Rapamycin ameliorates brain metabolites alterations after transient focal ischemia in rats

Pharmacological inhibition of mTORC1 reduces neural death and damage volume after MCAO by modulating microglial reactivity

Ischemic stroke is a sudden and acute disease characterized by neuronal death, increment of reactive gliosis (reactive microglia and astrocytes), and a severe inflammatory process. Neuroinflammation is an early event after cerebral ischemia, with microglia playing a leading role. Reactive microglia involve functional and morphological changes that drive a wide variety of phenotypes. In this context, deciphering the molecular mechanisms underlying such reactive microglial is essential to devise strategies to protect neurons and maintain certain brain functions affected by early neuroinflammation after ischemia. Here, we studied the role of mammalian target of rapamycin (mTOR) activity in the microglial response using a murine model of cerebral ischemia in the acute phase. We also determined the therapeutic relevance of the pharmacological administration of rapamycin, a mTOR inhibitor, before and after ischemic injury. Our data show that rapamycin, administered before or after brain ischemia induction, reduced the volume of brain damage and neuronal loss by attenuating the microglial response. Therefore, our findings indicate that the pharmacological inhibition of mTORC1 in the acute phase of ischemia may provide an alternative strategy to reduce neuronal damage through attenuation of the associated neuroinflammation.

FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders

Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.

Study on the pharmacodynamic effect of Rhizoma Dioscoreae polysaccharides on cerebral ischemia-reperfusion injury in rats and the possible mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Dioscoreae (RD) is the rhizome of Dioscorea opposita Thunb., a traditional Chinese medicine, which can treat hypertension, diabetes, cerebral vasospasm headache and Alzheimer's disease. Meanwhile, RD is the main component of Liuwei Dihuang pill, a Chinese patent medicine. Rhizoma Dioscoreae polysaccharides (RDPS) are the primary active ingredient of RD. Modern medical research confirmed RDPS has multiple pharmacological effects, including neuroprotection, immunoregulation, antioxidant effect in many organs. The primary ischemia/hypoxia injury and secondary reperfusion injury are mainly caused by oxidative stress, which caused by hypoxia, such as free radical generation, energy metabolism disorder, intracellular calcium overload, excitatory amino acid release and inflammatory reaction.

AIM OF THE STUDY

We have investigated the pharmacodynamic effect of RDPS on cerebral ischemia-reperfusion (IR) injury in rats and the possible mechanism in vitro.

MATERIALS AND METHODS

The pharmacodynamic effect of RDPS on IR injury in rats was studied by the construction of the occlusion of middle cerebral artery (MCAO) model, measuring the volume of cerebral infarct area, the content of oxidation index, inflammatory cytokines, and the expression of CaMMKβ in brain tissue. The in vitro study was explored by oxygen-glucose deprivation/glycogen reoxygenation (OGD/R) model, construction of the CaMMKβ interference sequence, measuring the expression of CaMMKβ in BV2 cells before and after inhibition of CaMMKβ, and the influence of RDPS on Nrf2/HO-1 signal pathway, in order to investigate the possible mechanism.

RESULTS

Compared with the model group, the present study showed that RDPS with high-dose and low-dose groups could significantly reduce the volume of cerebral infarction. The content of MDA decreased and the activities of GSH and SOD increased in the two dose groups of RDPS. We confirmed that after RDPS treatment, the levels of IL-6, IL-1 β and TNF-α in brain tissue were lower than those in model group, and the expression of CaMMKβ in brain tissue of rats decreased in the model group, but increased in the groups of RDPS. In the in vitro study, compared with the control group, RDPS could regulate the OGD/R-induced apoptosis of BV2 cells and increase the level of CaMMKβ, Nrf2 and HO-1 induced by OGD/R. To our surprise, these therapeutic effects are no longer present after the inhibition of CaMMKβ protein. The activity of BV2 induced by OGD/R could not be enhanced by RDPS after the inhibition of CaMMKβ protein.

CONCLUSIONS

RDPS has the pharmacodynamic effect in IR injury, which reduce the area of cerebral infarction, up-regulate the activity of anti-oxidant kinase, and down-regulate the inflammatory cytokine. Additionally, RDPS could affect the activation of Nrf2/HO-1 signaling pathway by regulating the expression of CaMMKβ. Our observations justify the RDPS could be a new strategy for IR injury therapy, and the mechanism may be related to the improvement of antioxidant enzyme activity and inhibition of inflammatory reaction.

