Neuroprotective effects of methane-rich saline on experimental acute carbon monoxide toxicity

Background: Methane has been reported to play a protective role in ischemia-reperfusion injury via anti-oxidation, anti-inflammatory and anti-apoptotic activities. This study was designed to determine the protective effects of methane-rich saline (MRS) on acute carbon monoxide (CO) poisoning. Methods: A total of 36 male Sprague-Dawley rats were randomly divided into 3 groups: sham group, CO group and MRS group. Acute CO poisoning was induced by exposing rats to 1000 ppm CO in air for 40 min and then to 3000 ppm CO for an additional 20 min until they lost consciousness. MRS at 10 ml/kg was intraperitoneally administered at 0 h, 8 h and 16 h after CO exposure. Rats were sacrificed 24 h after CO exposure. Brains were collected for Nissl staining. The cortex and hippocampus were separated for the detections of malondialdehyde (MDA), 3-nitrotyrosine (3-NT), 8-hydroxydeoxyguanosine (8-OHdG), tumor necrosis factor-alpha (TNF-alpha), interleukin1-beta (1-beta), interleukin-6 (IL-6) and superoxide dismutase (SOD) activities. Results: The results showed that MRS treatment improved neuronal injury, reduced MDA, 3-NT and 8-OHdG, and increased SOD activity of the hippocampus and cortex compared with normal saline-treated rats. In addition, MRS reduced the expression of TNF-alpha and IL-beta in the brain but had no effect on IL-6 expression. Conclusion: These findings suggest that MRS may protect the brain against acute CO poisoning-induced injury via its anti-oxidative and anti-inflammatory activities. (C) 2016 Elsevier B.V. All rights reserved.