Protective effects of Cinnamomum cassia (Lamaceae) against gout and septic responses via attenuation of inflammasome activation in experimental models

Molecular mechanisms of Sepsis attacking the immune system and solid organs

Remarkable progress has been achieved in sepsis treatment in recent times, the mortality rate of sepsis has experienced a gradual decline as a result of the prompt administration of antibiotics, fluid resuscitation, and the implementation of various therapies aimed at supporting multiple organ functions. However, there is still significant mortality and room for improvement. The mortality rate for septic patients, 22.5%, is still unacceptably high, accounting for 19.7% of all global deaths. Therefore, it is crucial to thoroughly comprehend the pathogenesis of sepsis in order to enhance clinical diagnosis and treatment methods. Here, we summarized classic mechanisms of sepsis progression, activation of signal pathways, mitochondrial quality control, imbalance of pro-and anti- inflammation response, diseminated intravascular coagulation (DIC), cell death, presented the latest research findings for each mechanism and identify potential therapeutic targets within each mechanism.

Bioactive Phenylpropanoid Glycosides, Dimers, and Heterodimers from the Bark of Cinnamomum cassia (L.) J.Presl

Six new phenylpropanoid glycosides (1-6), two new phenylethanol glycosides (7 and 8), one new phenylmethanol glycoside (9), three new phenylpropanoid dimers (10-12), two new phenylpropanoid-flavan-3-ol heterodimers (13 and 14), and six known relevant compounds (15-20) were isolated and identified from the well-liked edible and medicinal substance (the bark of Cinnamomum cassia (L.) J.Presl). The structures of these isolates were determined by using spectroscopic analyses, chemical methods, and quantum chemical calculations. Notably, compounds 4-9 were rare apiuronyl-containing glycosides, and compounds 13 and 14 were heterodimers of phenylpropanoids and flavan-3-ols linked through C-9″-C-8 bonds. The antioxidant and α-glucosidase inhibitory activities of all isolates were evaluated. Compounds 10 and 12 exhibited DPPH radical scavenging capacities with IC50 values of 20.1 and 13.0 μM, respectively (vitamin C IC50 value of 14.3 μM). In the ORAC experiment, all these compounds exhibited different levels of capacity for scavenging free radicals, and compound 10 displayed extraordinary free radical scavenging capacity with the ORAC value of 6.42 ± 0.01 μM TE/μM (EGCG ORAC value of 1.54 ± 0.02 μM TE/μM). Compound 12 also showed significant α-glucosidase inhibitory activity with an IC50 of 56.3 μM (acarbose IC50 of 519.4 μM).

Mechanism and therapeutic potential of traditional Chinese medicine extracts in sepsis

Sepsis is a complex syndrome characterized by multi-organ dysfunction, due to the presence of harmful microorganisms in blood which could cause mortality. Complications associated with sepsis involve multiple organ dysfunction. The pathogenesis of sepsis remains intricate, with limited treatment options and high mortality rates. Traditional Chinese medicine (TCM) has consistently demonstrated to have a potential on various disease management. Its complements include reduction of oxidative stress, inhibiting inflammatory pathways, regulating immune responses, and improving microcirculation. Traditional Chinese medicine can mitigate or even treat sepsis in a human system. This review examines progress on the use of TCM extracts for treating sepsis through different pharmacological action and its mechanisms. The potential targets of TCM extracts and active ingredients for the treatment of sepsis and its complications have been elucidated through molecular biology research, network pharmacology prediction, molecular docking analysis, and visualization analysis. Our aim is to provide a theoretical basis and empirical support for utilizing TCM in the treatment of sepsis and its complications while also serving as a reference for future research and development of sepsis drugs.

Fangji Fuling Decoction Alleviates Sepsis by Blocking MAPK14/FOXO3A Signaling Pathway

OBJECTIVE

To examine the therapeutic effect of Fangji Fuling Decoction (FFD) on sepsis through network pharmacological analysis combined with in vitro and in vivo experiments.

METHODS

A sepsis mouse model was constructed through intraperitoneal injection of 20 mg/kg lipopolysaccharide (LPS). RAW264.7 cells were stimulated by 250 ng/mL LPS to establish an in vitro cell model. Network pharmacology analysis identified the key molecular pathway associated with FFD in sepsis. Through ectopic expression and depletion experiments, the effect of FFD on multiple organ damage in septic mice, as well as on cell proliferation and apoptosis in relation to the mitogen-activated protein kinase 14/Forkhead Box O 3A (MAPK14/FOXO3A) signaling pathway, was analyzed.