Metabolomics-based study of the potential interventional effects of Xiao-Xu-Ming Decoction on cerebral ischemia/reperfusion rats

ETHNOPHARMACOLOGICAL RELEVANCE

Xiao-Xu-Ming Decoction (XXMD) is a classical Chinese medicinal compound for the treatment of ischemic stroke, which has good efficacy in clinical studies and also plays a neuroprotective role in pharmacological studies.

AIM OF THE STUDY

The purpose of this study is to investigate the potential and integral interventional effects of XXMD on cerebral ischemia/reperfusion rat model.

MATERIALS AND METHODS

In this study, ¹H NMR metabolomics was used, combined with neurological functional assessments, cerebral infarct area measurements, and pathological staining including Nissl staining, immunofluorescence staining of NeuN and TUNEL, and immunohistochemical staining of MCT2, to analyze the metabolic effects of XXMD in the treatment of an ischemia/reperfusion rat model.

RESULTS

It's observed that XXMD treatment could improve the neurological deficit scores and reduce the cerebral infarct areas on cerebral ischemia/reperfusion rat model. The pathological staining results performed that XXMD treatment could improve the decrease of Nissl bodies and the expression of NeuN and MCT2, reduce the high expression of TUNEL. In ¹H NMR study, it revealed that the metabolic patterns among three experimental groups were different, the level of lactate, acetate, NAA, glutamate, and GABA were improved to varying degrees in different brain area.

CONCLUSION

Our findings indicated that XXMD has positive effect on neuroprotection and improvement of metabolism targeting cerebral ischemic injury in rats, which showed great potential for ischemic stroke.

Dysregulation of mTOR Signaling after Brain Ischemia

In this review, we provide recent data on the role of mTOR kinase in the brain under physiological conditions and after damage, with a particular focus on cerebral ischemia. We cover the upstream and downstream pathways that regulate the activation state of mTOR complexes. Furthermore, we summarize recent advances in our understanding of mTORC1 and mTORC2 status in ischemia–hypoxia at tissue and cellular levels and analyze the existing evidence related to two types of neural cells, namely glia and neurons. Finally, we discuss the potential use of mTORC1 and mTORC2 as therapeutic targets after stroke.

Metabolomics of neurological disorders in India

Metabolomics is the comprehensive study of the metabolome and its alterations within biological fluids and tissues. Over the years, applications of metabolomics have been explored in several areas, including personalised medicine in diseases, metabolome-wide association studies (MWAS), pharmacometabolomics and in combination with other branches of omics such as proteomics, transcriptomics and genomics. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy are the major analytical techniques widely employed in metabolomics. In addition, MS is coupled with chromatography techniques like gas chromatography (GC) and liquid chromatography (LC) to separate metabolites before analysis. These analytical techniques have made possible identification and quantification of large numbers of metabolites, encompassing characterization of diseases and facilitating a systematic and rational therapeutic strategy based on metabolic patterns. In recent years, the metabolomics approach has been used to obtain a deeper insight into the underlying biochemistry of neurodegenerative disorders and the discovery of biomarkers of clinical implications. The current review mainly focuses on an Indian perspective of metabolomics for the identification of metabolites and metabolic alterations serving as potential diagnostic biomarkers for neurological diseases including acute spinal cord injury, amyotrophic lateral sclerosis, tethered cord syndrome, spina bifida, stroke, Parkinson's disease, glioblastoma and neurological disorders with inborn errors of metabolism.

