“The main pathological feature of Parkinson’s disease (PD) is the loss of dopaminergic neurons in the substantia nigra. In this study, we investigated the role of cannabinoid receptor 2 (CB2R) agonist AM1241 on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity in a mouse model of PD. Upon treatment with AM1241, the decreased CB2R level in the PD mouse brain was reversed and the behavior score markedly elevated, accompanied with a dose-dependent increase of dopamine and serotonin. In addition, western blot assay and immunostaining results suggested that AM1241 significantly activated PI3K/Akt/MEK phosphorylation and increased the expression of Parkin and PINK1, both in the substantia nigra and hippocampus. The mRNA expression analysis further demonstrated that AM1241 increased expression of the CB2R and activated Parkin/PINK1 signaling pathways. Furthermore, the increased number of TH-positive cells in the substantia nigra indicated that AM1241 regenerated DA neurons in PD mice, and could therefore be a potential candidate for PD treatment. The clear co-localization of CB2R and DA neurons suggested that AM1241 targeted CB2R, thus also identifying a novel target for PD treatment. In conclusion, the selective CB2 agonist AM1241 has a significant therapeutic effect on PD mice and resulted in regeneration of DA neurons following MPTP-induced neurotoxicity. The possible mechanisms underlying the neurogenesis effect of AM1241 might be the induction of CB2R expression and an increase in phosphorylation of the PI3K/AKT signaling pathway.”
Tag Archives: neuroprotective
Endocannabinoids exert CB1 receptor-mediated neuroprotective effects in models of neuronal damage induced by HIV-1 Tat protein.
“In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is considered a chronic disease that specifically targets the brain and causes HIV-1-associated neurocognitive disorders (HAND). Endocannabinoids (eCBs) elicit neuroprotective and anti-inflammatory actions in several central nervous system (CNS) disease models, but their effects in HAND remain unknown. HIV-1 does not infect neurons, but produces viral toxins, such as transactivator of transcription (Tat), that disrupt neuronal calcium equilibrium and give rise to synaptodendritic injuries and cell death, the former being highly correlated with HAND. Consequently, we tested whether the eCBs N-arachidonoyl ethanolamine (anandamide/AEA) and 2-arachidonoyl-glycerol (2-AG) offer neuroprotective actions in a neuronal culture model. Specifically, we examined the neuroprotective actions of these eCBs on Tat excitotoxicity in primary cultures of prefrontal cortex neurons (PFC), and whether cannabinoid receptors mediate this neuroprotection. Tat-induced excitotoxicity was reflected by increased intracellular calcium levels, synaptodendritic damage, neuronal excitability, and neuronal death. Further, upregulation of cannabinoid 1 receptor (CB1R) protein levels was noted in the presence of HIV-1 Tat. The direct application of AEA and 2-AG reduced excitotoxic levels of intracellular calcium and promoted neuronal survival following Tat exposure, which was prevented by the CB1R antagonist rimonabant, but not by the CB2R antagonist AM630. Overall, our findings indicate that eCBs protect PFC neurons from Tat excitotoxicity in vitro via a CB1R-related mechanism. Thus, the eCB system possesses promising targets for treatment of neurodegenerative disorders associated with HIV-1 infection.”
https://www.ncbi.nlm.nih.gov/pubmed/28733129
http://www.sciencedirect.com/science/article/pii/S1044743117300830
The synthetic cannabinoid WIN55212-2 ameliorates traumatic spinal cord injury via inhibition of GAPDH/Siah1 in a CB2-receptor dependent manner.
“The essential role of GAPDH/Siah1 signaling pathway in the pathogenesis of various injurious conditions such as traumatic spinal cord injury (SCI) has been gradually recognized. However, the drugs targeting this signaling pathway are still lacking.
The endocannabinoid system, including its receptors (CB1 and CB2), act as neuroprotective and immunomodulatory modulators in SCI. WIN55212-2, an agonist for CB1 and CB2 receptors, has been demonstrated with anti-inflammatory and anti-apoptotic effects in multiple neurological diseases. Therefore, the present study aimed to investigate whether WIN55212-2 could promote functional recovery after traumatic SCI via inhibition of the GAPDH/Siah1 signaling.
