Evidence for the efficacy of statins in animal stroke models: a meta-analysis

A meta-analysis of animal studies evaluating the effect of hydrogen sulfide on ischemic stroke: is the preclinical evidence sufficient to move forward?

Hydrogen sulfide (H2S) is a gasotransmitter that has been studied for its potential therapeutic effects, including its role in the pathophysiology and treatment of stroke. This systematic review and meta-analysis aimed to determine the sufficiency of overall preclinical evidence to guide the initiation of clinical stroke trials with H2S and provide tailored recommendations for their design. PubMed, Web of Science, Scopus, EMBASE, and MEDLINE were searched for studies evaluating the effect of any H2S donor on in vivo animal models of regional ischemic stroke, and 34 publications were identified. Pooling of the effect sizes using the random-effect model revealed that H2S decreased the infarct area by 34.5% (95% confidence interval (CI) 28.2-40.8%, p < 0.0001), with substantial variability among the studies (I2 = 89.8%). H2S also caused a 37.9% reduction in the neurological deficit score (95% CI 29.0-46.8%, p < 0.0001, I2 = 63.8%) and in the brain water content (3.2%, 95% CI 1.4-4.9%, p = 0.0014, I2 = 94.6%). Overall, the studies had a high risk of bias and low quality of evidence (median quality score 5/15, interquartile range 4-9). The majority of the included studies had a "high" or "unclear" risk of bias, and none of the studies overall had a "low" risk. In conclusion, H2S significantly improves structural and functional outcomes in in vivo animal models of ischemic stroke. However, the level of evidence from preclinical studies is not sufficient to proceed to clinical trials due to the low external validity, high risk of bias, and variable design of existing animal studies.

Protective effect and possible mechanisms of resveratrol in animal models of osteoporosis: A preclinical systematic review and meta-analysis

Resveratrol (RES) has extensively been utilized to treat osteoporosis (OP) in animal models. However, the anti-OP effects of RES have not been tested during clinical application due to the lack of evidence and poor knowledge of the underlying mechanisms. Moreover, there is little preclinical evidence to support the use of RES in the management of OP. In the present paper, we conducted a preclinical systematic review and meta-analysis to assess the efficacy of RES in animal OP models. The potential mechanisms underlying the efficacy of RES against OP were summarized. The online databases PubMed, CNKI, EMBASE, Wanfang, Web of Science, Chinese Biomedical Literature, Cochrane Library, and Chinese VIP were retrieved from inception to December 2021. The CAMARADES 10-item quality checklist was utilized to assess the risk of bias of the included studies. STATA 12.0 software was employed to analyze the data. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. Thirteen studies containing 248 animals were included yielding a mean risk of bias score of 5.54 (range 4-7). The pooled estimates showed that the administration of RES could significantly elevate the bone mineral density (BMD) both at femur (SMD = 2.536; 95% CI = 1.950-3.122; p < 0.001) and lumbar spine (SMD = 1.363; 95% CI = 0894-1.832; p < 0.001), bone volume over total volume (BV/TV) (SMD = 2.543; 95% CI = 2.023-3.062; p < 0.001), trabecular linear density (Tb.N) (SMD = 2.724; 95% CI = 2.186-3.262; p < 0.001) and trabecular thickness (Tb.Th) (SMD = 1.745; 95% CI = 1.294-2.196; p < 0.001), while serum phosphorus (S-P) (SMD = -2.168; 95% CI = -2.753 to -1.583; p < 0.001) and trabecular separation (Tb.Sp) (SMD = -2.856; 95% CI = -4.218 to -1.494; p < 0.001) were significantly reduced in animal OP models. No significant change in serum calcium (S-Ca) (SMD = -2.448; 95% CI = -5.255-0.360; p = 0.087) was observed after RES treatment. Furthermore, RES could significantly improve the bone biomechanical indexes: bone maximum load (BML) (SMD = 2.563; 95% CI = 1.827-3.299; p < 0.001) and connectivity density (Conn.D) (SMD = 1.512; 95% CI = 0.909-2.116; p < 0.001) and decrease the structural model index (SMI) (SMD = -2.522; 95% CI = -3.243 to -1.801; p < 0.001). Overall, the present study revealed that RES has huge prospects as a medicine or dietary supplement for the clinical treatment of OP. High-quality studies with stringent designs and larger sample sizes are warranted to substantiate our conclusion.

Statins and 90-Day Functional Performance and Survival in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

The neuroprotective effect of statins has become a focus of interest in spontaneous intracerebral hemorrhage (sICH). The purpose of this study was: (1) to evaluate the effect of statin use by the analyzed patients with sICH in the period preceding the onset of hemorrhage on their baseline neurological status and baseline neuroimaging of the head; (2) to evaluate the effect of statin use in the acute period of hemorrhage on the course and prognosis in the in-hospital period, taking into account whether the statin was taken before the hemorrhage or only after its onset; (3) to evaluate the effect of continuing statin treatment after in-hospital treatment on the functional performance and survival of patients up to 90 days after the onset of sICH symptoms, taking into account whether the statin was taken before the onset of sICH.

MATERIAL AND METHODS

A total of 153 patients diagnosed with sICH were analyzed, where group I were not previously taking a statin and group II were taking a statin before sICH onset. After lipidogram assessment, group I was divided into patients without dyslipidemia and without statin treatment (Ia) and patients with dyslipidemia who received de novo statin treatment during hospitalization (Ib). Group II patients continued taking statin therapy. We evaluated the effect of prior statin use on the severity of hemorrhage; the effect of statin use during the acute period of sICH on its in-hospital course; and the effect of statin treatment on the severity of neurological deficit, functional capacity and survival of patients up to 90 days after the onset of sICH symptoms.

RESULTS

There was no effect of prior statin use on the severity of hemorrhage as assessed clinically and by neuroimaging of the head. At in-hospital follow-up, subgroup Ia was the least favorable in terms of National Institutes of Health Stroke Scale (NIHSS) score. This subgroup had the highest percentage of deaths during hospitalization. In the post-hospital period, the greatest number of patients with improvement in the NIHSS, modified Rankin Scale (mRS) and Barthel scales were among those taking statins, especially group II patients. At 90-day follow-up, survival analysis fell significantly in favor of subgroup Ib and group II.

CONCLUSIONS

1. The use of statins in the pre-sICH period did not adversely affect the patients' baseline neurological status or the results of baseline neuroimaging studies. 2. Continued statin therapy prior to the onset of sICH or the inclusion of statins in acute treatment in patients with sICH and dyslipidemia does not worsen the course of the disease and the in-hospital prognosis. Statin therapy should not be discontinued during the acute phase of sICH. 3. To conclude the eventual beneficial effect on the functional performance and survival of patients after sICH onset, comparability of the analyzed groups in terms of clinical, radiological and other prognostic factors in spontaneous intracerebral hemorrhage would be needed. Future studies are needed to confirm these findings.

Neurovascular Inflammation and Complications of Thrombolysis Therapy in Stroke

Intravenous thrombolysis via tPA (tissue-type plasminogen activator) is the only approved pharmacological treatment for acute ischemic stroke, but its benefits are limited by hemorrhagic transformation. Emerging evidence reveals that tPA swiftly mobilizes immune cells which extravasate into the brain parenchyma via the cerebral vasculature, augmenting neurovascular inflammation, and tissue injury. In this review, we summarize the pronounced alterations of immune cells induced by tPA in patients with stroke and experimental stroke models. We argue that neuroinflammation, triggered by ischemia-induced cell death and exacerbated by tPA, compromises neurovascular integrity and the microcirculation, leading to hemorrhagic transformation. Finally, we discuss current and future approaches to attenuate thrombolysis-associated hemorrhagic transformation via uncoupling immune cells from the neurovascular unit.

Antiosteoporosis effect and possible mechanisms of the ingredients of Radix Achyranthis Bidentatae in animal models of osteoporosis: systematic review and meta-analysis of in vivo studies

BACKGROUND

The effect and mechanisms of the ingredients (IRAB) of Radix Achyranthis Bidentatae (RAB) on treating osteoporosis (OP) remains debated. We aimed to summary the evidence to evaluate the efficacy of IRAB for animal model OP and elucidate the potential mechanism of IRAB in the treatment of OP.

METHODS

In this review and meta-analysis, we searched PubMed, EMBASE, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang, Chinese Biomedical Literature Database, as well as Chinese VIP databases for targeting articles published from inception to March 2023 in English or Chinese. All randomized controlled animal trials that assessed the efficacy and safety of IRAB for OP were included. We excluded trials according to exclusion criteria. The CAMARADES 10-item quality checklist was utilized to test the risk of potential bias for each including study and modifications were performed accordingly. The primary outcome measures were bone mineral density of the femoral neck (F-BMD), serum calcium (Ca), serum phosphorus (P), serum alkaline phosphatase (ALP), bone gla protein (BGP), bone maximum stress (M-STRESS). The secondary outcome measure was the antiosteoporosis mechanisms of IRAB.

