Vasicine is a quinazoline alkaloid primarily isolated from the plant Adhatoda vasica (also known as Malabar nut or Vasaka), which has a long history of use in Ayurvedic and traditional medicine for respiratory ailments. Its use in supporting the bronchial system is not only rooted in traditional practice but is also supported by modern scientific evidence. Preclinical studies have demonstrated that vasicine possesses bronchodilatory, expectorant, and anti-inflammatory properties. These effects are believed to result from its ability to relax bronchial smooth muscles, increase bronchial secretions, and reduce airway inflammation. Several animal studies have shown that vasicine and its derivatives (such as vasicinone) can reduce bronchoconstriction and improve airway clearance, which supports its application in managing conditions like asthma and bronchitis.

In addition, vasicine was the lead compound for the development of bromhexine, a widely used synthetic mucolytic agent. Although clinical data on vasicine itself in humans are limited, the pharmacological basis for its action is well-established in laboratory research. Reviews and in vitro studies further corroborate its expectorant and bronchodilator actions. Therefore, the use of vasicine to support the bronchial system is justified by both historical use and substantial scientific validation at the preclinical level, warranting a high evidence rating, though more clinical trials in humans would further strengthen the case.