Anti-inflammatory effect of Trichospira verticillata via suppression of the NLRP3 inflammasome in neutrophilic asthma.

Trichospira verticillata is an annual herb that belongs to the family Asteraceae. Trichospira verticillata extract (TVE) elicits anti-plasmodial activity; however, there has been no detailed report about its anti-inflammatory effects and molecular mechanisms. In addition, herbal plants exhibit anti-inflammatory effects by suppressing the NLRP3 inflammasome. Therefore, the primary goal of this study was to examine the effects of TVE on NLRP3 inflammasome activation by measuring interleukin-1ß (IL-1ß) secretion. We treated lipopolysaccharides (LPS)-primed J774A.1 and THP-1 cells with TVE, which attenuated NLRP3 inflammasome activation. Notably, TVE did not affect nuclear factor-kappa B (NF-κB) signalling or intracellular reactive oxygen species (ROS) production and potassium efflux, suggesting that it inactivates the NLRP3 inflammasome via other mechanisms. Moreover, TVE suppressed the formation of apoptosis-associated speck-like protein (ASC) speck and oligomerization. Immunoprecipitation data revealed that TVE reduced the binding of NLRP3 to NIMA-related kinase 7 (NEK7), resulting in reduced ASC oligomerization and speck formation. Moreover, TVE alleviated neutrophilic asthma (NA) symptoms in mice. This study demonstrates that TVE modulates the binding of NLPR3 to NEK7, thereby reporting novel insights into the mechanism by which TVE inhibits NLRP3 inflammasome. These findings suggest TVE as a potential therapeutic of NLRP3 inflammasome-mediated diseases, particularly NA.

Aiouea padiformis extract exhibits anti-inflammatory effects by inhibiting the ATPase activity of NLRP3.

Inflammation is implicated as a cause in many diseases. Most of the anti-inflammatory agents in use are synthetic and there is an unmet need for natural substance-derived anti-inflammatory agents with minimal side effects. Aiouea padiformis belongs to the Lauraceae family and is primarily found in tropical regions. While some members of the Aiouea genus are known to possess anti-inflammatory properties, the anti-inflammatory properties of Aiouea padiformis extract (AP) have not been investigated. In this study, we aimed to examine the anti-inflammatory function of AP through the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome and elucidate the underlying mechanisms. Treatment with AP inhibited the secretion of interleukin-1 beta (IL-1ß) mediated by NLRP3 inflammasome in J774A.1 and THP-1 cells without affecting the viability. In addition, AP treatment did not influence NF-κB signaling, potassium efflux, or intracellular reactive oxygen species (ROS) production-all of which are associated with NLRP3 inflammasome activation. However, intriguingly, AP treatment significantly reduced the ATPase activity of NLRP3, leading to the inhibition of ASC oligomerization and speck formation. Consistent with cellular experiments, the anti-inflammatory property of AP in vivo was also evaluated using an LPS-induced inflammation model in zebrafish, demonstrating that AP hinders NLRP3 inflammasome activation.

Guarea microcarpa C. DC. extract inhibits NLRP3 inflammasome by suppressing its ATPase activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Guarea genus comprises tropical and subtropical terrestrial herbs inhabiting Central and South America. These plants, including Guarea guidonia (L.) Sleumer, have anti-inflammatory, analgesic, antibacterial, antiviral, and immune-enhancing properties. AIM OF THE STUDY: Although various species of the Guarea genus are known for their medicinal properties, comprehensive data on their anti-inflammatory effects remain limited. Therefore, we investigated the NLRP3 inflammasome-inhibiting effects of the Guarea genus in this study. MATERIALS AND METHODS: To evaluate the anti-inflammatory activities of 18 members of the Guarea genus, we treated NLRP3 inflammasome activators with their extracts in LPS-primed J774A.1 and THP-1 cells. Cell viability was determined by water soluble tetrazolium salt (WST) and cytokine production, protein expression, and nuclear fractionation were determined by western blotting. Reactive oxygen species (ROS) production and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) oligomerization were measured using confocal microscopic analysis. Inflammation-induced zebrafish was used in the in vivo experiments. RESULTS: Among the 18 Guarea members tested, Guarea microcarpa C. DC. extract (GM) exhibited no cytotoxicity and specifically suppressed the activation of the NLRP3 inflammasome, but not of the AIM2 or NLRC4 inflammasomes, by inhibiting the ATPase activity of NLRP3. This was achieved without affecting NF-κB signaling, potassium efflux, or intracellular ROS production, all of which are involved in NLRP3 activation. The reduced ATPase activity of NLRP3 led to decreased ASC oligomerization. Furthermore, GM exhibited anti-inflammatory effects in vivo. Additionally, GM treatment alleviated inflammation at the organismal level in an LPS-induced inflammation model using zebrafish embryos. CONCLUSION: Our results demonstrate the anti-inflammatory effects of GM via suppressing the NLRP3 inflammasome. Therefore, GM can be a potential therapeutic candidate for various inflammatory diseases caused by aberrant NLRP3 inflammasome activation.