RESULTS

Data from nine articles were included in the systematic review and meta-analysis, which focused on 196 animals. Egger's test revealed the presence of publication bias in various studies regarding the primary outcome. Administration of IRAB or RAB could significantly increases the F-BMD (SMD = 2.09; 95% CI = 1.29 to 2.89; P < 0.001, I² = 76%), Ca (SMD = 0.86; 95% CI = 0.39to1.34; P = 0.07, I² = 49%); P (SMD = 1.01; 95% CI = 0.45-4.57; P = 0.08, I² = 50%), BGP (SMD = 2.13; 95% CI = 1.48 to 2.78; I² = 46%, P = 0.10), while the ALP (SMD = - 0.85; 95% CI =  - 1.38 to - 0.31; I² = 46%, P = 0.10) was remarkably decreased in OP model animals. Moreover, the bone biomechanical indicator M-STRESS (SMD = 2.39; 95% CI = 1.74-3.04; I² = 32%, P = 0.21) was significantly improved.

CONCLUSION

Collectively, the findings suggest that the RAB or IRAB could be an effective drug or an ingredient in diet for the clinical treatment of OP in future.

Neuroprotective effects of coenzyme Q10 on neurological diseases: a review article

Neurological disorders affect the nervous system. Biochemical, structural, or electrical abnormalities in the spinal cord, brain, or other nerves lead to different symptoms, including muscle weakness, paralysis, poor coordination, seizures, loss of sensation, and pain. There are many recognized neurological diseases, like epilepsy, Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), stroke, autosomal recessive cerebellar ataxia 2 (ARCA2), Leber's hereditary optic neuropathy (LHON), and spinocerebellar ataxia autosomal recessive 9 (SCAR9). Different agents, such as coenzyme Q10 (CoQ10), exert neuroprotective effects against neuronal damage. Online databases, such as Scopus, Google Scholar, Web of Science, and PubMed/MEDLINE were systematically searched until December 2020 using keywords, including review, neurological disorders, and CoQ10. CoQ10 is endogenously produced in the body and also can be found in supplements or foods. CoQ10 has antioxidant and anti-inflammatory effects and plays a role in energy production and mitochondria stabilization, which are mechanisms, by which CoQ10 exerts its neuroprotective effects. Thus, in this review, we discussed the association between CoQ10 and neurological diseases, including AD, depression, MS, epilepsy, PD, LHON, ARCA2, SCAR9, and stroke. In addition, new therapeutic targets were introduced for the next drug discoveries.

Cerebroprotective effects of Moringa oleifera derivatives extracts against MCAO ischemic stroke: A systematic review and meta-analysis

Moringa oleifera (MO), has been studied extensively, and has numerous medicinal and socioeconomic benefits. Emerging research has investigated the efficacy of MO extract and/or its phytochemical derivatives against ischemic stroke in-vivo. To date, no studies comprehensively reviewing the effects of MO extract and/or its phytochemical derivatives against ischemic stroke have been published. A systematic review and meta-analysis was conducted to assess the effects of MO extract and/or its phytochemical derivatives against focal ischemic stroke, modeled in-vivo. Compared with control groups, significant reduction in infarct volume and malondialdehyde levels, and signficant increase in antioxidant enzymes superoxide dismutase, glutathione peroxidase and catalase. The primary mechanism of action of MO extract and its phytochemical derivatives which confers neuroprotection is reduction in oxidative stress by increasing antioxidant enzymes. On the whole, the present systematic review critically assessed evidence which demonstrated that MO extract may confer protective effect on experimental ischemic stroke. Although effect size may have been overestimated due to the limited number of included studies, small sample sizes and possible publication bias, results generated in this meta-analysis dmeonstrate that MO extract may be a promising neuroprotective agent against human ischemic stroke.

Effect of tanshinone IIA for myocardial ischemia/reperfusion injury in animal model: preclinical evidence and possible mechanisms

Introduction: Tanshinone IIA (Tan IIA), the major active lipophilic ingredient of Radix Salviae Miltiorrhizae, exerts various therapeutic effects on the cardiovascular system. We aimed to identify the preclinical evidence and possible mechanisms of Tan IIA as a cardioprotective agent in the treatment of myocardial ischemia/reperfusion injury. Methods: The study quality scores of twenty-eight eligible studies and data analyses were separately assessed using the CAMARADES 10-item checklist and Rev-Man 5.3 software. Results: The study quality score ranged from 3/10 to 7/10 points. The present study provided preliminary preclinical evidence that Tan IIA could significantly decrease the myocardial infarct size, cardiac enzyme activity and troponin levels compared with those in the control group (p < 0.05). Discussion: Tan IIA alleviated myocardial I/R injury via antioxidant, anti-inflammatory, anti-apoptosis mechanisms and improved circulation and energy metabolism. Thus, Tan IIA is a promising cardioprotective agent for the treatment of myocardial ischemia/reperfusion injury and should be further investigated in clinical trials.

Association of statin pre-treatment with baseline stroke severity and outcome in patients with acute ischemic stroke and received reperfusion treatment: An observational study

BACKGROUND

Statins have an important role in stroke prevention, especially in high-risk populations and may also affect the initial stroke severity and outcomes in patients taking them before an ischemic stroke.

AIMS

Our aim was to evaluate the association of statin pre-treatment with the severity in acute ischemic stroke (AIS).

METHODS

We analyzed AIS patients received intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT) and recorded in the SITS International Thrombolysis and Thrombectomy Registry from 2011 to 2017. We identified patients with statin information at baseline. The primary outcome was baseline National Institutes of Health Stroke Scale (NIHSS) score. Secondary outcomes were NIHSS score at 24 h, symptomatic intracerebral hemorrhage (SICH) and functional outcome at 90 days after acute intervention. Multivariable linear and logistic regression and propensity score matching (PSM) was used to quantify the effect of statin pre-treatment.

RESULTS

Of 93,849 patients, 23,651 (25.2%) were treated with statins prior the AIS. Statin pre-treatment group was older and had higher comorbidity. Median NIHSS at baseline was similar between groups. In the adjusted and PSM analysis, statin pre-treatment was inversely associated with baseline NIHSS (odds ratio (OR) = 0.77, 95% confidence interval (CI) = 0.6-0.99 and OR for PSM 0.73, 95% CI = 0.54-0.99, p = 0.004) and independently associated with mild stroke defined as NIHSS ⩽8 in adjusted and PSM analysis (OR = 1.21, 95% CI = 1.1-1.34, p < 0.001 and OR for PSM 1.17, 95% CI = 1.05-1.31, p = 0.007). Regarding secondary outcomes, there were no differences in functional outcomes, death nor SICH rates between groups.

CONCLUSION

Prior treatment with statins was associated with lower NIHSS at baseline. However, this association did not translate into any difference regarding functional outcome at 90 days. No association was found regarding SICH. These findings indicate the need of further studies to assess the effect on statin pre-treatment on initial stroke severity.

A systematic review and meta-analysis of cognitive and behavioral tests in rodents treated with different doses of D-ribose

Background

D-ribose is an aldehyde sugar and a necessary component of all living cells. Numerous reports have focused on D-ribose intervention in animal models to assess the negative effects of D-ribose on cognition. However, the results across these studies are inconsistent and the doses and actual effects of D-ribose on cognition remain unclear. This systematic review aimed to evaluate the effect of D-ribose on cognition in rodents.

Methods

The articles from PubMed, Embase, Sciverse Scopus, Web of Science, the Chinese National Knowledge Infrastructure, SinoMed, Wanfang, and Cqvip databases were screened. The results from the abstract on cognitive-related behavioral tests and biochemical markers from the included articles were extracted and the reporting quality was assessed.

Results

A total of eight trials involving 289 rodents met the eligibility criteria, and both low- and high-dose groups were included. Meta-analyses of these studies showed that D-ribose could cause a significant decrease in the number of platform crossings (standardized mean difference [SMD]: -0.80; 95% CI: -1.14, -0.46; p < 0.00001), percentage of distance traversed in the target quadrant (SMD: -1.20; 95% CI: -1.47, -0.92; p < 0.00001), percentage of time spent in the target quadrant (SMD: -0.93; 95% CI: -1.18, -0.68; p < 0.00001), and prolonged escape latency (SMD: 0.41; 95% CI: 0.16, 0.65; p = 0.001) in the Morris water maze test. Moreover, D-ribose intervention increased the levels of advanced glycation end products (AGEs) in the brain (SMD: 0.49; 95% CI: 0.34, 0.63; p < 0.00001) and blood (SMD: 0.50; 95% CI: 0.08, 0.92; p = 0.02). Subsequently, subgroup analysis for the dose of D-ribose intervention revealed that high doses injured cognitive function more significantly than low D-ribose doses.

Conclusion

D-ribose treatment caused cognitive impairment, and cognition deteriorated with increasing dose. Furthermore, the increase in AGEs in the blood and brain confirmed that D-ribose may be involved in cognitive impairment through non-enzymatic glycosylation resulting in the generation of AGEs. These findings provide a new research idea for unveiling basic mechanisms and prospective therapeutic targets for the prevention and treatment of patients with cognitive impairment.

