Platycodon root, also known as Platycodon grandiflorus or balloon flower root, has a long history of use in traditional East Asian medicine, particularly in Traditional Chinese Medicine (TCM) and Korean herbal medicine. Traditionally, it is used to support the respiratory system, especially for conditions involving the lungs and bronchi such as cough, phlegm, and sore throat. In TCM, platycodon root is believed to help "open up" the lungs, expel phlegm, and relieve cough due to its expectorant and anti-inflammatory properties.

Scientific studies on platycodon root are limited but growing. Some in vitro and animal studies have demonstrated anti-inflammatory, expectorant, and immunomodulatory effects of its active components, such as saponins. These findings lend some support to traditional uses, but robust human clinical trials are lacking. Systematic reviews suggest potential benefits, but they generally call for more high-quality research. Thus, while traditional use is well-established and some preclinical studies are promising, strong scientific validation in humans is not yet available.

In summary, platycodon root is traditionally justified and moderately supported by preclinical evidence for supporting the bronchial and respiratory systems, but more human studies are needed for conclusive scientific endorsement.