In conclusion, our study indicates that, WIN55212-2 improves the functional recovery after SCI via inhibition of GAPDH/Siah1 cascades in a CB2 receptor dependent manner, indicative of its therapeutic potential for traumatic SCI or other traumatic conditions.”
An Overview on Medicinal Chemistry of Synthetic and Natural Derivatives of Cannabidiol.
“Cannabidiol (CBD) has been traditionally used in Cannabis-based preparation, however historically, it has received far less interest as a single drug than the other components of Cannabis. Currently, CBD generates considerable interest due to its beneficial neuroprotective, antiepileptic, anxiolytic, antipsychotic, and anti-inflammatory properties. Therefore, the CBD scaffold becomes of increasing interest for medicinal chemists. This review provides an overview of the chemical structure of natural and synthetic CBD derivatives including the molecular targets associated with these compounds. A clear identification of their biological targets has been shown to be still very challenging.” https://www.ncbi.nlm.nih.gov/pubmed/28701957
Neuroprotective Effects of β-Caryophyllene against Dopaminergic Neuron Injury in a Murine Model of Parkinson’s Disease Induced by MPTP.
“Parkinson’s disease (PD) is one of the most common neurodegenerative disorders and is characterized by the loss of dopaminergic neurons in the substantia nigra (SN). Although the causes of PD are not understood, evidence suggests that its pathogenesis is associated with oxidative stress and inflammation. Recent studies have suggested a protective role of the cannabinoid signalling system in PD. β-caryophyllene (BCP) is a natural bicyclic sesquiterpene that is an agonist of the cannabinoid type 2 receptor (CB2R). Previous studies have suggested that BCP exerts prophylactic and/or curative effects against inflammatory bowel disease through its antioxidative and/or anti-inflammatory action. The present study describes the neuroprotective effects of BCP in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced murine model of PD, and we report the results of our investigation of its neuroprotective mechanism in neurons and glial cells. In the murine model, BCP pretreatment ameliorated motor dysfunction, protected against dopaminergic neuronal losses in the SN and striatum, and alleviated MPTP-induced glia activation. Additionally, BCP inhibited the levels of inflammatory cytokines in the nigrostriatal system. The observed neuroprotection and inhibited glia activation were reversed upon treatment with the CB2R selective antagonist AM630, confirming the involvement of the CB2R. These results indicate that BCP acts via multiple neuroprotective mechanisms in our murine model and suggest that BCP may be viewed as a potential treatment and/or preventative agent for PD.” https://www.ncbi.nlm.nih.gov/pubmed/28684694
Endocannabinoid System in Neurodegenerative Disorders.
“Most neurodegenerative disorders (NDDs) are characterized by cognitive impairment and other neurological defects. The definite cause of and pathways underlying the progression of these NDDs are not well defined. Several mechanisms have been proposed to contribute to the development of NDDs. These mechanisms may proceed concurrently or successively, and they differ among cell types at different developmental stages in distinct brain regions. The endocannabinoid system, which involves cannabinoid receptors type 1 (CB1R) and type 2 (CB2R), endogenous cannabinoids and the enzymes that catabolize these compounds, has been shown to contribute to the development of NDDs in several animal models and human studies. In this review, we discuss the functions of the endocannabinoid (EC) system in NDDs and converse the therapeutic efficacy of targeting the endocannabinoid system to rescue NDDs.”
https://www.ncbi.nlm.nih.gov/pubmed/28608560
http://onlinelibrary.wiley.com/doi/10.1111/jnc.14098/abstract
Regulation of human glioblastoma cell death by combined treatment of cannabidiol, γ-radiation and small molecule inhibitors of cell signaling pathways.
“Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. The challenging problem in cancer treatment is to find a way to upregulate radiosensitivity of GBM while protecting neurons and neural stem/progenitor cells in the brain. The goal of the present study was upregulation of the cytotoxic effect of γ-irradiation in GBM by non-psychotropic and non-toxic cannabinoid, cannabidiol (CBD).
