Effects of lisofylline on hyperoxia-induced lung injury

Lisofylline [1-(5R-hydroxyhexyl)-3,7-dimethylxanthine] decreases lipid peroxidation in vitro and in vivo suppresses proinflammatory cytokine expression in models of lung injury due to sepsis, blood loss, and oxidative damage. In the present experiments, we used a murine hyperoxia model to examine the effects of lisofylline on the activation of nuclear transcriptional regulatory factors [nuclear factor-kappaB and cAMP response element binding protein (CREB)], the expression of proinflammatory cytokines in the lungs, and the circulating levels of oxidized free fatty acids as well as on hyperoxia-induced lung injury and mortality. Treatment with lisofylline inhibited hyperoxia-associated increases in tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 in the lungs as well as decreased the levels of hyperoxia-induced serum-oxidized free fatty acids. Although hyperoxic exposure produced activation of both nuclear factor-kappaB and CREB in lung cell populations, only CREB activation was reduced in the mice treated with lisofylline. Lisofylline diminished hyperoxia-associated increases in lung wet-to-dry weight ratios and improved survival in animals exposed to hyperoxia. These results suggest that lisofylline ameliorates hyperoxia-induced lung injury and mortality through inhibiting CREB activation, membrane oxidation, and proinflammatory cytokine expression in the lungs.