Platonin Mitigates Acute Lung Injury Induced by Bilateral Lower Limb Ischemia-Reperfusion in Rats

Abstract

Oxidative stress and inflammatory response are crucial in mediating the development of acute lung injury induced by bilateral lower limb ischemia-reperfusion (I/R). Platonin, a potent antioxidant, possesses anti-inflammation capacity. We sought to elucidate whether platonin could mitigate acute lung injury induced by lower limb I/R. Forty-eight adult male rats were allocated to receive I/R, I/R plus platonin (100 μg/kg intravenous injection immediately after reperfusion), sham instrumentation, or sham instrumentation plus platonin (denoted as the I/R, I/R-platonin, Sham, or Sham-platonin group, respectively; n = 12 in each group). Bilateral hind limb I/R was induced by applying rubber band tourniquets high around each thigh for 3 h followed by reperfusion for 3 h. After sacrifice, the degree of lung injury was determined. Histologic findings revealed moderate inflammation in lung tissues of the I/R group and mild inflammation in those of the I/R-platonin group. Total cell number and protein concentration in bronchoalveolar lavage fluid as well as the leukocyte infiltration and myeloperoxidase activity in lung tissues of the I/R group were significantly higher than those of the I/R-platonin group. The pulmonary concentrations of macrophage inflammatory protein-2, interleukin-6, and prostaglandin E(2) of the I/R group were significantly higher than those of the I/R-platonin group. Moreover, the plasma nitric oxide concentration as well as the nitric oxide and malondialdehyde concentrations in lung tissues of the I/R group were significantly higher than those of the I/R-platonin group. Platonin mitigates acute lung injury induced by bilateral lower limb I/R in rats.