient quantitative data precluded us from assessing changes in the anti-inflammatory cytokine, IL-10. In experimental RA, RES decreased TNF-α (p < 0.001), IL-6 (p < 0.001) and IL-1 (p = 0.001) and increased IL-10. This meta-analysis suggests that RES can be a clinically effective therapy for RA, pending clinical trials.

Effect of red wine or its polyphenols on induced apical periodontitis in rats

AIM

To evaluate the effect of red wine consumption or its polyphenols on the inflammation/resorption processes associated with apical periodontitis in rats.

METHODOLOGY

Thirty-two three-month-old Wistar rats had apical periodontitis induced in four first molars and were then arranged into four groups: control (C)-rats with apical periodontitis; wine (W)-rats with apical periodontitis receiving 4.28 ml/kg of red wine; resveratrol+quercetin (R+Q)-rats with apical periodontitis receiving 4.28 ml/kg of a solution containing 1.00 mg/L of quercetin and 0.86 mg/L of resveratrol and alcohol (ALC)-rats with apical periodontitis receiving the alcoholic dose contained in the wine. The oral gavage treatments were administered daily, from day 0 to day 45. On the 15th day, apical periodontitis was induced, and on the 45th day, the animals were euthanized. Histological, immunohistochemical (RANKL, OPG, TRAP, IL-10, TNF-⍺ and IL-1β) and micro-computed tomography for bone resorption analysis were performed in the jaws. The Kruskal-Wallis with Dunn's test was performed for nonparametric data, and the anova with Tukey's test for parametric data, p < .05.

RESULTS

The median score of the inflammatory process was significantly lower in the R+Q group (1) compared to the C (2) (p = .0305) and ALC (3) (p = .0003) groups, and not different from the W (1.5) group. The immunolabeling for OPG was significantly higher in the R+Q group (p = .0054) compared to all groups; the same was observed for IL-10 (p = .0185), different from groups C and ALC. The R+Q group had the lowest TRAP cell count (p < .0001), followed by the W group, both inferior to C and ALC groups. The lowest bone resorption value was in the R+Q group (0.50mm³  ± 0.21mm³ ), significantly lower (p = .0292) than the C group (0.88mm³  ± 0.10mm³ ). The W group (0.60 mm³  ± 0.25 mm³ ) and R+Q group had less bone resorption compared to the ALC group (0.97 mm³  ± 0.22 mm³ ), p = .0297 and p = .0042, respectively.

CONCLUSION

Red wine administration to rats for 15 days before induction of apical periodontitis decreased inflammation, TRAP marking and periapical bone resorption compared to alcohol. Resveratrol-quercetin administration reduced the inflammatory process in apical periodontitis, periapical bone resorption, and altered the OPG, IL-10 and TRAP expression compared to C and ALC groups.

Luffa operculata at a late period of gestation dysregulates melatonin and cytokines interfering with weight of dams and their male offspring

ETHNOPHARMACOLOGICAL RELEVANCE

The tea made with the fruits of Luffa operculata (L.) Cogn. (Cucurbitaceae; EBN) is popularly used as abortive.

AIM OF THE STUDY

The present work aimed at accessing how the exposition of female Wistar rats to 1.0 mg/kg of EBN (experimental group, EG), or distilled water (control group, CG), by gavage, at gestational days (GD) 17-21 interfered with the reproductive performance, and with dams' behavior after weaning.

MATERIALS AND METHODS

At post-natal day 2 (PND2), the number of male and female pups was evaluated, as well as their weight. After weaning (PND21), dams were euthanized, and their liver and kidneys were removed for histological and biochemical analyses, while the blood was used in the evaluation of cytokines IL-1α, IL-1β, IL-6 and TNF-α, corticosterone, adrenocorticotrophic hormone, melatonin, AST, ALT and creatinine levels.

RESULTS AND DISCUSSION

Dams that were treated with EBN showed an anxiety-like behavior, weight loss at the end of gestation and weight gain at weaning, accompanied with a significant decrease in pro-inflammatory cytokines and in the melatonin level. No significant histological or biochemical alterations have occurred in the liver or kidneys. The number of female pups was significantly higher in the EG. The male pups showed weight gain at PND60.

