How do stupendous cannabinoids modulate memory processing via affecting neurotransmitter systems?

Novel pyrrole based CB2 agonists: New insights on CB2 receptor role in regulating neurotransmitters' tone

The cannabinoid system is one of the most investigated neuromodulatory systems because of its involvement in multiple pathologies such as cancer, inflammation, and psychiatric diseases. Recently, the CB2 receptor has gained increased attention considering its crucial role in modulating neuroinflammation in several pathological conditions like neurodegenerative diseases. Here we describe the rational design of pyrrole-based analogues, which led to a potent and pharmacokinetically suitable CB2 full agonist particularly effective in improving cognitive functions in a scopolamine-induced amnesia murine model. Therefore, we extended our study by investigating the interconnection between CB2 activation and neurotransmission in this experimental paradigm. To this purpose, we performed a MALDI imaging analysis on mice brains, observing that the administration of our lead compound was able to revert the effect of scopolamine on different neurotransmitter tones, such as acetylcholine, serotonin, and GABA, shedding light on important networks not fully explored, so far.

Novel Dual-Acting Hybrids Targeting Type-2 Cannabinoid Receptors and Cholinesterase Activity Show Neuroprotective Effects In Vitro and Amelioration of Cognitive Impairment In Vivo

Alzheimer's disease (AD) is a neurodegenerative form of dementia characterized by the loss of synapses and a progressive decline in cognitive abilities. Among current treatments for AD, acetylcholinesterase (AChE) inhibitors have efficacy limited to symptom relief, with significant side effects and poor compliance. Pharmacological agents that modulate the activity of type-2 cannabinoid receptors (CB2R) of the endocannabinoid system by activating or blocking them have also been shown to be effective against neuroinflammation. Herein, we describe the design, synthesis, and pharmacological effects in vitro and in vivo of dual-acting compounds that inhibit AChE and butyrylcholinesterase (BChE) and target CB2R. Within the investigated series, compound 4g proved to be the most promising. It achieved IC50 values in the low micromolar to submicromolar range against both human cholinesterase isoforms while antagonizing CB2R with Ki of 31 nM. Interestingly, 4g showed neuroprotective effects on the SH-SY5Y cell line thanks to its ability to prevent oxidative stress-induced cell toxicity and reverse scopolamine-induced amnesia in the Y-maze forced alternation test in vivo.

Interplay Between Astroglial Endocannabinoid System and the Cognitive Dysfunction in Alzheimer's Disease

Cannabinoid CB1 receptors have been shown to regulate wide array of functions ranging from homeostasis to the cognitive functioning but recent data support the hypothesis that astrocytes also operate as a mediator of synaptic plasticity and contribute to cognition and learning. The receptor heterogeneity plays a key role in understanding the molecular mechanisms underlying these processes. Despite the fact that the majority of CB1 receptors act on neurons, studies have revealed that cannabinoids have direct control over astrocytes, including energy generation and neuroprotection. The tripartite synapse connects astrocytes to neurons and allows them to interact with one another and the astrocytes are key players in synaptic plasticity, which is associated with cognitive functions. This review focuses on our growing understanding of the intricate functions of astroglial CB1 that underpin physiological brain function, and in Alzheimer's disease.

Behavioral, biochemical and histopathological toxic profiles induced by sub-chronic cannabimimetic WIN55, 212-2 administration in mice

WIN55, 212-2 mesylate is a synthetic cannabinoid (SC) agonist of CB1 and CB2 receptors with much higher affinity to CB1 receptor than tetrahydrocannabinol and many potential therapeutic effects. Few studies have evaluated SCs effects on more complex animal behavior and sex differences in cannabinoids toxicology. The current study was undertaken for determination of behavioral (Open Field test), biochemical (liver and kidney function test plus GABA & Glutamate levels), histopathological and CB1 immunohistochemistry risks of sub-chronic administration of SC WIN55, 212-2 mesylate in male and female mice. A total of 40 healthy adult mice were randomly divided into four groups (5 mice each): a negative control group, a vehicle group, a low dose (0.05 mg/kg) group and a high dose group (0.1 mg/kg) for each gender.Open Field Test revealed dose and gender-dependent anxiogenic effect with reduced locomotor activity in both sexes especially the higher doses with female mice being less compromised. GABA and glutamate levels increased significantly in both dose groups compared to controls alongside female mice versus males. No significant biochemical alterations were found in all groups with minimal histopathological changes. The CB1 receptors immunohistochemistry revealed a significant increase in the number of CB1 positive neurons in both low and high dose groups against controls with higher expression in female brains.ConclusionsThere were sexual dimorphism effects induced by sub-chronic exposure to WIN55, 212-2 with lesser female mice affection and dose-dependent influences.

