Tormentic acid inhibits LPS-induced inflammatory response in human gingival fibroblasts via inhibition of TLR4-mediated NF-κB and MAPK signalling pathway

Galectin-3 inhibition alleviated LPS-induced periodontal inflammation in gingival fibroblasts and experimental periodontitis mice

OBJECTIVES

Clinical studies have confirmed that galectin-3 (Gal-3) levels are significantly elevated in periodontitis patients. The present study aimed to explore the effects of Gal-3 inhibition on periodontal inflammation in vitro and in vivo.

METHODS

Human gingival fibroblasts (HGFs) with or without Gal-3 knockdown were stimulated by lipopolysaccharide (LPS), and a ligation-induced mouse periodontitis model treated with a Gal-3 inhibitor was established. Hematoxylin-eosin (H&E) and immunohistochemistry (IHC) staining were used to evaluate Gal-3 levels in gingival tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect Gal-3, interleukin (IL)-6, IL-8, and C-C motif ligand 2 (CCL2) expression. Immunofluorescence and western blotting were used to detect NF-κB and ERK signaling pathway activation. Micro-computed tomography was used to analyse the degree of bone loss.

RESULTS

Gal-3 was significantly up-regulated in inflamed gingival tissues and LPS-induced HGFs. Gal-3 knockdown markedly decreased LPS-induced IL-6, IL-8, and CCL2 expression and blocked NF-κB and ERK signaling pathway activation in HGFs. In the mouse periodontitis model, Gal-3 inhibition significantly alleviated IL-1β and IL-6 infiltration in gingival tissue and mitigated periodontal bone loss.

CONCLUSIONS

Gal-3 inhibition notably alleviated periodontal inflammation partly through blocking NF-κB and ERK signaling pathway activation.

Integrated Metabolomics and Transcriptomics Analysis Reveals New Insights into Triterpene Biosynthesis in Rosa rugosa

Rosa rugosa is highly regarded for its aesthetic and therapeutic qualities. In particular, R. rugosa's flowers are known to produce essential oils containing a mixture of volatile terpenes, phenylpropanoids, and other compounds. Despite this, extensive research exists on volatile terpenes in flowers, while the knowledge of non-volatile terpenes in distinct tissues is still limited. Using UPLC-ESI-MS/MS, a comprehensive analysis of the terpene metabolites in five different tissues of R. rugosa was conducted. These metabolites accumulated in distinct tissues, and the majority of them were triterpenoids. Transcriptome data were collected from five tissues using RNA-seq. Transcriptomics and metabolomics were utilized to evaluate the triterpene biosynthesis pathway, resulting in new insights into its regulation and biosynthesis. The RrOSC10 was identified as a key enzyme in converting 2,3-oxidosqualene into α-amyrin, potentially contributing to the triterpene biosynthesis pathway. Furthermore, the expression of the RrOSC10 gene was upregulated by salinity for 0.5 h and 1 h, with subsequent downregulation at 2 h. This study lays a foundation for future research on the biosynthesis and accumulation of triterpenes in R. rugosa.

Hispidulin Inhibits the Vascular Inflammation Triggered by Porphyromonas gingivalis Lipopolysaccharide

Hispidulin is a natural bioactive flavonoid that has been studied for its potential therapeutic properties, including its anti-inflammatory, antioxidant, and neuroprotective effects. The aim of this study was to explore whether hispidulin could inhibit the endothelial inflammation triggered by Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). The adhesion of monocytes to the vascular endothelium was evaluated through in vitro and ex vivo monocyte adhesion assays. We analyzed the migration of monocytes across the endothelial layer using a transmigration assay. The results showed that treatment with hispidulin decreased the P. gingivalis LPS-induced adhesion of monocytes to endothelial cells and their migration by suppressing the P. gingivalis LPS-triggered expression of intercellular adhesion molecule-1 (ICAM-1) through downregulating nuclear factor-қB (NF-қB). In addition, hispidulin inhibited P. gingivalis LPS-induced mitogen-activated protein kinases (MAPKs) and AKT in endothelial cells. Altogether, the results indicate that hispidulin suppresses the vascular inflammation induced by P. gingivalis LPS. Mechanistically, it prevents the adhesion of monocytes to the vascular endothelium and migration and inhibits NF-қB, MAPKs, and AKT signaling in endothelial cells.

C5aR antagonist inhibits LPS-induced inflammation in human gingival fibroblasts via NF-κB and MAPK signaling pathways

OBJECTIVE

Abnormal complement activation is associated with periodontitis. W54011 is a novel non-peptide C5aR antagonist (C5aRA) that exhibits favorable anti-inflammatory effects in various inflammatory models. However, whether W54011 inhibits periodontitis has not yet been fully elucidated. To address this, we have investigated the probable anti-inflammatory mechanism of W54011 in LPS-treated inflammation in human gingival fibroblasts (HGFs).

METHODOLOGY

HGFs were isolated from healthy gingival tissue samples using the tissue block method and were identified with immunofluorescence staining. The CCK8 assay and reverse transcription-PCR (RT-PCR) were used to select the optimal induction conditions for Lipopolysaccharide (LPS) and C5aRA (according to supplementary data S1, S2 and S3). The levels of inflammatory cytokines, C5aR, and the activation of NF-κB/MAPK signaling pathways were determined by RT-quantitative PCR (RT-qPCR) and Western blotting.

RESULTS

Immunofluorescence results showed that vimentin and FSP-1 were positive in HGFs and Keratin was negative in HGFs. Immunofluorescence staining demonstrated that C5aRA inhibited LPS-stimulated nuclear translocation of p-p65. RT-qPCR and Western blotting showed that C5aRA reduced the expression of IL-1β, IL-6, TNF-α, C5aR, p-p65, p-IκBα, p-JNK, p-c-JUN, and TLR4 in LPS-induced HGFs.

CONCLUSION

These findings suggested that C5aRA attenuated the release of inflammatory cytokines in LPS-induced HGFs by blocking the activation of the NF-κB and MAPK signaling pathways.

