Tanshinones inhibit NLRP3 inflammasome activation by alleviating mitochondrial damage to protect against septic and gouty inflammation

Folium Hibisci Mutabilis extract suppresses M1 macrophage polarization through mitochondrial function enhancement in murine acute gouty arthritis

BACKGROUND

Acute gout arthritis (AGA) is a common metabolic joint disease and urgently needs a safer alternative therapy due to the significant side effects from long-term use of primary medications. Folium Hibisci Mutabilis, a traditional medicinal herb, has demonstrated promising therapeutic efficacy in the clinical management of AGA, but its pharmacological mechanisms remain to be elucidated.

METHODS

Folium Hibisci Mutabili was isolated and refined into the Folium Hibisci Mutabilis Extract (FHME). Then, monosodium urate-induced AGA animal models were applied to identify the anti-inflammatory and analgesic effects of FHME in vivo through various techniques, including ultrasonography, Paw withdrawal thresholds, histological staining, etc. We used RNA-seq, qRT-PCR, ELISA, and flow cytometry to evaluate the efficacy of FHME on M1 polarization. Utilizing transmission electron microscope and oxygen consumption rate examinations in conjunction with Mito-Tracker staining, we observed the effects of FHME on mitochondrial morphology and function. Finally, we employed proteomics analysis, siRNA, qRT-PCR, western blot and other techniques to investigate the underlying mechanism of FHME's actions between the two phenotypes and the key targets.

RESULTS

We observed a notable reduction in inflammation and pain, as well as the decreased infiltration of inflammatory cells and expression of IL-1β in synovial tissue of AGA mice upon treatment with FHME. FHME suppressed TNF-α, IL-1β, iNOS, and IL-18 expression in BMDM-derived macrophages and inhibited the formation of F4/80+CD86+ cells. Mechanically, FHME protected mitochondrial morphology and stimulated the expression of key oxidative phosphorylation proteins, such as Ubiquinol Cytochrome c Reductase Core Protein I (UQCRC1), UQCRC2, CYCS, and NDUFA4. Additionally, it enhanced the activity of respiratory complex III, recovered cellular aerobic respiration under LPS and MSU induction. FHME lost its effect to downregulate M1 macrophage polarization with the presence of rotenone or si-UQCRC1. Finally, 10 compounds were identified from FHME having potential binding affinity with the UQCRC1 protein.

CONCLUSIONS

The therapeutic potential of FHME for AGA is associated with the maintenance of mitochondrial function to inhibit M1 macrophage polarization, which is intimately linked to the UQCRC1. Our findings highlight the potential of Folium Hibisci Mutabilis as a safe and effective approach for AGA.

Traditional herbal medicine: Therapeutic potential in acute gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Acute gouty arthritis (AGA) is characterized by a rapid inflammatory reaction caused by the build-up of monosodium urate (MSU) crystals in the tissues surrounding the joints. This condition often associated with hyperuricemia (HUA), is distinguished by its symptoms of intense pain, active inflammation, and swelling of the joints. Traditional approaches in AGA management often fall short of desired outcomes in clinical settings. However, recent ethnopharmacological investigations have been focusing on the potential of Traditional Herbal Medicine (THM) in various forms, exploring their therapeutic impact and targets in AGA treatment.

AIM OF THE REVIEW

This review briefly summarizes the current potential pharmacological mechanisms of THMs - including active ingredients, extracts, and prescriptions -in the treatment of AGA, and discusses the relevant potential mechanisms and molecular targets in depth. The objective of this study is to offer extensive information and a reference point for the exploration of targeted AGA treatment using THMs.

