Platycodon grandiflorus – An Ethnopharmacological, phytochemical and pharmacological review

Platycodon grandiflorus (Jacq.) A. DC., the sole species in genus Platycodon A. DC. (Campanulaceae) has a long history of use as a traditional herbal medicine for the treatments of cough, phlegm, sore throat, lung abscess, chest pain, dysuria, and dysentery. As a legal medicine and dietary supplement, it is also frequently used as an ingredient in health foods and vegetable dishes. The aim of this review is to provide up-to-date information on the botanical characterization and distribution, ethnopharmacology, phytochemistry, pharmacology, and toxicity of Platycodon grandiflorus based on literature published in recent years. It will build a foundation for further study of the mechanism of action and the development of better therapeutic agents and healthy products from Platycodon grandiflorus. All of the available information on Platycodon grandiflorus was collected via electronic search (using PubMed, SciFinder Scholar, CNKI, TPL (www.theplantlist.org), Google Scholar, Baidu Scholar, and Web of Science). A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that ethno-medical uses of Platycodon grandiflorus have been recorded in China, Japan, Mongolia, and Korea for thousands of years. A phytochemical investigation revealed that this product contains steroidal saponins, flavonoids, polyacetylenes, sterols, phenolics, and other bioactive compounds. Crude extracts and pure compounds isolated from Platycodon grandiflorus exhibited significant anti-inflammatory and immunostimulatory effects. They also showed valuable bioactive effects, such as anti-tumor, anti-oxidant, anti-diabetic, anti-obesity, hepatoprotective and cardiovascular system effects, among others. In light of its long traditional use and the modern phytochemical and pharmacological studies summarized here, Platycodon grandiflorus has been demonstrated to show a strong potential for therapeutic and health-maintaining uses. Both the extracts and chemical components isolated from the plant showed a wide range of biological activities. Thus, more studies on the pharmacological mechanisms of its main active compounds (e.g., platycodin D, D2) need to be conducted. In addition, as one of the most popular traditional herbal medicines, clinical studies of the main therapeutic aspects, toxicity and adverse effects of Platycodon grandiflorus will also undoubtedly be the focus of future investigation.