Malabar Nut Tree Leaf Extract, derived from Justicia adhatoda (also known as Vasaka), has a long history of use in Ayurvedic and traditional medicine systems for supporting respiratory health and the bronchial system. Modern scientific investigations provide a substantial basis for this traditional use. The leaves contain alkaloids such as vasicine and vasicinone, which have been shown in multiple studies to exert bronchodilatory, expectorant, and anti-inflammatory effects.

Preclinical studies (including animal models) have demonstrated that extracts from the leaves can relax tracheal muscles, reduce bronchial congestion, and facilitate the expulsion of mucus. Additionally, vasicine has been shown to possess antitussive (cough-suppressing) actions. Several in vitro and in vivo experiments suggest that Malabar Nut Leaf Extract can inhibit histamine-induced bronchoconstriction, which is relevant to conditions like asthma and bronchitis.

Clinical evidence in humans, though limited, is promising. Small-scale trials and observational studies in India and other countries have reported improvements in symptoms of bronchitis, asthma, and chronic cough after administration of standardized Vasaka preparations. Safety profiles are generally favorable at recommended dosages.

Overall, both traditional use and scientific research support the use of Malabar Nut Tree Leaf Extract for supporting the bronchial system, particularly for conditions involving mucus buildup and bronchial irritation.