RESULTS

FFD reduced organ damage and inflammation in LPS-induced septic mice and suppressed LPS-induced macrophage apoptosis and inflammation in vitro (P<0.05). Network pharmacology analysis showed that FFD could regulate the MAPK14/FOXO signaling pathway during sepsis. As confirmed by in vitro cell experiments, FFD inhibited the MAPK14 signaling pathway or FOXO3A expression to relieve LPS-induced macrophage apoptosis and inflammation (P<0.05). Furthermore, FFD inhibited the MAPK14/FOXO3A signaling pathway to inhibit LPS-induced macrophage apoptosis in the lung tissue of septic mice (P<0.05).

CONCLUSION

FFD could ameliorate the LPS-induced inflammatory response in septic mice by inhibiting the MAPK14/FOXO3A signaling pathway.

Integrated metabolomic and transcriptomic analyses revealed metabolite variations and regulatory networks in Cinnamomum cassia Presl from four growth years

To understand the mechanism of the dynamic accumulation of active ingredients in Cinnamomum cassia Presl, metabolomic and transcriptomic analyses of 5~8 years old C. cassia were performed. A total of 72 phenylpropanoids, 146 flavonoids, and 130 terpenoids showed marked changes. Most phenylpropanoids and flavonoids showed markedly higher abundances in 6-year-old C. cassia than in others, which was related to the higher expression of genes that synthesize and regulate phenylpropanoids and flavonoid. We identified transcription factors (TFs) and genes involved in phenylpropanoids and flavonoids synthesis and regulation through co-expression network analyses. Furthermore, most of the terpenoids in 5-year-old C. cassia showed markedly higher abundances than in others, which was due to the differentially expressed genes upstream of the terpenoids pathway. The results of our study provide new insights into the synthesis and accumulation of phenylpropanoid, flavonoids and terpenoids in C. cassia at four growth stages.

The Power of the Underutilized and Neglected Medicinal Plants and Herbs of the Middle East

The Middle east and North Africa harbour many native species with pharmaceutical and nutraceutical potential. Since the beginning of history, food and herbal medicinal plants have been an essential part of human lives and the traditional Middle Eastern healthcare system. The notable medicinal plants that have been mentioned in the Bible, which are common in West Asia and some regions of North Africa, are Aloe vera, anise, balm, cassia, cinnamon, cumin, flax, and fig. Chemical components of Aloe vera are aloin, sinapinic acid, catechin, chromone, myricetin, quercitrin and syringic acid. Anethole, safrole, and estragole are the main chemical components of anise. The chemical components of cassia are coumarin, emodin, cinnamyl alcohol, and cinnamaldehyde. The major chemical ingredients of cumin are terpinene, cuminaldehyde, sabinene, thujene, and thymoquinone. The goal of this article is to review the considerable health benefits and pharmaceutical benefits of medicinal herbs and plants that have been neglected and underutilized in the Middle East and North Africa, as well as to promote their utilization. On the basis of the results, the experimented neglected medicinal plant can offer various advantages when used together with conventional medicinal treatments for various health conditions, such as palliative care in managing the side effects of conventional treatments, access to a wider range of treatments, increased patient satisfaction, and improved emotional and mental well-being. Moreover, consuming medicinal plants may help to manage and prevent diabetes, cancer, and heart disease with notable anti-tumor, and anti-inflammatory properties.

Significant difference of differential expression pyroptosis-related genes and their correlations with infiltrated immune cells in sepsis

Background

Sepsis is regarded as a life-threatening organ dysfunction syndrome that responds to infection. Pyroptosis, a unique form of programmed cell death, is characterized by inflammatory cytokine secretion. Recently, an increasing number of studies have investigated the relationship between sepsis and pyroptosis. Appropriate pyroptosis can help to control infection during sepsis, but an immoderate one may cause immune disorders. The present study aimed to identify pyroptosis-related gene biomarkers and their relationship with the immune microenvironment using the genome-wide technique.

