Author Archives: David Worrell
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 ]]>
Antiallodynic effect of β-caryophyllene on paclitaxel-induced peripheral neuropathy in mice.
“Painful peripheral neuropathy is a common side effect of paclitaxel (PTX). The use of analgesics is an important component for management of PTX-induced peripheral neuropathy (PINP). However, currently employed analgesics have several side effects and are poorly effective. β-caryophyllene (BCP), a dietary selective CB2 agonist, has shown analgesic effect in neuropathic pain models, but its role in chemotherapy-induced neuropathic pain has not yet been investigated. Herein, we used the mouse model of PINP to show the therapeutic effects of BCP in this neuropathy. Our findings show that BCP effectively attenuated PINP, possibly through CB2-activation in the CNS and posterior inhibition of p38 MAPK/NF-κB activation and cytokine release. Taken together, our results suggest that BCP could be used to attenuate the establishment and/or treat PINP.” https://www.ncbi.nlm.nih.gov/pubmed/28729222 http://www.sciencedirect.com/science/article/pii/S0028390817303465 “β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.” http://www.ncbi.nlm.nih.gov/pubmed/23138934]]>
[Cannabidiol: its use in refractory epilepsies].
“Some epileptic syndromes are characterised by seizures that are difficult to control and are associated to delayed neuropsychomotor development, which results in a deterioration in the patient’s quality of life as well as in that of his or her family.
“Selective CB2 agonists represent an attractive therapeutic strategy for the treatment of a variety of diseases without psychiatric side effects mediated by the CB1 receptor.
We carried out a rational optimization of a black market designer drug SDB-001 that led to the identification of potent and selective CB2 agonists. A 7-methoxy or 7-methylthio substitution at the 3-amidoalkylindoles resulted in potent CB2 antagonists (27 or 28, IC50 = 16-28 nM). Replacement of the amidoalkyls from 3-position to the 2-position of the indole ring dramatically increased the agonist selectivity on the CB2 over CB1 receptor. Particularly, compound 57 displayed a potent agonist activity on the CB2 receptor (EC50 = 114-142 nM) without observable agonist or antagonist activity on the CB1 receptor.
Furthermore, 57 significantly alleviated the clinical symptoms and protected the murine central nervous system from immune damage in an experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis.”
“The endocannabinoid system is thought to modulate nociceptive signaling making it a potential therapeutic target for treating pain.
However, there is evidence that endocannabinoids have both pro- and anti-nociceptive effects. In previous studies using Hirudo verbana (the medicinal leech), endocannabinoids were found to depress nociceptive synapses, but enhance non-nociceptive synapses. Here we examined whether endocannabinoids have similar bidirectional effects on behavioral responses to nociceptive vs. non-nociceptive stimuli in vivo.
These results provide evidence that endocannabinoids can have opposing effects on nociceptive vs. non-nociceptive pathways and suggest that 
“The beta amyloid (Aβ) and other aggregating proteins in the brain increase with age and are frequently found within neurons. The mechanistic relationship between intracellular amyloid, aging and neurodegeneration is not, however, well understood.
We use a proteotoxicity model based upon the inducible expression of Aβ in a human central nervous system nerve cell line to characterize a distinct form of nerve cell death caused by intracellular Aβ. It is shown that intracellular Aβ initiates a toxic inflammatory response leading to the cell’s demise. Aβ induces the expression of multiple proinflammatory genes and an increase in both arachidonic acid and eicosanoids, including prostaglandins that are neuroprotective and leukotrienes that potentiate death.