CONCLUSION

The presence of cucurbitacins is probably involved in the dysregulations that were found, due to their polycyclic steroid triterpene structure.

The 15-Months Clinical Experience of SARS-CoV-2: A Literature Review of Therapies and Adjuvants

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for the coronavirus disease of 2019 (COVID-19) that emerged in December 2019 in Wuhan, China, and rapidly spread worldwide, with a daily increase in confirmed cases and infection-related deaths. The World Health Organization declared a pandemic on the 11th of March 2020. COVID-19 presents flu-like symptoms that become severe in high-risk medically compromised subjects. The aim of this study was to perform an updated overview of the treatments and adjuvant protocols for COVID-19.

METHODS

A systematic literature search of databases was performed (MEDLINE PubMed, Google Scholar, UpToDate, Embase, and Web of Science) using the keywords: "COVID-19", "2019-nCoV", "coronavirus" and "SARS-CoV-2" (date range: 1 January 2019 to 31st October 2020), focused on clinical features and treatments.

RESULTS

The main treatments retrieved were antivirals, antimalarials, convalescent plasma, immunomodulators, corticosteroids, anticoagulants, and mesenchymal stem cells. Most of the described treatments may provide benefits to COVID-19 subjects, but no one protocol has definitively proven its efficacy.

CONCLUSIONS

While many efforts are being spent worldwide in research aimed at identifying early diagnostic methods and evidence-based effective treatments, mass vaccination is thought to be the best option against this disease in the near future.

Molecular insights into phytochemicals exhibiting anti-arthritic activity: systematic review : John Di Battista

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease with an unclear etiology causing severe inflammation, joint pain, and destruction that increases the chance of disability over time. Dysregulation of various immune signaling cascades regulates the formation of synovial hyperplasia and pannus formation. Imbalance in cytokine levels, predominantly proinflammatory cytokines like TNF-α, IL-1, IL-6, IL-17, and IL-12p70 profoundly influences the disease's pathogenesis. Even though various strategies are adopted to treat arthritis, their side effects and cost limit their usage. This review discusses the multiple pathways involved in the pathogenesis of rheumatoid arthritis, provides a systematic analysis of various phytochemicals, and discusses their potential molecular targets in RA treatment.

METHODS

The literature mining was done from scientific databases such as PubMed, Europe PMC, Web of Science, Scopus, etc. The terminologies used for literature mining were Rheumatoid arthritis, phytochemicals, cell signaling pathways, molecular mechanism, etc. RESULTS: NF-κB, MAPKs, and JAK-STAT are the key pathways potentially targeted for RA treatment. However, specific susceptible pathways and potential targets remain unexplored. Besides, the phytochemicals remain an immense source to be exploited for the effective treatment of RA, overcoming the demerits of the conventional strategies. Various in vitro and in vivo findings suggest that polyphenols and flavonoids effectively treat RA conditions overcoming the demerits, such as limitations in usage and toxicity. The phytochemicals should be explored in par with the pathological mechanisms with all the available targets to determine their therapeutic efficacy. Through the established therapeutic efficacy, phytochemicals can help developing therapeutics that are safe and efficacious for RA treatment.

Influence of immunosuppression on the progression of experimental periodontitis and on healthy periodontal tissue: A rat in vivo study

Background. The potent anti-inflammatory and immunosuppressive properties of glucocorticoids (GCs) might influence the progression of some disorders, such as periodontitis. Hence, this study aimed to investigate the influence of dexamethasone (DEX) on the alveolar bone loss (ABL) of healthy and periodontally compromised molars in rats.

Methods. Thirty male rats were randomly assigned to two groups: physiological saline solution (PSS) and DEX. The animals received subcutaneous injections of either 0.5 mL of PSS) (group PSS) or 2 mg/kg of DEX (group DEX) from one day before experimental periodontitis (EP) induction until euthanasia. EP was induced through ligature placement around the mandibular lower first molars at day 0. Contralateral molars remained unligated. Ten animals per period were euthanized on days 3, 7, and 14. Morphometric analysis was performed to access the ABL. Data were statistically analyzed with ANOVA followed by post hoc Tukey tests (P ≤ 0.05).