Rapamycin restores brain vasculature, metabolism, and blood-brain barrier in an inflammaging model

Rapamycin (RAPA) is found to have neuro-protective properties in various neuroinflammatory pathologies, including brain aging. With magnetic resonance imaging (MRI) techniques, we investigated the effect of RAPA in a lipopolysaccharide (LPS)-induced inflammaging model in rat brains. Rats were exposed to saline (control), or LPS alone or LPS combined with RAPA treatment (via food over 6 weeks). Arterial spin labeling (ASL) perfusion imaging was used to measure relative cerebral blood flow (rCBF). MR spectroscopy (MRS) was used to measure brain metabolite levels. Contrast-enhanced MRI (CE-MRI) was used to assess blood-brain barrier (BBB) permeability. Immunohistochemistry (IHC) was used to confirm neuroinflammation. RAPA restored NF-κB and HIF-1α to normal levels. RAPA was able to significantly restore rCBF in the cerebral cortex post-LPS exposure (p < 0.05), but not in the hippocampus. In the hippocampus, RAPA was able to restore total creatine (Cr) acutely, and N-acetyl aspartate (NAA) at 6 weeks, post-LPS. Myo-inositol (Myo-Ins) levels were found to decrease with RAPA treatment acutely post-LPS. RAPA was also able to significantly restore the BBB acutely post-LPS in both the cortex and hippocampus (p < 0.05 for both). RAPA was found to increase the percent change in BOLD signal in the cortex at 3 weeks, and in the hippocampus at 6 weeks post-LPS, compared to LPS alone. RAPA treatment also restored the neuronal and macro-vascular marker, EphB2, back to normal levels. These results indicate that RAPA may play an important therapeutic role in inhibiting neuroinflammation by normalizing brain vascularity, BBB, and some brain metabolites, and has a high translational capability.

Rapamycin Pretreatment Alleviates Cerebral Ischemia/Reperfusion Injury in Dose-Response Manner Through Inhibition of the Autophagy and NFκB Pathways in Rats

Although rapamycin can attenuate cerebral ischemia/reperfusion (I/R) injury, the potential roles of rapamycin on cerebral I/R injury remain largely controversial. The present work aims to evaluate underlying molecular mechanisms of rapamycin pretreatment on I/R injury. In total, 34 Sprague-Dawley rats were randomly grouped to 3 groups: sham group (n = 2), vehicle group (n = 16), and rapamycin-pretreatment group (n = 16). Before the focal cerebral ischemia was induced, those rats in the pretreatment group were intraperitoneally injected rapamycin (1 mg/kg body) for 20 hours, while rats in the vehicle group received same-volume saline. Then, rats in these 2 groups received focal cerebral ischemia for 3 and 6 hours, respectively (n = 8 in each group), which was followed by the application of reperfusion for 4, 24, 72 hours, and 1 week (n = 2 in each group). The results showed that the rapamycin pretreatment improved the memory functions of rats after I/R injury, which was evaluated using a Y-maze test. Rapamycin pretreatment significantly reduced the size of triphenyltetrazolium chloride infarction and decreased the expression of I/R injury markers. Moreover, the expression of LC-3 and NFκB was also significantly reduced after rapamycin pretreatment. Taken together, rapamycin pretreatment may alleviate cerebral I/R injury partly through inhibiting autophagic activities and NFκB pathways in rats.

1 H NMR metabolomic profiling elucidated attenuation of neurometabolic alterations by lercanidipine in MCAo model in rats

OBJECTIVES

Stroke is a leading cause of death and disability worldwide with limited therapeutic interventions. The current study explored proton nuclear magnetic resonance spectroscopy (¹ H NMR)-based metabolomic approach to elucidate the effect of lercanidipine on neurometabolic alterations in transient model of ischaemic stroke in rats.

METHODS

In the present investigation, male Wistar rats were subjected to middle cerebral artery occlusion (MCAo) for 2 h followed by reperfusion using intraluminal filament method. Rats were randomly divided into three groups as vehicle-treated sham control, vehicle-treated MCAo control and lercanidipine-treated MCAo. Vehicle or lercanidipine (0.5 mg/kg, i.p.) was administered 120 min post-reperfusion. The rat brain cortex tissues were isolated 24 h post-MCAo and were investigated by ¹ H NMR spectroscopy through perchloric extraction method.

KEY FINDINGS

A total of 23 metabolites were altered significantly after cerebral ischaemic-reperfusion injury in MCAo control as compared to sham control rats. Lercanidipine significantly reduced the levels of valine, alanine, lactate, acetate and tyrosine, while N-acetylaspartate, glutamate, glutamine, aspartate, creatine/phosphocreatine, choline, glycerophosphorylcholine, taurine, myo-inositol and adenosine di-phosphate were elevated as compared to MCAo control.

