Baphicacanthus cusia, also known as Strobilanthes cusia or "Qing Dai" in traditional Chinese medicine (TCM), has a long-standing use in East Asian herbal medicine, primarily for its purported anti-inflammatory, antiviral, and antimicrobial properties. In traditional practice, the leaves and stems are used in preparations aimed at clearing heat and detoxifying the body, and one of its historical uses includes support for respiratory ailments such as bronchitis, cough, and sore throat. The rationale in TCM is based on syndrome differentiation, where "heat" in the lungs (manifesting as bronchitis) is countered by herbs like Baphicacanthus cusia.

While some in vitro and animal studies have found that extracts from this plant possess anti-inflammatory and antimicrobial activities, direct clinical evidence specifically supporting its efficacy for bronchitis in humans is lacking. Most uses are based on traditional formulations and empirical experience rather than rigorous scientific trials. Thus, the evidence rating is moderate (2/5), primarily supported by tradition and some preliminary pharmacological studies, but not by robust clinical research.