Results. Higher ABL was observed in both groups on days 7 and 14 than on day 3 (P ≤ 0.05). Concerning periodontitis, higher ABL was observed in group DEX on days 3, 7, and 14 days than group PSS at the same time intervals (P ≤ 0.05). Also, even in the contralateral unligated molars, group DEX exhibited higher ABL on days 3, 7, and 14 days than group PSS at the same time intervals (P ≤ 0.05).

Conclusions. Collectively, it can be concluded that DEX aggravates EP and induces spontaneous ABL in the healthy periodontium.

Inhibitory Effect of Resveratrol on Candida albicans Biofilm Formation

Candida albicans is the primary candidiasis-causing fungal pathogen in humans, and one of its most important virulence factors is the ability to form biofilms. Moreover, these biofilms are often resistant to antifungal agents, so there is a need to develop alternative elimination strategies and therapeutic agents for such infections. The antifungal activity of resveratrol, a phytoalexin polyphenolic compound, impairs the morphological transition of C. albicans under various hypha-inducing conditions and inhibits growth of the yeast-form and mycelia. The purpose of this study was to investigate the effect of resveratrol against C. albicans biofilm formation. The developmental, sustained, and mature stages of biofilm formation were affected or inhibited by resveratrol. Exposure to resveratrol at the developmental stage inhibited growth of C. albicans in a dose-dependent manner. A >30% reduction was observed in sustained biofilm growth in the presence of 200 μg/ml resveratrol in comparison with in its absence. In terms of disruption of matured biofilm, 6.25-100 μg/ml resveratrol significantly reduced cell viability of C. albicans compared with in a control sample (p<0.05). The present results indicate that resveratrol has the potential to serve as an anti-Candida treatment and preventive tool which functions by inhibiting existing or under-forming C. albicans biofilms.

Resveratrol enhances bone formation by modulating inflammation in the mouse periodontitis model

OBJECTIVE

To evaluate the effect of resveratrol on periodontal bone regeneration after local delivery and to determine its effect on inflammatory mediators.

BACKGROUND

Resveratrol is considered an anti-inflammatory polyphenolic stilbene involved in the modulation of inflammation.

MATERIALS AND METHODS

Periodontitis was induced in mouse molars using a 5-day ligature model followed by the left second molar extraction and 50 µM resveratrol treatment for 1 and 2 weeks. We then examined specimens treated for 1 week histologically and with immunostaining. Microfocus-computed tomography (micro-CT) was used to examine the bone volume formation.

RESULTS

After 1 week of treatment, proinflammatory cytokine levels (TNF-alpha and IL6), cells exhibiting neutrophil and macrophage marker (MPO), cell proliferation marker (Ki67), and preosteoblastic marker (RUNX2) reactivity decreased in the resveratrol-treated specimens compared to the control group. In contrast, we observed a higher number of CD31-, F4/80-, and osteocalcin- (OCN-) positive cells in the resveratrol-treated specimens. After 2 weeks, micro-CT confirmed an increased bone mass in the region of the extraction socket in the resveratrol-treated group.

CONCLUSION

After 1 week, the resveratrol-treated specimens revealed evidence of inflammation modulation compared to the control group. These data suggest that resveratrol not only affects inflammation control but also is useful for treating periodontitis-related tissue defects and bone regeneration.