Advances in novel therapeutic approaches for periodontal diseases

Periodontal diseases are pathological processes resulting from infections and inflammation affecting the periodontium or the tissue surrounding and supporting the teeth. Pathogenic bacteria living in complex biofilms initiate and perpetuate this disease in susceptible hosts. In some cases, broad-spectrum antibiotic therapy has been a treatment of choice to control bacterial infection. However, increasing antibiotic resistance among periodontal pathogens has become a significant challenge when treating periodontal diseases. Thanks to the improved understanding of the pathogenesis of periodontal disease, which involves the host immune response, and the importance of the human microbiome, the primary goal of periodontal therapy has shifted, in recent years, to the restoration of homeostasis in oral microbiota and its harmonious balance with the host periodontal tissues. This shift in therapeutic goals and the drug resistance challenge call for alternative approaches to antibiotic therapy that indiscriminately eliminate harmful or beneficial bacteria. In this review, we summarize the recent advancement of alternative methods and new compounds that offer promising potential for the treatment and prevention of periodontal disease. Agents that target biofilm formation, bacterial quorum-sensing systems and other virulence factors have been reviewed. New and exciting microbiome approaches, such as oral microbiota replacement therapy and probiotic therapy for periodontal disease, are also discussed.

Plant-derived tormentic acid alters the gut microbiota of the silkworm (Bombyx mori)

In recent years, phytochemicals have started to attract more attention due to their contribution to health and bioactivity. Microorganisms in the intestines of organisms contribute to the processing, function, and biotransformation of these substances. The silkworm (Bombyx mori) is one of the organisms used for the biotransformation of phytochemicals due to its controlled reproduction and liability to microbial manipulation. In this study, a bioactive compound, tormentic acid (TA), extracted from Sarcopoterium spinosum was used in the silkworm diet, and the alterations of intestinal microbiota of the silkworm were assessed. To do this, silkworms were fed on a diet with various tormentic acid content, and 16S metagenomic analysis was performed to determine the alterations in the gut microbiota profile of these organisms. Diet with different TA content did not cause a change in the bacterial diversity of the samples. A more detailed comparison between different feeding groups indicated increased abundance of bacteria associated with health, i.e., Intestinibacter spp., Flavonifractor spp., Senegalimassilia spp., through the utilization of bioactive substances such as flavonoids. In conclusion, it might be said that using TA as a supplementary product might help ameliorate the infected gut, promote the healthy gut, and relieve the undesirable effects of medicines on the gastrointestinal system.

Tamquam alter idem: formal similarities in a subset of reports on anti-inflammatory compounds in the years 2008–2019

A literature search on the in vitro testing of anti-inflammatory compounds of natural origin revealed a considerable number of studies adopting a similar template for data reporting in the years up to 2019. Sixty-five such reports appear to have been published between the years 2008 and 2019. Interestingly, this format template was clearly recognizable by a few hallmarks, such as a precise way of plotting cell viability data, extremely consistent endpoints, and the way these were graphically represented. In some instances the similarities extended to some textual features, such as in the case of figure legends. The similarity was so high that chance can be excluded and these studies can be safely assumed to have intentionally followed a template. By 2020, however, no new reports following this format have been published. Although a consistent and reproducible formatting for data reporting may improve report readability, this phenomenon should also be closely scrutinized to assess the rationale why it occurred, the validity of the endpoints that were chosen and why it was then abandoned. The present report reviewed the mean features of this format, traced its origin and its evolution over time, while discussing the limitations of this model.

Chlorogenic Acid as a Positive Regulator in LPS-PG-Induced Inflammation via TLR4/MyD88-Mediated NF-κB and PI3K/MAPK Signaling Cascades in Human Gingival Fibroblasts

Gingival inflammation is one of the main causes that can be related to various periodontal diseases. Human gingival fibroblast (HGF) is the major constituent in periodontal connective tissue and secretes various inflammatory mediators, such as nitric oxide (NO) and prostaglandin E₂ (PGE₂), upon lipopolysaccharide stimulation. This study is aimed at investigating the anti-inflammatory mechanism of chlorogenic acid (CGA) on Porphyromonas gingivalis LPS- (LPS-PG-) stimulated HGF-1 cells. The concentration of NO and PGE₂, as well as their responsible enzymes, inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2), was analyzed by Griess reaction, ELISA, and western blot analysis. LPS-PG sharply elevated the production and protein expression of inflammatory mediators, which were significantly attenuated by CGA treatment in a dose-dependent manner. CGA treatment also suppressed activation of Toll-like receptor 4 (TLR4)/myeloid differentiation primary response gene 88 (MyD88) and nuclear factor- (NF-) κB in LPS-PG-stimulated HGF-1 cells. Furthermore, LPS-PG-induced phosphorylation of extracellular regulated kinase (ERK) and Akt was abolished by CGA treatment, while c-Jun N-terminal kinase (JNK) and p38 did not have any effect. Consequently, these results suggest that CGA ameliorates LPS-PG-induced inflammatory responses by attenuating TLR4/MyD88-mediated NF-κB, phosphoinositide-3-kinase (PI3K)/Akt, and MAPK signaling pathways in HGF-1 cells.

Natural Compounds for Counteracting Nonalcoholic Fatty Liver Disease (NAFLD): Advantages and Limitations of the Suggested Candidates

The booming prevalence of nonalcoholic fatty liver disease (NAFLD) in adults and children will threaten the health system in the upcoming years. The "multiple hit" hypothesis is the currently accepted explanation of the complex etiology and pathophysiology of the disease. Some of the critical pathological events associated with the development of NAFLD are insulin resistance, steatosis, oxidative stress, inflammation, and fibrosis. Hence, attenuating these events may help prevent or delay the progression of NAFLD. Despite an increasing understanding of the mechanisms involved in NAFLD, no approved standard pharmacological treatment is available. The only currently recommended alternative relies on lifestyle modifications, including diet and physical activity. However, the lack of compliance is still hampering this approach. Thus, there is an evident need to characterize new therapeutic alternatives. Studies of food bioactive compounds became an attractive approach to overcome the reticence toward lifestyle changes. The present study aimed to review some of the reported compounds with beneficial properties in NAFLD; namely, coffee (and its components), tormentic acid, verbascoside, and silymarin. We provide details about their protective effects, their mechanism of action in ameliorating the critical pathological events involved in NAFLD, and their clinical applications.