MATERIALS AND METHODS

This review obtained scientific publications focused on in vitro and in vivo studies of anti-AGA THMs conducted between 2013 and 2023. The literature was collected from various journals and electronic databases, including PubMed, Elsevier, ScienceDirect, Web of Science, and Google Scholar. The retrieval and analysis of relevant articles were guided by keywords such as "acute gouty arthritis and Chinese herbal medicine," "acute gouty arthritis herbal prescription," "acute gouty arthritis and immune cells," "acute gouty arthritis and inflammation," "acute gouty arthritis and NOD-like receptor thermoprotein domain associated protein 3 (NLRP3)," "acute gouty arthritis and miRNA," and "acute gouty arthritis and oxidative stress."

RESULTS

We found that AGA has a large number of therapeutic targets, highlighting the effectiveness the potential of THMs in AGA treatment through in vitro and in vivo studies. THMs and their active ingredients can mitigate AGA symptoms through a variety of therapeutic targets, such as influencing macrophage polarization, neutrophils, T cells, natural killer (NK) cells, and addressing factors like inflammation, NLRP3 inflammasome, signaling pathways, oxidative stress, and miRNA multi-target interactions. The anti-AGA properties of THMs, including their active components and prescriptions, were systematically summarized and categorized based on their respective therapeutic targets.

CONCLUSION

phenolic, flavonoid, terpenoid and alkaloid compounds in THMs are considered the key ingredients to improve AGA. THMs and their active ingredients achieve enhanced efficacy through interactions with multiple targets, of which NLRP3 is a main therapeutic target. Nonetheless, given the intricate composition of traditional Chinese medicine (TCM), additional research is required to unravel the underlying mechanisms and molecular targets through which THMs alleviate AGA.

Mechanism of Reactive Oxygen Species-Guided Immune Responses in Gouty Arthritis and Potential Therapeutic Targets

Gouty arthritis (GA) is an inflammatory disease caused by monosodium urate (MSU) crystals deposited in the joint tissues causing severe pain. The disease can recur frequently and tends to form tophus in the joints. Current therapeutic drugs for the acute phase of GA have many side effects and limitations, are unable to prevent recurrent GA attacks and tophus formation, and overall efficacy is unsatisfactory. Therefore, we need to advance research on the microscopic mechanism of GA and seek safer and more effective drugs through relevant targets to block the GA disease process. Current research shows that the pathogenesis of GA is closely related to NLRP3 inflammation, oxidative stress, MAPK, NET, autophagy, and Ferroptosis. However, after synthesizing and sorting out the above mechanisms, it is found that the presence of ROS is throughout almost the entire spectrum of micro-mechanisms of the gout disease process, which combines multiple immune responses to form a large network diagram of complex and tight connections involved in the GA disease process. Current studies have shown that inflammation, oxidative stress, cell necrosis, and pathological signs of GA in GA joint tissues can be effectively suppressed by modulating ROS network-related targets. In this article, on the one hand, we investigated the generative mechanism of ROS network generation and its association with GA. On the other hand, we explored the potential of related targets for the treatment of gout and the prevention of tophus formation, which can provide effective reference ideas for the development of highly effective drugs for the treatment of GA.

Targeting the NLRP3 inflammasome in psoriasis

The NLRP3 inflammasome, a complex consisting of the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing protein 3, has emerged as a critical mediator of pathological inflammation and a significant therapeutic target for various inflammatory diseases. Psoriasis, a chronic inflammatory skin condition without a definitive cure, has shown promising results in animal models through the inhibition of the NLRP3 inflammasome. This review aims to explore the development of the NLRP3 inflammasome in psoriasis and the molecular mechanisms responsible for its inhibition by natural products and small molecules currently being developed for psoriasis treatment. Furthermore, we are examining clinical trials using agents that block the NLRP3 pathway for the treatment of psoriasis. This study is timely to provide a new perspective on managing psoriasis.