New Strategies for Stroke Therapy: Nanoencapsulated Neuroglobin

Stroke is a global health and socio-economic problem. However, no efficient preventive and/or palliative treatments have yet been found. Neuroglobin (Ngb) is an endogen neuroprotective protein, but it only exerts its beneficial action against stroke after increasing its basal levels. Therefore, its systemic administration appears to be an efficient therapy applicable to stroke and other neurodegenerative pathologies. Unfortunately, Ngb cannot cross the blood-brain barrier (BBB), making its direct pharmacological use unfeasible. Thus, the association of Ngb with a drug delivery system (DDS), such as nanoparticles (NPs), appears to be a good strategy for overcoming this handicap. NPs are a type of DDS which efficiently transport Ngb and increase its bioavailability in the infarcted area. Hence, we previously built hyaluronate NPS linked to Ngb (Ngb-NPs) as a therapeutic tool against stroke. This nanoformulation induced an improvement of the cerebral infarct prognosis. However, this innovative therapy is still in development, and a more in-depth study focusing on its long-lasting neuroprotectant and neuroregenerative capabilities is needed. In short, this review aims to update the state-of-the-art of stroke therapies based on Ngb, paying special attention to the use of nanotechnological drug-delivering tools.

Effect and Mechanisms of Quercetin for Experimental Focal Cerebral Ischemia: A Systematic Review and Meta-Analysis

Quercetin, a naturally occurring flavonoid, is mainly extracted from tea, onions, and apples. It has the underlying neuroprotective effect on experimental ischemic stroke. A systematic review and meta-analysis were used to assess quercetin’s efficacy and possible mechanisms in treating focal cerebral ischemia. Compared with the control group, twelve studies reported a remarkable function of quercetin in improving the neurological function score (NFS) ( $P<0.05$ ), and twelve studies reported a significant effect on reducing infarct volume ( $P<0.05$ ). Moreover, two and three studies showed that quercetin could alleviate blood-brain barrier (BBB) permeability and brain water content, respectively. The mechanisms of quercetin against focal cerebral ischemia are diverse, involving antioxidation, antiapoptotic, anti-inflammation, and calcium overload reduction. On the whole, the present study suggested that quercetin can exert a protective effect on experimental ischemic stroke. Although the effect size may be overestimated because of the quality of studies and possible publication bias, these results indicated that quercetin might be a promising neuroprotective agent for human ischemic stroke. This study is registered with PROSPERO, number CRD 42021275656.

Biological Implications of a Stroke Therapy Based in Neuroglobin Hyaluronate Nanoparticles. Neuroprotective Role and Molecular Bases

Exogenous neuroprotective protein neuroglobin (Ngb) cannot cross the blood-brain barrier. To overcome this difficulty, we synthesized hyaluronate nanoparticles (NPs), able to deliver Ngb into the brain in an animal model of stroke (MCAO). These NPs effectively reached neurons, and were microscopically identified after 24 h of reperfusion. Compared to MCAO non-treated animals, those treated with Ngb-NPs showed survival rates up to 50% higher, and better neurological scores. Tissue damage improved with the treatment, but no changes in the infarct volume or in the oxidative/nitrosative values were detected. A proteomics approach (p-value < 0.02; fold change = 0.05) in the infarcted areas showed a total of 219 proteins that significantly changed their expression after stroke and treatment with Ngb-NPs. Of special interest, are proteins such as FBXO7 and NTRK2, which were downexpressed in stroke, but overexpressed after treatment with Ngb-NPs; and ATX2L, which was overexpressed only under the effect of Ngb. Interestingly, the proteins affected by the treatment with Ngb were involved in mitochondrial function and cell death, endocytosis, protein metabolism, cytoskeletal remodeling, or synaptic function, and in regenerative processes, such as dendritogenesis, neuritogenesis, or sinaptogenesis. Consequently, our pharmaceutical preparation may open new therapeutic scopes for stroke and possibly for other neurodegenerative pathologies.

Antiosteoporosis Effect and Possible Mechanisms of the Ingredients of Fructus Psoraleae in Animal Models of Osteoporosis: A Preclinical Systematic Review and Meta-Analysis

Objective

Fructus Psoraleae (FP) and its ingredients (IFP) have a variety of biological activities and are widely used to treat osteoporosis (OP). Herein, we conducted a systematic review to evaluate the efficacy of IFP for an animal model of OP from the current literatures. Potential mechanisms of IFP in the treatment of OP were also summarized.

Materials and Methods

We carried out a search for electronic literature in the PubMed, Chinese National Knowledge Infrastructure, EMBASE, Wanfang, Web of Science, Chinese Biomedical Literature Database, and Cochrane Library, as well as Chinese VIP databases targeting articles published from inception to June 2021. The inclusion criteria were animal studies that assessed the efficacy and safety of IFP for OP, regardless of publication status or language. The exclusion criteria included (1) other types of studies (in vitro studies, case reports, clinical trials, reviews, abstracts, comments, and editorials), (2) combination with other compounds, (3) compared with other traditional Chinese medicine, (4) not osteoporosis or bone loss model, (5) studies with insufficient data, (6) lack of a control group, and (7) duplicate publications. The modified Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Stroke (CAMARADES) 10-item quality checklist was used to evaluate the risk of bias of included studies. We computed the relative risk (RR) and the standard mean difference (SMD) for dichotomous outcomes and continuous outcomes, respectively. When heterogeneity was detected or there was significant statistical heterogeneity (P < 0.05 or I² > 50%), a random-effects model was employed, followed by further subgroup analysis and metaregression estimations to ascertain the origins of heterogeneity. Otherwise, we used a fixed-effects model (P ≥ 0.05 or I² ≤ 50%). The primary outcome measures were bone mineral density (BMD), serum osteocalcin(S-OCN), bone volume over total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), bone maximum load, and elasticity modulus. The secondary outcome measure was the antiosteoporosis mechanisms of IFP. The STATA 12.0 software was used to analyze the data.

Results

Overall, 16 studies focusing on 379 animals were enrolled into the study. The risk of bias score of included studies ranged from 4 to 7 with an average score of 5.25. The present study provided the preliminary preclinical evidence that administration of IFP could significantly increase the S-OCN, BMD, BV/TV, and Tb.N while Tb.Th and Tb.Sp were remarkably decreased by IFP in OP model animals (P < 0.05). Moreover, IFP could significantly improve the bone biomechanical indicator bone maximum load and elasticity modulus (P < 0.05). In terms of the possible mechanisms of treatment of OP, IFP exerts anti-OP effects in animal models probably through osteoprotegerin/receptor activator of the nuclear factor-κB ligand/receptor activator of nuclear factor-κB (OPG/RANKL/RANK), peroxisome proliferator activated receptor γ (PPAR-γ)/Axin2/Wnt, antioxidative stress via forkhead box O3a (FoxO3a)/Axin2/Wnt, phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR), estrogen-like effect, and gamma-aminobutyric acid/gamma-aminobutyric acid receptor (GABA/GABA_BRI) signaling pathway.

Conclusion

Taken together, the findings suggest the possibility of developing IFP as a drug or an ingredient in diet for the clinical treatment of OP. We recommend that rigorous, as well as high-quality, trials involving large sample sizes should be conducted to confirm our findings.

Preclinical animal studies in ischemic stroke: Challenges and some solutions

Despite the impressive efficacies demonstrated in preclinical research, hundreds of potentially neuroprotective drugs have failed to provide effective neuroprotection for ischemic stroke in human clinical trials. Lack of a powerful animal model for human ischemic stroke could be a major reason for the failure to develop successful neuroprotective drugs for ischemic stroke. This review recapitulates the available cerebral ischemia animal models, provides an anatomical comparison of the circle of Willis of each species, and describes the functional assessment tests used in these ischemic stroke models. The distinct differences between human ischemic stroke and experimental stroke in available animal models is explored. Innovative animal models more closely resembling human strokes, better techniques in functional outcome assessment and better experimental designs generating clearer and stronger evidence may help realise the development of truly neuroprotective drugs that will benefit human ischemic stroke patients. This may involve use of newer molecules or revisiting earlier studies with new experimental designs. Translation of any resultant successes may then be tested in human clinical trials with greater confidence and optimism.

Clinical perspectives on ischemic stroke

Treatments for acute stroke have improved over the past years, but have largely been limited to revascularization strategies. The topic of neuroprotection, or strategies to limit brain tissue damage or even reverse it, has remained elusive. Thus, the clinical mainstays for stroke management have focused on prevention. The lack of clinical translation of neuroprotective therapies which have shown promise in the laboratory may, in part, be due to a historic inattention to comorbidities suffered by a majority of stroke patients. With the advent of more stroke models that include one or more relevant comorbidities, it may be possible to identify effective treatments that may translate into new treatments at the clinical level. In the meantime, we review comorbidities in stroke patients, modification of stroke risk factors and available acute stroke treatments in the clinic.