Extracellular CIRP Induces an Inflammatory Phenotype in Pulmonary Fibroblasts via TLR4

Extracellular cold-inducible RNA-binding protein (eCIRP), a new damage-associated molecular pattern (DAMP), has been recently shown to play a critical role in promoting the development of bleomycin-induced pulmonary fibrosis. Although fibroblast activation is a critical component of the fibrotic process, the direct effects of eCIRP on fibroblasts have never been examined. We studied eCIRP’s role in the induction of inflammatory phenotype in pulmonary fibroblasts and its connection to bleomycin-induced pulmonary fibrosis in mice. We found that eCIRP causes the induction of proinflammatory cytokines and differentially expression-related pathways in a TLR4-dependent manner in pulmonary fibroblasts. Our analysis further showed that the accessory pathways MD2 and Myd88 are involved in the induction of inflammatory phenotype. In order to study the connection of the enrichment of these pathways in priming the microenvironment for pulmonary fibrosis, we investigated the gene expression profile of lung tissues from mice subjected to bleomycin-induced pulmonary fibrosis collected at various time points. We found that at day 14, which corresponds to the inflammatory-to-fibrotic transition phase after bleomycin injection, TLR4, MD2, and Myd88 were induced, and the transcriptome was differentially enriched for genes in those pathways. Furthermore, we also found that inflammatory cytokines gene expressions were induced, and the cellular responses to these inflammatory cytokines were differentially enriched on day 14. Overall, our results show that eCIRP induces inflammatory phenotype in pulmonary fibroblasts in a TLR4 dependent manner. This study sheds light on the mechanism by which eCIRP induced inflammatory fibroblasts, contributing to pulmonary fibrosis.

The Occurrence and Biological Activity of Tormentic Acid-A Review

This review focuses on the natural sources and pharmacological activity of tormentic acid (TA; 2α,3β,19α-trihydroxyurs-2-en-28-oic acid). The current knowledge of its occurrence in various plant species and families is summarized. Biological activity (e.g., anti-inflammatory, antidiabetic, antihyperlipidemic, hepatoprotective, cardioprotective, neuroprotective, anti-cancer, anti-osteoarthritic, antinociceptive, antioxidative, anti-melanogenic, cytotoxic, antimicrobial, and antiparasitic) confirmed in in vitro and in vivo studies is compiled and described. Biochemical mechanisms affected by TA are indicated. Moreover, issues related to the biotechnological methods of production, effective eluents, and TA derivatives are presented.

Asperuloside ameliorates lipopolysaccharide-induced primary human periodontal ligament cell injury by decreasing TLR4 expression and NF-κB activation

OBJECTIVE

The mechanism underlying lipopolysaccharide (LPS)-induced primary human periodontal ligament (PDLC) cell injury is unclear. In this study, we focused on the therapeutic function of asperuloside (ASP) on LPS-induced cell injury.

DESIGN

The study enrolled 41 participants, including 18 healthy controls and 23 CP patients. Western blotting was used to measure the expression of Toll-like receptor 4 (TLR4), phosphorylated p65 (p-p65) and cyclin D1. Enzyme-linked immunosorbent assays (ELISAs) were utilized to evaluate the protein levels of proinflammatory factors interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). MTT assays and 5-ethynyl-2'-deoxyuridine (EdU) staining were performed to investigate cell proliferation. Immunohistochemistry was used to detect TLR4 and p65 expression in gingival tissues.

RESULTS AND CONCLUSIONS

Asperuloside ameliorates lipopolysaccharide-induced PDLC cell injury by decreasing TLR4 expression and NF-κB activation, while this protective effect of ASP was reversed by TLR4 overexpression.

Porphyromonas gingivalis lipopolysaccharide and gingival fibroblast augment MMP-9 expression of monocytic U937 cells through cyclophilin A

BACKGROUND

Intercellular cross-talking was suggested in matrix metalloproteinase (MMP)-9 expression with unknown mechanisms. Studies showed cyclophilin A (CypA) playing an important role in regulating MMP-9 expression in varied diseases. The aim of the study was to examine the CyPA on the MMP-9 augmentation in monocytic U937 cells after Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) treatment and human gingival fibroblast (hGF) co-culture.

METHODS

In independent culture or co-culture of hGF and U937 cell, quantitative real-time polymerase chain reaction (qPCR) and zymography were selected to examine the mRNA and protein activity of MMP-9, respectively. The CyPA expression was determined by qPCR.

RESULTS

LPS could enhance MMP-9 mRNA expression and enzyme activity in U937 cell. However, the enhancements were not observed in hGF. Similarly, LPS enhanced CyPA mRNA in U937, but not in hGF. After co-cultured with hGF, however, MMP-9 and CyPA in U937 increased regardless of the presence/absence of LPS. In U937 cells, the extra-supplied CyPA increased MMP-9 mRNA and enzyme activity, whereas the CyPA inhibitor, cyclosporine A, suppressed the LPS- and co-culture-enhanced MMP-9. Moreover, the inhibitors for MAP kinase, including PD98059 (ERK) and SP600125 (JNK), suppressed the CyPA-enhanced MMP-9 in U937.

CONCLUSION

Through the CyPA pathway, the LPS and the hGF could augment the MMP-9 expression in the U937 cells.

Periodontal Pathogens and Neuropsychiatric Health

Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.

Knockdown of TRIM52 alleviates LPS-induced inflammatory injury in human periodontal ligament cells through the TLR4/NF-κB pathway

Tripartite motif-containing (TRIM) 52 (TRIM52) is a vital regulator of inflammation. However, the function and mechanisms of TRIM52 in lipopolysaccharide (LPS)-induced inflammatory injury of human periodontal ligament cells (HPDLCs) in periodontitis remain undefined. In the present research, gene expression was determined using a quantitative polymerase chain reaction and Western blot. The effect of TRIM52 on LPS-induced inflammatory injury was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and enyzme-linked immunosorbent assay (ELISA). We found that TRIM52 expression was up-regulated in LPS-treated HPDLCs. Knockdown of TRIM52 alleviated LPS-induced proliferative inhibition and apoptosis promotion in HPDLCs, as evidenced by a decrease in cleaved caspase-3 expression and caspase-3 activity. Silencing TRIM52 suppressed LPS-induced inflammatory response of HPDLCs, as indicated by the decrease in interleukin (IL)-6, IL-8, tumor necrosis factor-α (TNF-α) levels, and increase in IL-10 levels. TRIM52 knockdown inhibited LPS-induced activation of TLR4/nuclear factor-κ B (NF-κB) signaling pathway. Taken together, knockdown of TRIM52 mitigated LPS-induced inflammatory injury via the TLR4/NF-κB signaling pathway, providing an effective therapeutic target for periodontitis.