Methods

The training dataset GSE154918 and the validation dataset GSE185263 were downloaded for bioinformatics analysis. Differentially expressed pyroptosis-related genes (DEPRGs) were identified between sepsis (including septic shock) and healthy samples. Gene Set Enrichment Analysis (GSEA) was performed to explore gene function. CIBERSORT tools were applied to quantify infiltrating immune cells, and the correlation between differentially infiltrating immune cells and DEPRG expression was investigated. Furthermore, based on multivariable Cox regression, the study also utilized a random forest (RF) model to screen biomarkers.

Results

In total, 12 DEPRGs were identified. The expression level of PLCG1 was continuously significantly decreased, while the expression level of NLRC4 was elevated from control to sepsis and then to septic shock. GSEA found that one DEPRG (PLCG1) was involved in the T-cell receptor signaling pathway and that many T cell-related immunologic signature gene sets were enriched. The proportions of plasma cells, T cells CD4 memory activated, and some innate cells in the sepsis group were significantly higher than those in the healthy group, while the proportions of T cells CD8, T cells CD4 memory resting, T cells regulatory (Tregs), and NK cells were lower. Additionally, CASP4 was positively correlated with Neutrophils and negatively correlated with T cells CD4 memory resting and Tregs. Lastly, two biomarkers (CASP4 and PLCG1) were identified, and a nomogram model was constructed for diagnosis with area under the curve (AUC) values of 0.998.

Conclusion

This study identified two potential pyroptosis-related diagnostic genes, CASP4 and PLCG1, and explored the correlation between DEPRGs and the immune microenvironment. Also, our study indicated that some DEPRGs were satisfactorily correlated with several representative immune cells that can regulate pyroptosis.

Reduction of invasion and cell stemness and induction of apoptotic cell death by Cinnamomum cassia extracts on human osteosarcoma cells

Cinnamomum cassia possesses antioxidative activity and induces the apoptotic properties of various cancer types. However, its effect on osteosarcoma invasion and cancer stemness remains ambiguous. Here, we examined the molecular evidence of the anti-invasive effects of ethanoic C. cassia extracts (CCE). Invasion and migration were obviously suppressed after the expression of urokinase-type plasminogen activator and matrix metalloprotein 2 in human osteosarcoma 143B cells were downregulated. CCE reversed epithelial-to-mesenchymal transition (EMT) induced by transforming growth factor β1 and downregulated mesenchymal markers, such as snail-1 and RhoA. CCE suppressed self-renewal property and the expression of stemness genes (aldehyde dehydrogenase, Nanog, and CD44) in the 143B cells. CCE suppressed cell viability, reduced the colony formation of osteosarcoma cancer cells, and induced apoptotic cell death in the 143B cells, as indicated by caspase-9 activation. The xenograft tumor model of immunodeficient BALB/c nude mice showed that CCE administered in vivo through oral gavage inhibited the growth of implanted 143B cells. These findings indicated that CCE inhibited the invasion, migration, and cancer stemness of the 143B cells. CCE reduced proliferation of 143B cell possibly because of the activation of caspase-9 and the consequent apoptosis, suggesting that CCE is a potential anticancer supplement for osteosarcoma.

Inflammatory Response to Regulated Cell Death in Gout and Its Functional Implications

Gout, a chronic inflammatory arthritis disease, is characterized by hyperuricemia and caused by interactions between genetic, epigenetic, and metabolic factors. Acute gout symptoms are triggered by the inflammatory response to monosodium urate crystals, which is mediated by the innate immune system and immune cells (e.g., macrophages and neutrophils), the NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome activation, and pro-inflammatory cytokine (e.g., IL-1β) release. Recent studies have indicated that the multiple programmed cell death pathways involved in the inflammatory response include pyroptosis, NETosis, necroptosis, and apoptosis, which initiate inflammatory reactions. In this review, we explore the correlation and interactions among these factors and their roles in the pathogenesis of gout to provide future research directions and possibilities for identifying potential novel therapeutic targets and enhancing our understanding of gout pathogenesis.

Natural Products as a Novel Therapeutic Strategy for NLRP3 Inflammasome-Mediated Gout

Gout is the most common form of inflammatory arthritis. It occurs when monosodium urate crystals (MSU) are deposited within joints due to hyperuricemia and persistent elevations of serum uric acid levels. Traditional gout treatment such as urate-lowering therapy is difficult to continue for a long period of time due to the risk of side effects. Recent studies have shown that the modulation of MSU-induced inflammatory responses is dependent on the inflammatory cytokine IL-1β, which has a central role in a chain of processes involving multiple cytokines and mediators. In this regard, the NLRP3 inflammasome is known to play a crucial part and thus has been proposed as a novel target in the treatment for gout. However, the biochemical mechanism for NLRP3 inflammasome activation has not yet been clearly elucidated. Therefore, this report can provide an overview of natural extractions targeted to prevent or treat NLRP3 inflammasome-mediated gout in the MSU-induced gout model. In addition, the research and development of such natural products are suggested as a potential strategy in the treatment of gout.

