Vitamin C Exacerbates Hydrogen Peroxide Induced Apoptosis and Concomitant PGE 2Release in Amnion Epithelial and Mesenchymal Cells, and in Intact Amnion

Abstract

This study was undertaken to investigate the effect of hydrogen peroxide (HP), a reactive oxygen species, and vitamin C, an antioxidant, on apoptosis and prostaglandin (PGE 2) release in human amnion epithelial and mesenchymal cells, and intact amnion. Amnion cells and explants were incubated with and without HP and vitamin C. Cytoproliferation assay for viability, DNA fragmentation and PARP cleavage for apoptosis, EIA for PGE 2, and western blots for cyclooxygenases (COX) were performed. In amnion cells and explants, HP (0–5 m m) induced dose dependent apoptosis as per DNA fragmentation and PARP cleavage. HP (0–0.5 m m) also induced PGE 2release concomitant with apoptosis in both cell types. In amnion explants, HP (0–10 m m) induced COX-2 protein and PGE 2release concomitant with apoptosis. Vitamin C (0.01–10 m m), alone, enhanced epithelial but inhibited mesenchymal cell viability. It induced PGE 2release in amnion explants. Vitamin C (1 m m) failed to inhibit HP induced apoptosis, but instead exacerbated it in epithelial and mesenchymal cells, and amnion explants. Vitamin C (0–10 m m) enhanced HP induced PGE 2in mesenchymal cells. HP induces concomitant apoptosis and PGE 2release in amnion epithelial and mesenchymal cells, and in intact amnion explants. HP induced apoptosis is not inhibited but enhanced by vitamin C.