Effect of free radical scavenger, edaravone, for patients with carbon monoxide poisoning

Edaravone combined with hyperbaric oxygen therapy in delayed encephalopathy after acute carbon monoxide poisoning: A meta-analysis

BACKGROUND

The use of both edaravone (EDA) and hyperbaric oxygen therapy (HBOT) is increasingly prevalent in the treatment of delayed encephalopathy after carbon monoxide poisoning (DEACMP). This meta-analysis aims to evaluate the efficacy of using EDA and HBOT in combination with HBOT alone in the treatment of DEACMP.

METHODS

We searched and included all randomized controlled trials (RCTs) published before November 6, 2023, from 12 Chinese and English databases and clinical trial centers in China and the United States. The main outcome indicator was the total effective rate. The secondary outcome indicators included the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), Hasegawa Dementia Scale (HDS), Fugl-Meyer Assessment (FMA), Superoxide Dismutase (SOD), and Malondialdehyde (MDA). Statistical measures utilized include risk ratios (RR), weighted mean difference (WMD), and 95 % confidence intervals (95 % CI).

RESULTS

Thirty studies involving a combined total of 2075 participants were ultimately incorporated. It was observed that the combination of EDA with HBOT for the treatment of DEACMP demonstrated an improvement in the total effective rate (RR: 1.25; 95 % CI: 1.20-1.31; P < 0.01), MMSE (WMD: 3.67; 95 % CI: 2.59-4.76; P < 0.01), MoCA (WMD: 4.38; 95 % CI: 4.00-4.76; P < 0.01), BI (WMD: 10.94; 95 % CI: 5.23-16.66; P < 0.01), HDS (WMD: 6.80; 95 % CI: 4.05-9.55; P < 0.01), FMA (WMD: 8.91; 95 % CI: 7.22-10.60; P < 0.01), SOD (WMD: 18.45; 95 % CI: 16.93-19.98; P < 0.01); and a reduction in NIHSS (WMD: -4.12; 95 % CI: -4.93 to -3.30; P < 0.01) and MDA (WMD: -3.05; 95 % CI: -3.43 to -2.68; P < 0.01).

CONCLUSION

Low-quality evidence suggests that for DEACMP, compared to using HBOT alone, the combined use of EDA and HBOT may be associated with better cognition and activity of daily living. In the future, conducting more meticulously designed multicenter and large-sample RCTs to substantiate our conclusions is essential.

Hydrogen gas protects against delayed encephalopathy after acute carbon monoxide poisoning in a rat model

Objective: The protective effects of 2%-4% hydrogen gas in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) have been previously reported. This study aimed to assess the neuroprotective effects of high concentration hydrogen (HCH) on DEACMP.Methods: A total of 36 male Sprague-Dawley rats were divided into 3 groups. In the DEACMP group, rats were exposed to CO to induce CO poisoning; in the HCH group, the animals were exposed to 67% H₂ and 33% O₂ at 3,000 mL/min for 90 min immediately after CO poisoning. Neurological function was evaluated at 1 and 9 days after poisoning. Then, the contents of malondialdehyde, 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine, as well as superoxide dismutase activity in the serum, cortex and hippocampus were detected by ELISA. Additionally, the mRNA and protein expression levels of Nrf2 and downstream genes were detected by RT-PCR and Western blotting, respectively.Results: Our results showed that CO poisoning significantly impaired neurological function which was improved over time, and HCH markedly attenuated neurological impairment following CO poisoning. In addition, CO poisoning resulted in increased levels of malondialdehyde, 3-nitrotyrosine and 8-hydroxy-2-deoxyguanosine and markedly reduced superoxide dismutase activity at 1 and 9 days, which were significantly inhibited by HCH at 9 days. Finally, CO poisoning increased the mRNA and protein levels of Nrf2 and downstream genes, and HCH further induced the anti-oxidative capability.Conclusion: These findings indicate the neuroprotective effects of HCH on DEACMP, which are related to the activation of Nrf2 signaling pathway.