SARS-CoV-2 Disease Adjuvant Therapies and Supplements Breakthrough for the Infection Prevention

The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a high-risk viral agent involved in the recent pandemic stated worldwide by the World Health Organization. The infection is correlated to a severe systemic and respiratory disease in many cases, which is clinically treated with a multi-drug pharmacological approach. The purpose of this investigation was to evaluate through a literature overview the effect of adjuvant therapies and supplements for the SARS-CoV-2 infection. The research has analyzed the advantage of the EK1C4, by also assessing the studies on the resveratrol, vitamin D, and melatonin as adjuvant supplements for long hauler patients' prognosis. The evaluated substances reported important benefits for the improvement of the immune system and as a potential inhibitor molecules against SARS-CoV-2, highlighting the use of sartans as therapy. The adjuvant supplements seem to create an advantage for the healing of the long hauler patients affected by chronic symptoms of constant chest and heart pain, intestinal disorders, headache, difficulty concentrating, memory loss, and tachycardia.

Design, synthesis, and evaluation of mono-carbonyl analogues of curcumin (MCACs) as potential antioxidants against periodontitis

BACKGROUND AND OBJECTIVE

The application of curcumin is limited by its instability. Mono-carbonyl analogues of curcumin (MCACs) are structurally stable, yet the intermediate bridging ketones in their skeletons account for increased toxicity. This study aimed to synthesize and screen MCACs that exhibit low cytotoxicity and high antioxidant ability, and the effects of MCACs on experimental periodontitis were also investigated.

MATERIALS AND METHODS

The cytotoxicity of MCACs on MC3 T3-E1 was determined by MTT assay. The antioxidant capacity was investigated by the cell viability against H₂ O₂ -induced damage and the level of reactive oxygen species (ROS) and malondialdehyde (MDA). The localization and protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was detected by immunofluorescence and western blot, respectively. In addition, MCAC was intragastrically administrated in rats with ligature-induced experimental periodontitis. The effects were assessed by bone resorption, as well as the immunohistology staining of inflammatory and oxidative stress markers.

RESULTS

MCACs with cyclopentanone and containing pyrone showed lower toxicity than natural curcumin were synthesized (1A-10A, 1H-10H), among which, 1A exhibited the most potent cytoprotective effect against H₂ O₂ -induced damage. Such effects could be explained by the reduced MDA and ROS level, possibly through the nucleus translocation of Nrf2 and the induction of HO-1. Micro-CT results further indicated that 1A significantly reduced bone loss, along with an increased level of Nrf2 and HO-1, and decreased TNF-α and IL-1β.

CONCLUSION

The present study has synthesized a novel antioxidant MCAC 1A with good biosafety and stability. MCAC 1A could serve as a host response modulator with preventive and protective effects on periodontitis.

TNFα expression by Porphyromonas gingivalis-stimulated macrophages relies on Sirt1 cleavage

OBJECTIVE

Periodontitis is one the most common chronic inflammatory conditions, resulting in destruction of tooth-supporting tissues and leading to tooth loss. Porphyromonas gingivalis activates host macrophages to secrete pro-inflammatory cytokines and elicit tissue damage, in part by inducing NF-kappa-B transactivation. Since NFκB transactivation is negatively regulated by the Nicotinamide adenine dinucleotide (NAD)-dependent deacetylase enzyme Sirt1, we sought to assess if RAW264.7 macrophages exposed to P. gingivalis demonstrate impaired Sirt1 activity, to ultimately induce a pro-inflammatory response.

METHODS

RAW264.7 macrophages were incubated with heat- killed P. gingivalis for 2, 4, 8, and 24 h. Stimulated RAW264.7 were assessed for TNFα expression via PCR, ELISA, and ChIP analysis. Following the activation of RAW264.7 macrophages, immunoblot analysis was executed to detect modifications in Sirt1 and the NFκB subunit RelA that is essential for NFκB transcriptional activity.

RESULTS

TNFα expression was elevated 4 h after exposure to P. gingivalis. ChIP confirmed that RelA was enriched in the mouse TNFα promoter 4 h following stimulation, which correlated with the increased TNFα mRNA levels. Preceding TNFα expression, we detected Phosphoserine 536 and acetylated lysine 310 of RelA after 2 hours exposure with P. gingivalis. Moreover, reduced Sirt1 activity was associated with its cleavage in RAW264.7 protein extracts, after 2 hours of P. gingivalis exposure. Blocking TLR2/4 signaling prevented Sirt1 cleavage, loss of deacetylase activity, and TNFα secretion, while co-administering CA074Me (a cathepsin B inhibitor) with P. gingivalis reduced RelA promoter enrichment, resulting in impaired TNFα expression.

