Antenatal creatine supplementation reduces persistent fetal lung inflammation and oxidative stress in an ovine model of chorioamnionitis

Chorioamnionitis is a common antecedent of preterm birth and induces inflammation and oxidative stress in the fetal lungs. Reducing inflammation and oxidative stress in the fetal lungs may improve respiratory outcomes in preterm infants. Creatine is an organic acid with known anti-inflammatory and antioxidant properties. The objective of the study was to evaluate the efficacy of direct fetal creatine supplementation to reduce inflammation and oxidative stress in fetal lungs arising from an in utero proinflammatory stimulus. Fetal lambs (n = 51) were instrumented at 90 days gestation to receive a continuous infusion of creatine monohydrate (6 mg·kg^-1·h^-1) or saline for 17 days. Maternal chorioamnionitis was induced with intra-amniotic lipopolysaccharide (LPS; 1 mg, O55:H6) or saline 7 days before delivery at 110 days gestation. Tissue creatine content was assessed with capillary electrophoresis, and inflammatory markers were analyzed with Luminex Magpix and immunohistochemistry. Oxidative stress was measured as the level of protein thiol oxidation. The effects of LPS and creatine were analyzed using a two-way ANOVA. Fetal creatine supplementation increased lung creatine content by 149% (P_Cr < 0.0001) and had no adverse effects on lung morphology. LPS-exposed groups showed increased levels of interleukin-8 in the bronchoalveolar lavage (P_LPS < 0.0001) and increased levels of CD45⁺ leukocytes (P_LPS < 0.0001) and MPO⁺ (P_LPS < 0.0001) cells in the lung parenchyma. Creatine supplementation significantly reduced the levels of CD45⁺ (P_Cr = 0.045) and MPO⁺ cells (P_Cr = 0.012) in the lungs and reduced thiol oxidation in plasma (P_Cr < 0.01) and lung tissue (P_Cr = 0.02). In conclusion, fetal creatine supplementation reduced markers of inflammation and oxidative stress in the fetal lungs arising from chorioamnionitis.