Bioguided identification of pentacyclic triterpenoids as anti-inflammatory bioactive constituents of Ocimum gratissimum extract

ETHNOPHARMACOLOGICAL RELEVANCE

Ocimum gratissimum is a plant spice widely used in African traditional medicine to treat pain-related conditions. However, the anti-inflammatory mechanisms underlying this activity and the main active ingredients in O. gratissimum have not yet been fully characterized.

AIM OF THE STUDY

To isolate and identify the main anti-inflammatory active constituents of Ocimum gratissimum extract and their underlying mechanisms in murine macrophages.

MATERIAL AND METHODS

Chromatographic techniques and spectroscopic data were used for compounds isolation and identification. Inflammatory conditions were produced in cultured RAW 264.7 macrophage cells by the application of lipopolysaccharide (LPS). The WST-1 assay was used to evaluate the cell viability, and the nitric oxide production was quantified by the Griess reagent method. The fluorometric cyclooxygenase (COX) activity assay kit was used to assess the activity of COX-1 and COX-2 enzymes. The levels of IFN-γ, TNF-α, IL-2, IL-4, IL-6, and IL-10 cytokines and the apoptosis-inducing effect were measured by flow cytometer using the cytometric Bead Array (CBA) Human Th1/Th2 Cytokine Kit II and FITC Annexin V Apoptosis Detection kit, respectively.

RESULTS

The results showed that the extract and fractions of Ocimum gratissimum inhibit nitric oxide production and the proliferation of Raw 264.7 macrophage cells. The bioguided fractionation led to the identification of pentacyclic triterpenes as anti-inflammatory bioactive compounds. Pomolic and tormentic acids being the most active, inhibiting the secretion of IFN-γ cytokine, COX enzyme, and inducing apoptosis in activated Raw 264.7 macrophage cells.

CONCLUSIONS

This study revealed that pomolic and tormentic acids are the main active principles responsible at least in part for the anti-inflammatory effect of the extract of Ocimum gratissimum. Besides of providing more evidence for the traditional use of Ocimum gratissimum against inflammatory disorders, this study reveals the multitarget potential of pomolic and tormentic acids as promising future drugs against inflammatory diseases.

Pentacyclic Triterpene Profile and Its Biosynthetic Pathway in Cecropia telenitida as a Prospective Dietary Supplement

Promising research over the past decades has shown that some types of pentacyclic triterpenes (PTs) are associated with the prevention of type 2 diabetes (T2D), especially those found in foods. The most abundant edible sources of PTs are those belonging to the ursane and oleanane scaffold. The principal finding is that Cecropia telenitida contains abundant oleanane and ursane PT types with similar oxygenation patterns to those found in food matrices. We studied the compositional profile of a rich PT fraction (DE16-R) and carried out a viability test over different cell lines. The biosynthetic pathway connected to the isolated PTs in C. telenitida offers a specific medicinal benefit related to the modulation of T2D. This current study suggests that this plant can assemble isobaric, positional isomers or epimeric PT. Ursane or oleanane scaffolds with the same oxygenation pattern are always shared by the PTs in C. telenitida, as demonstrated by its biosynthetic pathway. Local communities have long used this plant in traditional medicine, and humans have consumed ursane and oleanane PTs in fruits since ancient times, two key points we believe useful in considering the medicinal benefits of C. telenitida and explaining how a group of molecules sharing a closely related scaffold can express effectiveness.

Neuroprotective effect of tormentic acid against memory impairment and neuro‑inflammation in an Alzheimer's disease mouse model

Cognitive impairment and neuro-inflammatory responses are the distinctive characteristics of Alzheimer's disease (AD). Tormentic acid (TA) is one of the major active components of Potentilla chinensis and has been demonstrated to have anti-inflammatory properties. However, the potential effects of TA on neuro-inflammatory responses and memory impairment in AD remain unknown. The present study investigated the therapeutic effect of TA on neuro-inflammation, as well as learning and memory impairment in AD mice. In addition, the effects of TA treatment were also examined in a co-culture system of microglia and primary neurons. Intraperitoneal administration of TA attenuated memory deficits in amyloid β precursor protein/presenilin 1 transgenic mice, with a marked decrease in amyloid plaque deposition. TA also reduced microglial activation and decreased the secretion of pro-inflammatory factors in AD mice. Furthermore, pre-treatment with TA suppressed the production of pro-inflammatory markers, as well as the nuclear translocation of nuclear factor-κB (NF-κB) p65 induced by Aβ exposure in BV2 cells. TA also reduced inhibited neurotoxicity and improved neuron survival in a neuron-microglia co-culture system. Taken together, these findings suggested that TA could attenuate neuro-inflammation and memory impairment, which may be closely associated with regulation of the NF-κB pathway.

Mangiferin Rich Products from Aphloia theiformis (Vahl) Benn Leaves: Extraction, Fractionation, Phytochemical Characterization, and Antioxidant Properties

Aphloia theiformis is traditionally used in Mauritius, Madagascar, and Reunion Island for treating several diseases. In this study, various extraction solvents and schemes were applied for the recovery of antioxidant rich fractions from the leaves of A. theiformis. The products were evaluated for their antioxidant capacity using well known in vitro assays. Major compounds were characterized by UPLC–QTOF–MS. Hydrophilic extracts of A. theiformis demonstrated strong antioxidant properties, which are comparable with the synthetic antioxidant Trolox. UPLC analysis confirmed mangiferin as the main secondary metabolite of A. theiformis. Tormentic and hydroxytormentic acids as well as their isomers were also abundant in A. theiformis extracts and fractions, while their amounts were determined for the first time. The most potential extract was further separated into the fractions by liquid-liquid extraction and by precipitation at low temperature. Antioxidant capacity and composition of secondary metabolites of derived fractions were determined. Some of the fractions possessed remarkable antioxidant capacity, comparable to pure mangiferin. The results obtained reveal high potential of A. theiformis for recovery of natural antioxidants and other bioactive phytochemicals, particularly mangiferin.

