Ibuprofen Augments Bilirubin Toxicity in Rat Cortical Neuronal Culture

Abstract

Premature infants are at risk for bilirubin-associated brain damage. In cell cultures bilirubin causes neuronal apoptosis and necrosis. Ibuprofen is used to close the ductus arteriosus, and is often given when hyperbilirubinemia is at its maximum. Ibuprofen is known to interfere with bilirubin-albumin binding. We hypothesized that bilirubin toxicity to cultured rat embryonic cortical neurons is augmented by coincubation with ibuprofen. Incubation with ibuprofen above a concentration of 125 g/mL reduced cell viability, measured by methylthiazole tetrazolium reduction, to 68% of controls (p Ͻ 0.05). Lactate dehydrogenase (LDH) release increased from 29 to 38% (p Ͻ 0.01). The vehicle solution did not affect cell viability. Coincubation with 10 M unconjugated bilirubin (UCB)/human serum albumin in a molar ratio of 3:1 and 250 g/mL ibuprofen caused additional loss of cell viability and increased LDH release (p Ͻ 0.01), DNA fragmentation, and activated caspase-3. Preincubation with the pan-caspase inhibitor z-val-alaasp-fluoromethyl ketone abolished ibuprofen-and UCB-induced DNA fragmentation. The study demonstrates that bilirubin in low concentration of 10 M reduces neuron viability and ibuprofen increases this effect. Apoptosis is the underlying cell death mechanism. (Pediatr Res 65: 392-396, 2009)

The protective effect of docosahexaenoic acid on the bilirubin neurotoxicity

“…These findings supports the previous studies that UCB has a dual effect on astrocyte cells, being neuroprotective at lower concentrations, but neurotoxic at higher concentrations. Furthermore, the present study also demonstrated that IC 50 36,38 .…”

Sila-Ibuprofen

“…Furthermore, the viability of the cells was not affected by a 72 h exposure to up to 300 μM of 1 or 2 (Figure S28). These data confirm the low toxicity of ibuprofen (1) 3,23 and also demonstrate a low toxic potential of sila-ibuprofen (2), as no differences in the parameters determined were observed (Figure S28). In addition, the exposure of C6 cells to 1000 μM of 1 or 2 did not lead to any obvious change in cell morphology or to any significant increase in extracellular lactate dehydrogenase activity, demonstrating that these high concentrations were not toxic to the cells either.…”

Patent ductus arteriosus in the preterm infant: to treat or not to treat?

“…38 Indeed, a recent study showed that ibuprofen augments bilirubin toxicity in rat cortical neuronal culture. 43 The clinical significance of this potential neurotoxicity remains unknown. Data on the long-term outcome of preterm infants randomized to ibuprofen would be helpful in clarifying these concerns.…”