Effect of docosahexaenoic acid on the recovery of motor function in rats with spinal cord injury: a meta-analysis

Astaxanthin promotes locomotor function recovery and attenuates tissue damage in rats following spinal cord injury: a systematic review and trial sequential analysis

Spinal cord injury (SCI) is a catastrophic condition with few therapeutic options. Astaxanthin (AST), a natural nutritional supplement with powerful antioxidant activities, is finding its new application in the field of SCI. Here, we performed a systematic review to assess the neurological roles of AST in rats following SCI, and assessed the potential for clinical translation. Searches were conducted on PubMed, Embase, Cochrane Library, the Web of Science, China National Knowledge Infrastructure, WanFang data, Vip Journal Integration Platform, and SinoMed databases. Animal studies that evaluated the neurobiological roles of AST in a rat model of SCI were included. A total of 10 articles were included; most of them had moderate-to-high methodological quality, while the overall quality of evidence was not high. Generally, the meta-analyses revealed that rats treated with AST exhibited an increased Basso, Beattie, and Bresnahan (BBB) score compared with the controls, and the weighted mean differences (WMDs) between those two groups showed a gradual upward trend from days 7 (six studies, n = 88, WMD = 2.85, 95% CI = 1.83 to 3.87, p < 0.00001) to days 28 (five studies, n = 76, WMD = 6.42, 95% CI = 4.29 to 8.55, p < 0.00001) after treatment. AST treatment was associated with improved outcomes in spared white matter area, motor neuron survival, and SOD and MDA levels. Subgroup analyses indicated there were differences in the improvement of BBB scores between distinct injury types. The trial sequential analysis then firmly proved that AST could facilitate the locomotor recovery of rats following SCI. In addition, this review suggested that AST could modulate oxidative stress, neuroinflammation, neuron loss, and autophagy via multiple signaling pathways for treating SCI. Collectively, with a protective effect, good safety, and a systematic action mechanism, AST is a promising candidate for future clinical trials of SCI. Nonetheless, in light of the limitations of the included studies, larger and high-quality studies are needed for verification.

Neuroprotective effect and possible mechanism of edaravone in rat models of spinal cord injury: a protocol for a systematic review and meta-analysis

BACKGROUND

Spinal cord injury (SCI) is one of the most disabling neurological conditions, afflicting thousands of human beings. Edaravone, a well-known reactive oxygen species scavenger, is expanding its new scope in field of SCI. The objective of this systematic review is to determine the neuroprotective effects and discuss the underlying mechanism of edaravone in management of SCI.

METHODS

The systematic review will include the controlled studies evaluating the neurological roles of edaravone on experiment rat models following SCI. The primary outcome will be the 21-point Basso, Beattie, and Bresnahan locomotor rating scale. The secondary outcomes will include the preservation of white matter areas and malondialdehyde levels. Two researchers will independently search PubMed, Embase, Web of Science, Scopus and Cochrane Library from their inception date. Following study selection, data extraction, and assessment of methodological quality in included studies using the SYRCLE's RoB tool, data from eligible studies will be pooled and analyzed using random-effects models with RevMan 5.3 software. In case of sufficient data, subgroup analyses with respect to species, age, gender, injury characteristics, or administration details will be carried out to explore the factors modifying efficacy of edaravone. For exploring the appropriate dose of edaravone, a network meta-analysis approach will be conducted based on the Bayesian method. Importantly, the proposed mechanisms and changes of related molecules will be also extracted from included studies for comprehensively investigating the mechanisms underlying the neuroprotective effects of edaravone.

DISCUSSION

In this study, we aim to quantitatively analyze the role of edaravone in locomotor recovery and tissue damage in SCI rat model. The efficacy of edaravone in distinct scenarios will be investigated by subgroup analyses, and we expect to predict the candidate dose that offers a superior treatment effect using network meta-analyses. Moreover, a comprehensive framework regarding the neuroprotective mechanisms behind edaravone will be constructed via a combination of systematic and traditional review. This study will bring implications for future preclinical studies and clinical applications of SCI. Nonetheless, in light of the anticipated limitations in animal experimental design and methodological quality, the results in this review should be interpreted with caution.

The potential effects of polyunsaturated ω-3 fatty acids on spinal cord injury: A systematic review & meta-analysis of preclinical evidence

