Cannabis-Based Cannabinoids Showed Neuroprotective Effects in MS Animal Models | Research

The takeaway

Synthetic CBD slowed disability accumulation in a mouse model of relapsing MS, possibly by blocking sodium channels, while low-dose THC slowed clinical progression without suppressing immune attacks.

Read this if you have MS and are interested in whether cannabinoids could slow disease progression beyond symptom relief.

THC slowed progression in MS trial subgroup of rapidly-progressing patients

What the researchers found

Researchers tested cannabis-derived cannabinoids in a mouse model of relapsing-remitting multiple sclerosis (experimental autoimmune encephalomyelitis in ABH mice).

Synthetic CBD slowed the accumulation of disability that occurs during the "inflammatory penumbra" (damage spreading from initial immune attack sites), possibly through blockade of voltage-gated sodium channels rather than through cannabinoid receptors.

Non-sedating doses of THC did not suppress the immune attacks (relapses) themselves but dose-dependently slowed the accumulation of disability between attacks. In a human clinical trial, a planned subgroup analysis of less-disabled MS patients who progressed more rapidly showed significant slowing of progression with oral THC versus placebo.

Why it matters

This study provided both animal and preliminary human evidence that cannabinoids may protect nerve cells during MS. The distinction between suppressing immune attacks (which THC did not do) and slowing disability accumulation (which it did) is critical for understanding how cannabinoids might help.

The numbers in context

Synthetic CBD slowed disability in relapsing EAE; non-sedating THC doses slowed progression dose-dependently; phase III subgroup: significant slowing of progression with oral THC in less-disabled, rapidly-progressing patients

How the study worked

Mouse studies using experimental autoimmune encephalomyelitis (EAE) model with synthetic CBD and THC. Also reported results from a subgroup analysis of a 3-year phase III clinical trial of oral THC in progressive MS.

What this study cannot tell us

Mouse model does not fully replicate human MS. The human clinical trial subgroup analysis was planned but not the primary outcome. CBD mechanism (sodium channel blockade) was suggested but not confirmed. THC doses that protect without sedation may be difficult to achieve clinically.

How to read the evidence

Animal studies plus a subgroup analysis from a phase III trial. Suggestive but not definitive evidence for neuroprotection.

When this study was published

Published in 2015. Further clinical trials investigating cannabinoid neuroprotection in MS are ongoing.

The bigger picture

If confirmed, neuroprotection by cannabinoids could complement existing MS therapies that target the immune system. Current treatments primarily reduce relapses but do not effectively prevent progressive disability. Cannabinoids might fill this gap.

Questions still open

Can the neuroprotective effects be confirmed in a dedicated clinical trial? Would CBD's sodium channel blockade be more practical than THC for MS neuroprotection? Could CBD and THC be combined for additive neuroprotective effects?

Common questions

Can CBD protect nerves in MS?

In this mouse model, synthetic CBD slowed the accumulation of disability, possibly by blocking sodium channels that contribute to nerve damage. Human clinical evidence for CBD neuroprotection in MS has not been established.

Did the clinical trial show THC helps MS?

The overall trial did not detect a benefit, but a planned subgroup analysis of less-disabled patients who were progressing faster showed significant slowing of progression with oral THC. A dedicated trial would be needed to confirm this finding.

Read the original research

Neuroprotection in Experimental Autoimmune Encephalomyelitis and Progressive Multiple Sclerosis by Cannabis-Based Cannabinoids.

Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 10(2), 281-92

View on PubMed ↗Publisher’s paper ↗

Citation

Pryce, Gareth; Riddall, Dieter R; Selwood, David L; Giovannoni, Gavin; Baker, David. (2015). Neuroprotection in Experimental Autoimmune Encephalomyelitis and Progressive Multiple Sclerosis by Cannabis-Based Cannabinoids.. Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 10(2), 281-92. https://doi.org/10.1007/s11481-014-9575-8