Malabar nut (Justicia adhatoda), also known as Vasaka, has a long history of use in traditional Ayurvedic and Unani medicine for respiratory health, particularly for its effects on the mucus membranes. The primary active compounds, vasicine and vasicinone, are alkaloids that have been scientifically investigated for their expectorant, bronchodilatory, and anti-inflammatory properties. Several preclinical studies have demonstrated that extracts of Malabar nut can enhance mucociliary clearance, reduce bronchial hyperreactivity, and facilitate the expulsion of mucus from the airways. These effects are attributed to both stimulation of bronchial gland secretions and suppression of inflammation in the respiratory tract.

A number of animal and in vitro studies support these findings. For example, research published in Journal of Ethnopharmacology and Phytomedicine has shown that vasicine can increase the volume and decrease the viscosity of respiratory tract secretions, making it easier to clear mucus. Clinical trials in humans, though limited, have found that preparations containing Malabar nut can alleviate symptoms in conditions such as chronic bronchitis and asthma, supporting its use to support and protect the mucus membranes of the respiratory system.

While more robust human trials are needed, the convergence of traditional use and emerging scientific data justifies the use of Malabar nut for supporting mucus membranes, particularly in the context of respiratory health.