The Endocannabinoid System as a Window Into Microglial Biology and Its Relationship to Autism.

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Image result for frontiers in cellular neuroscience“Microglia are the resident, innate immune cells of the central nervous system (CNS) and are critical in managing CNS injuries and infections. Microglia also maintain CNS homeostasis by influencing neuronal development, viability, and function. However, aberrant microglial activity and phenotypes are associated with CNS pathology, including autism spectrum disorder (ASD). Thus, improving our knowledge of microglial regulation could provide insights into the maintenance of CNS homeostasis as well as the prevention and treatment of ASD.

Control of microglial activity is in part overseen by small, lipid-derived molecules known as endogenous cannabinoids (endocannabinoids). Endocannabinoids are one component of the endocannabinoid system (ECS), which also includes the enzymes that metabolize these ligands, in addition to cannabinoid receptor 1 (CB1) and 2 (CB2).

Interestingly, increased ECS signaling leads to an anti-inflammatory, neuroprotective phenotype in microglia. Here, we review the literature and propose that ECS signaling represents a largely untapped area for understanding microglial biology and its relationship to ASD, with special attention paid to issues surrounding the use of recreational cannabis (marijuana). We also discuss major questions within the field and suggest directions for future research.”

https://www.ncbi.nlm.nih.gov/pubmed/31619967

“Microglial activity can be modulated by eCB signaling, which makes the ECS a potentially forceful tool in the prevention and management of CNS dysfunction.”

https://www.frontiersin.org/articles/10.3389/fncel.2019.00424/full

Coadministered cannabidiol and clobazam: Preclinical evidence for both pharmacodynamic and pharmacokinetic interactions.

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Epilepsia banner“Cannabidiol (CBD) has been approved by the US Food and Drug Administration (FDA) to treat intractable childhood epilepsies, such as Dravet syndrome and Lennox-Gastaut syndrome. However, the intrinsic anticonvulsant activity of CBD has been questioned due to a pharmacokinetic interaction between CBD and a first-line medication, clobazam. This recognized interaction has led to speculation that the anticonvulsant efficacy of CBD may simply reflect CBD augmenting clobazam exposure. The present study aimed to address the nature of the interaction between CBD and clobazam.

RESULTS:

CBD potently inhibited CYP3A4 mediated metabolism of clobazam and CYP2C19 mediated metabolism of N-CLB. Combination CBD-clobazam treatment resulted in greater anticonvulsant efficacy in Scn1a+/- mice, but only when an anticonvulsant dose of CBD was used. It is important to note that a sub-anticonvulsant dose of CBD did not promote greater anticonvulsant effects despite increasing plasma clobazam concentrations. In addition, we delineated a novel pharmacodynamic mechanism where CBD and clobazam together enhanced inhibitory GABAA receptor activation.

SIGNIFICANCE:

Our study highlights the involvement of both pharmacodynamic and pharmacokinetic interactions between CBD and clobazam that may contribute to its efficacy in Dravet syndrome.”

https://www.ncbi.nlm.nih.gov/pubmed/31625159

“Our results here suggest a novel benefit of CBD and clobazam combination therapy on premature death, a devastating aspect of the Dravet syndrome phenotype.”

https://onlinelibrary.wiley.com/doi/full/10.1111/epi.16355

Cannabis, alcohol and cigarette use during the acute post-concussion period.

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Publication Cover

“Objective: To document the prevalence of acute post-concussion cannabis, alcohol and cigarette use and their association with clinical recovery and symptom burden.

Results: A total of 307 acute concussions with a mean age of 33.7 years (SD, 13.0) were included. Acute post-concussion cannabis, alcohol and cigarette use were identified in 43 (14.0%), 125 (40.7%) and 61 (19.9%) individuals. Acute cannabis, alcohol and cigarette use were not associated with recovery to cognitive (p > .05) or physical activity (p > .05). Acute cigarette use was associated with a higher unadjusted symptom severity score at week1 (p = .003). Acute cannabis use was associated with lower symptom severity scores at week-3 (p = .061) and week-4 (p = .029).