CONCLUSIONS

Together, the results suggest that P. gingivalis induces TNFα expression, at least in part, by enhancing cleavage of Sirt1 via a TLR-dependent signaling circuit.

Autophagy Activation by Resveratrol Reduces Severity of Experimental Rheumatoid Arthritis

SCOPE

Previous work reported that dietary supplementation with resveratrol lowers synovial hyperplasia, inflammatory and oxidative damage in an antigen-induced arthritis (AIA) model. Here, it is investigated whether resveratrol can regulate the abnormal synovial proliferation by inducing autophagy and controlling the associated inflammatory response.

METHODS AND RESULTS

Animals treated with resveratrol 8 weeks before AIA induction show the highest significant signal for microtubule-associated protein 1 light chain 3 by confocal microscopy. Besides, resveratrol significantly reduces p62 expression, but it does not increase the signal of beclin-1. Also, active caspase-3 expression, as well as poly(ADP-ribose) polymerase, is upregulated in the AIA group, and is significantly reduced in resveratrol-treated AIA group. Resveratrol also mitigates angiopoietin-1 and vascular endothelial growth factor signals. Finally, resveratrol significantly reduces the serum levels of IL-1β, C reactive protein, and prostaglandin E2, as well as nuclear factor κB synovial tissue expression, which shows a significant correlation with p62 expression.

CONCLUSION

Dietary supplementation with resveratrol induces the noncanonical autophagy pathway and limits the cross-talk with inflammation, which in consequence modulates the synovial hyperplasia. Preventive strategies that incorporate dietary intervention with resveratrol may offer a potential therapeutic alternative to drugs to influence the risk of rheumatoid arthritis and influence its course.

A mechanistic insight of phytoestrogens used for Rheumatoid arthritis: An evidence-based review

Assessment of the potential therapeutic benefits offered by naturally occurring phytoestrogens necessitate inspection of their potency and sites of action in impeding the chronic, systemic, autoimmune, joint destructing disorder Rheumatoid arthritis (RA). Possessing structural and functional similarity with human estrogen, phytoestrogen promisingly replaces the use of hormone therapy in eradicating RA symptoms with their anti-inflammatory, anti-oxidative, anti-proliferative, anti-angiogenesis, immunomodulatory, joint protection properties abolishing the harmful side effects of synthetic drugs. Scientific evidences revealed that use of phytoestrogens from different chemical categories including flavonoids, alkaloids, stilbenoids derived from different plant species manifest beneficial effects on RA through various cellular mechanisms including suppression of pro-inflammatory cytokines in particular tumor necrosis factor (TNF-α), interleukin(IL-6) and nuclear factor kappa B (NF-κB) and destructive metalloproteinases, inhibition of oxidative stress, suppressing inflammatory signalling pathways, attenuating osteoclastogenesis ameliorating cartilage degradation and bone erosion. This review summarizes the evidences of different phytoestrogen treatment and their pharmacological mechanisms in both in vitro and in vivo studies along with discussing clinical evaluations in RA patients showing phytoestrogen as a promising agent for RA therapy. Further investigations and more clinical trials are mandatory to clarify the utility of these plant derived compounds in RA prevention and in managing oestrogen deficient diseases in patients.

Nutritional Pearls: Diet and Rheumatoid Arthritis

Various studies have investigated the effect of diet on rheumatoid arthritis (RA) as a complimentary treatment along with standard drug therapy. Various types of diet have been investigated. Fasting, the Mediterranean diet, the Cretan Mediterranean diet, vegetarian diet, an anti-inflammatory diet and the use of various specific food substances have been in the focus of research interest. The relationship of obesity with disease activity in RA has also been investigated. A period of fasting followed by Mediterranean diet, the Cretan Mediterranean diet and an anti-inflammatory diet have been found to have a beneficial effect on disease activity in RA. Obesity has been found to be associated with increased disease activity in RA. However, weight loss appears to be related to increased mortality in RA. The use of flavonoids, resveratrol and curcumin may have a beneficial effect in RA. It appears that diet may aid in RA management as a complimentary factor to standard drug treatment.

