Hydroxylated fullerene: a potential antiinflammatory and antioxidant agent for preventing mouse preterm birth

OBJECTIVE: Intrauterine infection such as by Escherichia coli and Ureaplasma spp induce placental inflammation and are one of the leading causes of preterm birth. Here we evaluated hydroxylated fullerene (C-60[OH](44)) for its in vitro antiinflammatory and antioxidant effects against host cellular responses to the ureaplasma toll-like receptor 2 (TLR2) ligand, UPM-1. In addition, we investigated the preventative effects of C-60(OH)(44) in vivo in a mouse preterm birth model that used UPM-1. STUDY DESIGN: TLR2-overexpressing cell lines and the primary cultures of mouse peritoneal macrophages were pretreated with C-60(OH)(44). After UPM-1 addition to the cell lines, the activation of the nuclear factor kappa-light chain-enhancer of activated B cells (NF-kappaB) signaling cascade and the production of reactive oxygen species were monitored. The levels of expression of inflammatory cytokines of interleukin (IL)-6, IL-1 beta, tumor necrosis factor (TNF)-alpha, and the production of reactive oxygen species were quantified after stimulation with UPM-1. The in vivo preventative effects of C-60(OH)(44) on mice preterm birth were evaluated by analyzing the preterm birth rates and fetal survival rates in the preterm birth mouse model with placental histological analyses. RESULTS: Pretreatment with C-60(OH)(44) significantly suppressed UPM-1- induced NF-kappaB activation and reactive oxygen species production in TLR2-overexpressing cell lines. In the primary culture of mouse peritoneal macrophages, UPM-1-induced production of reactive oxygen species and the expression of inflammatory cytokines such as IL-6, IL-1 beta, and TNF-alpha were significantly reduced by pretreatment with C-60(OH)(44). In the UPM-1-induced preterm birth mouse model, the preterm birth rate decreased from 72.7% to 18.2% after an injection of C-60(OH)(44). Placental examinations of the group injected with C-60(OH)(44) reduced the damage of the spongiotrophoblast layer and reduced infiltration of neutrophils. CONCLUSION: C-60(OH)(44) was effective as a preventative agent of preterm birth in mice.