Polycyclic aromatic hydrocarbons exposure was associated with microRNA differential expression and neurotransmitter changes: a cross-sectional study in coal miners

Exposure to polycyclic aromatic hydrocarbons (PAHs) may cause neurobehavioral changes. This study aimed to explore the underlying mechanism of PAH neurotoxicity in coal miners. Urinary PAH metabolites, neurotransmitters, and oxidative stress biomarkers of 652 coal miners were examined. Subjects were divided into high and low-exposure groups based on the median of total urinary PAH metabolites. Differentially expressed miRNAs were screened from 5 samples in the low-exposure group (≤ 4.88 μmol/mol Cr) and 5 samples in the high-exposure group (> 4.88 μmol/mol Cr) using microarray technology, followed by bioinformatics analysis of the potential molecular functions of miRNA target genes. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to validate differentially expressed miRNAs. Restricted cubic splines (RCS) were applied to assess the possible dose-response relationships. Compared to the low PAH exposure group, the high-exposure group had higher levels of 5-hydroxytryptamine (5-HT), epinephrine (E), and acetylcholine (ACh), and lower levels of acetylcholinesterase (AChE). 1-OHP had a dose-response relationship with malondialdehyde (MDA), dopamine (DA), 5-HT, and AChE (P for overall associations < 0.05). There were 19 differentially expressed microRNAs in microarray analysis, significantly enriched in the cell membrane, molecular binding to regulate transcription, and several signaling pathways such as PI3K-Akt. And in the validation stage, miR-885-5p, miR-20a-5p, and let-7i-3p showed differences in the low and high-exposure groups (P < 0.05). Changes in neurotransmitters and microRNA expression levels among the coal miners were associated with PAH exposure. Their biological functions are mainly related to the transcriptional regulation of nervous system diseases or signaling pathways of disorders. These findings provide new insights for future research of PAH neurotoxicity.

Endocannabinoids and addiction memory: Relevance to methamphetamine/morphine abuse

AIM

This review aims to summarise the role of endocannabinoid system (ECS), incluing cannabinoid receptors and their endogenous lipid ligands in the modulation of methamphetamine (METH)/morphine-induced memory impairments.

METHODS

Here, we utilized the results from researches which have investigated regulatory role of ECS (including cannabinoid receptor agonists and antagonists) on METH/morphine-induced memory impairments.

RESULTS

Among the neurotransmitters, glutamate and dopamine seem to play a critical role in association with the ECS to heal the drug-induced memory damages. Also, the amygdala, hippocampus, and prefrontal cortex are three important brain regions that participate in both drug addiction and memory task processes, and endocannabinoid neurotransmission have been investigated.

CONCLUSION

ECS can be regarded as a treatment for the side effects of METH and morphine, and their memory-impairing effects.

Cannabinoid CB2 Receptors in Neurodegenerative Proteinopathies: New Insights and Therapeutic Potential

Some of the most prevalent neurodegenerative disorders, including Alzheimer's and Parkinson's disease, are proteinopathies characterized by the accumulation of specific protein aggregates in the brain. Such misfolded protein aggregates can trigger modulation of the innate and adaptive immune systems and subsequently lead to chronic neuroinflammation that drives the onset and progression of neurodegenerative diseases. Since there is still no effective disease-modifying treatment, new therapeutic targets for neurodegenerative proteinopathies have been sought. The endocannabinoid system, and in particular the cannabinoid CB2 receptors, have been extensively studied, due to their important role in neuroinflammation, especially in microglial cells. Several studies have shown promising effects of CB2 receptor activation on reducing protein aggregation-based pathology as well as on attenuating inflammation and several dementia-related symptoms. In this review, we discuss the available data on the role of CB2 receptors in neuroinflammation and the potential benefits and limitations of specific agonists of these receptors in the therapy of neurodegenerative proteinopathies.