Effect of uric acid in animal models of ischemic stroke: A systematic review and meta-analysis

Addition of uric acid (UA) to thrombolytic therapy, although safe, showed limited efficacy in improving patients' stroke outcome, despite alleged neuroprotective effects of UA in preclinical research. This systematic review assessed the effects of UA on brain structural and functional outcomes in animal models of ischemic stroke. We searched Medline, Embase and Web of Science to identify 16 and 14 eligible rodent studies for qualitative and quantitative synthesis, respectively. Range of evidence met 10 of a possible 13 STAIR criteria. Median (Q1, Q3) quality score was 7.5 (6, 10) on the CAMARADES 15-item checklist. For each outcome, we used standardised mean difference (SMD) as effect size and random-effects modelling. Meta-analysis showed that UA significantly reduced infarct size (SMD: -1.18; 95% CI [-1.47, -0.88]; p < 0.001), blood-brain barrier (BBB) impairment/oedema (SMD: -0.72; 95% CI [-0.97, -0.48]; p < 0.001) and neurofunctional deficit (SMD: -0.98; 95% CI [-1.32, -0.63]; p < 0.001). Overall, there was low to moderate between-study heterogeneity and sizeable publication bias. In conclusion, published rodent data suggest that UA improves outcome following ischemic stroke by reducing infarct size, improving BBB integrity and ameliorating neurofunctional condition. Specific recommendations are given for further high-quality preclinical research required to better inform clinical research.

SSAO/VAP-1 in Cerebrovascular Disorders: A Potential Therapeutic Target for Stroke and Alzheimer's Disease

The semicarbazide-sensitive amine oxidase (SSAO), also known as vascular adhesion protein-1 (VAP-1) or primary amine oxidase (PrAO), is a deaminating enzyme highly expressed in vessels that generates harmful products as a result of its enzymatic activity. As a multifunctional enzyme, it is also involved in inflammation through its ability to bind and promote the transmigration of circulating leukocytes into inflamed tissues. Inflammation is present in different systemic and cerebral diseases, including stroke and Alzheimer’s disease (AD). These pathologies show important affectations on cerebral vessels, together with increased SSAO levels. This review summarizes the main roles of SSAO/VAP-1 in human physiology and pathophysiology and discusses the mechanisms by which it can affect the onset and progression of both stroke and AD. As there is an evident interrelationship between stroke and AD, basically through the vascular system dysfunction, the possibility that SSAO/VAP-1 could be involved in the transition between these two pathologies is suggested. Hence, its inhibition is proposed to be an interesting therapeutical approach to the brain damage induced in these both cerebral pathologies.

Effect of Simvastatin in Serum Interleukin-6 Level in Patients with Acute Ischemic Stroke

Acute ischemic stroke is the leading cause of death and causing permanent disability in adults worldwide. In acute ischemic stroke, IL-6 levels positively correlated to more severe neurological deficits, more extensive brain damage and worse prognoses. The use of statin was associated with milder initial stroke severity, better functional outcome and lower mortality. This clinically randomized controlled trial study was aimed to analyze the serum levels of IL 6 in acute ischemic stroke patients who treated with Simvastatin 20 mg compare to placebo. Samples were taken using consecutive sampling method from hospitalized acute ischemic stroke patients in Neurology Department of Dr. Soetomo Teaching Hospital Surabaya and Airlangga University Hospital Surabayafrom August to November 2017. Total of 44 patients met the inclusion criteria, consisting of 22 patients in treatment group and 22 patients in control group.There were no significant difference in the characteristic of the patients in both groups (p>0.05). Averages of serum IL-6 in the control and the treatment group are 38.594±74.313 and 17.760±25.253(p=0,438) while averages of serum IL-6 post in the control group and the treatment are 46.586±103.484 and 15.275±17.183 (p=0,589). There were no significant level escalation in pre and post of control group (p = 0.205) and also no significant level reduction in pre and post of treatment group (p = 0.411), while the average difference in the control group (-7.992 + 78.912 pg/ml) and in the treatment group (2.485 + 23.738 pg/ml).

Treatment with Atorvastatin During Vascular Remodeling Promotes Pericyte-Mediated Blood-Brain Barrier Maturation Following Ischemic Stroke

We previously showed that newly formed vessels in ischemic rat brain have high blood-brain barrier (BBB) permeability at 3 weeks after stroke due to a lack of major endothelial tight junction proteins (TJPs), which may exacerbate edema in stroke patients. Atorvastatin was suggested a dose-dependent pro-angiogenic effect and ameliorating BBB permeability beyond its cholesterol-lowering effects. This study examined our hypothesis that, during vascular remodeling after stroke, treatment with atorvastatin could facilitate BBB maturation in remodeling vasculature in ischemic brain. Adult spontaneously hypertensive rats underwent middle cerebral artery occlusion with reperfusion (MCAO/RP). Atorvastatin, at dose of 3 mg/kg, was delivered daily starting at 14 days after MCAO/RP onset for 7 days. The rats were studied at multiple time points up to 8 weeks with multimodal-MRI, behavior tests, immunohistochemistry, and biochemistry. The delayed treatment of atorvastatin significantly reduced infarct size and BBB permeability, restored cerebral blood flow, and improved the neurological outcome at 8 weeks after MCAO/RP. Postmortem studies showed that atorvastatin promoted angiogenesis and stabilized the newly formed vessels in peri-infarct areas. Importantly, atorvastatin facilitated maturation of BBB properties in the new vessels by promoting endothelial tight junction (TJ) formation. Further in vivo and in vitro studies demonstrated that proliferating peri-vascular pericytes expressing neural-glial antigen 2 (NG2) mediated the role of atorvastatin on BBB maturation through regulating endothelial TJ strand formations. Our results suggested a therapeutic potential of atorvastatin in facilitating a full BBB integrity and functional stroke recovery, and an essential role for pericyte-mediated endothelial TJ formation in remodeling vasculature.

Repurposing FDA Approved Drugs as JNK3 Inhibitor for Prevention of Neuroinflammation Induced by MCAO in Rats

Background

Stress-associated kinases are considered major pathological mediators in several incurable neurological disorders. Importantly, among these stress kinases, the c-Jun NH2-terminal kinase (JNK) has been linked to numerous neuropathological conditions, including oxidative stress, neuroinflammation, and brain degeneration associated with brain injuries such as ischemia/reperfusion injury. In this study, we adopted a drug repurposing/reprofiling approach to explore novel JNK3 inhibitors from FDA-approved medications to supplement existing therapeutic strategies.

Materials and Methods

We performed in silico docking analysis and molecular dynamics simulation to screen potential candidates from the FDA approved drug library using the standard JNK inhibitor SP600125 as a reference. After the virtual screening, dabigatran, estazolam, leucovorin, and pitavastatin were further examined in ischemic stroke using an animal rodent model of focal cerebral ischemia using transient middle cerebral artery occlusion (t-MCAO). The selected drugs were probed for neuroprotective effectiveness by measuring the infarct area (%) and neurological deficits using a 28-point composite score. Biochemical assays including ELISA and immunohistochemical experiments were performed.

Results

We obtained structural insights for dabigatran, estazolam, and pitavastatin binding to JNK3, revealing a significant contribution of the hydrophobic regions and significant residues of active site regions. To validate the docking results, the pharmacological effects of dabigatran, estazolam, leucovorin, and pitavastatin on MCAO were tested in parallel with the JNK inhibitor SP600125. After MCAO surgery, severe neurological deficits were detected in the MCAO group compared with the sham controls, which were significantly reversed by dabigatran, estazolam, and pitavastatin treatment. Aberrant morphological features and brain damage were observed in the ipsilateral cortex and striatum of the MCAO groups. The drugs restored the anti-oxidant enzyme activity and reduced the levels of oxidative stress-induced p-JNK and neuroinflammatory mediators such as NF-kB and TNF-ɑ in rats subjected to MCAO.

Conclusion

Our results demonstrated that the novel FDA-approved medications attenuate ischemic stroke-induced neuronal degeneration, possibly by inhibiting JNK3. Being FDA-approved safe medications, the use of these drugs can be clinically translated for ischemic stroke-associated brain degeneration and other neurodegenerative diseases associated with oxidative stress and neuroinflammation.

Strategies to prevent hemorrhagic transformation after reperfusion therapies for acute ischemic stroke: A literature review

BACKGROUND

Reperfusion therapies by tissue plasminogen activator (tPA) and mechanical thrombectomy (MT) have ushered in a new era in the treatment of acute ischemic stroke (AIS). However, reperfusion therapy-related HT remains an enigma.

AIM

To provide a comprehensive review focused on emerging concepts of stroke and therapeutic strategies, including the use of protective agents to prevent HT after reperfusion therapies for AIS.

METHODS

A literature review was performed using PubMed and the ClinicalTrials.gov database.

RESULTS

Risk of HT increases with delayed initiation of tPA treatment, higher baseline glucose level, age, stroke severity, episode of transient ischemic attack within 7 days of stroke onset, and hypertension. At a molecular level, HT that develops after thrombolysis is thought to be caused by reactive oxygen species, inflammation, remodeling factor-mediated effects, and tPA toxicity. Modulation of these pathophysiological mechanisms could be a therapeutic strategy to prevent HT after tPA treatment. Clinical mechanisms underlying HT after MT are thought to involve smoking, a low Alberta Stroke Program Early CT Score, use of general anesthesia, unfavorable collaterals, and thromboembolic migration. However, the molecular mechanisms are yet to be fully investigated. Clinical trials with MT and protective agents have also been planned and good outcomes are expected.