Design, synthesis and biological evaluation of tanshinone IIA derivatives as NLRP3 inflammasome inhibitors

Natural product structures have long provided valuable pharmacophores and even candidates for drug discovery. Tanshinone scaffold showed moderately inhibitory activity in NLRP3 inflammasome/IL-1β pathway. Herein, we designed a series of derivatives on different regions of Tanshinone IIA (TNA) scaffold. The biological evaluation identified compound T10, a scaffold hybrid of TNA and salicylic acid, as a potent NLRP3 inflammasome inhibitor. Mechanistically, T10 inhibits the production of ROS and prevents NLRP3 inflammasome-dependent IL-1β production. In addition, treatment with T10 significantly attenuated inflammatory response in DSS-induced peritonitis. Our work describes a potential tanshinone-based derivative, which needs to be further structurally optimized as NLRP3 inflammasome inhibitors for treating inflammatory disorders.

Ozone alleviates MSU-induced acute gout pain via upregulating AMPK/GAS6/MerTK/SOCS3 signaling pathway

BACKGROUND

Gout pain seriously affects the quality of patients' life. There is still no effective treatment. The inflammatory response is the main mechanism of gout. Here, we found that ozone can reduce the inflammatory reaction in the joints of gouty mice and relieve gout pain, and we further explore its protective mechanism.

METHODS

MSU was used to establish the gouty mice model. Nociception was assessed by Von Frey hairs. Cell signaling assays were performed by western blotting and immunohistochemistry. The mouse leukemia cells of monocyte macrophage line RAW264.7 were cultured to investigate the effects of ozone administration on macrophage.

RESULTS

Ozone reduced inflammation, relieved gout pain and improved the paw mean intensity and duty cycle of the gouty mice. Ozone increased the phosphorylation of AMP-activated protein kinase (AMPK), induced suppressor of cytokine signaling 3 (SOCS3) expression and inhibited metallopeptidase 9 (MMP9) expression. In vivo, ozone activated AMPK to induce Gas6 release, and upregulated MerTK/SOCS3 signaling pathway to reduce inflammation in mouse macrophage line RAW264.7. Inhibitors of AMPK and MerTK, respectively abolished the analgesic and anti-inflammatory effects of ozone in vivo and in vitro. Gas6 knockout cancelled the protectively effects of ozone on gout pain and the paw mean intensity and duty cycle of gouty mice. Additionally, the level of Gas6 and protein S in plasma of patients with hyperuricemia was significantly higher than that of healthy contrast group.

CONCLUSION

Ozone reduces inflammation and alleviates gout pain by activating AMPK to up-regulate Gas6/MerTK/SOCS3 signaling pathway.

Advanced application of nanotechnology in active constituents of Traditional Chinese Medicines

Traditional Chinese Medicines (TCMs) have been used for centuries for the treatment and management of various diseases. However, their effective delivery to targeted sites may be a major challenge due to their poor water solubility, low bioavailability, and potential toxicity. Nanocarriers, such as liposomes, polymeric nanoparticles, inorganic nanoparticles and organic/inorganic nanohybrids based on active constituents from TCMs have been extensively studied as a promising strategy to improve the delivery of active constituents from TCMs to achieve a higher therapeutic effect with fewer side effects compared to conventional formulations. This review summarizes the recent advances in nanocarrier-based delivery systems for various types of active constituents of TCMs, including terpenoids, polyphenols, alkaloids, flavonoids, and quinones, from different natural sources. This review covers the design and preparation of nanocarriers, their characterization, and in vitro/vivo evaluations. Additionally, this review highlights the challenges and opportunities in the field and suggests future directions for research. Nanocarrier-based delivery systems have shown great potential in improving the therapeutic efficacy of TCMs, and this review may serve as a comprehensive resource to researchers in this field.