Amantadine Combines Astroglial System Xc- Activation with Glutamate/NMDA Receptor Inhibition

A glutamate/NMDA receptor (NMDA-R) antagonist, amantadine (AMA) exhibits a broad spectrum of clinically important properties, including antiviral, antiparkinsonian, neuroprotective, neuro-reparative and cognitive-enhancing effects. However, both clinical and pre-clinical studies have demonstrated that noncompetitive NMDA-R antagonists induce severe schizophrenia-like cognitive deficits. Therefore, this study aims to clarify the clinical discrepancy between AMA and noncompetitive NMDA-R antagonists by comparing the effects of AMA with those of a noncompetitive NMDA-R antagonist, MK801, on rat tripartite glutamatergic synaptic transmission using microdialysis and primary cultured astrocytes. Microdialysis study demonstrated that the stimulatory effects of AMA on L-glutamate release differed from those of MK801 in the globus pallidus, entorhinal cortex and entopeduncular nucleus. The stimulatory effect of AMA on L-glutamate release was modulated by activation of cystine/glutamate antiporter (Sxc). Primary cultured astrocytes study demonstrated that AMA also enhanced glutathione synthesis via Sxc activation. Furthermore, carbon-monoxide induced damage of the astroglial glutathione synthesis system was repaired by AMA but not MK801. Additionally, glutamate/AMPA receptor (AMPA-R) antagonist, perampanel enhanced the protective effects of AMA. The findings of microdialysis and cultured astrocyte studies suggest that a combination of Sxc activation with inhibitions of ionotropic glutamate receptors contributes to neuroprotective, neuro-reparative and cognitive-enhancing activities that can mitigate several neuropsychiatric disorders.

Retrospective study of clinical features and prognosis of edaravone in the treatment of paraquat poisoning

To observe whether edaravone can protect organs and inhibit pulmonary fibrosis in patients with paraquat poisoning and to provide a method for clinical intervention for paraquat poisoning.Forty-four cases of paraquat poisoning were collected from March 2011 to December 2017 in our hospital. Eighteen cases from March 2011 to November 2013 did not receive edaravone treatment and were considered the control group, and 26 cases from January 2014 to December 2017 were treated with edaravone and were considered the observation group. Injuries to the central nervous system, heart, liver, kidney, and digestive system were evaluated on at 24 hours, 3 days, and 7 days after hospitalization. The expression of serum inflammatory factors (interleukin [IL]-6, IL-10, tumor necrosis factor-α [TNF-α]) and oxidative stress correlation (superoxide dismutase [SOD] and malondialdehyde [MDA]) were assayed at 24 hours, 3 days, and 7 days after being hospitalized. After 7, 14, and 30 days, the changes in pathological lung characteristics in the 2 groups were assessed, and survival rates were calculated.Edaravone significantly increased the serum levels of SOD and obviously markedly reduce the serum levels of IL-6, IL-10, TNF-α, and MDA in patients poisoned with paraquat (P < .05). Edaravone significantly protected the liver (P = .021), cardiovascular (P = .031), and renal (P = .028) organs of patients from paraquat poisoning-induced injury after 7 days but had no significant protection or improvement on respiratory and digestive tract damage. Edaravone delayed the occurrence of pulmonary fibrosis and increase the survival time of patients at 7 and 14 days (P < .05). However, the 1-month follow-up found that edaravone did not reduce pulmonary fibrosis (77.8% vs 73.1%, P = .615) and did not increase the survival rate of the patients (61.1% vs 65.3%, P = .853).Edaravone is beneficial for protecting the kidneys and liver from paraquat poisoning through reducing oxidative stress and inhibiting inflammatory response. It can also inhibit the pulmonary fibrosis process and prolong the survival time of the patients. However, no significant improvements were seen in the probability of pulmonary fibrosis and the survival rate.

Efficacy of Combined XingZhi-YiNao Granules and Hyperbaric Oxygen Therapy for Cognition and Motor Dysfunction in Patients with Delayed Encephalopathy after Acute Carbon Monoxide Poisoning

Purpose

To investigate the efficacy of XingZhi-YiNao (XZYN) granules and hyperbaric oxygenation (HBO) for cognition and motor dysfunction in patients with delayed encephalopathy after acute carbon monoxide poisoning (DEACMP).

Methods

Eighty-nine patients with DEACMP were randomly divided into control group (n = 19), HBO group (n = 32), and XZYN group (n = 38). All patients received conventional treatment. HBO group received HBO therapy once daily. XZYN group received extra XZYN granules plus HBO treatment. The related indexes including activity of daily living (ADL) scale, Montreal cognitive assessment (MoCA) scale, and mini mental state examination (MMSE) scale were measured. Cerebral white matter injury, age related white matter changes (ARWMC) scale, and the amplitude and latency of P300 were assessed.

Results

Compared with control group, the neurological function scores of ADL, MoCA, and MMSE in HBO and XZYN groups were significantly improved, the impairment degree of brain white matter and cognition function were obviously alleviated, the latencies of P300 were significantly shortened, and the amplitudes of P300 were evidently increased (P < 0.05). Treatment efficacy of XZYN group was superior to that of HBO group (P < 0.05).

Conclusion

Combined XZYN granules and HBO can significantly improve cognition and motor functions in patients with DEACMP.