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.