Objective:To explore the neuroprotective effect and molecular mechanism of sulforaphane (SFN) on acute carbon monoxide poisoning (ACOP) in rats.Methods:A total of 135 healthy adult male Sprague-Dawley (SD) rats were randomly divided into normal control group, ACOP model group, and SFN intervention group, with 45 rats in each group. The ACOP animal model was reproduced using carbon monoxide (CO) inhalation in a hyperbaric oxygen chamber, while the normal control group was allowed to breathe fresh air freely. The rats in the SFN intervention group received intraperitoneal injection of SFN at a dose of 20 mg/kg once daily starting 2 hours after CO poisoning and continuing until euthanasia. The normal control group and the ACOP model group received equivalent volume of saline injection. Three rats from each group were sacrificed 1 day after intervention to observe the changes in the ultrastructure of neuronal mitochondria in brain tissues under transmission electron microscopy. Six rats from each group were evaluated for cognitive function using neurobehavioral test 7 days after intervention. Brain tissues of 6 rats in each group were collected 1, 3, and 7 days after intervention, and the expressions of phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK), mitofusin 2 (MFN2), and dynamin-related protein 1 (DRP1) were detected using immunohistochemistry staining and Western blotting. Linear regression analysis was performed to assess the correlations between the expression levels of above proteins.Results:In the normal control group, the rats did not exhibit any abnormalities in cognitive function or the ultrastructure of neuronal mitochondria in brain tissues. ACOP induced cognitive impairment and ultrastructural injury to neuronal mitochondria in rats. However, SFN significantly improved cognitive function in poisoned rats and mitigated the extent of neuronal mitochondrial damage. Over poisoning time, the expression levels of p-AMPK and MFN2 in the brain tissues of ACOP rats were gradually decreased, while the expression level of DRP1 was gradually increased. Compared with the normal control group, the ACOP model group showed significant differences in the expressions of p-AMPK, MFN2, and DRP1. After SFN intervention, the expression levels of above proteins were significantly reversed. Compared with the ACOP model group, the SFN intervention group exhibited a marked increase in the expressions of p-AMPK and MFN2 [p-AMPK positive expression ( A value): 0.226±0.003 vs. 0.177±0.033, p-AMPK protein (p-AMPK/GAPDH): 1.41±0.05 vs. 0.89±0.05, MFN2 positive expression ( A value): 0.241±0.004 vs. 0.165±0.007, MFN2 protein (MFN2/GAPDH): 1.33±0.04 vs. 0.79±0.03, all P < 0.05], along with a significant decrease in DRP1 expression [DRP1 positive expression ( A value): 0.103±0.002 vs. 0.214±0.011, DRP1 protein (DRP1/GAPDH): 1.00±0.03 vs. 1.50±0.03, both P < 0.05]. Linear regression analysis revealed a strong negative linear correlation between DRP1 protein expression and MFN2, p-AMPK protein expressions ( R2 values were 0.977 and 0.971, both P < 0.01), and a positive linear correlation between p-AMPK protein expression and MFN2 protein expression ( R2 = 0.985, P < 0.01). Conclusion:SFN can help maintain neuronal mitochondrial homeostasis by activating the adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, thereby alleviating neuronal injury caused by ACOP.

Objective:To observe the effect of early temperature control on the prognosis of brain injury patients after severe carbon monoxide poisoning (COP).Methods:A total of 277 patients hospitalized with severe COP were randomly divided into a fever group ( n=78), a normal temperature group ( n=113) and a mild hypothermia group ( n=86). All were given hyperbaric oxygen therapy and any necessary supportive treatment. The mild hypothermia group were kept in a room at 34 to 35℃. Evaluation was with the Glasgow Coma Scale (GCS), version II of the Acute Physiology and Chronic Health Evaluation (APACHE), the Hasegawa dementia scale (HDS) and the mini mental state examination (MMSE). The incidence of delayed encephalopathy (DEACMP) and mortality were compared among the three groups. The bispectral index (BIS) and neuron-specific enolase (NSE) levels were correlated with DEACMP. Results:After the treatments, improvement was observed in multiple indexes of all three groups compared with before the treatment. Compared with the fever group, the average GCS of the mild hypothermia group was significantly higher on the 2nd, 4th, 8th and 31st day after the intervention. It was significantly higher than the normal temperature group′s averages on the 4th, 8th and 31st day. The average APACHE scores of the normal temperature and the mild hypothermia groups were significantly lower than the fever group′s average, with that of the mild hypothermia group significantly lower than that of the normal group. The average HDS scores of the normal temperature and mild hypothermia groups were significantly higher than the fever group′s average, with that of the mild hypothermia group significantly higher than that of the normal group. The average MMSE score of the mild hypothermia group was significantly improved after 7 days, one month and three months of treatment. That of the normal group showed significant improvement after one and three months, but the mild hypothermia group′s averages were superior. Compared with the fever group, the average BIS score of the mild hypothermia group was significantly better after one, three and seven days, and one month. This was true for the normal group beyond three days after the intervention. The average NSE concentration of the normal group after 7 days and one month was significantly lower than that of the fever group. For the mild hypothermia group this was true after only 3 days. Compared with the other two groups, the average coma time, incidence of DEACMP and nervous system injury were significantly lower in the hypothermia group. The average GCS, BIS and NSE values were closely related to the occurrence of DEACMP.Conclusions:Early temperature control can significantly reduce the severity of brain injury after COP and reduce the incidence of neurological sequelae. Early dynamic detection of GCS, NSE concentration and BIS is of great significance for predicting the incidence of DEACMP.