Molecular Mechanism of Cinnamomum cassia against Gastric Damage and Identification of Active Compounds

Cinnamomum cassia is a natural product found in plants that has been used as a folk remedy for inflammation. In this study, we investigated the mechanism underlying the anti-inflammatory and antioxidant properties of C. cassia extract (ECC) in lipopolysaccharide (LPS)-induced murine RAW 264.7 cells, in comparison with 4-hydroxycinnamaldehyde, a C. cassia extract component. ECC and 4-hydroxycinnamaldehyde inhibited the production of nitrite oxide in a dose-dependent manner and did not show any change in cellular toxicity when treated with the same dose as that used in the nitrite assay. Moreover, they attenuated ROS accumulation after lipopolysaccharide (LPS) stimulation. ECC and 4-hydroxycinnamaldehyde decreased the mRNA and protein expression levels of inflammatory mediators (iNOS and COX-2) and cytokines such as TNF and IL-6. We also found that ECC and 4-hydroxycinnamaldehyde mitigated the phosphorylation of ERK, JNK, and transcription factors, such as NF-κB and STAT3, suppressing NF-κB nuclear translocation in LPS-activated macrophages. In addition, administration of ECC in a Sprague Dawley rat model of acute gastric injury caused by indomethacin significantly increased the gastric mucus volume. Analysis of serum and tissue levels of inflammatory mediators revealed a significant decrease in serum PGE2 and myeloperoxidase levels and a reduction in gastric iNOS, COX-2, and p65 protein levels. Collectively, these results suggest that ECC has antioxidant and anti-inflammatory effects and is a potential candidate for curing gastritis.

In Vitro and In Vivo Model for Sepsis Through Non-canonical NLRP3 Inflammasome Activation

Sepsis is a complex disorder related to dysregulation of the host response to infection and is a major health problem worldwide owing to its high mortality rates. However, the exact mechanisms causing sepsis remains unclear because of the complexity of the underlying pathways. Dysregulation of non-canonical NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation induces septic shock by promoting pyroptosis and pro-inflammatory cytokine production (e.g., interleukin-1β) via caspase-11 and Gasdermin-D. Herein, we describe a rapid, simple method for evaluation of the degree of sepsis by investigating non-canonical inflammasome activation in both in vitro and in vivo models. The method is expected to be useful for testing and screening drugs for the treatment of sepsis.

Resveratrol Relieves Gouty Arthritis by Promoting Mitophagy to Inhibit Activation of NLRP3 Inflammasomes

Background

Gouty arthritis (GA) is a common inflammatory disease with pain caused by the deposition of monosodium urate (MSU) crystals into joints and surrounding tissues. Resveratrol (Res), derived from grapes and peanuts and the traditional Chinese medicine (TCM) Reynoutria japonica for GA, acts against oxidation and inflammation. The present study aimed to investigate the therapeutic effect and mechanism of Res on GA.

Methods

Arthritis rat models, MSU-induced peritonitis mouse models, and inflammatory models of mouse bone marrow-derived macrophage (BMDM) were used in this study. Enzyme-linked immunosorbent assay (ELISA), JC-1, histopathological, immunofluorescence, flow cytometry, Western blot methods were applied to observe the effects of resveratrol on NLRP3 inflammasomes and mitophagy.

Results

Res significantly improves the gait score and synovitis of rats with GA and inhibits the peritoneal inflammation induced by MSU. Res inhibits the MSU-induced activation of NLRP3 inflammasomes by reducing the levels of IL-1β, IL-18, and Caspase-1 and the pyroptosis of macrophages. In addition, Res raises the level of mitochondrial membrane potential, inhibits the expression of P62 and Pink1, enhances the expressions of LC3B-II, Parkin, and TOMM20, and promotes mitophagy, while mitophagy inhibitors reverse the inhibitory effect of Res on the activation of NLRP3 inflammasomes.

