Natural molecule Munronoid I attenuates LPS-induced acute lung injury by promoting the K48-linked ubiquitination and degradation of TAK1

Inhalable and bioactive lipid-nanomedicine based on bergapten for targeted acute lung injury therapy via orchestrating macrophage polarization

Acute lung injury (ALI) or its more severe form, acute respiratory distress syndrome, is a life-threatening disease closely associated with an imbalance of M1/M2 macrophage polarization. However, current therapeutic strategies for ALI are controversial due to their side effects, restricted administration routes, or poor targeted delivery. The development of herbal medicine has uncovered numerous anti-inflammatory compounds potentially beneficial for ALI therapy. One such compound is the bergapten, a coumarin, which has been isolated from Ficus simplicissima Lour. However, it's been used as an anti-cancer drug and it's effects on ALI remain unexplored. The poor solubility and biodistribution of bergapten heavily limit its application. In this timely report, we developed a bioactive and lung-targeting lipid-nanomedicine by integrating bergapten and DPPC liposome, named as Ber-lipo. A comprehensive series of in vitro experiments confirmed the anti-inflammatory effects of Ber-lipo and its protective roles in maintaining the homeostasis of macrophage polarization and epithelial-endothelial integrity. In a lipopolysaccharide (LPS)-induced ALI mouse model, Ber-lipo can target inflamed lungs and significantly improve lung edema, tissue injury, and pulmonary function, relieve body weight loss, pulmonary permeability, and proinflammatory status, and especially maintain a balance of M1/M2 macrophage polarization. Furthermore, RNA sequencing analysis showed Ber-lipo's potential in effectively treating inflammatory lung diseases such as pneumonia, inhibiting proinflammatory signals, and altering the transcriptome of M1/M2 macrophages-associated genes in lung tissues. Molecular docking and Western blot analyses validated that Ber-lipo suppressed the activation of the TLR4/MyD88/NF-κB signaling axis responsible for ALI progression. In conclusion, this study demonstrates for the first time that new inhalable nanomedicine (Ber-lipo) can target inflamed lungs and ameliorates ALI by reprogramming macrophage polarization to an anti-inflammatory state via inactivating the TLR4/MyD88/NF-κB pathway, hence providing a promising strategy for enhanced ALI therapy in the clinic.

Epigenetic Effects of Natural Products in Inflammatory Diseases: Recent Findings

Inflammation is an essential step for the etiology of multiple diseases. Clinically, due to the limitations of current drugs for the treatment of inflammatory diseases, such as serious side effects and expensive costs, it is urgent to explore novel mechanisms and medicines. Natural products have received extensive attention recently because of their multi-component and multi-target characteristics. Epigenetic modifications are crucial pathophysiological targets for developing innovative therapies for pharmacological interventions. Investigations examining how natural products improving inflammation through epigenetic modifications are emerging. This review state that natural products relieve inflammation via regulating the gene transcription levels through chromosome structure regulated by histone acetylation levels and the addition or deletion of methyl groups on DNA duplex. They could also exert anti-inflammatory effects by modulating the proteins in typical inflammatory signaling pathways by ubiquitin-related degradation and the effect of glycolysis derived free glycosyls. Studies on epigenetic modifications have the potential to facilitate the development of natural products as therapeutic agents. Future research directed at better understanding of how natural products modulate inflammatory processes through less studied epigenetic modifications including neddylation, SUMOylation, palmitoylation and lactylation, may provide new implications. Meanwhile, higher quality preclinical studies and more powerful clinical evidence are still needed to firmly establish the clinical efficacy of the natural products. Trial Registration: ClinicalTrials.gov Identifier: NCT01764204; ClinicalTrials.gov Identifier: NCT05845931; ClinicalTrials.gov Identifier: NCT04657926; ClinicalTrials.gov Identifier: NCT02330276.

Natural products: A potential immunomodulators against inflammatory-related diseases

The incidence and prevalence of inflammatory-related diseases (IRDs) are increasing worldwide. Current approved treatments for IRDs in the clinic are combat against inhibiting the pro-inflammatory cytokines. Though significant development in the treatment in the IRDs has been achieved, the severe side effects and inefficiency of currently practicing treatments are endless challenge. Drug discovery from natural sources is efficacious over a resurgence and also natural products are leading than the synthetic molecules in both clinical trials and market. The use of natural products against IRDs is a conventional therapeutic approach since it is a reservoir of unique structural chemistry, accessibility and bioactivities with reduced side effects and low toxicity. In this review, we discuss the cause of IRDs, treatment of options for IRDs and the impact and adverse effects of currently practicing clinical drugs. As well, the significant role of natural products against various IRDs, the limitations in the clinical development of natural products and thus pave the way for development of natural products as immunomodulators against IRDs are also discussed.