CONCLUSION

To fully utilize the easily accessible drug-tPA-and the high recanalization rate of MT, it is important to reduce bleeding complications after recanalization. A future study direction could be to investigate the recovery of neurological function by combining reperfusion therapies with cell therapies and/or use of pleiotropic protective agents.

Effect of statins on amyloidosis in the rodent models of Alzheimer's disease: Evidence from the preclinical meta-analysis

INTRODUCTION

Previous studies have shown contrasting results in determining efficacy of statins against amyloid beta accumulation. The aim of this study was to assess the impact of statin in AD.

METHOD

We searched PubMed and Embase for relevant preclinical studies. A meta-analysis of the statin's efficacy on amyloidosis and cognitive impairment was performed. Also, stratified analysis was performed on several covariates including the type of statin used, gender and age of rodents and duration of statin therapy, to account for the reported heterogeneity in the results obtained. The study protocol was registered in PROSPERO (CRD42018102557).

RESULT

17 studies including 22 comparisons, containing a sample size of 446 rodents, participated in the meta-analysis of statin's effect on overall Aβ deposition. Although the effect of statin on overall Aβ deposition was found to be protective (p < 0.00001) but as we categorized the efficacy of statin on different Aβ species (soluble and insoluble Aβ40/42) and Aβ plaque load, we found that significance in the protection decreased. A stratified meta-analysis demonstrated a significant role in the duration of statin supplements and rodent's age on the heterogeneity of the results. Statin administered to rodents for the longest duration (>6 months) and younger rodents (<6 months of age) demonstrated significant efficacy of statin on Aβ deposition.

CONCLUSION

Statin showed reduction in Aβ level but stratified analysis revealed that this effect of statin was dependent on rodent's age and duration of the treatment.

A Preclinical Systematic Review of Curcumin for Protecting the Kidney with Ischemia Reperfusion Injury

Renal ischemia-reperfusion injury (RIRI) refers to a phenomenon associated with dysfunction of the kidney and tissue damage. Unfortunately, no specific drugs have been found that effectively prevent and treat RIRI. Curcumin (Cur), a polyphenol extracted from turmeric, possesses a variety of biological activities involving antioxidation, inhibition of apoptosis, inhibition of inflammation, and reduction of lipid peroxidation. Eight frequently used databases were searched using prespecified search strategies. The CAMARADES 10-item quality checklist was used to evaluate the risk of bias of included studies, and the RevMan 5.3 software was used to analyze the data. The risk of bias score of included studies ranged from 3 to 6 with an average score of 5.22. Compared with the control group, Cur significantly alleviated renal pathology, reduced blood urea nitrogen and serum creatinine levels, and improved inflammatory indexes, oxidant, and apoptosis in RIRI animal models. Despite the heterogeneity of the response to Cur in terms of serum creatinine, BUN, TNF-alpha, and SOD, its effectiveness for improving the injury of RIRI was remarkable. In the mouse model subgroup of serum creatinine, the effect size of the method of unilateral renal artery ligation with contralateral nephrectomy and shorter ischemic time showed a greater effect than that of the control group. No difference was seen in the methods of model establishment, mode administration, or medication times. The preclinical systematic review provided preliminary evidence that Cur partially improved RIRI in animal models, probably via anti-inflammatory, antioxidant, antiapoptosis, and antifibrosis activities and via improving microperfusion. ARRIVE guidelines are recommended; blinding and sample size calculation should be focused on in future studies. These data suggest that Cur is a potential renoprotective candidate for further clinical trials of RIRI.

Emerging neuroprotective strategies for the treatment of ischemic stroke: An overview of clinical and preclinical studies

Stroke is the leading cause of disability and thesecond leading cause of death worldwide. With the global population aged 65 and over growing faster than all other age groups, the incidence of stroke is also increasing. In addition, there is a shift in the overall stroke burden towards younger age groups, particularly in low and middle-income countries. Stroke in most cases is caused due to an abrupt blockage of an artery (ischemic stroke), but in some instances stroke may be caused due to bleeding into brain tissue when a blood vessel ruptures (hemorrhagic stroke). Although treatment options for stroke are still limited, with the advancement in recanalization therapy using both pharmacological and mechanical thrombolysis some progress has been made in helping patients recover from ischemic stroke. However, there is still a substantial need for the development of therapeutic agents for neuroprotection in acute ischemic stroke to protect the brain from damage prior to and during recanalization, extend the therapeutic time window for intervention and further improve functional outcome. The current review has assessed the past challenges in developing neuroprotective strategies, evaluated the recent advances in clinical trials, discussed the recent initiative by the National Institute of Neurological Disorders and Stroke in USA for the search of novel neuroprotectants (Stroke Preclinical Assessment Network, SPAN) and identified emerging neuroprotectants being currently evaluated in preclinical studies. The underlying molecular mechanism of each of the neuroprotective strategies have also been summarized, which could assist in the development of future strategies for combinational therapy in stroke treatment.

Mesenchymal stem cells in experimental autoimmune encephalomyelitis model of multiple sclerosis: A systematic review and meta-analysis

BACKGROUND/AIMS

Mesenchymal stem cells (MSCs) transplantation has been considered a possible therapeutic method for Multiple Sclerosis (MS). However, no quantitative data synthesis of MSCs therapy for MS exists. We conducted a systematic review and meta-analysis to evaluate the effects of MSCs in experimental autoimmune encephalomyelitis (EAE) animal model of MS.

METHODS

We identified eligible studies published from January 1980 to January 2017 by searching four electronic databases (PubMed, MEDLINE, Embase and Web of Science). The outcome was the effects of MSCs on clinical performance evaluated by the EAE clinical score.

RESULTS

36 preclinical studies including 675 animals in MSCs treatment group, and 693 animals in control group were included in this meta-analysis. We found that MSCs transplantation significantly ameliorated the symptoms and delayed the disease progression (SMD = -1.25, 95% CI: -1.45 to -1.05, P < 0.001). However, no significant differences in effect sizes were unveiled relative to clinical score standard (P = 0.35), type of MSCs (P = 0.35), source of MSCs (P = 0.06), MSCs dose (P = 0.44), delivery methods (P = 0.31) and follow up period (P = 0.73).

CONCLUSIONS

The current study showed that MSCs transplantation could ameliorate clinical performance in EAE animal model of MS. These findings support the further studies translate MSCs to treat MS in humans.

Protective effect and possible mechanisms of ligustrazine isolated from Ligusticum wallichii on nephropathy in rats with diabetes: A preclinical systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Ligusticum wallichii has been used to treat renal diseases for thousands of years in China. Ligustrazine (Lig) is the active ingredient of Ligusticum wallichii that possesses a variety of biological activities against kidney disease.

AIM OF THE STUDY

The purpose of this review is to further evaluate whether the supplementation with Lig has an effect on improving renal pathology, renal function indexes and blood glucose levels in animal model of diabetic nephropathy (DN). Potential mechanisms of Lig for DN as well as the existing problems regarding the modeling method and limitations in this area of research were also summarized.

MATERIALS AND METHODS

The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) checklist was used to organize the search of eight databases from inception to June 2019. We used Cochrane Collaboration's 10-item checklist and Rev-Man 5.3 software to analyze the data as well as risk of bias.

RESULTS

The study quality scores ranged from 2 to 6 points with an average of 4.471. Compared with the control group, Lig significantly improved pathological changes of kidney including glomeruli and tubules, and induced significant decreases in levels of blood urea nitrogen, serum creatinine, 24-h urinary albumin and HbA1c, as well as increasing creatinine clearance rates. In subgroup analysis, the groups of high-dose STZ (≥60 mg/kg) and longer period of Lig treatment (>8 w) showed better results than those of the control group. No difference was seen between the high (>150 mg/kg, QD) and low (≤150 mg/kg, QD) dose of Lig treatment groups.

CONCLUSION

Lig exerts renoprotective functions in an animal model of DN mediated by antioxidant action, inhibition of apoptosis, anti-inflammatory action, reduction of renal fibrosis, reduction of the proliferation of mesangial cells, inhibition of endotheliosis, inhibition of atherosclerosis and promotion of renal autophagy. The positive conclusion should be treated cautiously because of various methodological flaws. Further studies are recommended according to ARRIVE guidelines. The method of modeling with high-dose STZ should be avoided and improved STZ modeling schemes are recommended. Considering the large dosage range of Lig used clinically and in animals, the future studies on the basis of animal renal histology are urgently needed to determine the optimal dosages to delay histological changes. Nevertheless, together, our findings suggest that Lig is a renoprotective candidate drug for treatment of DN.

