Cannabinoids protect cells from oxidative cell death: a receptor-independent mechanism.

Journal of Pharmacology and Experimental Therapeutics

“Serum is required for the survival and growth of most animal cells. In serum-free medium, B lymphoblastoid cells and fibroblasts die after 2 days.

We report that submicromolar concentrations of Delta(9)-tetrahydrocannabinol (THC), Delta(8)-THC, cannabinol, or cannabidiol, but not WIN 55,212-2, prevented serum-deprived cell death. Delta(9)-THC also synergized with platelet-derived growth factor in activating resting NIH 3T3 fibroblasts.

The cannabinoids‘ growth supportive effect did not correlate with their ability to bind to known cannabinoid receptors and showed no stereoselectivity, suggesting a nonreceptor-mediated pathway.

Direct measurement of oxidative stress revealed that cannabinoids prevented serum-deprived cell death by antioxidation.

The antioxidative property of cannabinoids was confirmed by their ability to antagonize oxidative stress and consequent cell death induced by the retinoid anhydroretinol.

Therefore, cannabinoids act as antioxidants to modulate cell survival and growth of B lymphocytes and fibroblasts.”

http://www.ncbi.nlm.nih.gov/pubmed/10869379/

Synthetic and endogenous cannabinoids protect retinal neurons from AMPA excitotoxicity in vivo, via activation of CB1 receptors: Involvement of PI3K/Akt and MEK/ERK signaling pathways.

“Cannabinoids have been suggested to protect retinal ganglion cells in different models of toxicity…

These results suggest that endogenous and synthetic cannabinoids protect retinal amacrine neurons from AMPA excitotoxicity in vivo via a mechanism involving the CB1 receptors, and the PI3K/Akt and/or MEK/ERK1/2 signaling pathways.”

http://www.ncbi.nlm.nih.gov/pubmed/25989217

Neuroprotective effect of (-)Delta9-tetrahydrocannabinol and cannabidiol in N-methyl-D-aspartate-induced retinal neurotoxicity: involvement of peroxynitrite.

“In glaucoma, the increased release of glutamate is the major cause of retinal ganglion cell death. Cannabinoids have been demonstrated to protect neuron cultures from glutamate-induced death.

In this study, we test the hypothesis that glutamate causes apoptosis of retinal neurons via the excessive formation of peroxynitrite, and that the neuroprotective effect of the psychotropic Delta9-tetrahydroxycannabinol (THC) or nonpsychotropic cannabidiol (CBD) is via the attenuation of this formation.

These results suggest the potential use of CBD as a novel topical therapy for the treatment of glaucoma.

“Cannabinoid components of marijuana, such as (−)Δ9-tetrahydrocannabinol (THC), or the synthetic cannabinoid WIN55,212-2, have been shown to prevent glutamate- or NMDA-induced neurotoxicity in isolated neurons or in the brain via activation of the cannabinoid receptor subtype CB1.

…the nonpsychotropic component of marijuana, cannabidiol (CBD), and the synthetic nonpsychotropic cannabinoid, HU-211, as well as THC have been demonstrated as potent antioxidants and/or NMDA receptor antagonists that protect neuron cultures from glutamate-induced death or from oxidative stress.

… we demonstrated that THC and CBD are neuroprotective against NMDA-induced retinal injury and that their protective actions are in part because of an effect in reducing formation of lipid peroxides, nitrite/nitrate, and nitrotyrosine.

In addition to possessing neuroprotective or retinal neuroprotective activity as demonstrated here and elsewhere, cannabinoids such as THC, WIN55,212-2, endogenous cannabinoid 2-arachidonoylglycerol, as well as nonpsychotropic HU-211 have been demonstrated to induce dose-related reductions in intraocular pressure in human and in animal models.

 This suggests that cannabinoids may offer a multifaceted therapy for glaucoma.

In conclusion, our results indicate that lipid peroxidation and ONOO− formation play an important role in NMDA-induced retinal neurotoxicity and cell loss in the retina, and that THC and CBD, by reducing the formation of these compounds, are effective neuroprotectants.

The present studies could form the basis for the development of new topical therapies for the treatment of glaucoma.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892413/

http://www.thctotalhealthcare.com/category/glaucoma-2/

Activation of cannabinoid 2 receptors protects against cerebral ischemia by inhibiting neutrophil recruitment

Figure 1.

“THE CONSEQUENCES OF ISCHEMIC INJURY in liver, heart, and brain can be ameliorated by cannabinoids, a group of diverse compounds that include constituents of the plant Cannabis sativa (phytocannabinoids), endogenous lipids (endocannabinoids), and synthetic substances. Most of the effects of cannabinoids are mediated by the G-protein-coupled receptors cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2)… 

Cannabinoids protect against ischemic stroke…

Activation of the cannabinoid 2 receptor (CB2) reduces ischemic injury in several organs…

In conclusion, our data demonstrate that by activating p38 in neutrophils, CB2 agonists inhibit neutrophil recruitment to the brain and protect against ischemic brain injury.”

http://www.fasebj.org/content/24/3/788.long

CB1 cannabinoid receptor induction in experimental stroke.

“Cannabinoids protect cortical neurons from ischemic injury by interacting with CB1 receptors. Because a variety of neuroprotective genes are induced in cerebral ischemia, we examined the effect of experimental stroke, produced by 20 minutes of middle cerebral artery occlusion in rats, on CB1 receptor expression.

Western blotting and immunohistochemistry showed that CB1 expression on neurons was increased in the arterial boundary zone of the cortical mantle, beginning by 2 hours and persisting for 72 hours or more after ischemia.

These findings are consistent with a neuroprotective role for endogenous cannabinoid signaling pathways and with a potential therapeutic role in stroke for drugs that activate CB1 receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/10939579