We emphasized three main aspects of signaling mechanisms induced by CBD treatment (alone or in combination with γ-irradiation) in human GBM that govern cell death: 1) CBD significantly upregulated the active (phosphorylated) JNK1/2 and MAPK p38 levels with the subsequent downregulation of the active phospho-ERK1/2 and phospho-AKT1 levels. MAPK p38 was one of the main drivers of CBD-induced cell death, while death levels after combined treatment of CBD and radiation were dependent on both MAPK p38 and JNK. Both MAPK p38 and JNK regulate the endogenous TRAIL expression. 2) NF-κB p65-P(Ser536) was not the main target of CBD treatment and this transcription factor was found at high levels in CBD-treated GBM cells. Additional suppression of p65-P(Ser536) levels using specific small molecule inhibitors significantly increased CBD-induced apoptosis. 3) CBD treatment substantially upregulated TNF/TNFR1 and TRAIL/TRAIL-R2 signaling by modulation of both ligand and receptor levels followed by apoptosis.
Our results demonstrate that radiation-induced death in GBM could be enhanced by CBD-mediated signaling in concert with its marginal effects for neural stem/progenitor cells and astrocytes. It will allow selecting efficient targets for sensitization of GBM and overcoming cancer therapy-induced severe adverse sequelae.”
Plastic and Neuroprotective Mechanisms Involved in the Therapeutic Effects of Cannabidiol in Psychiatric Disorders.
“Beneficial effects of cannabidiol (CBD) have been described for a wide range of psychiatric disorders, including anxiety, psychosis, and depression. The mechanisms responsible for these effects, however, are still poorly understood. Similar to clinical antidepressant or atypical antipsychotic drugs, recent findings clearly indicate that CBD, either acutely or repeatedly administered, induces plastic changes. For example, CBD attenuates the decrease in hippocampal neurogenesis and dendrite spines density induced by chronic stress and prevents microglia activation and the decrease in the number of parvalbumin-positive GABA neurons in a pharmacological model of schizophrenia. More recently, it was found that CBD modulates cell fate regulatory pathways such as autophagy and others critical pathways for neuronal survival in neurodegenerative experimental models, suggesting the potential benefit of CBD treatment for psychiatric/cognitive symptoms associated with neurodegeneration. These changes and their possible association with CBD beneficial effects in psychiatric disorders are reviewed here.”
https://www.ncbi.nlm.nih.gov/pubmed/28588483
http://journal.frontiersin.org/article/10.3389/fphar.2017.00269/full
Correlation Between Cannabidiol-Induced Reduction of Infarct Volume and Inflammatory Factors Expression in Ischemic Stroke Model.
“Recent studies demonstrated that cannabidiol had neuroprotective property. There is some evidence about effective role of cannabidiol in reduction of ischemic damages. It has been reported that infarct size is influenced by various factors after MCAO, including inflammatory factors. The aim of the present study was to evaluate the effect of cannabidiol on infarction volume and correlation of infarct size with tumor necrosis factor receptor 1 (TNFR1), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression.
RESULTS:
The present results indicate that in the MCAO-induced cerebral ischemia, administration of cannabidiol (100 and 200 ng/rat) causes a significant reduction in infarction volume in comparison with the vehicle group. Also, there were significant correlations between decrease of regional infarct volume and TNFR1/NF-κB expression.
CONCLUSION:
The results of this study indicate that cannabidiol reduced cerebral infarction possibly through diminishing TNFR1/NF-κB-induced neurotoxicity in transient focal cerebral ischemia.”
Δ9-Tetrahydrocannabinol (THC) and AM 404 protect against cerebral ischaemia in gerbils through a mechanism involving cannabinoid and opioid receptors
“It has been suggested that the endocannabinoid system elicits neuroprotection against excitotoxic brain damage.
In the present study the therapeutic potential of AM 404 on ischaemia-induced neuronal injury was investigated in vivo and compared with that of the classical cannabinoid receptor type 1 (CB1) agonist, Δ9-tetraydrocannabinol (THC), using a model of transient global cerebral ischaemia in the gerbil.
Our findings demonstrate that AM 404 and THC reduce neuronal damage caused by bilateral carotid occlusion in gerbils and that this protection is mediated through an interaction with CB1 and opioid receptors.
Endocannabinoids might form the basis for the development of new neuroprotective drugs useful for the treatment of stroke and other neurodegenerative pathologies.
There is some evidence from experiments with mice that increasing anandamide or 2-arachidonoyl glycerol content may lead to neuroprotection.
Collectively, our data demonstrate that AM 404 and THC protect against neuronal ischaemia-induced injury through a mechanism involving cannabinoid and opioid receptors but not vanilloid receptors.”