Statin Therapy in Ischemic Stroke Models: A Meta-Analysis

Statins, drugs known for lipid lowering capabilities and reduction of cardiovascular disease, have demonstrated neuroprotective effects following ischemic stroke in retrospective clinical and animal studies. However, dosing (methods, time, type of statin, and quantity) varies across studies, limiting the clinical applicability of these findings. Furthermore, a comprehensive review of statins in edema and blood-brain barrier (BBB) breakdown is needed to provide insight on diverse, less explored neuroprotective effects. In the present study, we conduct a meta-analysis of publications evaluating statin administration in animal models of ischemic stroke. We review statins' most effective dosing regimen in four outcomes-infarct, edema, BBB breakdown, and functional outcome-to characterize several parameters of benefit associated with statin administration. A search term was constructed to identify experimental murine studies exploring statin use after transient middle cerebral artery occlusion (tMCAO) in PubMed, Web of Science, and Embase. Extracted data included statin type, dose, time and method of administration, and the four predetermined outcomes (functional outcome, edema, BBB breakdown, and infarction). A meta-analysis and stratified meta-regression were conducted using the standardized mean difference (SMD) method for continuous measurements. Included publications were assessed for bias using SYRCLE's RoB tool for animal studies. A total of 24 studies were included. Statin administration significantly reduced infarct volume (p < 0.0001), edema volume (p < 0.002), and neurological deficit (p < 0.0001). Simvastatin and pravastatin were most effective in reducing infarct volume when compared with atorvastatin (p = 0.0475, p = 0.0004) and rosuvastatin (p = 0.0036, p < 0.0001). Pravastatin outperformed all others in functional outcome. Subcutaneous (SC) injection was most effective in all outcomes. Statin therapy reduced BBB breakdown according to our systematic review. Mean study quality was 4.6/10. While statin therapy evidently improves neurological outcome following ischemic stroke, this analysis adds to our understanding of dosing and statins' effects on edema and BBB breakdown. These findings will aid the design of future studies investigating statin use and have larger implications for the clinical care of ischemic stroke patients.

HMG-CoA Reductase Inhibitors Attenuate Neuronal Damage by Suppressing Oxygen Glucose Deprivation-Induced Activated Microglial Cells

Ischemic stroke is usually followed by inflammatory responses mediated by microglia. However, the effect of statins on directly preventing posthypoxia microglia inflammatory factors to prevent injury to surrounding healthy neurons is unclear. Atorvastatin and rosuvastatin, which have different physical properties regarding their lipid and water solubility, are the most common HMG-CoA reductase inhibitors (statins) and might directly block posthypoxia microglia inflammatory factors to prevent injury to surrounding neurons. Neuronal damage and microglial activation of the peri-infarct areas were investigated by Western blotting and immunofluorescence after 24 hours in a middle cerebral artery occlusion (MCAO) rat model. The decrease in neurons was in accordance with the increase in microglia, which could be reversed by both atorvastatin and rosuvastatin. The effects of statins on blocking secretions from posthypoxia microglia and reducing the secondary damage to surrounding normal neurons were studied in a coculture system in vitro. BV2 microglia were cultured under oxygen glucose deprivation (OGD) for 3 hours and then cocultured following reperfusion for 24 hours in the upper wells of transwell plates with primary neurons being cultured in the bottom wells. Inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and cyclooxygenase-2 (COX2), which are activated by the nuclear factor-kappa B (NF-κB) signaling pathway in OGD-induced BV2 microglia, promoted decreased release of the anti-inflammatory cytokine IL-10 and apoptosis of neurons in the coculture systems according to ELISA and Western blotting. However, pretreatment with atorvastatin or rosuvastatin significantly reduced neuronal death, synaptic injury, and amyloid-beta (Aβ) accumulation, which might lead to increased low-density lipoprotein receptors (LDLRs) in BV2 microglia. We concluded that the proinflammatory mediators released from postischemia damage could cause damage to surrounding normal neurons, while HMG-CoA reductase inhibitors prevented neuronal apoptosis and synaptic injury by inactivating microglia through blocking the NF-κB signaling pathway.

Rhodiola rosea L. Improves Learning and Memory Function: Preclinical Evidence and Possible Mechanisms

Rhodiola rosea L. (R. rosea L.) is widely used to stimulate the nervous system, extenuate anxiety, enhance work performance, relieve fatigue, and prevent high altitude sickness. Previous studies reported that R. rosea L. improves learning and memory function in animal models. Here, we conducted a systematic review and meta-analysis for preclinical studies to assess the current evidence for R. rosea L. effect on learning and memory function. Ultimately, 36 studies involving 836 animals were identified by searching 6 databases from inception to May 2018. The primary outcome measures included the escape latency in Morris water maze (MWM) test on behalf of learning ability, the frequency and the length of time spent on the target quadrant in MWM test representing memory function, and the number of errors in step down test, dark avoidance test and Y maze test on behalf of memory function. The secondary outcome measures were mechanisms of R. rosea L. for learning and/or memory function. Compared with control, the pooled results of 28 studies showed significant effects of R. rosea L. for reducing the escape latency (P < 0.05); 23 studies for increasing the frequency and the length of time spent on the target quadrant (P < 0.05); and 6 studies for decreasing the number of errors (P < 0.01). The possible mechanisms of R. rosea L. are largely through antioxidant, cholinergic regulation, anti-apoptosis activities, anti-inflammatory, improving coronary blood flow, and cerebral metabolism. In conclusion, the findings suggested that R. rosea L. can improve learning and memory function.

Ligustrazine Exerts Cardioprotection in Animal Models of Myocardial Ischemia/Reperfusion Injury: Preclinical Evidence and Possible Mechanisms

Ligustrazine (Lig) is one of the main effective components of Ligusticum Chuanxiong Hort, which possesses a variety of biological activities in the cardiovascular system. Here, we conducted a preclinical systematic review to investigate the efficacy of Lig for animal models of myocardial ischemia/reperfusion injury and its possible mechanisms. Twenty-five studies involving 556 animals were identified by searching 6 databases from inception to August 2017. The methodological quality was assessed by using Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES) 10-item checklist. All the data were analyzed using Rev-Man 5.3 software. As a result, the score of study quality ranged from 2 to 6 points. Meta-analyses showed Lig can significantly decrease the myocardial infarct size, cardiac enzymes and troponin compared with control (P < 0.01). The possible mechanisms of Lig for myocardial infarction are antioxidant, anti-inflammatory, anti-apoptosis activities and improving coronary blood flow and myocardial metabolism. In conclusion, the findings indicated that Lig exerts cardio protection through multiple signaling pathways in myocardial ischemia/reperfusion injury.

Refocusing Neuroprotection in Cerebral Reperfusion Era: New Challenges and Strategies

Pathophysiological processes of stroke have revealed that the damaged brain should be considered as an integral structure to be protected. However, promising neuroprotective drugs have failed when translated to clinical trials. In this review, we evaluated previous studies of neuroprotection and found that unsound patient selection and evaluation methods, single-target treatments, etc., without cerebral revascularization may be major reasons of failed neuroprotective strategies. Fortunately, this may be reversed by recent advances that provide increased revascularization with increased availability of endovascular procedures. However, the current improved effects of endovascular therapy are not able to match to the higher rate of revascularization, which may be ascribed to cerebral ischemia/reperfusion injury and lacking of neuroprotection. Accordingly, we suggest various research strategies to improve the lower therapeutic efficacy for ischemic stroke treatment: (1) multitarget neuroprotectant combinative therapy (cocktail therapy) should be investigated and performed based on revascularization; (2) and more efforts should be dedicated to shifting research emphasis to establish recirculation, increasing functional collateral circulation and elucidating brain–blood barrier damage mechanisms to reduce hemorrhagic transformation. Therefore, we propose that a comprehensive neuroprotective strategy before and after the endovascular treatment may speed progress toward improving neuroprotection after stroke to protect against brain injury.

Enhanced oxidative stress response and neuroprotection of combined limb remote ischemic conditioning and atorvastatin after transient ischemic stroke in rats

BACKGROUND:

Limb remote ischemic conditioning (LRIC) and atorvastatin (AtS) both provide neuroprotection in stroke. We evaluated the enhanced neuroprotective effect of combining these two treatments in preventing ischemia/reperfusion (I/R)-induced cerebral injury in a rat model and investigated the corresponding molecular mechanisms.

MATERIALS AND METHODS:

Transient cerebral ischemia was induced in Sprague–Dawley male rats by middle cerebral artery occlusion (MCAO) for 90 min followed by reperfusion (I/R). Rats were divided into 5 groups, sham, I/R, I/R + AtS, I/R + LRIC and I/R + AtS + LRIC. Pretreatment with LRIC and/or AtS for 14 days before MCAO surgery. Infarct volume, neurological score, Western blot, immuno-histochemical analyses were performed.

RESULTS:

The combination of LRIC plus AtS pretreatment decreased infarct volume and inhibited neuronal apoptosis. Combination treatment achieved stronger neuroprotection than monotherapy with LRIC or AtS. These therapies reduced reactive oxygen species production in the peri-ischemia region, associated with significantly increased expression and activation of superoxide dismutase 1, hemeoxygenase 1 and nuclear factor erythroid 2-related factor 2.

CONCLUSIONS:

Both LRIC and AtS + LRIC treatments conferred neuroprotection in ischemic stroke by reducing brain oxidative stress. AtS plus LRIC is an attractive translational research option due to its ease of use, tolerability, economical, and tremendous neuroprotective potential in stroke.

