Cyclosporin and tacrolimus do not potentiate oxidative damage in pulmonary epithelial cells

Oxidative stress can lead to cellular injury and apoptosis within the pulmonary allograft. We investigated the effects of oxidative damage on the growth and survival of cultured human pulmonary epithelial cells treated with hydrogen peroxide (H₂O₂) in the presence and absence of cyclosporin A (CsA) and tacrolimus. Treatment of A549 cells with 1 mmol/l H ₂O₂ for 48 h led to a 39% decrease in cell growth. Treatment with 500 ng/ml CsA for 48 h reduced cell survival by 68%, and treatment with 30 ng/ml tacrolimus reduced cell survival by 32%. The addition of CsA or tacrolimus to cells grown in H₂O₂ did not further diminish cell survival. These studies demonstrated that H ₂O₂, CsA, and tacrolimus treatments decrease survival of pulmonary epithelial cells. However, CsA and tacrolimus do not further potentiate H₂O₂-induced toxicity.