Echinatin attenuates acute lung injury and inflammatory responses via TAK1-MAPK/NF-κB and Keap1-Nrf2-HO-1 signaling pathways in macrophages

Echinatin is an active ingredient in licorice, a traditional Chinese medicine used in the treatment of inflammatory disorders. However, the protective effect and underlying mechanism of echinatin against acute lung injury (ALI) is still unclear. Herein, we aimed to explore echinatin-mediated anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated ALI and its molecular mechanisms in macrophages. In vitro, echinatin markedly decreased the levels of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated murine MH-S alveolar macrophages and RAW264.7 macrophages by suppressing inducible nitric oxide synthase and cyclooxygenase-2 (COX-2) expression. Furthermore, echinatin reduced LPS-induced mRNA expression and release of interleukin-1β (IL-1β) and IL-6 in RAW264.7 cells. Western blotting and CETSA showed that echinatin repressed LPS-induced activation of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways through targeting transforming growth factor-beta-activated kinase 1 (TAK1). Furthermore, echinatin directly interacted with Kelch-like ECH-associated protein 1 (Keap1) and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway to enhance heme oxygenase-1 (HO-1) expression. In vivo, echinatin ameliorated LPS-induced lung inflammatory injury, and reduced production of IL-1β and IL-6. These findings demonstrated that echinatin exerted anti-inflammatory effects in vitro and in vivo, via blocking the TAK1-MAPK/NF-κB pathway and activating the Keap1-Nrf2-HO-1 pathway.

TRIM44 aggravates cardiac fibrosis after myocardial infarction via TAK1 stabilization

Myocardial infarction (MI) is one of the most dangerous cardiovascular events. Cardiac fibrosis is a common pathological feature of remodeling after injury that is related to adverse clinical results with no effective treatment. Previous studies have confirmed that TRIM44, an E3 ligase, can promote the proliferation and migration of various tumor cells. However, the role of TRIM44 in cardiac fibrosis remains unknown. Models of TGF-β1 stimulation and MI-induced fibrosis were established to investigate the role and potential underlying mechanism of TRIM44 in cardiac fibrosis. The results showed that cardiac fibrosis was significantly inhibited after TRIM44 knockdown in a mouse model of MI, while it was enhanced when TRIM44 was overexpressed. Furthermore, in vitro studies showed that fibrosis markers were significantly reduced in cardiac fibroblasts (CFs) with TRIM44 knockdown, whereas TRIM44 overexpression promoted the expression of fibrosis markers. Mechanistically, TRIM44 maintains TAK1 stability by inhibiting the degradation of k48-linked polyubiquitination-mediated ubiquitination, thereby increasing phosphorylated TAK1 expression in the fibrotic environment and activating MAPKs to promote fibrosis. Pharmacological inhibition of TAK1 phosphorylation reversed the fibrogenic effects of TRIM44 overexpression. Combined, these results suggest that TRIM44 is a potential therapeutic target for cardiac fibrosis.

Effects of Herbs and Derived Natural Products on Lipopolysaccharide-Induced Toxicity: A Literature Review

Introduction

Oxidative stress (OS) during inflammation can increase inflammatory responses and damage tissue. Lipopolysaccharide (LPS) can induce oxidative stress and inflammation in several organs. Natural products have several biological activities including anti-inflammatory, antioxidant, and immunoregulatory properties. The aims of the study are to study the possible therapeutic effects of natural products on LPS inducing toxicity on the nervous system, lung, liver, and immune system.

Methods

The in vitro and in vivo research articles that were published in the last 5 years were included in the current study. The keywords included "lipopolysaccharide," "toxicity," "natural products," and "plant extract" were searched in different databases such as Scopus, PubMed, and Google Scholar until October 2021.

Results

The results of most studies indicated that some medicinal herbs and their potent natural products can help to prevent, treat, and manage LPS-induced toxicity. Medicinal herbs and plant-derived natural products showed promising effects on managing and treating oxidative stress, inflammation, and immunomodulation by several mechanisms.

Conclusion

However, these findings provide information about natural products for the prevention and treatment of LPS-induced toxicity, but the scientific validation of natural products requires more evidence on animal models to replace modern commercial medicine.

Protective Effects of Atractylodis lancea Rhizoma on Lipopolysaccharide-Induced Acute Lung Injury via TLR4/NF-κB and Keap1/Nrf2 Signaling Pathways In Vitro and In Vivo