Tiliroside Attenuates NLRP3 Inflammasome Activation in Macrophages and Protects against Acute Lung Injury in Mice

The Nod-like receptor family PYRIN domain containing 3 (NLRP3) inflammasome is a multiprotein signaling complex that plays a pivotal role in innate immunity, and the dysregulated NLRP3 inflammasome activation is implicated in various diseases. Tiliroside is a natural flavonoid in multiple medicinal and dietary plants with known anti-inflammatory activities. However, its role in regulating NLRP3 inflammasome activation and NLRP3-related disease has not been evaluated. Herein, it was demonstrated that tiliroside is inhibitory in activating the NLRP3 inflammasome in macrophages. Mechanistically, tiliroside promotes AMP-activated protein kinase (AMPK) activation, thereby leading to ameliorated mitochondrial damage as evidenced by the reduction of mitochondrial reactive oxygen species (ROS) production and the improvement of mitochondrial membrane potential, which is accompanied by attenuated NLRP3 inflammasome activation in macrophages. Notably, tiliroside potently attenuated lipopolysaccharide (LPS)-induced acute lung injury in mice, which has been known to be NLRP3 inflammasome dependent. For the first time, this study identified that tiliroside is an NLRP3 inflammasome inhibitor and may represent a potential therapeutic agent for managing NLRP3-mediated inflammatory disease.

Influence of intestinal microecology in the development of gout or hyperuricemia and the potential therapeutic targets

Gout and hyperuricemia are common metabolic diseases. Patients with purine metabolism disorder and/or decreased uric acid excretion showed increased uric acid levels in the blood. The increase of uric acid in the blood leads to the deposition of urate crystals in tissues, joints, and kidneys, and causes gout. Recent studies have revealed that imbalance of the intestinal microecology is closely related to the occurrence and development of hyperuricemia and gout. Disorder of the intestinal flora often occurs in patients with gout, and high purine and high fructose may induce the disorder of intestinal flora. Short-chain fatty acids and endotoxins produced by intestinal bacteria are closely related to the inflammatory response of gout. This article summarizes the characteristics of intestinal microecology in patients or animal models with hyperuricemia or gout, and explores the relationship between intestinal microecology and gout or hyperuricemia from the aspect of the intestinal barrier, intestinal microorganisms, intestinal metabolites, and intestinal immune system. We also review the current status of hyperuricemia treatment by targeting intestinal microecology.

Metformin derivatives - Researchers' friends or foes?

Metformin has been used for ages to treat diabetes mellitus due to its safety profile and low cost. However, metformin has variable pharmacokinetics in patients, and due to its poor oral absorption, the therapeutic doses are relatively high, causing unpleasant gastrointestinal adverse effects. Therefore, novel derivatives of metformin have been synthesized during the past decades. Particularly, after the mid-2000 s, when organic cation transporters were identified as the main metformin carriers, metformin derivatives have been under intensive investigation. Nevertheless, due to the biguanide structure, derivatives of metformin have been challenging to synthesize. Moreover, the mechanisms of metformin's action are not fully understood to date, and since it has multifunctional properties, the interests have switched to re-purposing for other diseases. Indeed, metformin derivatives have been demonstrated in many cases to be more effective than metformin itself and have the potential to be used in different diseases, including several types of cancers and neurodegenerative diseases. On the other hand, the pleiotropic nature of metformin and its derivatives can also create challenges. Not all properties are fit for all diseases. In this review, the history of the development of metformin-like compounds is summarized, and insights into their potential for future drug discovery are discussed.

Tanshinone I specifically suppresses NLRP3 inflammasome activation by disrupting the association of NLRP3 and ASC

BACKGROUND

Abnormal activation of NLRP3 inflammasome is related to a series of inflammatory diseases, including type 2 diabetes, gouty arthritis, non-alcoholic steatohepatitis (NASH), and neurodegenerative disorders. Therefore, targeting NLRP3 inflammasome is regarded as a potential therapeutic strategy for many inflammatory diseases. A growing number of studies have identified tanshinone I (Tan I) as a potential anti-inflammatory agent because of its good anti-inflammatory activity. However, its specific anti-inflammatory mechanism and direct target are unclear and need further study.