Simvastatin blocks soluble SSAO/VAP-1 release in experimental models of cerebral ischemia: Possible benefits for stroke-induced inflammation control

Beyond cholesterol reduction, statins mediate their beneficial effects on stroke patients through pleiotropic actions. They have shown anti-inflammatory properties by a number of different mechanisms, including the inhibition of NF-κB transcriptional activity and the consequent increase and release of adhesion molecules. We have studied simvastatin's effects on the vascular enzyme semicarbazide-sensitive amine oxidase/vascular adhesion protein 1 (SSAO/VAP-1), which is involved in stroke-mediated brain injury. SSAO/VAP-1 has leukocyte-binding capacity and mediates the expression of other adhesion proteins through signaling molecules generated by its catalytic activity. Our results indicate that soluble SSAO/VAP-1 is released into the bloodstream after an ischemic stimulus, in parallel with an increase in E-selectin and VCAM-1 and correlating with infarct volume. Simvastatin blocks soluble SSAO/VAP-1 release and prevents E-selectin and VCAM-1 overexpression as well. Simvastatin also effectively blocks SSAO/VAP-1-mediated leukocyte adhesion, although it is not an enzymatic inhibitor of SSAO in vitro. In addition, simvastatin-induced changes in adhesion molecules are greater in human brain endothelial cell cultures expressing SSAO/VAP-1, compared to those not expressing it, indicating some synergic effect with SSAO/VAP-1. We think that part of the beneficial effect of simvastatin in stroke is mediated by the attenuation of the SSAO/VAP-1-dependent inflammatory response.

Specific rescue by ortho-hydroxy atorvastatin of cortical GABAergic neurons from previous oxygen/glucose deprivation: role of pCREB

The statin atorvastatin (ATV) given as a post-treatment has been reported beneficial in stroke, although the mechanisms involved are not well understood so far. Here, we investigated in vitro the effect of post-treatment with ATV and its main bioactive metabolite ortho-hydroxy ATV (o-ATV) on neuroprotection after oxygen and glucose deprivation (OGD), and the role of the pro-survival cAMP response element-binding protein (CREB). Post-OGD treatment of primary cultures of rat cortical neurons with o-ATV, but not ATV, provided neuroprotection to a specific subset of cortical neurons that were large and positive for glutamic acid decarboxylase (large-GAD⁽⁺⁾ neurons, GABAergic). Significantly, only these GABAergic neurons showed an increase in phosphorylated CREB (pCREB) early after neuronal cultures were treated post-OGD with o-ATV. We found that o-ATV, but not ATV, increased the neuronal uptake of glutamate from the medium; this provides a rationale for the specific effect of o-ATV on pCREB in large-GABAergic neurons, which have a higher ratio of synaptic (pCREB-promoting) vs extrasynaptic (pCREB-reducing) N-methyl-D-aspartate (NMDA) receptors (NMDAR) than that of small-non-GABAergic neurons. When we pharmacologically increased pCREB levels post-OGD in non-GABAergic neurons, through the selective activation of synaptic NMDAR, we observed as well long-lasting neuronal survival. We propose that the statin metabolite o-ATV given post-OGD boosts the intrinsic pro-survival factor pCREB in large-GABAergic cortical neurons in vitro, this contributing to protect them from OGD.

Coenzyme Q10 supplementation improves acute outcomes of stroke in rats pretreated with atorvastatin

OBJECTIVES

Coenzyme Q10 (CoQ10, ubiquinone) stands among the safest supplements in the elderly to protect against cardiovascular disorders. Noteworthy, CoQ10 deficiency is common in many surviving stroke patients as they are mostly prescribed statins for the secondary prevention of stroke incidence lifelong. Accordingly, the current study aims to experimentally examine whether CoQ10 supplementation in animals receiving atorvastatin may affect acute stroke-induced injury.

METHODS

Adult rats underwent transient middle cerebral artery occlusion after atorvastatin pretreatment (5 or 10 mg/ kg/day; po; 30 days) with or without CoQ10 (200 mg/kg/day). After 24 hours ischemic/reperfusion injury, animals were subjected to functional assessments followed by cerebral molecular and histological to detect inflammation, apoptosis and oxidative stress.

RESULTS

Animals dosed with 10 mg/kg presented the worst neurological function and brain damage in the acute phase of stroke injury. CoQ10 supplementation efficiently improved functional deficit and cerebral infarction in all stroke animals, particularly those exhibiting statin toxicity. Such benefits were associated with remarkable anti-inflammatory and anti-apoptotic effects, based on the analyzed tumor necrosis factor-α, interleukin-6, Bax/Bcl2 and cleaved caspase 3/9 immunoblots. Importantly, our fluoro-jade staining data indicated CoQ10 may revert the stroke-induced neurodegeneration. No parallel alteration was detected in stroke-induced oxidative stress as determined by malondialdehyde and 8-oxo-2'-deoxyguanosine levels.

DISCUSSION

These data suggest that all stroke animals may benefit from CoQ10 administration through modulating inflammatory and degenerative pathways. This study provides empirical evidence for potential advantages of CoQ10 supplementation in atorvastatin-receiving patients which may not shadow its antioxidant properties.

Anti-Inflammatory Targets for the Treatment of Reperfusion Injury in Stroke

While the mainstay of acute stroke treatment includes revascularization via recombinant tissue plasminogen activator or mechanical thrombectomy, only a minority of stroke patients are eligible for treatment, as delayed treatment can lead to worsened outcome. This worsened outcome at the experimental level has been attributed to an entity known as reperfusion injury (R/I). R/I is occurred when revascularization is delayed after critical brain and vascular injury has occurred, so that when oxygenated blood is restored, ischemic damage is increased, rather than decreased. R/I can increase lesion size and also worsen blood barrier breakdown and lead to brain edema and hemorrhage. A major mechanism underlying R/I is that of poststroke inflammation. The poststroke immune response consists of the aberrant activation of glial cell, infiltration of peripheral leukocytes, and the release of damage-associated molecular pattern (DAMP) molecules elaborated by ischemic cells of the brain. Inflammatory mediators involved in this response include cytokines, chemokines, adhesion molecules, and several immune molecule effectors such as matrix metalloproteinases-9, inducible nitric oxide synthase, nitric oxide, and reactive oxygen species. Several experimental studies over the years have characterized these molecules and have shown that their inhibition improves neurological outcome. Yet, numerous clinical studies failed to demonstrate any positive outcomes in stroke patients. However, many of these clinical trials were carried out before the routine use of revascularization therapies. In this review, we cover mechanisms of inflammation involved in R/I, therapeutic targets, and relevant experimental and clinical studies, which might stimulate renewed interest in designing clinical trials to specifically target R/I. We propose that by targeting anti-inflammatory targets in R/I as a combined therapy, it may be possible to further improve outcomes from pharmacological thrombolysis or mechanical thrombectomy.

Shexiang Baoxin Pills for Coronary Heart Disease in Animal Models: Preclinical Evidence and Promoting Angiogenesis Mechanism

Shexiang Baoxin Pill (SBP) originated from a classical TCM Fufang Suhexiang Pill for chest pain with dyspnea in the Southern Song Dynasty (1107–110 AD). Here, we aimed to evaluate preclinical evidence and possible mechanism of SBP for experimental coronary heart disease (CHD). Studies of SBP in animal models with CHD were identified from 6 databases until April 2016. Study quality for each included article was evaluated according to the CAMARADES 10-item checklist. Outcome measures were myocardial infarction area, vascular endothelial growth factor (VEGF) and microvessel count (MVC). All the data were analyzed by using RevMan 5.1 software. As a consequence, 25 studies with 439 animals were identified. The quality score of studies ranged from 2 to 5, with the median of 3.6. Meta-analysis of seven studies showed more significant effects of SBP on the reduction of the myocardial infarction area than the control (P < 0.01). Meta-analysis of eight studies showed significant effects of SBP for increasing VEGF expression compared with the control (P < 0.01). Meta-analysis of 10 studies indicated that SBP significantly improved MVC compared with the control (P < 0.01). In conclusion, these findings preliminarily demonstrated that SBP can reduce myocardial infarction area, exerting cardioprotective function largely through promoting angiogenesis.

The impact of fraudulent and irreproducible data to the translational research crisis - solutions and implementation

One of the aims of basic neuroscience research is ultimately the development of therapeutics to cure diseases. Funders granting money to research institutions increasingly express interest into how their financial resources are used and look for successful translation in clinical practice. Disappointingly, many findings that started out promising in basic research projects and phase I trials did not live up to the promise of therapeutic efficacy in later phase II or III trials. An inordinately high amount of time and money is thus spent on research that does not always have the required human impact. Potential reasons for these problems are numerous. Although research misconduct occurs and contributes to this shortcoming, it is not the only important factor. Frequently, basic science results turn out to be irreproducible. Irreproducibility, outside of malfeasance, is multifactorial and can include poor experimental design, conduct, statistical analysis, reporting standards, and conceptual flaws. Further confounding problems include an insufficient transferability of animal to human physiology, as well as intersubject group variability, for example, sexual dimorphisms. While the causes of poor data reproducibility are therefore numerous, equally there are many groups that can contribute to improvements in how basic science is reported. Here, we will review how the Journal of Neurochemistry can contribute to increasing the value of preclinical and translational research. Despite a vast amount of very promising basic research findings, these failed to successfully translate into the clinical practice so far. The reasons for this 'data reproducibility crisis' are numerous, for example, rooting in insufficient experimental design, conceptual flaws, incorrect statistical planning and evaluation, incomplete model system that do not adequately reproduce the human physiology, and further reasons discussed in this Review with the aim to present practical solutions that can be implemented by researchers, journals editors, and reviewers. We will also explain measures the Journal of Neurochemistry have implemented to overcome these issues and weaknesses in preclinical research. These includes adherence to the ARRIVE ( www.nc3rs.org) guidelines, NINDS standards (doi: 10.1038/nature11556), and The Transparency and Openness Promotion Guidelines (TOP) Committee guidelines (https://cos.io/top/#TOP). This article is part of the 60th Anniversary special issue.

