Anti-Allergic Potential of Chamaecrista nomame and Its Compound Luteolin for Novel Asthma Therapy

Asthma is a chronic inflammatory disease driven by dysregulated immune responses and mast cell activation. While corticosteroids remain the primary treatment, their long-term use is associated with adverse effects, necessitating safer alternatives. This study aims to evaluate the therapeutic potential and underlying mechanisms of Chamaecrista nomame (CN) extract and its active compound luteolin in allergic asthma. We performed bioactivity-guided fractionation to identify active compounds from CN extract. An ovalbumin-induced murine asthma model was utilized to investigate the efficacy of CN in vivo. Transcriptomic analysis of bone marrow-derived mast cells was conducted to elucidate molecular pathways regulated by luteolin. Additionally, cytokine release assays were performed using house dust mite-stimulated human peripheral blood mononuclear cells (PBMCs). CN extract demonstrated potent anti-allergic effects by significantly inhibiting mast cell degranulation and inflammatory mediator release. Luteolin was identified as the primary active compound, modulating FcεRI-mediated signaling in mast cells. In the murine asthma model, CN markedly reduced airway inflammation, mucus hypersecretion, and immune cell infiltration, with efficacy comparable to corticosteroids. Transcriptomic data indicated that luteolin suppresses proinflammatory cytokine production by downregulating NF-κB and MAPK signaling pathways. Moreover, CN and luteolin significantly inhibited cytokine release from house dust mite-stimulated human PBMCs, highlighting clinical relevance. These findings suggest that CN and luteolin may serve as promising natural therapeutic agents for allergic asthma, offering a potential alternative to conventional treatments.