Micronutrients: Essential Treatment for Inflammatory Arthritis?

PURPOSE OF REVIEW

Synovial inflammation is characteristic of inflammatory chronic arthropathies and can cause progressive articular damage, chronic pain, and functional loss. Scientific research has increasingly focused on investigating anti-inflammatory micronutrients present in fruits, vegetables, spices, seeds, tea, and wine. This review aims to examine the anti-inflammatory effect of polyphenols (phytonutrients present in plants) and other micronutrients described in randomized clinical trials conducted in patients with chronic inflammatory arthropathies.

RECENT FINDINGS

There is an increasing evidence that differences in micronutrient intake might play an essential role in pathogenesis, therapeutic response, and remission of synovitis. Randomized clinical trials with specific micronutrient- or nutrient-enriched food intake show improvement of symptoms and modulation of both pro- and anti-inflammatory mediators. We found convincing evidence of the anti-inflammatory effect of several micronutrients in arthritis symptoms and inflammation. Although in clinical practice nutritional recommendations to patients with chronic joint inflammation are not consistently prescribed, the addition of these nutrients to day-to-day eating habits could potentially change the natural history of inflammatory arthritis. Future research is needed for a consensus on the specific nutritional recommendations for patients with chronic synovial inflammation.

Resveratrol and insulin association reduced alveolar bone loss and produced an antioxidant effect in diabetic rats

BACKGROUND

The present investigation studied the effects of systemic administration of resveratrol (RSV) on the development of experimental periodontitis (EP) and on the release of markers of inflammation, bone metabolism, and oxidative stress in diabetic rats.

METHODS

Seventy-five male rats were divided into five groups: DM+PLAC: Diabetes Mellitus + placebo solution; DM+INS: DM + insulin therapy; DM+RSV: DM + RSV; DM+RSV+INS: DM + RSV and insulin; NDM: non-diabetic. Streptozotocin was used to induce DM and EP was induced by the placement of a ligature at the fist mandibular and the second maxillary molars. Euthanasia occurred 30 days after the initiation of the study and mandible specimens were subjected for morphometric analysis of bone level. Gingival tissues from mandibular molars were collected for quantification of inflammatory and oxidative stress markers by multiplex assay system and ELISA assay, respectively. Maxillary gingival tissues were processed for real-time polymerase chain reaction (real-time PCR) assessment of markers of bone metabolism and oxidative stress.

RESULTS

Morphometric analysis revealed greater bone loss in DM+PLAC and DM+INS in comparison to the other treatments (P < 0.05). RSV used in conjunction with INS reduced the levels of interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN-γ) and superoxide dismutase 1 (SOD) (P < 0.05). RSV alone reduced nicotinamide adenine dinucleotide phosphatase oxidase (NADPH oxidase) levels, in comparison to DM+INS and DM+RSV+INS (P < 0.05). All treatments upregulated mRNA levels for osteoprotegerin (OPG) in comparison to PLAC (P < 0.05). Sirtuin 1 (SIRT) mRNA levels were lower in PLAC when compared to DM+RSV, DM+RSV+INS and NDM (P < 0.05).

CONCLUSION

RSV reduced the progression of EP and the levels of NADPH oxidase. Co-treatment with RSV and insulin reduced the levels of pro-inflammatory factors (either proteins or mRNA) and increased the levels of SOD. The data also demonstrated that treatment with RSV and INS alone or in combination had beneficial effects on bone loss.