Conclusion

Res significantly improves GA, and the underlying mechanism might be inhibiting the activation of NLRP3 inflammasomes by triggering the Pink1/Parkin pathway to promote mitophagy.

The Role and Mechanism of Pyroptosis and Potential Therapeutic Targets in Sepsis: A Review

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Recently was been found that pyroptosis is a unique form of proinflammatory programmed death, that is different from apoptosis. A growing number of studies have investigated pyroptosis and its relationship with sepsis, including the mechanisms, role, and relevant targets of pyroptosis in sepsis. While moderate pyroptosis in sepsis can control pathogen infection, excessive pyroptosis can lead to a dysregulated host immune response and even organ dysfunction. This review provides an overview of the mechanisms and potential therapeutic targets underlying pyroptosis in sepsis identified in recent decades, looking forward to the future direction of treatment for sepsis.

NLRC4 gene silencing-dependent blockade of NOD-like receptor pathway inhibits inflammation, reduces proliferation and increases apoptosis of dendritic cells in mice with septic shock

Septic shock is one of the most significant health concerns across the world, involving hypo-perfusion and defects in tissue energy. The current study investigates the role of NLR family CARD domain containing protein 4 (NLRC4) in septic shock-induced inflammatory reactions, lung tissue injuries, and dendritic cell (DC) apoptosis. Septic shock mice models were established by modified cecal ligation and puncture and injected with retroviral vector expressing siRNA-NLRC4. DCs were then isolated and transfected with siRNA-NLRC4. The degree of lung tissue injury, cell cycle distribution, cell apoptosis and cell viability of DCs were assessed. NLRC4 was found to be expressed at high levels in mice with septic shock. NLRC4 silencing inhibited the activation of the NOD-like receptor (NLR) pathway as evidenced by the decreased levels of NOD1, NOD2, RIP2, and NF-κB. In addition, NLRC4 silencing reduced the inflammatory reaction as attributed by reduced levels of IL-1β, TNF-α and IL-6. Suppressed NLRC4 levels inhibited cell viability and promoted cell apoptosis evidenced by inhibited induction of DC surface markers (CD80, CD86, and MHC II), along with alleviated lung tissue injury. In conclusion, NLRC4 silencing ameliorates lung injury and inflammation induced by septic shock by negatively regulating the NLR pathway.

Traditional uses, phytochemistry and pharmacological activities of the genus Cinnamomum (Lauraceae): A review

Species of Cinnamomum exhibit excellent economic and medicinal value, and have found use in traditional medicine, are consumed as a spice, as well as being cultivated as landscape plants. Investigations into the pharmacological activities of the genus Cinnamomum revealed that it manifested a wide range of pharmacological properties including antimicrobial, antioxidant, anti-inflammatory and analgesic, antitumor, anti-diabetic and anti-obesity, immunoregulation, insecticidal and acaricidal, cardiovascular protective, cytoprotective, as well as neuroprotective properties both in vivo and in vitro. In the past five years, approximately 306 chemical constituents have been separated and identified from the genus Cinnamomum, covering 111 terpenes, 44 phenylpropanoids, 51 lignans, 17 flavonoids, 53 aromatic compounds, 17 aliphatic compounds, four coumarins, two steroids. This article highlights the traditional uses, phytochemistry and pharmacological properties of the few studied taxa of Cinnamomum through searching for the pieces of literature both at home and abroad, which would provide a reference for the pharmaceutical research and clinical application of this genus.

Ginsenoside metabolite 20(S)-protopanaxatriol from Panax ginseng attenuates inflammation-mediated NLRP3 inflammasome activation

ETHNOPHARMACOLOGICAL RELEVANCE

Panax ginseng C.A. Meyer (Araliaceae), has been used in traditional medicine for preventive and therapeutic purposes in Asian countries. One of the active ginsenoside metabolites, 20(S)-Protopanaxatriol (PPT), has been associated with diverse pharmacological effects, including anti-inflammatory properties.

AIM OF THE STUDY

Although the capacity of PPT as an anti-inflammatory agent has been studied, this study aimed to explore the intrinsic mechanism of PPT in regulating inflammasome activation-mediated inflammatory responses in experimental models.

MATERIALS AND METHODS

Lipopolysaccharide (LPS)-primed peritoneal macrophages in vitro was used to study the role of PPT on inflammasome activation. LPS-induced septic shock and monosodium urate (MSU)-induced murine peritonitis models were employed for in vivo evaluations.