Polyunsaturated fatty acids (PUFAs) have received attention for their anti-inflammatory and antioxidant properties. Preclinical studies have investigated the efficacy of PUFAs in animal models of spinal cord injury (SCI) to determine if these properties can translate to neuroprotection and locomotor recovery. Findings from such studies have been promising, suggesting PUFAs as potential treatments against the neurological dysfunction induced by SCI. This systematic review and meta-analysis sought to investigate the efficacy of PUFAs for promoting locomotor recovery in animal models of SCI. PubMed, Web of Science and Embase (Ovid) were searched for relevant papers and those that examined the restorative effects of PUFAs on locomotor recovery in preclinical SCI models were included in our analysis. A random effects meta-analysis (restricted maximum likelihood estimator) was employed. A total of 28 studies were included and the results showed the claim that PUFAs have a beneficial therapeutic effect for promoting locomotor recovery (SMD = 1.037, 95% CI = 0.809-1.2644, p = <0.001) and cell survival (SMD = 1.101, 95% CI = 0.889-1.313, p = <0.001) in animal models of SCI. No significant differences for the secondary outcomes of neuropathic pain and lesion volume. Moderate asymmetry was observed in the funnel plots for locomotor recovery, cell survival and neuropathic pain measures, suggesting publication bias. Trim-and-fill analysis estimated 13, 3, 0 and 4 missing studies for locomotor recovery, cell survival, neuropathic pain, and lesion volume, respectively. A modified CAMARADES checklist was also used to assess risk of bias, showing that the median score for all included papers was 4 out of a possible 7.

The effect of metformin on ameliorating neurological function deficits and tissue damage in rats following spinal cord injury: A systematic review and network meta-analysis

Spinal cord injury (SCI) is a devastating condition with few treatment options. Metformin, a classical antidiabetic and antioxidant, has extended its application to experimental SCI treatment. Here, we performed a systematic review to evaluate the neurobiological roles of metformin for treating SCI in rats, and to assess the potential for clinical translation. PubMed, Embase, China National Knowledge Infrastructure, WanFang data, SinoMed, and Vip Journal Integration Platform databases were searched from their inception dates to October 2021. Two reviewers independently selected controlled studies evaluating the neurobiological roles of metformin in rats following SCI, extracted data, and assessed the quality of methodology and evidence. Pairwise meta-analyses, subgroup analyses and network analysis were performed to assess the roles of metformin in neurological function and tissue damage in SCI rats. Twelve articles were included in this systematic review. Most of them were of moderate-to-high methodological quality, while the quality of evidence from those studies was not high. Generally, Basso, Beattie, and Bresnahan scores were increased in rats treated with metformin compared with controls, and the weighted mean differences (WMDs) between metformin and control groups exhibited a gradual upward trend from the 3rd (nine studies, n = 164, WMD = 0.42, 95% CI = −0.01 to 0.85, P = 0.06) to the 28th day after treatment (nine studies, n = 136, WMD = 3.48, 95% CI = 2.04 to 4.92, P < 0.00001). Metformin intervention was associated with improved inclined plane scores, tissue preservation ratio and number of anterior horn motor neurons. Subgroup analyses indicated an association between neuroprotection and metformin dose. Network meta-analysis showed that 50 mg/kg metformin exhibited greater protection than 10 and 100 mg/kg metformin. The action mechanisms behind metformin were associated with activating adenosine monophosphate-activated protein kinase signaling, regulating mitochondrial function and relieving endoplasmic reticulum stress. Collectively, this review indicates that metformin has a protective effect on SCI with satisfactory safety and we demonstrate a rational mechanism of action; therefore, metformin is a promising candidate for future clinical trials. However, given the limitations of animal experimental methodological and evidence quality, the findings of this pre-clinical review should be interpreted with caution.

Ginseng extract and ginsenosides improve neurological function and promote antioxidant effects in rats with spinal cord injury: A meta-analysis and systematic review

Spinal cord injury (SCI) is defined as damage to the spinal cord that temporarily or permanently changes its function. There is no definite treatment established for neurological complete injury patients. This study investigated the effect of ginseng extract and ginsenosides on neurological recovery and antioxidant efficacies in rat models following SCI and explore the appropriate dosage. Searches were done on PubMed, Embase, and Chinese databases, and animal studies matches the inclusion criteria were selected. Pair-wise meta-analysis and subgroup analysis were performed. Ten studies were included, and the overall methodological qualities were low quality. The result showed ginseng extract and ginsenosides significantly improve neurological function, through the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale (pooled MD = 4.40; 95% CI = 3.92 to 4.88; p < 0.00001), significantly decrease malondialdehyde (MDA) (n = 290; pooled MD = −2.19; 95% CI = −3.16 to −1.22; p < 0.0001) and increase superoxide dismutase (SOD) levels (n = 290; pooled MD = 2.14; 95% CI = 1.45 to 2.83; p < 0.00001). Both low (<25 mg/kg) and high dosage (≥25 mg/kg) showed significant improvement in the motor function recovery in SCI rats. Collectively, this review suggests ginseng extract and ginsenosides has a protective effect on SCI, with good safety and a clear mechanism of action and may be suitable for future clinical trials and applications.

Effect of Metformin on Locomotor Function Recovery in Rat Spinal Cord Injury Model: A Meta-analysis

Background

Disorder of locomotor function is universal in patients with spinal cord injury (SCI) and has a severe impairment on their quality of life. Metformin, the first-line antidiabetic drug, has been used to improve locomotor function in SCI rats through antioxidative mechanisms recently.