METHODS

IL-1β and caspase-1 were detected by immunoblotting and ELISA, and mtROS levels were measured by flow cytometry. Immunoprecipitation was used to explore the interaction between NLRP3, NEK7 and ASC. In a mouse model of LPS-induced septic shock, IL-1β levels in peritoneal lavage fluid and serum were measured by ELISA. Liver inflammation and fibrosis in the NASH model were analyzed by HE staining and immunohistochemistry.

RESULTS

Tan I inhibited the activation of NLRP3 inflammasome in macrophages, but had no effect on the activation of AIM2 or NLRC4 inflammasome. Mechanistically, Tan I inhibited NLRP3 inflammasome assembly and activation by targeting NLRP3-ASC interaction. Furthermore, Tan I exhibited protective effects in mouse models of NLRP3 inflammasome-mediated diseases, including septic shock and NASH.

CONCLUSIONS

Tan I specifically suppresses NLRP3 inflammasome activation by disrupting the association of NLRP3 and ASC, and exhibits protective effects in mouse models of LPS-induced septic shock and NASH. These findings suggest that Tan I is a specific NLRP3 inhibitor and may be a promising candidate for treating NLRP3 inflammasome-related diseases.

Crocin Attenuates NLRP3 Inflammasome Activation by Inhibiting Mitochondrial Reactive Oxygen Species and Ameliorates Monosodium Urate-Induced Mouse Peritonitis

Crocin is a hydrophilic carotenoid pigment found in the stigma of Crocus sativus or the fruit of Gardenia jasminoides. In this study, we investigated the effects of Crocin on the activation of the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 (NLRP3) inflammasome in J774A.1 murine macrophage cells and monosodium urate (MSU)-induced peritonitis. Crocin significantly inhibited Nigericin-, adenosine triphosphate (ATP)-, MSU-induced interleukin (IL)-1β secretion, and caspase-1 cleavage without affecting pro-IL-1β and pro-caspase-1. Crocin also suppressed gasdermin-D cleavage and lactate dehydrogenase release and enhanced cell viability, indicating that Crocin reduces pyroptosis. Similar effects were observed in primary mouse macrophages. However, Crocin did not affect poly(dA:dT)-induced absent in melanoma 2 (AIM2) and muramyl dipeptide-induced NLRP1 inflammasomes. Crocin decreased Nigericin-induced oligimerization and the speck formation of apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC). Crocin also dramatically alleviated the ATP-induced production of mitochondrial reactive oxygen species (mtROS). Finally, Crocin ameliorated the MSU-induced production of IL-1β and IL-18 and the recruitment of neutrophils during peritoneal inflammation. These results suggest that Crocin suppresses NLRP3 inflammasome activation by blocking mtROS production and ameliorates MSU-induced mouse peritonitis. Thus, Crocin may have therapeutic potential in various NLRP3 inflammasome-related inflammatory diseases.

Scaffold Hybrid of the Natural Product Tanshinone I with Piperidine for the Discovery of a Potent NLRP3 Inflammasome Inhibitor

Natural products provide inspiration and have proven to be the most valuable source for drug discovery. Herein, we report a scaffold hybrid strategy of Tanshinone I for the discovery of NLRP3 inflammasome inhibitors. 36 compounds were designed and synthesized, and the cheminformatic analyses showed that these compounds occupy a unique chemical space. The biological evaluation identified compounds 5j, 12a, and 12d as NLRP3 inflammasome inhibitors with significant potency, selectivity, and drug-likeness. Mechanistic studies revealed that these Tanshinone I derivatives could inhibit the degradation of the protein NLRP3 and block the oligomerization of NLRP3-induced apoptosis-associated speck-like proteins, thus inhibiting NLRP3 inflammasome activation. In addition, the water solubility, in vitro metabolic stability, and oral bioavailability of these compounds were also greatly improved compared to Tanshinone I. Therefore, this protocol provides a new structural evolution of Tanshinone I and a new class of potent NLRP3 inflammasome inhibitors.