CONCLUSIONS

Present study illustrates effect of lercanidipine on neurometabolic alterations which might be mediated through its antioxidant, anti-inflammatory, vasodilatory and anti-apoptotic property in MCAo model of stroke.

Leeches attenuate blood hyperviscosity and related metabolic disorders in rats differently than aspirin

ETHNOPHARMACOLOGICAL RELEVANCE

Whitmania pigra Whitman (Whitmania pigra, WP), firstly recorded in the Shennong's Herbal Classic and officially listed in the Chinese Pharmacopoeia, is a well-used cardiovascular protective traditional Chinese medicine derived from leeches. Traditional Chinese physicians prefer to prescribe the dried whole body of leech processed under high temperatures. It has been reported that dried WP remains clinically effective. However, the therapeutic mechanism has yet not be clearly elucidated.

AIM OF THE STUDY

This study was designed to investigate the protective activity of the extract of WP in a high-molecular-weight dextran-induced blood hyperviscosity rat model, and to explore the role of WP in improving blood hyperviscosity related metabolic disorders and to clarify the possible mechanism of metabolic regulation.

MATERIALS AND METHODS

The hemorheological parameters were measured with an automated blood rheology analyzer. Hematoxylin-eosin staining was used to observe the pathological changes in aortic tissues samples. Further, a liquid chromatography-mass-spectrometry (LC-MS)-based untargeted metabolomics approach was applied to characterize the metabolic alterations.

RESULTS

WP has evident attenuating effects on blood hyperviscosity and related metabolic disorders, and the influences are distinct from those of aspirin. The results showed that WP had good effects in reducing blood viscosity and ameliorating histopathological changes in the thoracic aorta in a high molecular weight dextran-induced blood hyperviscosity rat model. The middle dose (2.5 g raw material/kg body weight) of WP exhibited effects equivalent to aspirin (100 mg/kg) on hemorheological and histopathological parameters (P > 0.05). However, when using metabolomics profiling, we found that WP could significantly improve blood hyperviscosity-related metabolic disorders and restore metabolites to normal levels; while aspirin showed little effect. With principal component analysis and orthogonal partial least-squares discriminant analysis, WP regulated many more endogenous metabolites than aspirin. With pathway enrichment analysis, the differential endogenous metabolites were involved in cysteine and methionine metabolism, TCA cycle, arachidonic acid metabolism, etc., highlighting the metabolic reprogramming potential of WP against blood hyperviscosity-induced metabolic disorders.

CONCLUSIONS

The study suggest that WP has a more potent effect, but a different mechanism, than aspirin in improving either blood hyperviscosity or related metabolic disorders associated with cardio- and cerebrovascular diseases.

Citalopram attenuated neurobehavioral, biochemical, and metabolic alterations in transient middle cerebral artery occlusion model of stroke in male Wistar rats

Oxidative stress and inflammation are implicated as cardinal mechanisms of neuronal death following stroke. In the present study citalopram (Cit) was investigated in a 2 h middle cerebral artery occlusion (MCAo) model of stroke in male Wistar rats. Pretreatment, posttreatment (Post Cit) and pre plus posttreatment (Pre + Post Cit) with Cit were evaluated for its neuroprotective effect. In pretreatment protocol, effect of Cit at three doses (2, 4, and 8 mg/kg) administered i.p., 1 h prior to MCAo was evaluated using neurological deficit score (NDS), motor deficit paradigms, and cerebral infarction 24 h post-MCAo. In posttreatment and pre plus posttreatment protocol, the effective dose of Cit (4 mg/kg) was administered i.p., 0.5 h post-reperfusion (Post Cit) only, and 1 h prior to MCAo and again at 0.5 h post-reperfusion (Pre + Post Cit), respectively. These two groups were assessed for NDS and cerebral infarction. Though NDS was significantly reduced in both Post Cit and Pre + Post Cit groups, significant reduction in cerebral infarction was evident only in Pre + Post Cit group. Infarct volume assessed by magnetic resonance imaging was significantly attenuated in Pre + Post Cit group (10.6 ± 1.1%) compared to MCAo control group (18.5 ± 3.0%). Further, Pre + Post Cit treatment significantly altered 17 metabolites along with attenuation of malondialdehyde, reduced glutathione, matrix metalloproteinases, and apoptotic markers as compared to MCAo control. These results support the neuroprotective effect of Cit, mediated through amelioration of oxidative stress, inflammation, apoptosis, and altered metabolic profile.

