Triterpenoids and sterols from Pseudocydonia sinensis fruits and their anti-inflammatory activity.

The fruit of Pseudocydonia sinensis is widely valued for both medicinal and dietary applications in East Asia. Ethnomedical records describe its traditional use for relieving various diseases, such as diarrhoea, vomiting, myalgia, and rheumatoid arthritis. Here, we reported the discovery of one new megastigmane ester (1), two new triterpenoid esters (2 and 3), and 12 known compounds (4-15) from the ethanol extract of P. sinensis fruits. These isolates were further evaluated for their anti-inflammatory properties in vitro. Among them, triterpenoids 5, 7, and 8 significantly suppressed the generation of three key pro-inflammatory cytokines, tumour necrosis factor-α, interleukin-6, and interleukin-12, in bone marrow-derived dendritic cells stimulated by lipopolysaccharide. These findings suggest that the edible and medicinal fruit of P. sinensis, as well as certain triterpenoid constituents derived from it, may have promising potential for preventing or alleviating inflammatory diseases.