Between Innovation and Standardization, Is There Still a Room for Scientific Reports? The Rise of a Formatting Tradition in Periodontal Research

Everybody, regardless of their role, is aware that biomedical research is rapidly evolving, and the demand for reproducibility is increasing together with the amount of novel information. “Before reproducibility must come pre-producibility” “Checklists work to improve science”, just to quote some of the articles querying how to find a new bridge between ethics in science and the urgency for publishing. Looking for papers on anti-inflammatory compounds in periodontics, we came across a significant number of articles that could be considered a prototype of a consistent study format. The literature on the testing of active compounds on lipopolysaccharides- (LPS)-induced inflammation in gingival fibroblasts was searched to identify studies that followed a consistent format, to better understand their similarities and assess the appropriateness of their methods. Several studies were identified with a degree of similarity in their methods and formatting that was so high that it was possible to rule out that it was due to chance, and a format template common to these studies was outlined. Although this was most likely beyond the intentions of their authors, these studies may pose the basis for an in-vitro testing standard for anti-inflammatory compounds; however, the dangers of acritical uniformity are also apparent.

N-acetyl cysteine inhibits lipopolysaccharide-mediated synthesis of interleukin-1β and tumor necrosis factor-α in human periodontal ligament fibroblast cells through nuclear factor-kappa B signaling

BACKGROUND

The aim of this study was to investigate the role of n-acetyl cysteine (NAC) in the lipopolysaccharide (LPS)-mediated induction of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) synthesis by human periodontal ligament fibroblast cells (hPDLFs). In addition, we aimed to determine the involvement of the nuclear factor-kappa B (NF-κB) pathway in any changes in IL-1β and TNF-α expression observed in response to LPS and NAC.

METHODS

HPDLFs were obtained by primary culture. The culture medium used in this experiment was Dulbecco's Modified Eagle Medium (DMEM low-glucose). Cells were stimulated with various concentrations of NAC or LPS. Cell proliferation was measured at various time-points with the cell Counting Kit 8 (CCK-8) assay. mRNA levels of IL-1β and TNF-α were determined by real-time quantitative polymerase chain reaction (RT-qPCR) analysis. Protein levels of IL-1β and TNF-α were measured by enzyme-linked immunosorbent assay (ELISA). Protein and mRNA expression levels of NF-κB were measured by western blot and RT-qPCR.

RESULTS

The results showed that LPS treatment in hPDLFs induced mRNA and protein expression of IL-1β, TNF-α, and NF-κB. However, these effects were eliminated by pretreatment with NAC. Pretreatment with both NAC (1 mmol/L) and BAY11-7082 (10 μmol/L) significantly inhibited the NF-κB activity induced by LPS.

CONCLUSION

NAC inhibits the LPS-mediated synthesis of tumor TNF-α and IL-1β in hPDLFs, through the NF-κB pathway.

Quercetin Inhibits Inflammatory Response Induced by LPS from Porphyromonas gingivalis in Human Gingival Fibroblasts via Suppressing NF-κB Signaling Pathway

Quercetin, a natural flavonol existing in many food resources, has been reported to be an effective antimicrobial and anti-inflammatory agent for restricting the inflammation in periodontitis. In this study, we aimed to investigate the anti-inflammatory effects of quercetin on Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide- (LPS-) stimulated human gingival fibroblasts (HGFs). HGFs were pretreated with quercetin prior to LPS stimulation. Cell viability was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The levels of inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), along with chemokine interleukin-8 (IL-8), were determined by enzyme-linked immunosorbent assay (ELISA). The mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IκBα, p65 subunit of nuclear factor-kappa B (NF-κB), peroxisome proliferator-activated receptor-γ (PPAR-γ), liver X receptor α (LXRα), and Toll-like receptor 4 (TLR4) were measured by real-time quantitative PCR (RT-qPCR). The protein levels of IκBα, p-IκBα, p65, p-p65, PPAR-γ, LXRα, and TLR4 were characterized by Western blotting. Our results demonstrated that quercetin inhibited the LPS-induced production of IL-1β, IL-6, IL-8, and TNF-α in a dose-dependent manner. It also suppressed LPS-induced NF-κB activation mediated by TLR4. Moreover, the anti-inflammatory effects of quercetin were reversed by the PPAR-γ antagonist of GW9662. In conclusion, these results suggested that quercetin attenuated the production of IL-1β, IL-6, IL-8, and TNF-α in P. gingivalis LPS-treated HGFs by activating PPAR-γ which subsequently suppressed the activation of NF-κB.

Green tea polyphenols attenuate LPS-induced inflammation through upregulating microRNA-9 in murine chondrogenic ATDC5 cells

BACKGROUND

Osteoarthritis (OA), a universal chronic musculoskeletal disorder, is closely related to inflammation. More effective drugs for improving OA outcome are definitely needed. Herein, we attempted to verify the protective role of green tea polyphenols (GTP) after treatment with murine in ATDC5 cells to reveal the regulatory mechanism.

METHODS

ATDC5 cells were stimulated with lipopolysaccharide (LPS) to mimic an inflammatory response during OA. Cell activity, apoptosis, levels of relative proteins, and prophlogistic factors were tested via a Cell Counting Kit-8 experiment, a flow cytometry experiment, western blot, and RT-qPCR (ELISA and Western blot), separately. miR-9 level was detected by RT-qPCR and altered via miR-9 mimic and inhibitor transfection. We finally studied MAPK and NF-κB pathways in GTP-related modulations using western blot.

RESULTS

LPS caused inflammatory cell damage in ATDC5 cells, showing decreased cell activity, enhanced apoptosis, and increased levels of pro-inflammatory cytokines. GTP pretreatments could significantly attenuate LPS-induced alterations. In addition, LPS-induced miR-9 upregulation was further positively regulated in ATDC5 cells. The effects of GTP pretreatments in LPS-caused ATDC5 cells were enhanced via miR-9 upregulation, whereas they were reduced via miR-9 suppression. Finally, we found that GTP pretreatments could suppress the MAPK and NF-κB pathways through miR-9 regulation.

CONCLUSION

GTP pretreatments attenuated LPS-induced inflammatory response accompanied by the suppression of the MAPK and NF-κB pathways via positively regulating miR-9 in ATDC5 cells.