Role of mTORC1 Controlling Proteostasis after Brain Ischemia

Intense efforts are being undertaken to understand the pathophysiological mechanisms triggered after brain ischemia and to develop effective pharmacological treatments. However, the underlying molecular mechanisms are complex and not completely understood. One of the main problems is the fact that the ischemic damage is time-dependent and ranges from negligible to massive, involving different cell types such as neurons, astrocytes, microglia, endothelial cells, and some blood-derived cells (neutrophils, lymphocytes, etc.). Thus, approaching such a complicated cellular response generates a more complex combination of molecular mechanisms, in which cell death, cellular damage, stress and repair are intermixed. For this reason, animal and cellular model systems are needed in order to dissect and clarify which molecular mechanisms have to be promoted and/or blocked. Brain ischemia may be analyzed from two different perspectives: that of oxygen deprivation (hypoxic damage per se) and that of deprivation of glucose/serum factors. For investigations of ischemic stroke, middle cerebral artery occlusion (MCAO) is the preferred in vivo model, and uses two different approaches: transient (tMCAO), where reperfusion is permitted; or permanent (pMCAO). As a complement to this model, many laboratories expose different primary cortical neuron or neuronal cell lines to oxygen-glucose deprivation (OGD). This ex vivo model permits the analysis of the impact of hypoxic damage and the specific response of different cell types implicated in vivo, such as neurons, glia or endothelial cells. Using in vivo and neuronal OGD models, it was recently established that mTORC1 (mammalian Target of Rapamycin Complex-1), a protein complex downstream of PI3K-Akt pathway, is one of the players deregulated after ischemia and OGD. In addition, neuroprotective intervention either by estradiol or by specific AT2R agonists shows an important regulatory role for the mTORC1 activity, for instance regulating vascular endothelial growth factor (VEGF) levels. This evidence highlights the importance of understanding the role of mTORC1 in neuronal death/survival processes, as it could be a potential therapeutic target. This review summarizes the state-of-the-art of the complex kinase mTORC1 focusing in upstream and downstream pathways, their role in central nervous system and their relationship with autophagy, apoptosis and neuroprotection/neurodegeneration after ischemia/hypoxia.

Exploring the biomarkers and therapeutic mechanism of kidney-yang deficiency syndrome treated by You-gui pill using systems pharmacology and serum metabonomics

In this study, systems pharmacology was used to predict the molecular targets of You-gui pill (YGP) and explore the therapeutic mechanism of Kidney-Yang Deficiency Syndrome (KYDS) treated with YGP. On the basis of this, serum samples from control group, KYDS model group and YGP group rats were studied using 1H NMR to verify the results of systems pharmacology from the level of metabonomics. Simultaneously, 1H NMR spectra of serum samples were obtained and statistically assessed using pattern recognition analysis. Biochemical analyses of serums were performed via radioimmunoassays. Furthermore, histopathological studies were conducted on the pituitary, adrenal, and thyroid glands, and testicles of the control, KYDS and YGP rats. Using systems pharmacology to analyze the active components of YGP, 61 active compounds were finally found. These compounds were likely to have an effect on 3177 target proteins and involve 234 pathways. Using metabonomics to analyze serum from KYDS rats treated with YGP, 22 endogenous biomarkers were found. These biomarkers were mainly involved in 10 metabolic pathways. Combining systems pharmacology and metabonomics, we found that the regulation of KYDS was primarily associated with 19 active compounds of 5 Chinese herbal medicines in YGP. These active compounds mainly had an effect on 8 target proteins, including phosphoenolpyruvate carboxykinase, betaine-homocysteine s-methyltransferase 1, alcohol dehydrogenase 1C, etc. These target proteins were primarily involved in 6 overlapping pathways, namely aminoacyl-tRNA biosynthesis, glycolysis/gluconeogenesis, glycine, serine and threonine metabolism, valine, leucine and isoleucine biosynthesis, arginine and proline metabolism, and pyruvate metabolism. In addition, there were 4 non-overlapping pathways, respectively alanine, aspartate and glutamate metabolism, d-glutamine and d-glutamate metabolism, ubiquinone and other terpenoid-quinone biosynthesis, and galactose metabolism. In summary, the therapeutic effects of YGP on KYDS were mainly associated with neuroendocrine regulation, energy metabolism, amino acid metabolism, inflammatory responses, apoptosis, oxidative stress and intestinal flora metabolism. What's more, we also found that YGP possessed the potential to protect liver and kidney function. Our study demonstrated that systems pharmacology and metabonomics methods were novel strategies for the exploration of the mechanisms of KYDS and TCM formulas.