Technological advances and proteomic applications in drug discovery and target deconvolution: identification of the pleiotropic effects of statins

Proteomic-based techniques provide a powerful tool for identifying the full spectrum of protein targets of a drug, elucidating its mechanism(s) of action, and identifying biomarkers of its efficacy and safety. Herein, we outline the technological advancements in the field, and illustrate the contribution of proteomics to the definition of the pharmacological profile of statins, which represent the cornerstone of the prevention and treatment of cardiovascular diseases (CVDs). Statins act by inhibiting 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, thus reducing cholesterol biosynthesis and consequently enhancing the clearance of low-density lipoproteins from the blood; however, HMG-CoA reductase inhibition can result in a multitude of additional effects beyond lipid lowering, known as 'pleiotropic effects'. The case of statins highlights the unique contribution of proteomics to the target profiling of a drug molecule.

Combination of Thrombolysis and Statins in Acute Stroke Is Safe: Results of the STARS Randomized Trial (Stroke Treatment With Acute Reperfusion and Simvastatin)

BACKGROUND AND PURPOSE

The STARS trial (Stroke Treatment With Acute Reperfusion and Simvastatin) was conducted to demonstrate the efficacy and safety of simvastatin treatment in acute stroke.

METHODS

STARS07 was a multicentre, phase IV, prospective, randomized, double-blind, placebo-controlled trial. Patients with Acute ischemic stroke recruited within 12 hours from symptom onset were randomized to oral simvastatin 40 mg or placebo, once daily for 90 days. Primary outcome was proportion of independent patients (modified Rankin Scale score of ≤2) at 90 days. Safety end points were hemorrhagic transformation, hemorrhagic events, death, infections, and serious adverse events.

RESULTS

From April 2009 to March 2014, 104 patients were included. Fifty-five patients received intravenous tissue-type plasminogen activator. No differences were found between treatment arms regarding the primary outcome (adjusted odds ratio, 0.99 [0.35-2.78]; P=0.98). Concerning safety, no significant differences were found in the rate of hemorrhagic transformation of any type, nor symptomatic hemorrhagic transformation. There were no differences in other predefined safety outcomes. In post hoc analyses, for patients receiving tissue-type plasminogen activator, a favorable effect for simvastatin treatment was noted with higher proportion of patients experiencing major neurological recovery (adjusted odds ratio, 4.14 [1.18-14.4]; P=0.02).

CONCLUSIONS

Simvastatin plus tissue-type plasminogen activator combination seems safe in acute stroke, with low rates of bleeding complications. Because of the low recruitment, the STARS trial was underpowered to detect differences in simvastatin efficacy.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01073007.

Atorvastatin Modulates Regulatory T Cells and Attenuates Cerebral Damage in a Model of Transient Middle Cerebral Artery Occlusion in Rats

Regulatory T cells (Tregs) inhibit the activation of the immune response which could down-regulate the systemic and focal activation observed during ischemic stroke. In fact, in animal models, Tregs infiltrate the infarcted brain and reduce the pro-inflammatory cytokine production and infarct volume, mainly in late stages of ischemia. Recently, an expansion and greater suppressive capacity of circulating Tregs after treatment with statins was observed, in addition to their cardio- and neuroprotective actions demonstrated previously. Thus, to determine whether Treg modulation mediated by statins can also be beneficial during stroke, cerebral ischemia was artificially induced in Wistar rats by transient middle cerebral artery occlusion (tMCAO) during 60 minutes with subsequent reperfusion for 7 days. Six hours after surgery, some animals were treated with atorvastatin (ATV, 10 mg/kg) or carboxymethylcellulose as vehicle at the same concentration every other day during 7 days. Some animals were sham operated as control group of surgery. Interestingly, ATV treatment prevented the development of infarct volume, reduced the neurological deficits, and the circulating and cervical lymph node CD25⁺FoxP3⁺ Treg population. Moreover, there was a reduction of glial cell activation, which correlated with decreased circulating Tregs. Remarkably, treatment with ATV induced an increase in the frequency of CD4⁺CD25⁺ T cells, in particular of those expressing CTLA-4, in brain samples. Together, these results suggest that ATV can modulate Tregs in peripheral tissue and favor their accumulation in the brain, where they can exert neuroprotective actions maybe by the reduction of glial cell activation.

Influence of Statin Pretreatment on Initial Neurological Severity and Short-Term Functional Outcome in Acute Ischemic Stroke Patients: The Fukuoka Stroke Registry

Background: Statins have neuroprotective effects against ischemic stroke. However, associations between pre-stroke statin treatment and initial stroke severity and between the treatment and functional outcome remain controversial. This study aimed at determining these associations in ischemic stroke patients. Methods: Among patients registered in the Fukuoka Stroke Registry from June 2007 to October 2014, 3,848 patients with ischemic stroke within 24 h of onset, who had been functionally independent before onset, were enrolled in this study. Ischemic stroke was classified as cardioembolic or non-cardioembolic infarction. Primary and secondary study outcomes were mild neurological symptoms defined as a National Institutes of Health Stroke Scale score of ≤4 on admission and favorable functional outcome defined as a modified Rankin Scale score of ≤2 at discharge, respectively. Multivariable logistic regression models were used to quantify associations between pre-stroke statin treatment and study outcomes. Results: Of all 3,848 participants, 697 (18.1%) were taking statins prior to the stroke. The frequency of mild neurological symptoms was significantly higher in patients with pre-stroke statin treatment (64.1%) than in those without the treatment (58.3%, p < 0.01). Multivariable analysis showed that pre-stroke statin treatment was significantly associated with mild neurological symptoms (OR 1.31; 95% CI 1.04-1.65; p < 0.01). Sensitivity analysis in patients with dyslipidemia (n = 1,998) also showed the same trend between pre-stroke statin treatment and mild neurological symptoms (multivariable-adjusted OR 1.26; 95% CI 0.99-1.62; p = 0.06). In contrast, the frequency of favorable functional outcome was not different between patients with (67.0%) and without (65.3%) the treatment (p = 0.40). Multivariable analysis also showed no significant association between pre-stroke statin treatment and favorable functional outcome (OR 1.21; 95% CI 0.91-1.60; p = 0.19). Continuation of statin treatment, however, was significantly associated with favorable functional outcome among patients with pre-stroke statin treatment (multivariable-adjusted OR 2.17; 95% CI 1.16-4.00; p = 0.02). Conclusions: Pre-stroke statin treatment in ischemic stroke patients was significantly associated with mild neurological symptoms within 24 h of onset. Pre-stroke statin treatment per se did not significantly influence the short-term functional outcome; however, continuation of statin treatment during the acute stage of stroke seems to relate with favorable functional outcome for patients with pre-stroke statin treatment.

Charge effect of a liposomal delivery system encapsulating simvastatin to treat experimental ischemic stroke in rats

BACKGROUND AND AIMS

Although the beneficial effects of statins on stroke have been widely demonstrated both in experimental studies and in clinical trials, the aim of this study is to prepare and characterize a new liposomal delivery system that encapsulates simvastatin to improve its delivery into the brain.

MATERIALS AND METHODS

In order to select the optimal liposome lipid composition with the highest capacity to reach the brain, male Wistar rats were submitted to sham or transitory middle cerebral arterial occlusion (MCAOt) surgery and treated (intravenous [IV]) with fluorescent-labeled liposomes with different net surface charges. Ninety minutes after the administration of liposomes, the brain, blood, liver, lungs, spleen, and kidneys were evaluated ex vivo using the Xenogen IVIS(®) Spectrum imaging system to detect the load of fluorescent liposomes. In a second substudy, simvastatin was assessed upon reaching the brain, comparing free and encapsulated simvastatin (IV) administration. For this purpose, simvastatin levels in brain homogenates from sham or MCAOt rats at 2 hours or 4 hours after receiving the treatment were detected through ultra-high-protein liquid chromatography.

RESULTS

Whereas positively charged liposomes were not detected in brain or plasma 90 minutes after their administration, neutral and negatively charged liposomes were able to reach the brain and accumulate specifically in the infarcted area. Moreover, neutral liposomes exhibited higher bioavailability in plasma 4 hours after being administered. The detection of simvastatin by ultra-high-protein liquid chromatography confirmed its ability to cross the blood-brain barrier, when administered either as a free drug or encapsulated into liposomes.

CONCLUSION

This study confirms that liposome charge is critical to promote its accumulation in the brain infarct after MCAOt. Furthermore, simvastatin can be delivered after being encapsulated. Thus, simvastatin encapsulation might be a promising strategy to ensure that the drug reaches the brain, while increasing its bioavailability and reducing possible side effects.