Alstonia scholaris, commonly known as the devil tree or blackboard tree, has a long-standing use in traditional systems of medicine, particularly in Ayurveda and traditional Chinese medicine, for supporting the respiratory system, including bronchial health. Traditional practitioners have used the bark and leaves for treating conditions such as asthma, chronic cough, and bronchitis. The plant is believed to possess anti-inflammatory, expectorant, and bronchodilatory properties according to these medical traditions.

Scientific investigation into Alstonia scholaris has provided some preliminary support for its traditional uses. Several in vitro and in vivo animal studies have demonstrated that extracts of the bark can exhibit anti-inflammatory and antitussive (cough-suppressant) activities. For instance, some studies have observed that alkaloids present in the bark may reduce airway inflammation and relax bronchial smooth muscle in animal models. However, robust clinical trials in humans are lacking, and most evidence remains preclinical or anecdotal.

In summary, while traditional use and some early laboratory research suggest a benefit of Alstonia scholaris for bronchial and respiratory health, high-quality human studies are limited. Therefore, its use is primarily justified by traditional knowledge with limited scientific validation to date.