Endocannabinoid Modulation in Neurodegenerative Diseases: In Pursuit of Certainty

Simple Summary

Neurodegenerative diseases represent an important cause of morbidity and mortality worldwide. Existing therapeutic options are limited and focus mostly on improving symptoms and reducing exacerbations. The endocannabinoid system is involved in the pathophysiology of such disorders, an idea which has been highlighted by recent scientific work. The current work focusses its attention on the importance and implications of this system and its synthetic and natural ligands in disorders such as Alzheimer’s, Parkinson’s, Huntington’s and multiple sclerosis.

Abstract

Neurodegenerative diseases are an increasing cause of global morbidity and mortality. They occur in the central nervous system (CNS) and lead to functional and mental impairment due to loss of neurons. Recent evidence highlights the link between neurodegenerative and inflammatory diseases of the CNS. These are typically associated with several neurological disorders. These diseases have fundamental differences regarding their underlying physiology and clinical manifestations, although there are aspects that overlap. The endocannabinoid system (ECS) is comprised of receptors (type-1 (CB1R) and type-2 (CB2R) cannabinoid-receptors, as well as transient receptor potential vanilloid 1 (TRPV1)), endogenous ligands and enzymes that synthesize and degrade endocannabinoids (ECBs). Recent studies revealed the involvement of the ECS in different pathological aspects of these neurodegenerative disorders. The present review will explore the roles of cannabinoid receptors (CBRs) and pharmacological agents that modulate CBRs or ECS activity with reference to Alzheimer’s Disease (AD), Parkinson’s Disease (PD), Huntington’s Disease (HD) and multiple sclerosis (MS).

Analysis of the therapeutic effect of Dimu Ningshen (TCM formula) on attention deficit hyperactivity disorder based on gut microbiota and serum metabolomics

Background

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder diagnosed during adolescence and adulthood. Assessment of the long-term risks of the current drugs for ADHD treatment has been insufficient, and little is known concerning the long-term therapeutic effects of psychostimulants. Commercially available traditional Chinese medicine compound oral preparations [e.g., Dimu Ningshen (DMNS)] have been widely used in the clinical treatment of ADHD, but their influence on the interaction between gut microbes and potential metabolomes remains inconclusive.

Methods

We used a series of behavioral experiments to evaluate the behavioral effects of DMNS on adolescent and adult ADHD rats and used 16S rDNA sequencing of gut microbes and nontarget metabolomics to evaluate the potential pathogenesis of ADHD and explore the biological mechanism of DMNS in ADHD treatment.

Results

For the first time, DMNS was shown to reduce the excessive activity of adult and adolescent ADHD rats and improve the attention deficit of adult ADHD rats. DMNS improved the structural composition of the ADHD gut microbiota and reduced the abundance of Ruminococcaceae_NK4A214_group, Ruminococcus_2, and Eubacterium_nodatum_group. Simultaneously, DMNS increased the circulating levels of peripheral monoamine neurotransmitter precursors (e.g., phenylalanine) and reduced the circulating levels of peripheral fatty acid amides (e.g., oleamide). Finally, the changes in the ADHD serum metabolites were strongly correlated with the gut microbiota.

Conclusion

DMNS has a good effect in treating ADHD, and it may exert this effect by regulating the gut microbiota and affecting metabolites in the peripheral circulation.

Cannabinoids and sleep-wake cycle: The potential role of serotonin

Cannabis sativa (Marijuana) has a long history as a medicinal plant and Δ9-tetrahydrocannabinol (Δ9-THC) is the most active component in this plant. Cannabinoids are interesting compounds with various modulatory effects on physiological processes and cognitive functions. The use of cannabinoids is a double-edged sword, because they induce both adverse and therapeutic properties. One of the most important roles of cannabinoids is modulating sleep-wake cycle. Sleep, its cycle, and its mechanism are highly unknown. Also, the effects of cannabinoids on sleep-wake cycle are so inconsistent. Thus, understanding the role of cannabinoids in modulating sleep-wake cycle is a critical scientific goal. Cannabinoids interact with many neurotransmitter systems. In this review article, we chose serotonin due to its important role in regulating sleep-wake cycle. We found that the interaction between cannabinoids and serotonergic signaling especially in the dorsal raphe is extensive, unknown, and controversial.