Acute lung injury (ALI) is a syndrome caused by an excessive inflammatory response characterized by intractable hypoxemia both inside and outside the lung, for which effective therapeutic drugs are lacking. Atractylodis rhizoma, a traditional Chinese medicine, has excellent anti-inflammatory and antiviral properties in addition to protecting the integrity of the cellular barrier. However, few studies of Atractylodis rhizoma for the treatment of ALI have been published, and its mechanism of action remains unclear. In the present study, the chemical composition of the ethanolic extract of Atractylodis rhizoma (EEAR) was initially clarified by high performance liquid chromatography (HPLC), after which it was studied in vivo using a lipopolysaccharide (LPS)-induced ALI rat model. Treatment with EEAR significantly reduced the lung wet/dry (W/D) ratio, neutrophil infiltration, and malondialdehyde (MDA) and myeloperoxidase (MPO) formation, and enhanced superoxide dismutase (SOD) and glutathione (GSH) depletion in rats with ALI, thereby improving lung barrier function and effectively reducing lung injury. In addition, EEAR significantly reduced histopathological changes, decreased the expression of inflammatory factors (such as tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β), inducible nitric oxide synthase (INOS), and cyclooxygenase-2 (COX-2)), and inhibited the activation of the NF-κB signaling pathway, thus reducing inflammation. In addition, EEAR was found to also reduce oxidative stress in ALI by upregulating the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream proteins heme oxygenase-1 (HO-1) and NADPH quinone acceptor oxidoreductase 1 (NQO-1). EEAR also reduced LPS-induced inflammatory factor expression in THP-1 cells in vitro by inhibition of the NF-κB signaling pathway, and reduced damage from lipopolysaccharide (LPS)-induced oxidative stress in THP-1 cells by promoting the expression of Nrf2 and its downstream targets HO-1 and NQO-1, the molecular mechanism of which was consistent with in vivo observations. Therefore, we conclude that EEAR attenuates oxidative stress and inflammatory responses via TLR4/NF-κB and Keap1/Nrf2 signaling pathways to alleviate LPS-induced ALI, suggesting that Atractylodis rhizoma is a potential drug candidate for the treatment of ALI.

Limonoids with anti-inflammatory activity: A review

The natural limonoids distributed mainly in the Meliaceae and Rutaceae plants are known for their unique and complex structure with high degree oxidation and cyclic rearrangement. However, these compounds exhibit a broad range of biological activities such as insecticidal, antibacterial, antifungal, antimalarial, antioxidant, anticancer, antiviral, and anti-inflammatory. There is still limited report about the biological activity of the anti-inflammatory effect of limonoids isolated from plants. Therefore, this study aimed to examine the effect of intact, deformed and rearranged limonoids as anti-inflammatory agents. The majority of anti-inflammatory investigations were evaluated by in vitro and in vivo assays of the isolated pure compounds and their derivatives. For the in vitro study, intact and C-ring seco limonoids showed a potent inhibitory effect against NO production. The in vivo analysis of Intact, C-seco, and AD-seco limonoids showed a potent effect based on the inhibition of pro-inflammatory cytokines expression, indicating their potency as anti-inflammatory agents.

Munronoid I Ameliorates DSS-Induced Mouse Colitis by Inhibiting NLRP3 Inflammasome Activation and Pyroptosis Via Modulation of NLRP3

Inflammatory bowel diseases (IBDs) are increasingly common diseases characterized by chronic and relapsing inflammation of the gastrointestinal tract. NLRP3 might be a crucial regulator of the homeostatic balance of the intestine, but its upregulation leads to pyroptosis. Munronoid I is extracted and purified from Munronia sinica, which has shown an anti-inflammatory effect, but the efficacy of Munronoid I in IBD remains unproven. In this study, we attempted to determine the effect of Munronoid I on NLRP3 to regulate the inflammasome activation and pyroptosis in IBD. Our data demonstrated that Munronoid I treatment attenuated DSS-induced body weight loss, pathological injury of the colon, the production of IL-1β and IL-18, and the expression of pyroptosis-associated proteins in colon tissue in mice. Moreover, Munronoid I inhibited LPS/ATP-induced pyroptosis in mouse peritoneal macrophages, MODE-K cells, and DSS-induced pyroptosis in mouse colonic epithelial cells, and decreased the release of inflammatory cytokines IL-1β and IL-18 in mouse peritoneal macrophages. Mechanically, Munronoid I could suppress the NLRP3 inflammasome activation and pyroptosis by promoting the K48-linked ubiquitination and NLRP3 degradation. It is suggested that Munronoid I might be a potential therapeutic candidate for IBD.

Research progress of meliaceous limonoids from 2011 to 2021

Covering: July 2010 to December 2021Limonoids, a kind of natural tetranortriterpenoids with diverse skeletons and valuable insecticidal and medicinal bioactivities, are the characteristic metabolites of most plants of the Meliaceae family. The chemistry and bioactivities of meliaceous limonoids are a continuing hot area of natural products research; to date, about 2700 meliaceous limonoids have been identified. In particular, more than 1600, including thirty kinds of novel rearranged skeletons, have been isolated and identified in the past decade due to their wide distribution and abundant content in Meliaceae plants and active biosynthetic pathways. In addition to the discovery of new structures, many positive medicinal bioactivities of meliaceous limonoids have been investigated, and extensive achievements regarding the chemical and biological synthesis have been made. This review summarizes the recent research progress in the discovery of new structures, medicinal and agricultural bioactivities, and chem/biosynthesis of limonoids from the plants of the Meliaceae family during the past decade, with an emphasis on the discovery of limonoids with novel skeletons, the medicinal bioactivities and mechanisms, and chemical synthesis. The structures, origins, and bioactivities of other new limonoids were provided as ESI. Studies published from July 2010 to December 2021 are reviewed, and 482 references are cited.