RESULTS

PPT attenuated NLRP3 inflammasome activation and also reduced ASC oligomerization, leading to attenuation of interleukin (IL)-1β secretion. Further, PPT inhibited IL-1β secretion in both LPS-induced septic shock and MSU-induced mouse peritonitis models.

CONCLUSIONS

This study revealed that ginsenoside metabolite PPT, inhibits inflammation-mediated inflammasome activation and supported the traditional use of ginseng in treating various inflammatory disorders.

Cinnamomum cassia Presl: A Review of Its Traditional Uses, Phytochemistry, Pharmacology and Toxicology

Cinnamomum cassia Presl is a tropical aromatic evergreen tree of the Lauraceae family, commonly used in traditional Chinese medicine. It is also a traditional spice, widely used around the world. This paper summarizes the achievements of modern research on C. cassia, including the traditional uses, phytochemistry, pharmacology and toxicology. In addition, this review also discusses some significant issues and the potential direction of future C. cassia research. More than 160 chemicals have been separated and identified from C. cassia. The main constituents of C. cassia are terpenoids, phenylpropanoids, glycosides, etc. Modern studies have confirmed that C. cassia has a wide range of pharmacological effects, including antitumour, anti-inflammatory and analgesic, anti-diabetic and anti-obesity, antibacterial and antiviral, cardiovascular protective, cytoprotective, neuroprotective, immunoregulatory effects, anti-tyrosinase activity and other effects. However, the modern studies of C. cassia are still not complete and more in-depth investigations need to be conducted in alimentotherapy, health product, toxicity and side effects, and more bioactive components and potential pharmacological effects need to be explored in the future.

AMPK as a potential pharmacological target for alleviating LPS-induced acute lung injury partly via NLRC4 inflammasome pathway inhibition

Old people are spectacularly susceptible to acute lung injury (ALI) and the accompanying complications. An acute aggravated inflammatory response is a characteristic feature of ALI, and inflammasomes play a critical role in the inflammatory response. Metformin has been shown to be an effective anti-inflammatory agent in ALI. However, the mechanism of this regulation still remains poorly understood. In this study, 18- to 19-month-old male mice were treated by intratracheal instillation of lipopolysaccharide (LPS) or PBS with or without metformin pretreatment. We found that the metformin pretreatment alleviated the lung injury and decreased the levels of TNF-a, IL-1β and IL-6 in the bronchoalveolar lavage fluid (BALF) and in lung tissues, as well as the levels of NLRP3, NLRC4 and cleaved caspase-1 associated with LPS-induced ALI in old mice. Furthermore, the in vitro study showed metformin dose-dependently suppressed NLRC4 inflammasome expression. Metformin activated AMPK by phosphorylation; thus, we investigated the role of AMPK in NLRC4 activation. The results demonstrated that the efficacy of metformin was reduced when using the AMPK pharmacological inhibitor compound C or AMPKα₁ expression was knocked down in RAW 264.7 cells. In conclusion, our data indicated that metformin may inhibit NLRC4 inflammasome activation in LPS-induced ALI in old mice through AMPK signaling, and further understanding of the AMPK/NLRC4 axis may provide a novel therapeutic strategy for LPS-induced ALI in the future.

4-(2-(4-chlorophenyl)-1-((4-chlorophenyl)amino)ethyl)benzene-1, 3-diol is a potential agent for gout therapy as a dual inhibitor of XOD and NLRP3

BACKGOUND

Gout is an inflammatory arthritis characterized by abrupt self-limiting attacks of inflammation caused by precipitation of monosodium urate crystals (MSU) in the joint. Both anti-hyperuricemia and anti-inflammation could be gout therapeutic strategies, whereas ideal drugs for gout treatment are deficient.

PURPOSE

4-(2-(4-chlorophenyl)-1-((4-chlorophenyl)amino)ethyl)benzene-1, 3-diol (CBED) was obtained from a cluster of deoxybenzoins derivatives synthesized by our research group with potent anti-hyperuricemic and anti-inflammatory activities, which was expected to be a dual inhibitor of xanthine oxidase (XOD) and NOD-like receptor protein 3 (NLRP3). This study aimed to investigate effects of CBED on XOD and NLRP3 in vitro, as well as the possible mechanisms by which CBED improved gout in vivo.

