Therapeutic Effects of Intranasal Administration of Resveratrol on the Rat Model of Brain Ischemia

Background

Resveratrol is a natural phenolic compound widely found in plants. Previous studies have suggested its neuroprotective role in cerebral ischemia due to its anti-oxidative, anti-inflammatory, and anti-apoptotic effects. Intranasal administration of resveratrol enhances its capacity to penetrate the blood-brain barrier, increasing therapeutic efficacy and safety.

Objective

We aimed to examine the therapeutic potential of intranasal administration of resveratrol treatment in rats exposed to cerebral ischemia.

Methods

Sixty-four male rats were divided into three groups: the sham group, which was exposed to only surgical stress; the vehicle and resveratrol groups, which received intranasal vehicle or 50 mg/kg resveratrol for 7 days following middle cerebral artery occlusion, respectively. We assessed the modified neurologic severity scores, wire hanging tests, blood-brain barrier disruption, brain water content, and infarct volume. Levels of matrix metalloproteinase-9, nuclear factor-kappa B, B-cell lymphoma protein 2, and B-cell lymphoma protein 2-associated X messenger RNA expression were examined.

Results

At 3- and 7-days post-ischemia, rats receiving intranasal resveratrol had lower modified neurological severity scores and a smaller brain infarct volume than the rats receiving vehicle. Additionally, the intranasal resveratrol-treated rats showed significantly prolonged wire-hanging performance at the 7-day mark post-ischemia compared to the vehicle group. The blood-brain barrier disruption and brain water content were significantly lower in the resveratrol group than in the vehicle group. Furthermore, the resveratrol-treated group displayed lower expression of Matrix Metalloproteinase-9 and Nuclear Factor-Kappa B in contrast to the vehicle group, while the difference in expression levels of B-cell lymphoma protein 2-associated X and B-cell lymphoma protein 2 were not significant.

Conclusion

Intranasal administration of resveratrol showed neuroprotective effects on ischemic stroke by improving neurobehavioral function, reducing blood-brain barrier disruption, cerebral edema, and infarct volume. This treatment also downregulated Matrix Metalloproteinase-9 and Nuclear Factor-Kappa B expression, indicating its potential as a therapeutic option for ischemic stroke.

Mesenchymal stem cell therapy in perinatal arterial ischemic stroke: systematic review of preclinical studies

BACKGROUND

Perinatal arterial ischemic stroke (PAIS) is a neurologic disorder leading to long-term complications. Mesenchymal stem cells (MSCs) have emerged as a novel therapeutic agent. This systematic review aims to determine the effects of stem cell-based interventions for the treatment of PAIS in preclinical studies.

METHODS

We included all controlled studies on MSCs in neonatal animals with PAIS. Functional outcome was the primary outcome. The literature search was performed in February 2021.

RESULTS

In the 20 included studies, MSCs were most frequently delivered via intracerebral injection (n = 9), 3 days after the induction of PAIS (n = 8), at a dose ranging from 5 × 104 to 5 × 106 cells. The meta-analysis showed an improvement on the cylinder rearing test (MD: -10.62; 95% CI: -14.38 to -6.86) and on the water maze test (MD: 1.31 MD; 95% CI: 0.80 to 1.81) in animals treated with MSCs compared to the control group animals.

CONCLUSION

MSCs appear to improve sensorimotor and cognitive performance in PAIS-injured animals; however, the certainty of the evidence is low. Registration of the protocol of preclinical studies, appropriate sample size calculation, rigorous randomization, and reporting of the data on animal sex and survival are warranted. PROSPERO registration number: CRD42021239642.

IMPACT

This is the first systematic review and meta-analysis of preclinical studies investigating the effects of MSCs in an experimental model of PAIS. MSCs appear to improve sensorimotor and cognitive performance in PAIS-injured neonatal animals. The certainty of the evidence is low due to high or unclear risk of bias in most domains.

