Safranal Alleviated OVA-Induced Asthma Model and Inhibits Mast Cell Activation.

Introduction: Asthma is a chronic and recurring airway disease, which related to mast cell activation. Many compounds derived from Chinese herbal medicine has promising effects on stabilizing mast cells and decreasing inflammatory mediator production. Safranal, one of the active compounds from Crocus sativus, shows many anti-inflammatory properties. In this study, we evaluated the effect of safranal in ovalbumin (OVA)-induced asthma model. Furthermore, we investigate the effectiveness of safranal on stabilizing mast cell and inhibiting the production of inflammatory mediators in passive systemic anaphylaxis (PSA) model. Methods: OVA-induced asthma and PSA model were used to evaluate the effect of safranal in vivo. Lung tissues were collected for H&E, TB, IHC, and PAS staining. ELISA were used to determine level of IgE and chemokines (IL-4, IL-5, TNF-α, and IFN-γ). RNA sequencing was used to uncovers genes that safranal regulate. Bone marrow-derived mast cells (BMMCs) were used to investigate the inhibitory effect and mechanism of safranal. Cytokine production (IL-6, TNF-α, and LTC4) and NF-κB and MAPKs signaling pathway were assessed. Results: Safranal reduced the level of serum IgE, the number of mast cells in lung tissue were decreased and Th1/Th2 cytokine levels were normalized in OVA-induced asthma model. Furthermore, safranal inhibited BMMCs degranulation and inhibited the production of LTC4, IL-6, and TNF-α. Safranal inhibits NF-κB and MAPKs pathway protein phosphorylation and decreases NF-κB p65, AP-1 nuclear translocation. In the PSA model, safranal reduced the levels of histamine and LTC4 in serum. Conclusions: Safranal alleviates OVA-induced asthma, inhibits mast cell activation and PSA reaction. The possible mechanism occurs through the inhibition of the MAPKs and NF-κB pathways.

Safranal Alleviates Dextran Sulfate Sodium-Induced Colitis and Suppresses Macrophage-Mediated Inflammation.

Introduction: Crocus sativus (saffron) is widely used in China, Iran, and India for dyeing and as a food additive and medicinal plant. Safranal, as one of the main constituents of saffron, is responsible for its aroma and has been reported to have anticancer, antioxidant, and anti-inflammation properties. Objective: In this study, we investigated the anti-inflammatory effects of Safranal in RAW264.7 cells, bone marrow-derived macrophages (BMDMs), and dextran sulfate sodium (DSS)-induced colitis mice. Methods: Safranal toxicity was determined using an MTT assay. We evaluated the inhibitory effect of nitric oxide (NO) and levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in RAW264.7 cells and BMDMs. We assessed the inhibitory effect of pro-inflammatory cytokines, and the mRNA expressions of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), classical inflammatory pathways (MAPK and NF-κB), and the nuclear translocation factors AP-1 and NF-κB p65 were investigated. The in vivo anti-inflammatory effects of Safranal were assessed in a DSS-induced colitis model. DSS3.5% was used to induce colitis in mice with or without Safranal for 7 days; weight and disease activity index (DAI) were recorded daily. At the end of the experiment, the colon, mesenteric lymph nodes (MLNs), and spleen were collected for flow cytometry, ELISA, and Western blot analysis. Results: Safranal suppressed NO production, iNOS, and COX-2 in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and BMDMs. Safranal decreased the production and mRNA expression of IL-6 and TNF-α in the RAW264.7 cell line and inhibited the phosphorylation and nuclear translocation of components of the MAPK and NF-κB pathways. Safranal alleviated clinical symptoms in the DSS-induced colitis model, and colon histology showed decreased severity of inflammation, depth of inflammatory involvement, and crypt damage. Immunohistochemical staining and flow cytometry showed reduced macrophage infiltration in colonic tissues and macrophage numbers in MLNs and the spleen. The levels of colonic IL-6 and TNF-α also decreased in Safranal-treated colitis mice. This study elucidates the anti-inflammation activity of Safranal, which may be a candidate for inflammatory bowel syndrome (IBD) therapy.

Andrographolide inhibits inflammatory responses in LPS-stimulated macrophages and murine acute colitis through activating AMPK.

Andrographolide (Andro), a well-known labdane diterpenoid of Andrographis paniculata, has been reported to have anti-inflammatory effects in various inflammatory disease models. Despite ongoing efforts to elucidate the anti-inflammatory mechanism of Andro, its specific mechanism is not entirely clear. In this study, we confirmed the inhibitory effect of Andro on inflammatory activity and studied its mechanism in depth to find potential anti-inflammatory targets of Andro using lipopolysaccharide (LPS)-induced macrophages in vitro and a dextran sulfate sodium (DSS)-induced mouse model of acute colitis in vivo. We found that Andro significantly reduced proinflammatory cytokines by suppressing nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and their upstream signaling pathways and activating the AMP activated protein kinase (AMPK) pathway in LPS-induced macrophages. Interestingly, Andro could not regulate the activation of the AMPK/NF-κB/MAPK pathway nor inhibit NF-κB and activator protein 1 (AP-1) nuclear translocation and nitric oxide (NO) production following knockdown of AMPKα2. Moreover, Andro attenuated DSS-induced intestinal barrier dysfunction and inflammation by suppressing the NF-κB and MAPK pathways in colon tissues while activating the AMPK pathway. In conclusion, our study demonstrates that Andro effectively inhibits LPS-induced inflammatory responses via AMPK activation in macrophages, whereby Andro can ameliorate DSS-induced acute colitis in mice.