Oridonin inhibits LPS-induced inflammation in human gingival fibroblasts by activating PPARγ

Oridonin, the major terpene isolated from Rabdosia rubescens, has been used as dietary supplement. Recently, it has been known to exhibit anti-inflammatory effect. This study we employed an in vitro model of LPS-stimulated human gingival fibroblasts to investigate the anti-inflammatory effects and mechanism of oridonin. Oridonin (10-30 μg/mL) was administrated 1 h before LPS treatment. The results showed that oridonin significantly inhibited inflammatory mediators PGE₂, NO, IL-6, and IL-8 production. Immunoblotting experiments revealed that oridonin reduced the expression of phosphorylation levels of NF-κB p65 and IκBα. Furthermore, the expression of PPARγ was up-regulated by the treatment of oridonin. Further studies showed that PPARγ inhibitor GW9662 could reverse the inhibition of oridonin on PGE₂, NO, IL-6, and IL-8 production. In conclusion, oridonin inhibited LPS-induced microglia activation through activating PPARγ.

The Ovotransferrin-Derived Peptide IRW Attenuates Lipopolysaccharide-Induced Inflammatory Responses

IRW (Ile-Arg-Trp), a bioactive peptide isolated from egg ovotransferrin, has been shown to exert anti-inflammatory effects. In this study, the effects of IRW on inflammatory cytokines and microbiota were explored in human umbilical vein endothelial cells (HUVECs) and a lipopolysaccharide (LPS)-induced rat model of inflammatory peritonitis. Rats were injected intraperitoneally with LPS to establish peritonitis. HUVECs were exposed to IRW for 12 h before introducing LPS. Notably, IRW exerted beneficial effects against LPS-induced peritonitis, specifically, by reducing the serum levels of tumour necrosis factor (TNF)-α and interleukin (IL)-6 and myeloperoxidase (MPO) activity (P<0.05). A faecal microbiota analysis revealed that IRW significantly increased the Shannon and decreased the Simpson indices (P<0.05). Furthermore, IRW treatment significantly inhibited the LPS-induced enhancement of TNF-α, IL-8, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expression in HUVECs (P<0.05). In conclusion, IRW supplementation inhibited the inflammatory mediator synthesis and LPS-induced inflammatory responses and influenced the gut microbiota.

Antimicrobial and antioxidant potential of different solvent extracts of the medicinal plant Geum urbanum L

Many Geum species are known to be rich in biologically active compounds and therefore could be a source of new natural products with pharmacological potential. The medicinal plant Geum urbanum L. is widespread in Bulgaria and has been used in folk medicine. In the present study, the methanol extracts of the roots and aerial parts of G. urbanum and their fractions (petroleum ether, ethyl acetate and n-butanol) were investigated for antibacterial and radical scavenging activity. The ethyl acetate and n-butanol fractions inhibited the growth of Gram-positive pathogenic and opportunistic bacteria from the genus Staphylococcus (MIC EtOAc: 0.078 mg/ml aerial and 0.156 mg/ml roots; MIC n-BuOH: 0.156 mg/ml aerial and 1.25 mg/ml roots) and the species Bacillus cereus stronger than the other extracts and fractions tested (MIC EtOAc: 0.078 mg/ml aerial and 0.156 mg/ml roots; MIC n-BuOH: 0.156 mg/ml aerial and 0.078 mg/ml roots), and showed corresponding radical scavenging activity (EtOAc: EC50 1.5 µg/ml aerial, 0.8 µg/ml roots; n-BuOH: 4.5 µg/ml aerial; 3.7 µg/ml roots). Additionally, their total phenolic content was quantified (% of dry EtOAc fractions of roots 61%, of arial parts 32%; of dry n-BuOH fractions of roots 16%, of arial parts 13%). Seven compounds were isolated and identified spectroscopically from the ethyl acetate extract. Two acetylated ellagic acid rhamnosides were found for the first time in the genus Geum and three others, tormentic acid, niga-ichigoside F1, and 3,3'-di-O-methylellagic acid-4-O-β-D-glucopyranoside, were newly detected for the species G. urbanum. Our results reveal that G. urbanum L. is a perspective medicinal plant and deserves further, more detailed studies.

BRD7 plays an anti-inflammatory role during early acute inflammation by inhibiting activation of the NF-кB signaling pathway

Increasing evidence has shown a strong association between tumor-suppressor genes and inflammation. However, the role of BRD7 as a novel tumor suppressor in inflammation remains unknown. In this study, by observing BRD7 knockout mice for 6-12 months, we discovered that compared with BRD7+/+ mice, BRD7-/- mice were more prone to inflammation, such as external inflammation and abdominal abscess. By using mouse embryo fibroblast (MEF) cells from the BRD7 knockout mouse, an in vitro lipopolysaccharide (LPS)-stimulated MEF cell line was established. The mRNA levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), chemokine (C-X-C motif) ligand 1 (CXCL-1) and inducible nitric oxide synthase (iNOS) were significantly increased in BRD7-/- MEF cells compared with BRD7+/+ MEF cells after LPS stimulation for 1 or 6 h. In addition, the cytoplasm-to-nucleus translocation of nuclear factor kappa-B (NF-κB; p65) and an increased NF-κB reporter activity were observed in BRD7-/- MEF cells at the 1 h time point but not at the 6 h time point. Furthermore, an in vivo dextran sodium sulfate (DSS)-induced acute colitis model was created. As expected, the disease activity index (DAI) value was significantly increased in the BRD7-/- mice after DSS treatment for 1-5 days, which was demonstrated by the presence of a significantly shorter colon, splenomegaly and tissue damage. Moreover, higher expression levels of IL-6, TNF-α, p65, CXCL-1 and iNOS, and an increased level of NF-κB (p65) nuclear translocation were also found in the DSS-treated BRD7-/- mice. These findings suggest that BRD7 has an anti-inflammatory role during early acute inflammation by inhibiting activation of the NF-кB signaling pathway, which provides evidence to aid in understanding the therapeutic effects of BRD7 on inflammatory diseases.