Progress in the treatment of neonatal hypoxic-ischemic encephalopathy with umbilical cord blood mononuclear cells

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common disease among newborns, which is a leading cause of neonatal death and permanent neurological sequelae. Therapeutic hypothermia (TH) is the only method for the treatment of HIE that has been recognized effective clinically at home and abroad, but the efficacy is limited. Recent research suggests that the cord blood-derived mononuclear cells (CB-MNCs), which the refer to blood cells containing one nucleus in the cord blood, exert anti-oxidative, anti-inflammatory, anti-apoptotic effects and play a neuroprotective role in HIE. This review focuses on safety and efficacy, the route of administration, dose, timing and combination treatment of CB-MNCs in HIE.

Short-term beneficial effects of human dental pulp stem cells and their secretome in a rat model of mild ischemic stroke

Although cell therapy has been applied in regenerative medicine for decades, recent years have seen greatly increased attention being given to the use of stem cell-based derivatives such as cell-free secretome. Dental pulp stem cells (DPSCs) are widely available, easily accessible, and have high neuroprotective and angiogenic properties. In addition, DPSC-derived secretome contains a rich mixture of trophic factors. The current investigation evaluated the short-term therapeutic effects of human DPSCs and their secretome in a rat model of mild ischemic stroke. Mild ischemic stroke was induced by 30 min middle cerebral artery occlusion, and hDPSCs or their secretome was administered intra-arterially and intranasally. Neurological function, infarct size, spatial working memory, and relative expression of seven target genes in two categories of neurotrophic and angiogenic factors were assessed three days after stroke. In the short-term, all treatments reduced the severity of neurological and histological deficits caused by ischemic stroke. Moreover, transient middle cerebral artery occlusion led to the striatal and cortical over-expression of BDNF, NT-3, and angiogenin, while NGF and VEGF expression was reduced. Almost all interventions were able to modulate the expression of target genes after stroke. The obtained data revealed that single intra-arterial administration of hDPSCs or their secretome, single intranasal transplantation of hDPSCs, or repeated intranasal administration of hDPSC-derived secretome was able to ameliorate the devastating effects of a mild stroke, at least in the short-term.

From Hair to the Brain: The Short-Term Therapeutic Potential of Human Hair Follicle-Derived Stem Cells and Their Conditioned Medium in a Rat Model of Stroke

The short-term therapeutic impacts of stem cells and their derivatives were frequently reported in preclinical investigations of ischemic stroke (IS); however, several drawbacks including accessibility, abundancy, and ethical concerns limited their clinical application. We describe here for the first time the therapeutic potential of human hair follicle-derived stem cells (hHFSCs) and their conditioned medium (CM) in a rat model of IS. Furthermore, we hypothesized that a combination of cell therapy with repeated CM administration might enhance the restorative efficiency of this approach compared to each treatment alone. Middle cerebral artery occlusion was performed for 30 min to induce IS. Immediately after reperfusion, hHFSCs were transplanted through the intra-arterial route and/or hHFSC-CM administered intranasally. The neurological outcomes, short-term spatial working memory, and infarct size were evaluated. Furthermore, relative expression of seven target genes in three categories of neuronal markers, synaptic markers, and angiogenic markers was assessed. The hHFSCs and hHFSC-CM treatments improved neurological impairments and reduced infarct size in the IS rats. Moreover, molecular data elucidated that IS was accompanied by attenuation in the expression of neuronal and synaptic markers in the evaluated brain regions and the interventions rescued these expression changes. Although there was no considerable difference between hHFSCs and hHFSC-CM treatments in the improvement of neurological function and decrement of infarct size, combination therapy was more effective to reduce infarction and elevation of target gene expression especially in the hippocampus. These findings highlight the curative potential of hHFSCs and their CM in a rat model of IS.

