Platycodon grandiflorum (Jacq.) A. DC.: A review of phytochemistry, pharmacology, toxicology and traditional use

The traditional Chinese medicine Platycodon grandiflorum (Jacq.) A. DC. (PG, balloon flower) has medicinal and culinary value. It consists of a variety of chemical components including triterpenoid saponins, polysaccharides, flavonoids, polyphenols, polyethylene glycols, volatile oils and mineral components, which have medicinal and edible value. The ultimate goal of this review is to summarize the phytochemistry, pharmacological activities, safety and uses of PG in local and traditional medicine. A comprehensive search of published literature up to March 2022 was conducted using the PubMed, China Knowledge Network and Web of Science databases to identify original research related to PG, its active ingredients and pharmacological activities. Triterpene saponins are the primary bioactive compounds of PG. To date, 76 triterpene saponin compounds have been isolated and identified from PG. In addition, there are other biological components, such as flavonoids, polyacetylene and phenolic acids. These extracts possess antitussive, immunostimulatory, anti-inflammatory, antioxidant, antitumor, antiobesity, antidepressant, and cardiovascular system activities. The mechanisms of expression of these pharmacological effects include inhibition of the expression of proteins such as MDM and p53, inhibition of the activation of enzymes, such as AKT, the secretion of inflammatory factors, such as IFN-γ, TNF-α, IL-2 and IL-1β, and activation of the AMPK pathway. This review summarizes the chemical composition, pharmacological activities, molecular mechanism, toxicity and uses of PG in local and traditional medicine over the last 12 years. PG contains a wide range of chemical components, among which triterpene saponins, especially platycoside D (PD), play a strong role in pharmacological activity, representing a natural phytomedicine with low toxicity that has applications in food, animal feed and cosmetics. Therefore, PG has value for exploitation and is an excellent choice for treating various diseases.