MyD88/ERK/NFkB pathways and pro-inflammatory cytokines release in periodontal ligament stem cells stimulated by Porphyromonas gingivalis

The present study was aimed at investigating whether human Periodontal Ligament Stem Cells (hPDLSCs) were capable of sensing and reacting to lipopolysaccharide from Porphyromonas gingivalis (LPS-G) which is widely recognized as a major pathogen in the development and progression of periodontitis. At this purpose hPDLCs were stimulated with 5 μg/mL LPS-G at various times and the expression of toll-like receptor 4 (TLR4) was evaluated. Toll-like receptors (TLRs) play an essential role in innate immune signaling in response to microbial infections, and in particular TLR4, type-I transmembrane proteins, has been shown recognizing LPS-G. Our results put in evidence, in treated samples, an overexpression of TLR4 indicating that, hPDLSCs express a functional TLR4 receptor. In addition, LPS-G challenge induces a significant cell growth decrease starting from 24 h until 72 h of treatment. LPS-G leads the activation of the TLR4/MyD88 complex, triggering the secretion of proinflammatory cytokines cascade as: IL-1α, IL-8, TNF-α and β and EOTAXIN. Moreover, the upregulation of pERK/ERK signaling pathways and NFkB nuclear translocation was evident. On the basis of these observations, we conclude that hPDLSCs could represent an appropriate stem cells niche modeling leading to understand and evaluate the biological mechanisms of periodontal stem cells in response to LPS-G, mimicking in vitro an inflammatory process occurring in vivo in periodontal disease.

Tormentic Acid Inhibits IL-1β-Induced Inflammatory Response in Human Osteoarthritic Chondrocytes

The pro-inflammatory cytokine interleukin-1beta (IL-1β) plays critical roles in pathogenesis of osteoarthritis (OA). Tormentic acid (TA), a triterpene isolated from Rosa rugosa, has anti-inflammatory activity. However, the anti-inflammatory effect of TA on OA is still unclear. So, in the present study, we examined the effect of TA on IL-1β-induced inflammatory response in primary human OA chondrocytes. Our results demonstrated that TA significantly decreased the IL-1β-stimulated expression of matrix metalloproteinase-3 (MMP-3) and MMP-13. It also inhibited the IL-1β-induced expression of inducible nitric oxide (NO) synthase (iNOS) and cyclooxygenase-2 (COX-2), as well as the production of NO and prostaglandin E2 (PGE2) in human OA chondrocytes. Furthermore, TA greatly inhibited the IL-1β-induced NF-κB activation. In conclusion, this study is the first to demonstrate the anti-inflammatory activity of TA in human OA chondrocytes. TA significantly inhibits the IL-1β-induced inflammatory response by suppressing the NF-κB signaling pathway. Thus, TA may be a potential agent in the treatment of OA.

The role of short-chain fatty acids in kidney injury induced by gut-derived inflammatory response

It has been found that several circulating metabolites derived from gut microbiota fermentation associate with a systemic immuno-inflammatory response and kidney injury, which has been coined the gut-kidney axis. Recent evidence has suggested that short-chain fatty acids (SCFAs), which are primarily originated from fermentation of dietary fiber in the gut, play an important role in regulation of immunity, blood pressure, glucose and lipid metabolism, and seem to be the link between microbiota and host homeostasis. In addition to their important role as fuel for colonic epithelial cells, SCFAs also modulate different cell signal transduction processes via G-protein coupled receptors, and act as epigenetic regulators by the inhibition of histone deacetylase and as potential mediators involved in the autophagy pathway. Though controversial, an intimate connection between SCFAs and kidney injury has been revealed, suggesting that SCFAs may act as new therapeutic targets of kidney injury. This review is intended to provide an overview of the impact of SCFAs and the potential link to kidney injury induced by gut-derived inflammatory response.

Caffeic acid phenethyl ester attenuates lipopolysaccharide-stimulated proinflammatory responses in human gingival fibroblasts via NF-κB and PI3K/Akt signaling pathway

Periodontal diseases often begin with chronic gingival inflammation, which causes the destruction of periodontal tissues. Inflammatory immune responses from host cells to bacteria, such as Porphyromonas gingivalis (P. gingivalis), cause periodontal degradation. Human gingival fibroblasts (HGFs) are the major cells in periodontal soft tissues. When stimulated by lipopolysaccharide (LPS), HGFs could secrete several pro-inflammatory cytokines and chemokines, such as interleukins (ILs) IL-6, IL-8, inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2). Caffeic acid phenethyl ester (CAPE) is the main active component of propolis, which is collected by honeybees from different plants and known for its anti-inflammatory effects. The anti-inflammatory effects of CAPE on the LPS-induced HGFs were demonstrated in this study. HGFs were pretreated with CAPE (10, 20, and 30µm) for 1h, followed by LPS stimulation (1μg/ml) for 24h. Enzyme-linked immunosorbent assay, Western blot analysis, and immunofluorescence staining were used to evaluate the production of IL-6, IL-8, iNOS, and COX-2, as well as the activation of TLR4-mediated NF-κB, PI3K/AKT, and MAPK signaling pathways. The results indicated that CAPE inhibits LPS-induced IL-6, IL-8, iNOS, and COX-2 production in a dose-dependent manner. Moreover, CAPE suppresses LPS-induced TLR4/MyD88 and nuclear factor kappa B (NF-κB) activation. In addition, phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) phosphorylation was inhibited by CAPE. These results demonstrated that CAPE could be effective for treating of periodontal diseases.

Anti-Inflammatory Effects of Melandrii Herba Ethanol Extract via Inhibition of NF-κB and MAPK Signaling Pathways and Induction of HO-1 in RAW 264.7 Cells and Mouse Primary Macrophages

Melandrii Herba (MH) is a traditional Asian medicinal herb used to treat breast cancer, anuria, and diseases of lactation. However, its biological properties and molecular mechanisms have not been fully elucidated. The purpose of this study was to investigate the anti-inflammatory activity and underlying molecular mechanism of MH ethanol extract (MHE) on the lipopolysaccharide (LPS)-mediated inflammatory response in macrophages. MHE cytotoxicity was determined using a cell counting kit (CCK) assay. The effects of MHE on the production of NO, inflammatory cytokines, and related proteins and mRNAs were determined using the Griess test, ELISA, Western blotting, and real-time RT-PCR, respectively. In addition, intracellular signaling pathways, such as NF-κB, MAPK, and HO-1, were analyzed using Western blotting. Our results revealed that MHE treatment significantly inhibited the secretion of NO and inflammatory cytokines, including TNF-α, IL-6, and IL-1β in macrophages, at sub-cytotoxic concentrations. Furthermore, MHE treatment inhibited iNOS expression and induced HO-1 expression. Finally, the transcriptional activities of NF-κB and MAPK activation were significantly suppressed by MHE in LPS-stimulated macrophages. The results indicate that MHE exerts anti-inflammatory effects by suppressing inflammatory mediator production via NF-κB and MAPK signaling pathways inhibition and induction of HO-1 expression in macrophages. Therefore, our results suggest the potential value of MHE as an inflammatory therapeutic agent developed from a natural substance.

