Ozone treatment alleviates brain injury in cerebral ischemic rats by inhibiting the NF-κB signaling pathway and autophagy

Abstract

ABSTRACT Stroke is the most frequent cause of disability in developed countries. A common phenomenon of stroke, cerebral ischemia, is threatening many lives worldwide. In addition, ozone treatment was previously reported to exert functions in relieving brain injury. In the current study, the therapeutic effects of ozone on cerebral ischemia are investigated. A rat model of middle cerebral artery occlusion (MCAO) was established. The brain water content was calculated by weighing brain tissues, and the 2, 3, 5-triphenyltetrazolium chloride staining was performed to measure brain infarction volume in rats. A colorimetric assay was conducted to examine expression levels of malondialdehyde, superoxide dismutase, catalase, and glutathione in the rat hippocampus. Reverse transcription quantitative polymerase-chain reaction and Western blot analyses were employed to evaluate expression levels of Beclin1, LC3B, p62, and critical factors implicated in the NF-κB signaling pathway. We found that ozone significantly improved the survival rate of MCAO model rats, reduced the cerebral water content, and decreased the neurological scores of ischemic rats. Ozone markedly reduced cerebral ischemia-induced infarction in ischemic rats. Ozone decreased MDA levels and increased SOD, catalase, and GSH levels in the hippocampus of rats. Ozone significantly inhibited autophagy by decreasing Beclin1 and LC3B expression and increasing p62 expression. The ozone inactivated the NF-κB signaling pathway by decreasing the protein levels of TLR4, p-IKKβ, p-IKBα, and p-p65. We conclude that ozone treatment alleviates the brain injury in ischemic rats by suppressing autophagy and inactivating the NF-κB signaling pathway.