Butylphthalide ameliorates airway inflammation and mucus hypersecretion via NF-κB in a murine asthma model

Fine particulate matter promotes airway inflammation and mucin production by activating endoplasmic reticulum stress and the IRE1α/NOD1/NF‑κB pathway

Fine particulate matter (PM2.5) is a type of small particle that is <2.5 µm in diameter that may cause airway inflammation. Thus, the present study aimed to explore the effects of PM2.5 on endoplasmic reticulum (ER) stress and airway inflammation in human airway epithelial cells. For this purpose, HBE135‑E6E7 airway epithelial cells were cultured and exposed to specific concentrations of PM2.5 for various periods of time, and cell viability was determined using a Cell Counting Kit‑8 assay. The results of the present study demonstrated that exposure to PM2.5 increased the mRNA and protein expression levels of interleukin (IL)‑6, tumor necrosis factor (TNF)‑α and mucin 5AC (MUC5AC). Moreover, the expression levels of ER stress‑related proteins, such as glucose‑regulated protein 78, CCAAT‑enhancer binding protein homologous protein, activating transcription factor 6, protein kinase R‑like ER kinase (PERK), phosphorylated (p‑)PERK, inositol‑requiring enzyme 1α (IRE1α) and p‑IRE1α, and nucleotide‑binding oligomerization domain 1 (NOD1) expression levels were increased following exposure to PM2.5. Transfection with IRE1α small interfering RNA (siRNA) led to the increased production of IL‑6, TNF‑α and MUC5AC. Moreover, the expression of NOD1 and the translocation of NF‑κB p65 were inhibited following transfection with IRE1α siRNA. In addition, the results of the present study demonstrated that transfection with NOD1 siRNA decreased the production of IL‑6, TNF‑α and MUC5AC, and decreased the translocation of NF‑κB p65. The expression levels of IL‑6, TNF‑α and MUC5AC were increased in the HBE135‑E6E7 cells following treatment with C12‑iE‑DAP, a NOD1 agonist. Moreover, treatment with C12‑iE‑DAP led to the activation of NF‑κB p65. Collectively, the results of the present study suggest that PM2.5 promotes airway inflammation and mucin production by activating ER stress in HBE135‑E6E7 airway epithelial cells, and that the IRE1α/NOD1/NF‑κB pathway may be involved in this process.

View from the Biological Property: Insight into the Functional Diversity and Complexity of the Gut Mucus

Due to mucin's important protective effect on epithelial tissue, it has garnered extensive attention. The role played by mucus in the digestive tract is undeniable. On the one hand, mucus forms "biofilm" structures that insulate harmful substances from direct contact with epithelial cells. On the other hand, a variety of immune molecules in mucus play a crucial role in the immune regulation of the digestive tract. Due to the enormous number of microorganisms in the gut, the biological properties of mucus and its protective actions are more complicated. Numerous pieces of research have hinted that the aberrant expression of intestinal mucus is closely related to impaired intestinal function. Therefore, this purposeful review aims to provide the highlights of the biological characteristics and functional categorization of mucus synthesis and secretion. In addition, we highlight a variety of the regulatory factors for mucus. Most importantly, we also summarize some of the changes and possible molecular mechanisms of mucus during certain disease processes. All these are beneficial to clinical practice, diagnosis, and treatment and can provide some potential theoretical bases. Admittedly, there are still some deficiencies or contradictory results in the current research on mucus, but none of this diminishes the importance of mucus in protective impacts.

Aerosol inhalation of Mycobacterium vaccae ameliorates airway structural remodeling in chronic asthma mouse model

Background: Airway remodeling is accepted to be a determining component within the natural history of asthma. Nebulized inhalation of Mycobacterium vaccae (M. vaccae) has a protective effect on asthmatic mice. However, little is known regarding the effect of M. vaccae on airway structural remodeling in asthmatic mice. The purpose of this study was to explore the effect and the underlying mechanism of M. vaccae aerosol inhalation on airway structural remodeling in an asthma mouse model. Methods: Chronic asthma mouse models were established by ovalbumin induction. The number of inflammatory cells in bronchoalveolar lavage fluid (BALF), pathological alterations in lung tissue, and levels of associated cytokines (IL-5, IL-13, TNF-α, and ovalbumin-specific immunoglobulin E [OVA-sIgE]) were all assessed after M. vaccae therapy. The relative expression of interleukin (IL)-1β, tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), and Wnt1-induced signaling protein 1 (WISP1) mRNA were detected. Western blotting and immunohistochemistry detected the expression of Wnt/β-catenin pathway-related proteins in lung tissue. Results: M. vaccae aerosol inhalation relieved airway inflammation, airway hyper-responsiveness, and airway remodeling. M. vaccae reduced the levels of IL-5, IL-13, TNF-α, and OVA-sIgE in and downregulated the expression of IL-1β, TNF-α, NF-κB, and WISP1 mRNA in the pulmonary. In addition, M. vaccae inhibited the expression of β-catenin, WISP1, and Wnt1 protein and upregulated the expression of glycogen synthase kinase-3beta (GSK-3β). Conclusion: Nebulized inhalation of M. vaccae can reduce airway remodeling during asthma.