Accelerated ageing profile in inflammatory arthritis is unique and tissue compartment specific

Rheumatoid arthritis is prevalent in more than 1% of the global population, with the highest occurrence between ages 35 and 50, which places a huge burden on the economy. Drug discovery for the prevention of this chronic disease is; therefore, a priority. It is known that subclinical progression of many chronic non-communicable diseases is exacerbated via accelerated ageing, a pro-inflammatory phenotype shift. However, rheumatoid arthritis additionally has significant humoral immune activation, inflammatory signalling-and thus the accelerated ageing profile-may differ from other chronic inflammatory diseases. The current study simulated inflammatory arthritis onset in a collagen-induced arthritis (CIA) rodent model, to characterise the redox and inflammatory profile at the onset of clinical symptoms, in different tissues, in the presence and absence of preventative antioxidant treatment. The data illustrate that an increased free radical level are evident already very early on in RA disease progression. Furthermore, oxidative stress seems to somewhat precede a significant pro-inflammatory state, perhaps due to humoral immune activation. Our data across different compartments further suggest that the compensatory increase in endogenous antioxidant activity is gradually exhausted at a different pace, with the liver showing the first signs of oxidant damage, even before significant evidence exist in circulation. The current data further suggest that preventative antioxidant intervention may have a sparing effect on endogenous antioxidant mechanisms and preserve telomere length to delay disease progression-or at least the accelerated ageing known to exacerbate RA symptoms-although it did not seem to have a significant direct effect on the autoimmune activity.

Prospective, case-controlled study evaluating serum concentration of sirtuin-1 and mannose-binding lectin in patients with and without periodontal and coronary artery disease

Background:

Atherosclerosis and periodontal disease (PD) are inflammatory diseases that have been shown in studies to have a direct association. Mannose-binding lectin (MBL) is an immune system protein that binds to periodontal pathogens favoring phagocytosis. Conversely, increased serum sirtuin-1 (SIRT1) concentration reduces the inflammatory process.

Methods:

This was a prospective, case-controlled study that analyzed serum concentration of biomarkers in patients with or without coronary artery disease (CAD) and PD. A total of 78 patients were evaluated: 20 healthy individuals, 18 patients with CAD, 20 patients with PD, and 20 patients with both PD and CAD. Clinical and laboratory characteristics were analyzed before and after nonsurgical treatment of PD and also at two equivalent times in patients without PD. Serum MBL and SIRT1 concentration were analyzed by enzyme-linked immunosorbent assay.

Results:

A negative correlation was observed between changes in serum concentration of MBL and SIRT1 (r = −0.30; p = 0.006). Comparison between pre- and post-treatment of PD showed a reduction in MBL levels (886.27 ± 906.72 versus 689.94 ± 808.36; p = 0.002) and an increase in SIRT1 values (0.80 ± 1.01 versus 1.49 ± 1.55; p = 0.005) in patients with PD and without CAD. The same result was observed in patients with PD and CAD for MBL and SIRT1, respectively, of 1312.43 ± 898.21 versus 1032.90 ± 602.52 (p = 0.010) and 1.32 ± 1.0 versus 1.82 ± 1.75 (p = 0.044).

Conclusion:

PD treatment reduced MBL serum concentration and increased SIRT1 serum concentration in patients with and without CAD.

An Ayurvedic herbal extract inhibits oral epithelial cell IL-8 responses to host and bacterial agonists

BACKGROUND

Natural products constitute a promising class of therapeutics for the treatment of gingivitis and periodontitis as well as the maintenance of oral health. However, the limited understanding behind their potential mechanisms and modes of action have hampered their incorporation into popular western therapeutics. This in vitro study characterizes an Ayurvedic herbal extract mixture, which has been clinically shown to promote gingival health and homeostasis.

METHODS

Telomerase immortalized gingival keratinocytes (TIGK) were infected with either Fusobacterium nucleatum cell wall, live F. nucleatum, IL-1β or TNF-α for 4 hours with and without the herbal extract. The immunomodulatory effects of the extract on host IL-8 production was measured by ELISA.

RESULTS

It was found that the Ayurvedic herbal extract mixture inhibited gingival epithelial cell IL-8 expression in response to both bacterial and host cytokine agonists. The herbal extract inhibited IL-8 stimulated by F. nucleatum cell wall, live F. nucleatum, IL-1β, and TNF-α in a dose-dependent manner that was not a result of host cell death. Furthermore, the extract showed significantly different ID₅₀ doses demonstrating the differential ability to modulate both stimulated and basal IL-8 levels.

