Protective effect of Astragali radix extract on interleukin 1β‐induced inflammation in human amnion

The aim of this study was to investigate the effect of Astragali radix extract on interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha production and prostaglandin E(2) (PGE(2)) and leukotriene C(4) (LTC(4)) release from IL-1beta-stimulated human amnion. Primary monolayer cultures of amnion cells were established from women undergoing elective caesarean section before the onset of labour. Production of both IL-6 and TNF-alpha was stimulated in a concentration-dependent manner by proinflammatory cytokine IL-1beta (0.01-10 ng/mL). Astragalus extract inhibited IL-6 production by approximately 75% from cells under IL-1beta-stimulated conditions. Treatment of amnion cells with IL-1beta (0.01-10 ng/mL) resulted in a significant increase in PGE(2) release. Incubation of the cells with the extract for 24 h significantly inhibited IL-1beta-induced PGE(2) production. A concentration-dependent increase in LTC(4) production by amnion cells occurred in response to IL-1beta. Astragalus extract blocked the effect of IL-1beta in LTC(4) production in human amnion. These results indicate that Astragali radix has a broad antiinflammatory effect in human amnion and may be considered a promising agent to protect preterm labour.