Distribution, Biotransformation, Pharmacological Effects, Metabolic Mechanism and Safety Evaluation of Platycodin D: A Comprehensive Review

Platycodonis Radix (Jiegeng), the dried root of Platycodon grandiflorum, is a traditional herb used as both medicine and food. Its clinical application for the treatment of cough, phlegm, sore throat, pulmonary and respiratory diseases has been thousands of years in China. Platycodin D is the main active ingredient in Platycodonis Radix, which belongs to the family of pentacyclic triterpenoid saponins because it contains an oleanolane type aglycone linked with double sugar chains. Modern pharmacology has demonstrated that Platycodin D displays various biological activities, such as analgesics, expectoration and cough suppression, promoting weight loss, anti-tumor and immune regulation, suggesting that Platycodin D has the potential to be a drug candidate and an interesting target as a natural product for clinical research. In this review, the distribution and biotransformation, pharmacological effects, metabolic mechanism and safety evaluation of Platycodin D are summarized to lay the foundation for further studies.