METHODS

After molecular docking detection, inhibitory effects of CBED on XOD and NLRP3 were evaluated in vitro. Subsequently, hyperuricemia and acute gouty arthritis animal models were established by potassium oxonate or MSU, respectively. After CBED treatment, serum uric acid levels, synovial interleukin (IL)-1β concentrations, hepatic XOD activities, as well as synovial morphological changes were examined. More importantly, synovial expressions of NLRP3 inflammasome components including NLRP3, apoptosis-associated speck-like protein (ASC) and caspase-1 in rats were analyzed by immunofluorescence and western blot.

RESULTS

In vitro, CBED obviously inhibited XOD activity with an IC₅₀ value of 3.87 µM, moreover, it effectively inhibited MSU-induced NLRP3 inflammasome activation and IL-1β over-production in THP-1 cells. In addition, CBED dose-dependently decreased serum uric acid levels suppressed hepatic XOD activities in oxonate-induced hyperuricemic mice. On the other hand, CBED significantly improved MSU-induced ankle swelling and histopathological damage with elevated IL-1β. In addition, NLRP3 inflammasome activation could be blocked by CBED treatment in rats with acute gouty arthritis. Notbly, CBED exhibited no effects on all these indicators in normal animals, predicting its safety.

CONCLUSIONS

CBED might serve as a dual XOD and NLRP3 inhibitor for treatment of gout.

Artemisia Extract Suppresses NLRP3 and AIM2 Inflammasome Activation by Inhibition of ASC Phosphorylation

Artemisia princeps var. orientalis (Asteraceae, A. princeps) is a well-known traditional medicinal herb used for treating various inflammatory disorders in Korea, Japan, China, and other Asian countries. In the present study, we investigated the effects of A. princeps extract (APO) on interleukin- (IL-) 1β regulation and inflammasome activation in bone marrow-derived macrophages (BMDMs) and monosodium urate- (MSU-) induced peritonitis mouse model in vivo. The APO treatment to BMDMs primed with lipopolysaccharide (LPS) attenuated the NLRP3 and AIM2 inflammasome activation induced by danger signals, such as ATP, nigericin, silica crystals, and poly (dA:dT), respectively. Mechanistic study revealed that APO suppressed the ASC oligomerization and speck formation, which are required for inflammasome activation. APO treatment also reduced the ASC phosphorylation induced by the combination of LPS and a tyrosine phosphatase inhibitor. In vivo evaluation revealed that intraperitoneal administration of APO reduced IL-1β levels, significantly (p < 0.05) and dose dependently, in the MSU-induced peritonitis mouse model. In conclusion, our study is the first to report that the extract of A. princeps inhibits inflammasome activation through the modulation of ASC phosphorylation. Therefore, APO might be developed as therapeutic potential in the treatment of inflammasome-mediated inflammatory disorders, such as gouty arthritis.

BOT-4-one attenuates NLRP3 inflammasome activation: NLRP3 alkylation leading to the regulation of its ATPase activity and ubiquitination

The ATPase activity of NLRP3 has pivotal role in inflammasome activation and is recognized as a good target for the development of the NLRP3 inflammasome-specific inhibitor. However, signals in the vicinity of the ATPase activity of NLRP3 have not been fully elucidated. Here, we demonstrate NLRP3 inflammasome-specific action of a benzoxathiole derivative, BOT-4-one. BOT-4-one exhibited an inhibition of NLRP3 inflammasome activation, which was attributable to its alkylating capability to NLRP3. In particular, the NLRP3 alkylation by BOT-4-one led to an impaired ATPase activity of NLRP3, thereby obstructing the assembly of the NLRP3 inflammasome. Additionally, we found that NLRP3 alkylators, including BOT-4-one, enhance the ubiquitination level of NLRP3, which might also contribute to the inhibition of NLRP3 inflammasome activation. Finally, BOT-4-one appeared to be superior to other known NLRP3 alkylators in inhibiting the functionality of the NLRP3 inflammasome and its resulting anti-inflammatory activity was confirmed in vivo using a monosodium urate-induced peritonitis mouse model. Collectively, the results suggest that NLRP3 alkylators function by inhibiting ATPase activity and increasing the ubiquitination level of NLRP3, and BOT-4-one could be the type of NLRP3 inhibitor that may be potentially useful for the novel development of a therapeutic agent in controlling NLRP3 inflammasome-related diseases.