Cannabinoids and Multiple Sclerosis

Previous studies have indicated that cannabinoids can act as potent neuroprotectants in a variety of contexts. Hampson et al found that the two major cannabinoids in cannabis sativa, THC and cannabidiol, demonstrated antioxidant capacity greater than vitamins C and E and comparable to the most powerful laboratory antioxidant available to them. This finding may explain why, independent of cannabinoid receptor CB1 or CB2 activation, these cannabinoids demonstrate neuroprotective and anti-inflammatory properties.

This recent study highlights how CB2 receptor activation demonstrates powerful neuroprotective capacity in the animal model(EAE) of Multiple Sclerosis. (Click here for the news release.) In this study the administration of a CB2 agonist reduced neuron cell death by 50%, a remarkable result but one that is consistent with many other studies. They focused on activation of the CB2 receptor. This receptor plays an important regulatory role in the immune response and is also found in the broad equivalent of immune cells in the CNS: microglia.

The great promise of CB2 agonists is that these are non-psychoactive, thereby allowing a potent therapeutic effect without the patient having to deal with the psychoactive effects of THC, which activates the CB1 receptor. Some may retort that this is not a good thing and there may even be some merit in that because CB1 activation has been found to induce neurogenesis and also demonstrates some neuroprotective properties. However in relation to MS, because CB1 tends to inhibit neuronal activation(retrograde inhibitory transmitter), excessive activation of this receptor may make their symptoms worse. There have now been a number of studies where Multiple Sclerosis patients have been allowed to smoke cannabis. The results have been equivocal but there has been enough evidence that some governments have allowed the smoking of cannabis for those suffering MS. There are now so many studies pointing to the therapeutic of cannabinoids that even a study group in conservative Australia has called for the introduction of medicinal cannabis. Unfortunately there is also strong evidence that smoking marijuana can damage the lungs though there is no evidence of it increasing the risk of lung cancer.

A very important word of warning: women who are pregnant or planning to become pregnant must not smoke marijuana. While the evidence is slight it is sufficient to raise very serious concerns about smoking marijuana during pregnancy.

An important finding in this study is that CB2 agonists inhibited the recruitment of immune cells into the CNS. It may even be the case that this is a critical pre-condition for MS attacks to occur. Further research is required to clarify this issue.

With many studies now demonstrating considerable therapeutic potential for cannabinoids it is time for governments and the medical community to adopt a scientific attitude towards the use of cannabinoids in the treatment of a variety of inflammation related conditions. By way of example, consider this study of THC and cannabidiol in relation to Alzheimers. The results indicated that these cannabinoids not only inhibited production of ACHe, an enzyme targeted by many Alzheimers related drugs, but also played an important role in inhibiting the production of amyloid protein, considered by many to be very important in preventing Alzheimers Disease. In fact this study found that both THC and cannabidiol demonstrated greater efficacy than all the current Alzheimer drug interventions they tested.

Apart from their neuroprotective qualities, various studies have indicated that cannabinoid based therapies may be useful in the following pathologies:

Preventing the complications of diabetes
Allergies
Autoimmune conditions
Cancer treatment, particularly brain tumours.
Neuropathic pain.
Atherosclerosis