Methods

A search strategy was conducted from databases, including PubMed, Web of Science, MEDLINE, and Scopus database until April 2021. The methodological quality of the animal experimental studies was assessed according to the Systematic Review Centre for Laboratory animal Experimentation's Risk of Bias tool. The weighted mean difference was calculated with the random-effects model.

Results

Seven eligible studies on SCI and metformin were reviewed. The meta-analysis indicated that SCI rats receiving metformin therapy showed a significant locomotor function recovery. Limitations and no obvious publication bias were presented in the studies.

Conclusion

Metformin can promote the recovery of the locomotor function of SCI rats. However, the use of this meta-analysis was influenced due to the not high quality of studies. Consequently, more high-quality studies are necessary for preclinical studies of SCI in the future.

Characteristics and Research Waste Among Randomized Clinical Trials in Gastric Cancer

IMPORTANCE

The results of numerous large randomized clinical trials (RCTs) have changed clinical practice in gastric cancer (GC). However, research waste (ie, unpublished data, inadequate reporting, or avoidable design limitations) is still a major challenge for evidence-based medicine.

OBJECTIVES

To determine the characteristics of GC RCTs in the past 20 years and the presence of research waste and to explore potential targets for improvement.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study of GC RCTs, ClinicalTrials.gov was searched for phase 3 or 4 RCTs registered from January 2000 to December 2019 using the keyword gastric cancer. Independent investigators undertook assessments and resolved discrepancies via consensus. Data were analyzed from August through December 2020.

MAIN OUTCOMES AND MEASURES

The primary outcomes were descriptions of the characteristics of GC RCTs and the proportion of studies with signs of research waste. Research waste was defined as unpublished data, inadequate reporting, or avoidable design limitations. Publication status was determined by searching PubMed and Scopus databases. The adequacy of reporting was evaluated using the Consolidated Standards of Reporting Trials (CONSORT) reporting guideline checklist. Avoidable design limitations were determined based on existing bias or lack of cited systematic literature reviews. In the analyses of research waste, 125 RCTs that ended after June 2016 without publication were excluded.

RESULTS

A total of 262 GC RCTs were included. The number of RCTs increased from 25 trials in 2000 to 2004 to 97 trials in 2015 to 2019, with a greater increase among RCTs of targeted therapy or immunotherapy, which increased from 0 trials in 2000 to 2004 to 36 trials in 2015 to 2019. The proportion of RCTs that were multicenter was higher in non-Asian regions than in Asian regions (50 of 71 RCTs [70.4%] vs 96 of 191 RCTs [50.3%]; P = .004). The analysis of research waste included 137 RCTs, of which 81 (59.1%) were published. Among published RCTs, 65 (80.2%) were judged to be adequately reported and 63 (77.8%) had avoidable design defects. Additionally, 119 RCTs (86.9%) had 1 or more features of research waste. Study settings that included blinding (odds ratio [OR], 0.56; 95% CI, 0.33-0.93; P = .03), a greater number of participants (ie, ≥200 participants; OR, 0.07; 95% CI, 0.01-0.51; P = .01), and external funding support (OR, 0.22; 95% CI, 0.08-0.60; P = .004) were associated with lower odds of research waste. Additionally, 35 RCTs (49.3%) were referenced in guidelines, and 18 RCTs (22.2%) had their prospective data reused.

CONCLUSIONS AND RELEVANCE

To our knowledge, this study is the first to describe the characteristics of GC RCTs in the past 20 years, and it found a research waste burden, which may provide evidence for the development of rational RCTs and reduction of waste in the future.

Lipid Mediators in Critically Ill Patients: A Step Towards Precision Medicine

A dysregulated response to systemic inflammation is a common pathophysiological feature of most conditions encountered in the intensive care unit (ICU). Recent evidence indicates that a dysregulated inflammatory response is involved in the pathogenesis of various ICU-related disorders associated with high mortality, including sepsis, acute respiratory distress syndrome, cerebral and myocardial ischemia, and acute kidney injury. Moreover, persistent or non-resolving inflammation may lead to the syndrome of persistent critical illness, characterized by acquired immunosuppression, catabolism and poor long-term functional outcomes. Despite decades of research, management of many disorders in the ICU is mostly supportive, and current therapeutic strategies often do not take into account the heterogeneity of the patient population, underlying chronic conditions, nor the individual state of the immune response. Fatty acid-derived lipid mediators are recognized as key players in the generation and resolution of inflammation, and their signature provides specific information on patients' inflammatory status and immune response. Lipidomics is increasingly recognized as a powerful tool to assess lipid metabolism and the interaction between metabolic changes and the immune system via profiling lipid mediators in clinical studies. Within the concept of precision medicine, understanding and characterizing the individual immune response may allow for better stratification of critically ill patients as well as identification of diagnostic and prognostic biomarkers. In this review, we provide an overview of the role of fatty acid-derived lipid mediators as endogenous regulators of the inflammatory, anti-inflammatory and pro-resolving response and future directions for use of clinical lipidomics to identify lipid mediators as diagnostic and prognostic markers in critical illness.