CONCLUSIONS

In vitro investigation of this herbal extract mixture revealed that it has the ability to modulate gingival epithelial cell IL-8 expression in response to stimulation by bacterial components and host pro-inflammatory signals. This data demonstrates that the reduction in the gingival epithelial cell IL-8 response may in part be responsible for the previously reported ability of the Ayurvedic herbal extract mixture to reduce gingivitis in two separate human clinical studies.

Dual Role of Chondrocytes in Rheumatoid Arthritis: The Chicken and the Egg

Rheumatoid arthritis (RA) is one of the inflammatory joint diseases that display features of articular cartilage destruction. The underlying disturbance results from immune dysregulation that directly and indirectly influence chondrocyte physiology. In the last years, significant evidence inferred from studies in vitro and in the animal model offered a more holistic vision of chondrocytes in RA. Chondrocytes, despite being one of injured cells in RA, also undergo molecular alterations to actively participate in inflammation and matrix destruction in the human rheumatoid joint. This review covers current knowledge about the specific cellular and biochemical mechanisms that account for the chondrocyte signatures of RA and its potential applications for diagnosis and prognosis in RA.

Can Metabolic Pathways Be Therapeutic Targets in Rheumatoid Arthritis?

The metabolic rewiring of tumor cells and immune cells has been viewed as a promising source of novel drug targets. Many of the molecular pathways implicated in rheumatoid arthritis (RA) directly modify synovium metabolism and transform the resident cells, such as the fibroblast-like synoviocytes (FLS), and the synovial tissue macrophages (STM), toward an overproduction of enzymes, which degrade cartilage and bone, and cytokines, which promote immune cell infiltration. Recent studies have shown metabolic changes in stromal and immune cells from RA patients. Metabolic disruption in the synovium provide the opportunity to use in vivo metabolism-based imaging techniques for patient stratification and to monitor treatment response. In addition, these metabolic changes may be therapeutically targetable. Thus, resetting metabolism of the synovial membrane offers additional opportunities for disease modulation and restoration of homeostasis in RA. In fact, rheumatologists already use the antimetabolite methotrexate, a chemotherapy agent, for the treatment of patients with inflammatory arthritis. Metabolic targets that do not compromise systemic homeostasis or corresponding metabolic functions in normal cells could increase the drug armamentarium in rheumatic diseases for combination therapy independent of systemic immunosuppression. This article summarizes what is known about metabolism in synovial tissue cells and highlights chemotherapies that target metabolism as potential future therapeutic strategies for RA.

Can Resveratrol Treatment Control the Progression of Induced Periodontal Disease? A Systematic Review and Meta-Analysis of Preclinical Studies

Resveratrol is an anti-inflammatory compound found in several foods. Periodontal disease (PD) is associated to other systemic diseases, and inflammation may be responsible for the association. Consequently, controlling inflammation not only may benefit oral health but also may assist with the management of other chronic inflammatory conditions. We aimed to investigate the effects of resveratrol administration on PD control in preclinical studies. A systematic search was performed for scientific articles using both electronic databases and a manual search using combinations of the following keywords: "resveratrol" OR "3,5,4'-trihydroxystilbene" AND "periodontal disease" OR "periodontitis" OR "gingivitis". Only in vivo original studies investigating resveratrol treatment on experimental animal models of PD were selected. A quality assessment of the studies was performed using the Animal Research Reporting In Vivo Experiment (ARRIVE) guidelines, and the risk of bias was assessed using the Syrcle tool. The search returned 570 articles, and 11 matched the inclusion criteria. A meta-analysis showed that resveratrol treatment attenuated alveolar bone loss (τ2 = 0.0041; 95% CI: -0.14; -0.04). The ARRIVE criteria reported a good quality of studies in general (mean score 28.5 ± 2.5). However, five Syrcle domains indicated a high risk of bias or did not present information clearly. We concluded that, in preclinical studies, resveratrol treatment prevented PD progression.