Preclinical evaluation of drugs to block inflammation-driven preterm birth

Intrauterine inflammation, the major cause of early preterm birth, can have microbial and sterile aetiologies. We assessed in a Transwell model the anti-inflammatory efficacies of five drugs on human extraplacental membranes delivered after preterm spontaneous labour (30-34 wk). Drugs [TPCA1 (IKK beta inhibitor), 5 z-7-oxozeaenol (OxZ, TAK1 inhibitor), inhibitor of NF-kappa B essential modulator binding domain (iNBD), SB239063 (p38 MAPK inhibitor) and N-acetyl cysteine (free radical scavenger free radicals)] were added after 12 h equilibration to the amniotic compartment. Concentrations of IL-6, TNF-alpha, MCP-1, IL-1 beta and PGE2 in the media, and IL6, TNFA and PTGS2 mRNA expression levels in membranes, were determined after 12 h. Data were analysed using mixed models analyses. Thirteen of the 28 membranes had histological chorioamnionitis (HCA(+)); five were positive for bacterial culture and six for fetal inflammatory reaction. Baseline PGE2 and cytokine production was similar between HCA(-) and HCA(+) membranes. Anti-inflammatory effects were also similar between HCA(-) and HCA(+) membranes. TPCA1 and OxZ were the most effective drugs; each inhibited amniotic secretion of 4/5 pro-inflammatory mediators and mRNA levels of 2/3, regardless of stimulus. We conclude that treatment with TPCA1 or OxZ, in combination with antibiotics, may minimise the adverse effects of intrauterine inflammation in pregnancy.