Osthole: A potential AMPK agonist that inhibits NLRP3 inflammasome activation by regulating mitochondrial homeostasis for combating rheumatoid arthritis

BACKGROUND

Osthole (OST), a characteristic coumarin compound in Angelicae pubescentis radix (APR), has shown potent efficacy in the treatment of rheumatoid arthritis (RA), but its specific targets and potential mechanism are limited.

PURPOSE

This study aimed to explore the potential targets and molecular mechanisms of OST against RA using computer-assisted techniques in combination with RA fibroblast-like synoviocytes (FLS) inflammation model and CIA rat model.

METHODS

Network pharmacology and molecular docking were applied to initially predict the potential targets of OST for the treatment of RA. Thereafter, TNFα was used to stimulate FLS to build an in vitro model of inflammation, combined with RNA-seq technology and molecular biology such as qPCR to investigate the anti-inflammatory effects and related mechanisms of OST. Finally, the anti-RA effect of OST was demonstrated by establishing a CIA rat model.

RESULTS

The network model results showed that the anti-RA effect of OST was mainly related to its anti-inflammatory effect, and AMPK was identified as a potential target for the potency of OST. In the TNFα-induced FLS cells, OST inhibited the secretion of FLS inflammatory factors, which was attributed to the ability of OST to activate AMPK to inhibit the activation of the NLRP3 inflammasome. Further, it was observed that the activation of AMPK by OST facilitated mitochondrial biogenesis, and corrected abnormal mitochondrial dynamics in FLS, which was favoured to the restoration of mitochondrial homeostasis, and further promoted the occurrence of apoptosis and the decrease of ROS in FLS. Consistent with in vivo studies, administration of OST significantly improved joint deformity and toe erythema, reduced arthritis index scores and inhibited synovial inflammation in CIA rats.

CONCLUSION

Our study proposed for the first time that AMPK, served as a potential target of OST, positively participated in the anti-RA therapeutic effect of OST. By regulating mitochondrial homeostasis and function, OST can effectively inhibit the activation of inflammasome and the secretion of inflammatory factors in vitro and in vivo, and finally achieve beneficial effects in the treatment of RA, which provides support and greater possibility to make further efforts on pharmacological research and clinical application of OST.

NAD+ supplementation improves mAb productivity in CHO cells via a glucose metabolic shift

Aerobic glycolysis and its by-product lactate accumulation are usually associated with adverse culture phenotypes such as poor cell viability and productivity. Due to the lack of knowledge on underlying mechanisms and accompanying biological processes, the regulation of aerobic glycolysis has been an ongoing challenge in culture process development for therapeutic protein productivity. Nicotinamide adenine dinucleotide (NAD⁺ ), a coenzyme and co-substrate in energy metabolism, promotes the conversion of inefficient glycolysis into an efficient oxidative phosphorylation (OXPHOS) pathway. However, the effect of NAD⁺ on Chinese hamster ovary (CHO) cells for biopharmaceutical production has not been reported yet. In this work, we aimed to elucidate the influence of NAD⁺ on cell culture performance by examining metabolic shifts and mAb productivity. The supplementation of NAD⁺ increased the intracellular concentration of NAD⁺ and promoted SIRT3 expression. Antibody titer and the specific productivity in the growth phase were improved by up to 1.82- and 1.88-fold, respectively, with marginal restrictions on cell growth. NAD⁺ significantly reduced the accumulation of reactive oxygen species (ROS) and the lactate yield from glucose, determined by lactate accumulation versus glucose consumption (Y_LAC/GLC ). In contrast, OXPHOS capacity and amino acid consumption rate increased substantially. Collectively, these results suggest that NAD⁺ contributes to improving therapeutic protein productivity in bioprocessing via inducing an energy metabolic shift.