1H NMR studies on serum metabonomic changes over time in a kidney-Yang deficiency syndrome model

The central aim of this study was to investigate metabolite changes in metabolic pathwaysviametabonomic approaches in rats suffering from Kidney-Yang Deficiency Syndrome (KYDS) induced by hydrocortisone.

mTORC1 pathway disruption ameliorates brain inflammation following stroke via a shift in microglia phenotype from M1 type to M2 type

Inflammatory factors secreted by microglia play an important role in focal ischemic stroke. The mammalian target of rapamycin (mTOR) pathway is a known regulator of immune responses, but the role that mTORC1 signaling plays in poststroke neuroinflammation is not clear. To explore the relationship between microglial action in the mTORC1 pathway and the impact on stroke, we administered the mTORC1 inhibitors sirolimus and everolimus to mice. Presumably, disrupting the mTORC1 pathway after focal ischemic stroke should clarify the subsequent activity of microglia. For that purpose, we generated mice deficient in the regulatory associated protein of mTOR (Raptor) in microglia, whose mTORC1 signaling was blocked, by crossing Raptor loxed (Raptor^flox/flox) mice with CX3CR1^CreER mice, which express Cre recombinase under the control of the CX3C chemokine receptor 1 promoter. mTORC1 blockade reduced lesion size, improved motor function, dramatically decreased production of proinflammatory cytokines and chemokines, and reduced the number of M1 type microglia. Thus, mTORC1 blockade apparently attenuated behavioral deficits and poststroke inflammation after middle cerebral artery occlusion by preventing microglia polarization toward the M1 type.-Li, D., Wang, C., Yao, Y., Chen, L., Liu, G., Zhang, R., Liu, Q., Shi, F.-D., Hao, J. mTORC1 pathway disruption ameliorates brain inflammation following stroke via a shift in microglia phenotype from M1 type to M2 type.

(1)H NMR-based metabonomics revealed protective effect of Naodesheng bioactive extract on ischemic stroke rats

ETHNOPHARMACOLOGICAL RELEVANCE

Stroke is a leading cause of death and disability in the world. However, current therapies are limited. Naodesheng, a widely used traditional Chinese medicine prescription, has shown a good clinical curative effect on ischemic stroke. Also, Naodesheng has been suggested to have neuroprotective effect on focal cerebral ischemia rats, but the underlying molecular mechanism remains unclear.

AIM OF THE STUDY

The present study was designed to evaluate the effect of Naodesheng bioactive extract on the metabolic changes in brain tissue, plasma and urine induced by cerebral ischemia perfusion injury, and explore the possible metabolic mechanisms by using a (1)H NMR-based metabonomics approach.

MATERIALS AND METHODS

A middle cerebral artery occlusion rat model was established and confirmed by the experiments of neurobehavioral abnormality evaluation, brain tissue TTC staining and pathological examination. The metabolic changes in brain tissue, plasma and urine were then assessed by a (1)H NMR technique combined with multivariate statistical analysis method.

RESULTS

These NMR data showed that cerebral ischemia reperfusion induced great metabolic disorders in brain tissue, plasma and urine metabolisms. However, Naodesheng bioactive extract could reverse most of the imbalanced metabolites. Meanwhile, it was found that both the medium and high dosages of Naodesheng bioactive extract were more effective on the metabolic changes than the low dosage, consistent with histopathological assessments.

CONCLUSIONS

These results revealed that Naodesheng had protective effect on ischemic stroke rats and the underlying mechanisms involved multiple metabolic pathways, including energy metabolism, amino acid metabolism, oxidative stress and inflammatory injury. The present study could provide evidence that metabonomics revealed its capacity to evaluate the holistic efficacy of traditional Chinese medicine and explore the underlying mechanisms.