Investigation of molecular mechanisms and therapeutic potential of thyme (Thymus vulgaris) extract in bronchitis

Abstract

Background: Bronchitis is a common inflammatory airway disease characterized by cough, mucus hypersecretion, and airway inflammation. Limitations of conventional therapies have increased interest in herbal medicines with anti-inflammatory and mucoregulatory properties. Thymus vulgaris has been traditionally used for respiratory disorders, yet its molecular mechanisms in bronchitis require comprehensive evaluation. Objective: This review work aimed to summarize and critically analyze experimental and clinical evidence regarding the effects and molecular mechanisms of Thymus vulgaris extract in bronchitis. Methods: A narrative review of in vitro, in vivo, and clinical studies published in peer-reviewed journals was conducted. Studies investigating anti-inflammatory, antioxidant, mucolytic, and clinical effects of thyme extract in bronchitis or airway inflammation were included. Results: The findings indicate that Thymus vulgaris exerts its therapeutic effects through multiple molecular pathways. Key mechanisms include inhibition of the NF-κB signaling pathway, resulting in reduced expression of pro-inflammatory cytokines (IL-1β, IL-6, IL-8), downregulation of MUC5AC gene expression leading to decreased mucus hypersecretion, modulation of the arachidonic acid pathway via inhibition of 5-lipoxygenase, and attenuation of oxidative stress through antioxidant activity. Clinical trials demonstrated significant reductions in cough frequency and bronchitis severity scores, with good tolerability. Conclusion: Thymus vulgaris extract shows promising multi-target effects in the management of bronchitis, particularly acute bronchitis. Although current evidence supports its use as a complementary therapy, further large-scale, well-designed clinical trials with standardized extracts are required to confirm its efficacy and safety.