Conclusion: In conclusion, cannabis, alcohol and cigarette use were prevalent in the acute period post-concussion; however, were not observed to impact recovery within the first 4 weeks post-injury. Amongst unrecovered individuals, acute cannabis use was associated with lower symptom burden, while cigarette use was associated with greater initial symptom burden.”

 https://www.ncbi.nlm.nih.gov/pubmed/31621424
https://www.tandfonline.com/doi/abs/10.1080/02699052.2019.1679885?journalCode=ibij20

CLG from Hemp Seed Inhibits LPS-Stimulated Neuroinflammation in BV2 Microglia by Regulating NF-κB and Nrf-2 Pathways.

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Go to Volume 4, Issue 15“The healthy benefits of hemp (Cannabis sativa L.) seed have often been attributed to its oils and proteins.

Recent studies reveal that hemp seed phenylpropionamides could also show various bioactivities. Continuation of our study on hemp seed provided a phenylpropionamide, coumaroylaminobutanol glucopyranoside (CLG). This work investigated the neuroprotective effect of CLG and its underlying mechanism using lipopolysaccharide-induced BV2 microglia.

Our study demonstrated that CLG increased adenosine monophosphate-activated protein kinase (AMPK) expression, suppressed the nuclear factor-kappa B (NF-κB) signaling pathway by inhibiting the phosphorylation of IκBα and NF-κB p65 and decreased proinflammatory cytokine levels in a concentration-dependent manner. Furthermore, CLG reduced the production of cellular reactive oxygen species and stimulated the nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling pathway.

Collectively, these results suggested that CLG effectively and simultaneously inhibited inflammatory responses and oxidative stress through the NF-κB and Nrf-2 signaling pathways. AMPK was also involved in the anti-inflammatory effect of CLG. This study provides new insights into the diverse bioactive constituents of hemp seed.”

https://www.ncbi.nlm.nih.gov/pubmed/31616830

“Hemp (Cannabis sativa L.) seed has been used as food and traditional medicine for centuries. Our findings contribute to the knowledge of diverse bioactive compounds from hemp seed and the potential of hemp seed in the treatment of microglia-related neuroinflammatory diseases.”

https://pubs.acs.org/doi/10.1021/acsomega.9b02168

Modulation of the Endocannabinoid and Oxytocinergic Systems as a Potential Treatment Approach for Social Anxiety Disorder.

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 “Social anxiety disorder (SAD), or social phobia, is one of the most common types of anxiety disorder, with a lifetime prevalence that can reach 15%.

Pharmacological treatments for SAD have moderate efficacy and are associated with significant adverse reactions. Therefore, recent studies have focused on searching for new treatments for this disorder.

Preclinical studies and preliminary evidence in humans suggest that the phytocannabinoid cannabidiol and the neuropeptide oxytocin have anxiolytic effects. In the present text, we review this evidence and its implications for pharmacological treatment.

We conclude that although current available studies show promising results regarding both the safety and efficacy of cannabidiol and oxytocin for the treatment of SAD, most studies were performed using single or few doses of these compounds, with small sample sizes.

Therefore, future studies should explore the anxiolytic potential of these compounds using long-term, placebo-controlled designs with larger samples to elucidate the possible use of these compounds in the treatment of SAD.”

https://www.ncbi.nlm.nih.gov/pubmed/31617149

https://link.springer.com/article/10.1007%2Fs40263-019-00669-5

Cannabinoid effects on responses to quantitative sensory testing among individuals with and without clinical pain: a systematic review.

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Image result for wolters kluwer“There has been an explosion of interest in the utility of cannabinoids as potential analgesics.

This systematic review critically synthesizes the evidence for cannabinoid analgesic effects on quantitative sensory testing outcomes in both healthy adults and patients with chronic non-cancer pain (CNCP).