Synthesis and Biological Evaluation of Novel Phthalide Analogs-1,2,4-Oxadiazole Hybrids as Potential Anti-Inflammatory Agents

A series of novel pathalide-1,2,4-oxadiazole analogs were synthesized for discovering novel anti-inflammatory agents. After the assessment of their cytotoxicity in vitro, all compounds had been screened for their anti-inflammatory activity by evaluating their inhibitory effect on LPS-induced NO production in RAW 264.7 macrophages. SARs had been concluded, and finally compound E13 was found to be the most potent compound. This compound could also significantly decrease the production of iNOS and COX-2. Preliminary mechanism studies indicated that compound E13 could inhibit the TLR4/NF-κB and ERK/p38 signaling pathways. These findings indicate that E13 holds great potential to be a lead compound for discovering novel anti-inflammatory drugs.

Bergamottin protects against LPS-induced endotoxic shock by regulating the NF-κB signaling pathway

Bergamottin is a natural furanocoumarin compound that possesses antioxidative and anti-cancer properties; however, the effect of Bergamottin on lipopolysaccharide (LPS)-induced inflammation response is unknown. In this study, we investigated the protective effects and mechanisms of Bergamottin against LPS-induced inflammatory responses.Raw264.7 cells were pre-treated with Bergamottin, then stimulated with LPS. Morphologic analysis and flow cytometry were used to measure Bergamottin-related cytotoxicity. ELISA and qPCR were performed to measure secretion and transcription activities of inflammatory cytokines. Biochemical analysis was used to determine the expression of tissues damage indicators. Western blots were used to determine protein expression, and immunofluorescence staining was used to determine the co-localization of NF-κB and RelA. Hematoxylin and eosin staining was used to show the pathological damages.Bergamottin had no cytotoxic effects on Raw264.7 cells. Pre-treatment with Bergamottin inhibited inflammatory cytokines expression and secretion induced by LPS, due to the inhibition of LPS-induced NF-κB signaling pathway activation, and improved pathological damages. These findings suggest that Bergamottin protects against LPS-induced endotoxin shock by regulating the NF-κB signaling pathway.

Vitex negundo Linn. extract alleviates inflammatory aggravation and lung injury by modulating AMPK/PI3K/Akt/p38-NF-κB and TGF-β/Smad/Bcl2/caspase/LC3 cascade and macrophages activation in murine model of OVA-LPS induced allergic asthma

ETHNOPHARMACOLOGICAL RELEVANCE

There is growing inclination towards developing bioactive molecule-based strategies for the management of allergic airway inflammation associated respiratory diseases. Vitex negundo Linn., also known as Nirgundi, is one such medicinal plant enriched with phytochemicals and used for inflammatory and respiratory disorders including asthma in traditional system of medicine. Preliminary studies have claimed anti-tussive and bronchodilator potential of V. negundo Linn. However, its attributes as well as molecular mechanism (s) in modulation of asthma mediated by allergic inflammation are yet to be delineated scientifically.

AIM OF THE STUDY

Present study attempted to assess the effectiveness of Vitex negundo leaf extract (VNLE) in mitigation of allergen induced inflammation associated asthmatic lung damage with emphasis to delineate its molecular mechanism (s).

MATERIALS AND METHODS

Allergic lung inflammation was established in Balb/c mice using Ovalbumin-lipopolysaccharide (OVA-LPS). Several allergic inflammatory parameters, histopathological changes, alveolar macrophage activation and signalling pathways were assessed to examine protective effects of VNLE. UHPLC-DAD-QTOF-ESI-IMS was used to characterize VLNE.