Chlorquinaldol inhibits the activation of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 inflammasome and ameliorates imiquimod-induced psoriasis-like dermatitis in mice

Psoriasis is a common chronic autoinflammatory/autoimmune skin disease associated with elevated pro-inflammatory cytokines. The pivotal role of interleukin (IL)-1β and nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome in the pathogenesis of psoriasis has been widely described. Accordingly, the suppression of NLRP3-dependent IL-1β release is a potential therapy for psoriasis. Repurposing marketed drugs is a strategy for identifying new inhibitors of NLRP3 inflammasome activation. Herein, chlorquinaldol (CQD), a historic antimicrobial agent used as a topical treatment for skin and vaginal infections, was found to have a distinct effect by inhibiting NLRP3 inflammasome activation at concentrations ranging from 2 to 6 μM. CQD significantly suppressed apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) oligomerization, NLRP3-ASC interaction, and pyroptosis in macrophages. The levels of cleaved IL-1β and caspase-1 were reduced by CQD in the cell lysates of macrophages, suggesting that CQD acted on upstream of pore formation in the cell membrane. Mechanistically, CQD reduced mitochondrial reactive oxygen species production but did not affect the nuclear factor-κB (NF-κB) pathway. Intraperitoneal administration of CQD (15 mg/kg) for 6 days was found to improve the skin lesions in the imiquimod-induced psoriatic mouse model (male C57BL/6 mice), while secretion of pro-inflammatory cytokines (IL-17 and IL-1β) and keratinocyte proliferation were significantly suppressed by CQD. In conclusion, CQD exerted inhibitory effects on NLRP3 inflammasome activation in macrophages and decreased the severity of psoriatic response in vivo. Such findings indicate that the repurposing of the old drug, CQD, is a potential pharmacological approach for the treatment of psoriasis and other NLRP3-driven diseases.

Tectoridin alleviates lipopolysaccharide -induced inflammaion via inhibiting TLR4-NF-κB/NLRP3 signaling in vivo and in vitro

BACKGROUD

Tectoridin, widely extracted and separated from the rhizome of Iris tectorum Maxium, is extensively reported to have affluent bioactivity, but rarely reported to have anti-inflammatory effects. In this study, we aim to investigate the anti-inflammatory effects and the underlying mechanisms of tectoridin.

METHODS

Here, RAW264.7 macrophages were stimulated with Lipopolysaccharide (LPS) for the inflammation model in vitro. Experimental animals received tectoridin and Dexamethasone (DEX) before LPS injection for endotoxic shock mouse model in vivo. The pro-inflammatory mediators and cytokines in the cell supernatant and serum were detected by ELISA kits. The tissue damages were assessed by biochemical indexes and H&E staining. Immunohistochemistry and Western blot were performed for the detection of proteins.

RESULTS

Our data showed that tectoridin attenuated the LPS-up-regulated nitric oxide (NO), interleukin-6, (IL-6) and interleukin-18, (IL-18) from macrophages and tumor necrosis factor-α, (TNF-α); (IL-6) and (IL-1β) in the serum levels. Besides, our histopathological study showed that the damages caused by LPS in the lung, liver and kidney tissues were decreased. Furthermore, our results demonstrated that tectoridin inhibited the activation of TLR4-NF-κB/NLRP3 signaling proved by immunohistochemistry assay and Western blot.

CONCLUSION

Taken all together, tectoridin might have the potential ability of anti-inflammatory effects and the possible mechanism may be relevant to its inhibition of TLR4-NF-κB/NLRP3 signaling.