Nose-to-Brain: The Next Step for Stem Cell and Biomaterial Therapy in Neurological Disorders

Neurological disorders are a leading cause of morbidity worldwide, giving rise to a growing need to develop treatments to revert their symptoms. This review highlights the great potential of recent advances in cell therapy for the treatment of neurological disorders. Through the administration of pluripotent or stem cells, this novel therapy may promote neuroprotection, neuroplasticity, and neuroregeneration in lesion areas. The review also addresses the administration of these therapeutic molecules by the intranasal route, a promising, non-conventional route that allows for direct access to the central nervous system without crossing the blood–brain barrier, avoiding potential adverse reactions and enabling the administration of large quantities of therapeutic molecules to the brain. Finally, we focus on the need to use biomaterials, which play an important role as nutrient carriers, scaffolds, and immune modulators in the administration of non-autologous cells. Little research has been conducted into the integration of biomaterials alongside intranasally administered cell therapy, a highly promising approach for the treatment of neurological disorders.

Therapeutic potential of hair follicle-derived stem cell intranasal transplantation in a rat model of ischemic stroke

BACKGROUND

Stem cell-based therapy has received considerable attention as a potential candidate in the treatment of ischemic stroke; however, employing an appropriate type of stem cells and an effective delivery route are still challenging. In the present study, we investigated the therapeutic effect of safe, noninvasive, and brain-targeted intranasal administration of hair follicle-derived stem cells (HFSCs) in a rat model of ischemic stroke.

METHODS

Stem cells were obtained from the adult rat hair follicles. In experiment 1, stroke was induced by 30 min middle cerebral artery occlusion (MCAO) and stem cells were intranasally transplanted immediately after ischemia. In experiment 2, stroke was induced by 120 min MCAO and stem cells were administered 24 h after cerebral ischemia. In all experimental groups, neurological performance, short-term spatial working memory and infarct volume were assessed. Moreover, relative expression of major trophic factors in the striatum and cortex was evaluated by the quantitative PCR technique. The end point of experiment 1 was day 3 and the end point of experiment 2 was day 15.

RESULTS

In both experiments, intranasal administration of HFSCs improved functional performance and decreased infarct volume compared to the MCAO rats. Furthermore, NeuN and VEGF expression were higher in the transplanted group and stem cell therapy partially prevented BDNF and neurotrophin-3 over-expression induced by cerebral ischemia.

CONCLUSIONS

These findings highlight the curative potential of HFSCs following intranasal transplantation in a rat model of ischemic stroke.

Experimental Models for Testing the Efficacy of Pharmacological Treatments for Neonatal Hypoxic-Ischemic Encephalopathy

Representing an important cause of long-term disability, term neonatal hypoxic-ischemic encephalopathy (HIE) urgently needs further research aimed at repurposing existing drug as well as developing new therapeutics. Since various experimental in vitro and in vivo models of HIE have been developed with distinct characteristics, it becomes important to select the appropriate preclinical screening cascade for testing the efficacy of novel pharmacological treatments. As therapeutic hypothermia is already a routine therapy for neonatal encephalopathy, it is essential that hypothermia be administered to the experimental model selected to allow translational testing of novel or repurposed drugs on top of the standard of care. Moreover, a translational approach requires that therapeutic interventions must be initiated after the induction of the insult, and the time window for intervention should be evaluated to translate to real world clinical practice. Hippocampal organotypic slice cultures, in particular, are an invaluable intermediate between simpler cell lines and in vivo models, as they largely maintain structural complexity of the original tissue and can be subjected to transient oxygen-glucose deprivation (OGD) and subsequent reoxygenation to simulate ischemic neuronal injury and reperfusion. Progressing to in vivo models, generally, rodent (mouse and rat) models could offer more flexibility and be more cost-effective for testing the efficacy of pharmacological agents with a dose-response approach. Large animal models, including piglets, sheep, and non-human primates, may be utilized as a third step for more focused and accurate translational studies, including also pharmacokinetic and safety pharmacology assessments. Thus, a preclinical proof of concept of efficacy of an emerging pharmacological treatment should be obtained firstly in vitro, including organotypic models, and, subsequently, in at least two different animal models, also in combination with hypothermia, before initiating clinical trials.