Our systematic review protocol is pre-registered on PROSPERO (CRD42018117367). An electronic search was made in PsycINFO, Cochrane, Google Scholar, Embase, and Pubmed of all literature published until August 2018. Of the 1,217 studies found from the search, a total 39 placebo-controlled studies that met the eligibility criteria were synthesized for the present study. Due to substantial heterogeneity of study designs, populations, cannabinoid compounds, and quantitative sensory testing outcomes, meta-analysis was not conducted.

More consistent evidence of cannabinoid analgesia was observed for inhaled cannabis than synthetic cannabinoids.

Analgesic effects were most commonly observed in tests of cold pain sensitivity, and hyperalgesic effects were most commonly observed in tests of electrical stimulation. Patterns of findings from studies with healthy subjects did not substantively differ from those with CNCP. However, these observations are qualified by the high degree of inconsistency across studies and methodological heterogeneity. We offer recommendations for future studies to improve study rigor and reproducibility.”

 https://www.ncbi.nlm.nih.gov/pubmed/31613869
https://insights.ovid.com/crossref?an=00006396-900000000-98577

Antitumor Activity of Abnormal Cannabidiol and Its Analog O-1602 in Taxol-Resistant Preclinical Models of Breast Cancer.

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Image result for frontiers in pharmacology“Cannabinoids exhibit anti-inflammatory and antitumorigenic properties.

Contrary to most cannabinoids present in the Cannabis plant, some, such as O-1602 and abnormal cannabidiol, have no or only little affinity to the CB1 or CB2 cannabinoid receptors and instead exert their effects through other receptors.

Here, we investigated whether the synthetic regioisomers of cannabidiol, abnormal cannabidiol, and a closely related compound, O-1602, display antitumorigenic effects in cellular models of breast cancer and whether it could reduce tumorigenesis in vivo.

Several studies have shown the effects of cannabinoids on chemotherapy-sensitive breast cancer cell lines, but less is known about the antitumorigenic effects of cannabinoids in chemotherapy-resistant cell lines.

Paclitaxel-resistant MDA-MB-231 and MCF-7 breast cancer cell lines were used to study the effect of O-1602 and abnormal cannabidiol on viability, apoptosis, and migration. The effects of O-1602 and abnormal cannabidiol on cell viability were completely blocked by the combination of GPR55 and GPR18-specific siRNAs. Both O-1602 and abnormal cannabidiol decreased viability in paclitaxel-resistant breast cancer cells in a concentration-dependent manner through induction of apoptosis. The effect of these cannabinoids on tumor growth in vivo was studied in a zebrafish xenograft model. In this model, treatment with O-1602 and abnormal cannabidiol (2 µM) significantly reduced tumor growth.

Our results suggest that atypical cannabinoids, like O-1602 and abnormal cannabidiol, exert antitumorigenic effects on paclitaxel-resistant breast cancer cells. Due to their lack of central sedation and psychoactive effects, these atypical cannabinoids could represent new leads for the development of additional anticancer treatments when resistance to conventional chemotherapy occurs during the treatment of breast and possibly other cancers.”

https://www.ncbi.nlm.nih.gov/pubmed/31611800

“Our results suggest that some cannabinoids acting through the GPR55 and/or GPR18 receptors can be helpful in inducing apoptosis in breast cancer cell lines that are unresponsive to paclitaxel. The effects of O-1602 and Abn-CBD on cell viability were observed both in vitro and in a zebrafish xenograft model. These drugs were also reducing cell migration. Taken together, even if no synergistic antitumor effect is always observed when cannabinoids and chemotherapeutic agents are combined as an anticancer treatment, cannabinoids can still provide anticancer benefits on top of their palliative effects. This is particularly important in the context of cancers that have developed resistance to current chemotherapies.”

https://www.frontiersin.org/articles/10.3389/fphar.2019.01124/full

Cannabidiol directly targets mitochondria and disturbs calcium homeostasis in acute lymphoblastic leukemia.