RESULTS

VNLE administration effectively attenuated LPS-induced oxi-inflammatory stress in macrophages suggesting its anti-inflammatory potential. Further, VNLE showed protective effect in mitigating asthmatic lung damage as evident by reversal of pathological changes including inflammatory cell influx, congestion, fibrosis, bronchial thickness and alveolar collapse observed in allergen group. VNLE suppressed expressions of inflammatory Th1/Th2 cytokines, chemokines, endopeptidases (MMPs), oxidative effector enzyme (iNOS), adhesion molecules, IL-4/IFN-γ release with simultaneous enhancement in levels of IL-10, IFN-γ, MUC3 and tight junction proteins. Subsequent mechanistic investigation revealed that OVA-LPS concomitantly enhanced phosphorylation of NF-κB, PI3K, Akt and p38MAPKs and downregulated AMPK which was categorically counteracted by VNLE treatment. VNLE also suppressed OVA-LPS induced fibrosis, apoptosis, autophagy and gap junction proteins which were affirmed by reduction in TGF-β, Smad2/3/4, Caspase9/3, Bax, LC3A/B, connexin 50, connexin 43 and enhancement in Bcl2 expression. Additionally, suppression of alveolar macrophage activation, inflammatory cells in blood and elevation of splenic CD8+T cells was demonstrated. UHPLC-DAD-QTOF-ESI-IMS revealed presence of iridoids glycoside and phenolics which might contribute these findings.

CONCLUSION

These findings confer protective effect of VNLE in attenuation of allergic lung inflammation and suggest that it could be considered as valuable medicinal source for developing safe natural therapeutics for mitigation of allergic inflammation during asthma.

Carvone Enantiomers Differentially Modulate IgE-Mediated Airway Inflammation in Mice

Carvone is a monoterpene found in nature in the form of enantiomers (S- and R-). While previous research has demonstrated the anti-inflammatory and anti-allergic effects of carvone, the influence of carvone enantiomeric composition on its anti-allergic activity remains to be investigated. This study aimed to evaluate the anti-allergic activity of carvone enantiomers in a murine model of airway allergic inflammation induced by sensitization and challenge with ovalbumin (OVA). The oral treatment with R-carvone or S-carvone 1 h before each challenge inhibited the number of leukocytes and eosinophils in the bronchoalveolar lavage (BAL). R-carvone inhibited leukocyte infiltration and mucus production in the lung, which was correlated with decreased production of OVA-specific IgE in the serum and increased concentrations of IL-10 in the BAL. On the other hand, the administration of S-carvone had little inhibitory effect on inflammatory infiltration and mucus production in the lung, which might be associated with increased production of IFN-γ in the BAL. When administered 1 h before each sensitization, both enantiomers inhibited eosinophil recruitment to the BAL but failed in decreasing the titers of IgE in the serum of allergic mice. Our data indicate that carvone enantiomers differentially modulated IgE-mediated airway inflammation in mice. In conclusion, unlike S-carvone, R-carvone has the potential to be used in anti-allergic drug development.

3,4,5-Trihydroxycinnamic acid exerts anti-asthmatic effects in vitro and in vivo

3,4,5-Trihydroxycinnamic acid (THCA) has been reported to possess anti-inflammatory activity. However, the effect of THCA for treating allergic asthma was unknown. Therefore, in the present study, the anti-asthmatic effects of THCA were studied in both in vitro and in vivo studies. In phorbol 12-myristate 13-acetate (PMA)-stimulated A549 airway epithelial cells, THCA pretreatment decreased the mRNA expression and secretion of interleukin (IL)-8, monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecules 1 (ICAM-1), and reduced the mRNA expression of matrix metalloproteinase 9 (MMP-9). THCA also inhibited PMA-induced protein kinase B (AKT), mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) activation in A549 cells. In lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, THCA pretreatment suppressed the mRNA expression of ICAM-1 and MMP-9. In addition, THCA suppressed the adhesion of EOL and A549 cells. In ovalbumin (OVA)-administered asthmatic mice, THCA exerted inhibitory activity on IL-5, IL-13, and MCP-1 in bronchoalveolar lavage fluid (BALF) and on OVA-specific immunoglobulin E (IgE) in serum. THCA attenuated the numbers of inflammatory cells in BALF and the influx of inflammatory cell in lung tissues. Furthermore, THCA downregulated the levels of inducible nitric oxide (iNOS), cyclooxygenase-2 (COX-2), and leukotriene B4 (LTB4) expression, mucus production and CREB phosphorylation as well as Penh value. These effects were accompanied by suppression of AKT, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and NF-κB activation. Therefore, the results of the current study suggest that THCA may be a valuable adjuvant or therapeutic in the prevention or treatment of allergic asthma.

From Seeds of Apium graveolens Linn. to a Cerebral Ischemia Medicine: The Long Journey of 3-n-Butylphthalide

3-n-Butylphthalide (NBP) as well as its derivatives and analogues (NBPs), in racemic or enantiomerically pure forms, possess potent and diverse pharmacological properties and have shown a great potential therapeutic interest for many human conditions, especially for cerebral ischemia. This Perspective outlines the synthesis and therapeutic applications of NBPs.