An Overview of Pathological Pathway of Asthma and Molecular Mechanisms of Anti-Asthmatic Phytoconstituents

Abstract

: Asthma presents with chronic inflammation and airway constriction triggered by allergens or pollution. Inflammatory mediators such as histamine and leukotrienes, released in response to inflammation, prompt bronchoconstriction, contracting the smooth muscles around the airways. This constriction obstructs airflow and worsens symptoms such as coughing, wheezing, and breathlessness. Additionally, airways become hyperresponsive, reacting excessively even to harmless stimuli. Persistent inflammation leads to the production of thick mucus, further blocking airflow and worsening symptoms. Mast cell-released histamine triggers bronchoconstriction, leukotrienes, and prostaglandins (eg, Interleukin-4, Interleukin-13) and promotes airway inflammation while cytokines drive Th2-mediated immune responses. Current therapies in asthma include long-acting beta agonists, leukotriene modifiers, inhaled corticosteroids, and immunomodulators. Natural products, due to their anti-inflammatory, antioxidant and immunomodulatory properties, have emerged as promising anti-asthmatic candidates. Polyphenols (quercetin, resveratrol, curcumin, etc.) and Omega-3 fatty acids offer anti-inflammatory benefits by suppressing cytokines and oxidative stress. Natural products intervene at various levels of these pathways. Quercetin inhibits the release of mast cell histamines, alleviating bronchoconstriction. Curcumin suppresses Th2 cytokines, mitigating the allergic response. Omega-3 fatty acids modulate leukotriene and prostaglandin production, reducing airway inflammation. This review concludes that natural phytobioactives have potential in asthma management due to their complex mechanisms that target various immuno-inflammatory mediators.