Platycodin D3

Platycodin D3 is a triterpenoid saponin isolated from Platycodonis Radix (*Platycodon grandiflorum*), a plant widely utilized in traditional Chinese medicine. It demonstrates anti-inflammatory properties by reducing the secretion of inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), and interleukin-17 (IL-17). Its mechanism of action involves inhibiting the protein expression of HSP90, TRAF6, phospho-NF-κB p65, and phospho-ERK1/2. Furthermore, Platycodin D3 mitigates chronic bronchitis inflammation through the inhibition of the TLR4/MyD88/NF-κB signaling pathway. When functionalized into biomimetic nanovaccines (PD3-SH-Lip), it acts as an immune stimulant, amplifying immune responses by activating NF-κB, MAPK, NOD-like, and TNF signaling pathways, leading to elevated levels of specific serum IgG and isotype titers, and robust CD4+ and CD8+ T cell immune responses, suggesting its potential for inhaled immunotherapy.