Anti-Inflammatory Effect of Meriania hexamera Sprague by Targeting Syk Kinase in NF-κB Signaling.

Inflammation is a protective mechanism against harmful stimuli. There are two types of inflammation, acute and chronic, and severe diseases such as cardiovascular disease and cancer can be caused by chronic inflammation. Therefore, this research was conducted to discover new anti-inflammatory drugs. Meriania hexamera Sprague is a common herb in the Amazon region in South America. It is used as a traditional medical herb by natives, but no studies to date have investigated its anti-inflammatory activity. Using lipopolysaccharide (LPS), pam3CSK4 (Pam3), and poly(I:C), we studied the M. hexamera Sprague-Methanol Extract's (Mh-ME) in vitro anti-inflammatory functions. Using RAW264.7 cells, we detected the released nitric oxide (NO) and mRNA expression extent of inducible nitric oxide synthase (iNOS) with pro-inflammatory proteins like tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and iterleukin-1 beta (IL-1ß). It was found that Mh-ME suppressed the inflammatory activities in a dose-dependent manner. In the luciferase assay, the nuclear factor kappa light chain enhancer of the activated B cells (NF-κB) pathway was inhibited by Mh-ME. Mh-ME especially acted as an inhibitor of Syk kinase according to the results from CETSA. We also confirmed that Mh-ME mitigates acute gastritis derived from HCl/EtOH in ICR mice, ameliorating the expression of IL-1ß and tumor necrosis factor-alpha (TNF-α). In conclusion, Mh-ME is an herb with anti-inflammatory effects that targets Syk in the NF-κB pathway, suggesting that Mh-ME could be used as an anti-inflammatory herbal medicine.

Guettarda crispiflora Vahl Methanol Extract Ameliorates Acute Lung Injury and Gastritis by Suppressing Src Phosphorylation.

Many species in the genus Guettarda are known to exert anti-inflammatory effects and are used as traditional medicinal plants to treat various inflammatory symptoms. However, no studies on the inflammatory activities of Guettarda crispiflora Vahl have been reported. The aim of the study was to investigate in vitro and in vivo the anti-inflammatory effects of a methanol extract of Guettarda crispiflora Vahl (Gc-ME). To determine the anti-inflammatory activity of Gc-ME, lipopolysaccharide (LPS)-, poly(I:C)-, or Pam3CSK4-treated RAW264.7 cells, HCl/EtOH- and LPS-treated mice were employed for in vitro and in vivo tests. LPS-induced nitric oxide production in RAW264.7 cells was determined by Griess assays and cytokine gene expression in LPS-activated RAW264.7 cells, confirmed by RT- and real-time PCR. Transcriptional activation was evaluated by luciferase reporter gene assay. Target protein validation was assessed by Western blot analysis and cellular thermal shift assays (CETSA) with LPS-treated RAW264.7 and gene-transfected HEK293 cells. Using both a HCl/EtOH-induced gastritis model and an LPS-induced lung injury model, inflammatory states were checked by scoring or evaluating gastric lesions, lung edema, and lung histology. Phytochemical fingerprinting of Gc-ME was observed by using liquid chromatography-mass spectrometry. Nitric oxide production induced by LPS and Pam3CSK4 in RAW264.7 cells was revealed to be reduced by Gc-ME. The LPS-induced upregulation of iNOS, COX-2, IL-6, and IL-1ß was also suppressed by Gc-ME treatment. Gc-ME downregulated the promotor activities of AP-1 and NF-κB triggered by MyD88- and TRIF induction. Upstream signaling proteins for NF-κB activation, namely, p-p50, p-p65, p-IκBα, and p-Src were all downregulated by Ch-EE. Moreover, Src was revealed to be directly targeted by Gc-ME. This extract, orally treated strongly, attenuated the inflammatory symptoms in HCl/EtOH-treated stomachs and LPS-treated lungs. Therefore, these results strongly imply that Guettarda crispiflora can be developed as a promising anti-inflammatory remedy with Src-suppressive properties.

