Excess cerebral TNF causing glutamate excitotoxicity rationalizes treatment of neurodegenerative diseases and neurogenic pain by anti-TNF agents.

Image result for J Neuroinflammation.

“The basic mechanism of the major neurodegenerative diseases, including neurogenic pain, needs to be agreed upon before rational treatments can be determined, but this knowledge is still in a state of flux. Most have agreed for decades that these disease states, both infectious and non-infectious, share arguments incriminating excitotoxicity induced by excessive extracellular cerebral glutamate.

Excess cerebral levels of tumor necrosis factor (TNF) are also documented in the same group of disease states.

Here, we link the two, collecting and arguing the evidence that, across the range of neurodegenerative diseases, excessive TNF harms the central nervous system largely through causing extracellular glutamate to accumulate to levels high enough to inhibit synaptic activity or kill neurons and therefore their associated synapses as well.

TNF can be predicted from the broader literature to cause this glutamate accumulation not only by increasing glutamate production by enhancing glutaminase, but in addition simultaneously reducing glutamate clearance by inhibiting re-uptake proteins.

We also discuss the effects of a TNF receptor biological fusion protein (etanercept) and the indirect anti-TNF agents dithio-thalidomides, nilotinab, and cannabinoids on these neurological conditions. The therapeutic effects of 6-diazo-5-oxo-norleucine, ceptriaxone, and riluzole, agents unrelated to TNF but which either inhibit glutaminase or enhance re-uptake proteins, but do not do both, as would anti-TNF agents, are also discussed in this context.

By pointing to excess extracellular glutamate as the target, these arguments greatly strengthen the case, put now for many years, to test appropriately delivered ant-TNF agents to treat neurodegenerative diseases in randomly controlled trials.”

http://www.ncbi.nlm.nih.gov/pubmed/27596607

Protection against septic shock and suppression of tumor necrosis factor alpha and nitric oxide production by dexanabinol (HU-211), a nonpsychotropic cannabinoid.

Image result for J Pharmacol Exp Ther

“Dexanabinol, HU-211, a synthetic cannabinoid devoid of psychotropic effects, improves neurological outcome in models of brain trauma, ischemia and meningitis.

Recently, HU-211 was found to inhibit brain tumor necrosis factor (TNFalpha) production after head injury. In the present study, we demonstrate the ability of HU-211 to suppress TNFalpha production and to rescue mice and rats from endotoxic shock after LPS (Escherichia coli 055:B5) inoculation.

Administration of LPS to Sprague-Dawley rats resulted in a 30% reduction in the mean arterial blood pressure within 30 min, which persisted for 3 hr. HU-211, given 2 to 3 min before LPS, completely abolished the typical hypotensive response. Furthermore, the drug also markedly suppressed in vitro TNFalpha production and nitric oxide generation (by >90%) by both murine peritoneal macrophages and rat alveolar macrophage cell line exposed to LPS.

HU-211 may, therefore, have therapeutic implications in the treatment of TNFalpha-mediated pathologies.”

http://www.ncbi.nlm.nih.gov/pubmed/9353414

2-Arachidonylglycerol, an endogenous cannabinoid, inhibits tumor necrosis factor-alpha production in murine macrophages, and in mice.

Image result for Eur J Pharmacol.

“2-Arachidonylglycerol (2-AG) inhibits the production in vitro of tumor necrosis factor-alpha (TNF-alpha) by mouse macrophages, as well as in mice. It has no effect on the production of nitric oxide (NO). The effect on TNF-alpha is enhanced when 2-AG is administered together with 2-linoleylglycerol (2-Lino-G) and 2-palmitylglycerol (2-PalmG), an ‘entourage effect’ previously noted in several behavioral and binding assays. 2-AG also suppresses the formation of radical oxygen intermediates.”