Sophoraflavanone G prevents Streptococcus mutans surface antigen I/II-induced production of NO and PGE2 by inhibiting MAPK-mediated pathways in RAW 264.7 macrophages

BACKGROUND

Sophora flavescens AITON (Leguminosae) is a typical traditional Korean medical herb considered to exhibit antibacterial, anti-inflammatory, and antipyretic effects, and is also used for the treatment of skin and mucosal ulcers, sores, diarrhea, gastrointestinal hemorrhage, arrhythmia, and eczema.

OBJECTIVE AND DESIGN

This study examined the inhibitory effects of sophoraflavanone G (SF) of S. flavescens on the bacterial fibrillar protein, Antigen I/II (AgI/II)-N recombinant protein isolated from Streptococcus mutans(rAg I/II)-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2). The investigation was focused on whether SF could inhibit the production of proinflammatory mediators such as nitric oxide (NO) and prostaglandin (PG) E2 as well as the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-a, interleukin (IL)-6, nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs) in rAgI/II-stimulated RAW 264.7 cells using Griess reagent, Enzyme linked immunosorbent assay (ELISA), and Western blotting analysis.

RESULTS

SG significantly inhibited the production of NO and PGE2 and pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor α in Ag I/II-N-stimulated RAW264.7 cells, which were mediated by the down-regulation of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. The SF inhibited the phosphorylation of IκB-α, nuclear translocation of p65, and subsequent activation of NF- κB in the rAgI/II-stimulated cells. In addition, the SF suppressed the rAgI/II-stimulated activation of ERK MAPK as well as the MAPK inhibitor significantly reduced the rAgI/II-induced production of NO and PGE2.

CONCLUSION

Collectively, we suggest that the SF inhibits the expression and production of inflammatory mediators by blocking the ERK MAPK mediated pathway and inhibiting the activation of NF-κB.

Protection against MPP(+)-induced neurotoxicity in SH-SY5Y cells by tormentic acid via the activation of PI3-K/Akt/GSK3β pathway

The cause of Parkinson's disease (PD) could be ascribed to the progressive and selective loss of dopaminergic neurons in the substantia nigra pars compacta, and thus molecules with neuroprotective ability may have therapeutic value against PD. In the current study, the neuroprotective effects and underlying mechanisms of tormentic acid (TA), a naturally occurring triterpene extracted from medicinal plants such as Rosa rugosa and Potentilla chinensis, were evaluated in a widely used cellular PD model in which neurotoxicity was induced by MPP(+) in cultured SH-SY5Y cells. We found that TA at 1-30 μM substantially protected against MPP(+)-induced neurotoxicity, as evidenced by the increase in cell viability, decrease in lactate dehydrogenase release and the reduction in apoptotic nuclei. Moreover, TA effectively inhibited the elevated intracellular accumulation of reactive oxygen species as well as Bax/Bcl-2 ratio caused by MPP(+). Most importantly, TA markedly reversed the inhibition of protein expression of phosphorylated Akt (Ser 473) and phosphorylated GSK3β (Ser 9) caused by MPP(+). LY294002, the specific inhibitor of PI3-K, significantly abrogated the up-regulated phosphorylated Akt and phosphorylated GSK3β offered by TA, suggesting that the neuroprotection of TA was mainly dependent on the activation of PI3-K/Akt/GSK3β signaling pathway. The results taken together indicate that TA may be a potential candidate for further preclinical study aimed at the prevention and treatment of PD.

Porphyromonas gingivalis: An Overview of Periodontopathic Pathogen below the Gum Line

Periodontal disease represents a group of oral inflammatory infections initiated by oral pathogens which exist as a complex biofilms on the tooth surface and cause destruction to tooth supporting tissues. The severity of this disease ranges from mild and reversible inflammation of the gingiva (gingivitis) to chronic destruction of connective tissues, the formation of periodontal pocket and ultimately result in loss of teeth. While human subgingival plaque harbors more than 500 bacterial species, considerable research has shown that Porphyromonas gingivalis, a Gram-negative anaerobic bacterium, is the major etiologic agent which contributes to chronic periodontitis. This black-pigmented bacterium produces a myriad of virulence factors that cause destruction to periodontal tissues either directly or indirectly by modulating the host inflammatory response. Here, this review provides an overview of P. gingivalis and how its virulence factors contribute to the pathogenesis with other microbiome consortium in oral cavity.

3,5,4'-Tri-O-acetylresveratrol Attenuates Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome via MAPK/SIRT1 Pathway

The aim of the present research was to investigate the protecting effects of 3,5,4′-tri-O-acetylresveratrol (AC-Rsv) on LPS-induced acute respiratory distress syndrome (ARDS). Lung injuries have been evaluated by histological examination, wet-to-dry weight ratios, and cell count and protein content in bronchoalveolar lavage fluid. Inflammation was assessed by MPO activities and cytokine secretion in lungs and cells. The results showed that AC-Rsv significantly reduced the mortality of mice stimulated with LPS. Pretreatment of AC-Rsv attenuated LPS-induced histological changes, alleviated pulmonary edema, reduced blood vascular leakage, and inhibited the MPO activities in lungs. What was more, AC-Rsv and Rsv treatment reduced the secretion of TNF-α, IL-6, and IL-1β in lungs and NR8383 cells, respectively. Further exploration revealed that AC-Rsv and Rsv treatment relieved LPS-induced inhibition on SIRT1 expression and restrained the activation effects of LPS on MAPKs and NF-κB activation both in vitro and in vivo. More importantly, in vivo results have also demonstrated that the protecting effects of Rsv on LPS-induced inflammation would be neutralized when SIRT1 was in-hibited by EX527. Taken together, these results indicated that AC-Rsv protected lung tissue against LPS-induced ARDS by attenuating inflammation via p38 MAPK/SIRT1 pathway.