Quadrella incana (Capparaceae) Leaf Extract Enhances Proliferation and Maintenance of Neural Stem/Progenitor Cells through Upregulating Glycolytic Flux and Redox Potential.

Neural stem/progenitor cells (NSPCs) are self-renewing, multipotent cells located in the embryonic and adult central nervous system (CNS). Extensive preclinical and clinical studies have shed light on the potential of stem cell replacement therapy for various neurodegenerative diseases. The key prerequisite for the success of these clinical applications is the procurement of a sufficient number of high-quality NSPCs. In this study, we explored the biological activity of Quadrella incana leaf in NSPC homeostasis. We showed that the leaf extract of Quadrella incana upregulated NSPC marker and proliferative potential. On the other hand, Quadrella incana leaf suppressed spontaneous unintended NSPC differentiation. Mechanistically, Quadrella incana leaf contributed to the maintenance of NSPCs by upregulating glycolytic flux and redox potential.

Viburnum pichinchense methanol extract exerts anti-inflammatory effects via targeting the NF-κB and caspase-11 non-canonical inflammasome pathways in macrophages.

ETHNOPHARMACOLOGICAL RELEVANCE: Viburnum pichinchense Benth. Mainly found in Ecuador and Colombia has been ethnopharmacologically utilized as a remedy for various female disorders with kidney inflammation and uterine relaxant. AIM OF THE STUDY: The pharmacological activity of Viburnum pichinchense has never been studied, therefore, this study explored anti-inflammatory activity of Viburnum pichinchense methanol extract (Vp-ME). MATERIALS AND METHODS: Anti-inflammatory activities of Vp-ME were evaluated in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and HCl/EtOH-induced gastritis mice by MTT assay, nitric oxide (NO) production assay, semi-quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR), luciferase reporter assay, Western blotting, and enzyme-linked immunosorbent assays (ELISA). Anti-inflammatory compounds in Vp-ME were identified by high performance liquid chromatography (HPLC). RESULTS: Vp-ME inhibited NO production in RAW264.7 cells stimulated with pam3CSK4, poly I:C or LPS and in LPS-stimulated peritoneal macrophages without cytotoxicity and downregulated mRNA expression of inflammatory enzymes, inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) and pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6. The anti-inflammatory activity was accomplished by inhibiting nuclear factor-kappa B (NF-κB) transcriptional activation, upstream signaling molecules in the NF-κB pathway, and caspase-11 non-canonical inflammasome in RAW264.7 cells. Moreover, Vp-ME exhibited in vivo anti-inflammatory activity by ameliorating gastritis symptoms, inhibiting iNOS and IL-6 mRNA expression and IκBα activation in mice. HPLC analysis identified resveratrol, quercetin, luteolin, and kaempferol as the anti-inflammatory components in Vp-ME. CONCLUSION: This study demonstrated Vp-ME has the anti-inflammatory activity via targeting NF-κB and caspase-11 non-canonical inflammasome pathways in macrophage-mediated inflammatory responses, suggesting Vp-ME could be developed as anti-inflammatory ethnopharmacological remedies to prevent and treat inflammatory diseases.