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 Image result for cell death & disease“Anticancer properties of non-psychoactive cannabinoid cannabidiol (CBD) have been demonstrated on tumors of different histogenesis. Different molecular targets for CBD were proposed, including cannabinoid receptors and some plasma membrane ion channels. Here we have shown that cell lines derived from acute lymphoblastic leukemia of T lineage (T-ALL), but not resting healthy T cells, are highly sensitive to CBD treatment. CBD effect does not depend on cannabinoid receptors or plasma membrane Ca2+-permeable channels. Instead, CBD directly targets mitochondria and alters their capacity to handle Ca2+. At lethal concentrations, CBD causes mitochondrial Ca2+ overload, stable mitochondrial transition pore formation and cell death. Our results suggest that CBD is an attractive candidate to be included into chemotherapeutic protocols for T-ALL treatment.”

https://www.ncbi.nlm.nih.gov/pubmed/31611561

“Considering the pivotal role of mitochondria in oncogenic re-programming, CBD may be plausible candidate to be included into chemotherapeutic protocols.”

https://www.nature.com/articles/s41419-019-2024-0

Cannabidiol Administration Prevents Hypoxia-Ischemia-Induced Hypomyelination in Newborn Rats.

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Image result for frontiers in pharmacology“Neonatal hypoxia-ischemia (HI) is a risk factor for myelination disturbances, a key factor for cerebral palsy.

Cannabidiol (CBD) protects neurons and glial cells after HI insult in newborn animals.

We hereby aimed to study CBD’s effects on long-lasting HI-induced myelination deficits in newborn rats.

In conclusion, HI injury in newborn rats resulted in long-lasting myelination disturbance, associated with functional impairment. CBD treatment preserved function and myelination, likely as a part of a general neuroprotective effect.”

https://www.ncbi.nlm.nih.gov/pubmed/31611802

“In conclusion, our study confirms that a HI insult in rats at a brain developmental stage equivalent to term infants leads to long-lasting myelination disturbance which is directly related to long-term functional disturbances. The administration of CBD single dose after the neonatal HI insult protects the maturational process of OL cells, as well as the mOL function and relationship with axons, thus, preserving normal myelination and restoring neurobehavioral function. Those results open exciting perspectives regarding a possible role for CBD in NHIE and other demyelinating pediatric conditions.”

https://www.frontiersin.org/articles/10.3389/fphar.2019.01131/full

‘Standard THC Units’: a proposal to standardise dose across all cannabis products and methods of administration.

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Publication cover image“Cannabis products are becoming increasingly diverse, and they vary considerably in concentrations of ∆9 -tetrahydrocannabinol (THC) and cannabidiol (CBD). Higher doses of THC can increase the risk of harm from cannabis, while CBD may partially offset some of these effects. Lower Risk Cannabis Use Guidelines currently lack recommendations based on quantity of use, and could be improved by implementing standard units. However, there is currently no consensus on how units should be measured or standardised across different cannabis products or methods of administration.

ARGUMENT:

Existing proposals for standard cannabis units have been based on specific methods of administration (e.g. joints) and these may not capture other methods including pipes, bongs, blunts, dabbing, vaporizers, vape pens, edibles and liquids. Other proposals (e.g. grams of cannabis) cannot account for heterogeneity in THC concentrations across different cannabis products. Similar to alcohol units, we argue that standard cannabis units should reflect the quantity of active pharmacological constituents (dose of THC). On the basis of experimental and ecological data, public health considerations, and existing policy we propose that a ‘Standard THC Unit’ should be fixed at 5 milligrams of THC for all cannabis products and methods of administration. If supported by sufficient evidence in future, consumption of Standard CBD Units might offer an additional strategy for harm reduction.

CONCLUSIONS:

Standard THC Units can potentially be applied across all cannabis products and methods of administration to guide consumers and promote safer patterns of use.”

https://www.ncbi.nlm.nih.gov/pubmed/31606008

https://onlinelibrary.wiley.com/doi/abs/10.1111/add.14842