Molecular Mechanism of Salvia miltiorrhiza Bunge in Treating Cerebral Infarction

Background

Cerebral infarction (CI) is a common brain disease in clinical practice, which is mainly due to the pathological environment of ischemia and hypoxia caused by difficult cerebral circulation perfusion function, resulting in ischemic necrosis of local brain tissue and neurological impairment. In traditional Chinese medicine (TCM) theory, CI is mainly due to blood stasis in the brain. Therefore, blood-activating and stasis-dissipating drugs are often used to treat CI in clinical practice. Salvia miltiorrhiza Bunge (SMB) is a kind of traditional Chinese medicine with good efficacy in promoting blood circulation and removing blood stasis, and treatment of CI with it is a feasible strategy. Based on the above analysis, we chose network pharmacology to investigate the feasibility of SMB in the treatment of CI and to study the possible molecular mechanisms by providing some reference for the treatment of CI with TCM.

Methods

The active ingredients and related targets of SMB were obtained through the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and CI-related targets were obtained from the GeneCards and DisGeNET databases. The target of SMB for the treatment of CI was obtained using Cytoscape software and visualized. GO and KEGG enrichment analysis was performed based on “clusterProfiler” within R, and the prediction results were validated by molecular docking technique.

Results

By constructing a compound-target (C-T) network, it was found that the active components in SMB mainly treated CI by regulating key proteins such as AKT1, IL-6, and EGFR. These key proteins mainly involve in pathways such as immune regulation, cancer and lipid metabolism, such as lipid and atherosclerosis, chemical carcinogenesis-receptor activation pathways, and IL-17 signaling pathway. In the GO term, it mainly regulates the response to steroid hormones, membrane rafts, and G protein-amine receptor coupled activity. Eventually, we verified that the luteolin and tanshinone IIA components in SMB have a good possibility of action with AKT1 and IL-6 by in silico techniques, indicating that SMB has some scientificity in the treatment of CI.

Conclusion

SMB mainly treats CI by regulating 94 proteins involved in lipid and atherosclerosis, chemical carcinogenesis-receptor activation, and IL-17 signaling pathway. Our research strategy provided a template for the drug development of TCM for the treatment of CI.

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.

Dihydrotanshinone I Specifically Inhibits NLRP3 Inflammasome Activation and Protects Against Septic Shock In Vivo

The abnormal activation of the NLRP3 inflammasome is closely related to the occurrence and development of many inflammatory diseases. Targeting the NLRP3 inflammasome has been considered an efficient therapy to treat infections. We found that dihydrotanshinone I (DHT) specifically blocked the canonical and non-canonical activation of the NLRP3 inflammasome. Nevertheless, DHT had no relation with the activation of AIM2 or the NLRC4 inflammasome. Further study demonstrated that DHT had no influences on potassium efflux, calcium flux, or the production of mitochondrial ROS. We also discovered that DHT suppressed ASC oligomerization induced by NLRP3 agonists, suggesting that DHT inhibited the assembly of the NLRP3 inflammasome. Importantly, DHT possessed a significant therapeutic effect on NLRP3 inflammasome–mediated sepsis in mice. Therefore, our results aimed to clarify DHT as a specific small-molecule inhibitor for the NLRP3 inflammasome and suggested that DHT can be used as a potential drug against NLRP3-mediated diseases.

Enhanced Bioavailability of Dihydrotanshinone I-Bovine Serum Albumin Nanoparticles for Stroke Therapy

Dihydrotanshinone I (DHT) is a natural component in Salvia miltiorrhiza and has been widely researched for its multiple bioactivities. However, poor solubility and biocompatibility of DHT limit its desirable application for clinical purposes. Herein, DHT was encapsulated with bovine serum albumin (BSA) to enhance bioavailability. Compared to free DHT, DHT-BSA NPs (nanoparticles) showed an improved solubility in normal saline and increased protection against hydrogen peroxide-induced oxidative damage in PC12 cells. In addition, DHT-BSA NPs administered by intravenous injection displayed a significant efficacy in the middle cerebral artery occlusion/reperfusion models, without any impact on the cerebral blood flow. In summary, DHT-BSA NPs show an enhanced bioavailability compared with free DHT and a successful penetration into the central nervous system for stroke therapy, demonstrating their application potential in cardio-cerebrovascular diseases.