The Science of Cannabis

“You can touch, smell, but not taste the marijuana”.

These were the words spoken by Prof. Clive Page, a King’s college pharmacologist who was chairing the wonderful talk on The Science of Cannabis last night. He was right – I could smell it from the third row.

While many people will be familiar with the psychoactive properties of THC found in cannabis, the talk last night was dealing with the varying medicinal properties of other chemicals produced by the plant.

Watch UCL’s Dr Andrea Sella explain the history and science of cannabis (6 minutes)

Our expert for the evening was the rather aptly named Dr. David Potter, a botanist and magistrate from GW Pharmaceuticals, who is part of the team responsible for last year producing the first legal medicinal product derived from marijuana.

Sativex was licensed in the UK last year for the treatment of spasticity in patients with Multiple Sclerosis, a debilitating and incurable condition that progressively damages the central nervous system.

David talked us through the production stages of the drug, from developing the strain of marijuana required, through the cloning process to ensure constant amounts of the right chemicals, all the way to extraction of the right compounds in order to produce the pure Sativex.

Summing up years of research always makes it sound easier than it was, but thankfully Clive Page was on hand to remind us what a fantastic labour it has been for David and GW to get this drug, an extract containing a variety of different, plant-produced chemicals, to market.

That it is a mixture is precisely why it is such an effective treatment, says David. Sativex is primarily a 1:1 mix of two cannabinoid molecules; THC and the lesser-known CBD, or cannabidiol. It is the combinatory action of these chemicals, as well as with other trace cannabinoids and essential oils from the cannabis, that has a synergistic effect in treating the symptoms of MS. Looking at the clinical trial results (and listening to the MS sufferer in the audience last night), it seems that David is right.

The talk was much more than just a discussion on Sativex; David clearly knows his stuff, as he talked us through the ancient history of cannabis use in man, through the interesting botanical properties of the plant itself, to the medicinal potential of its various chemicals, with pain and even anti-carcinogenic treatments possible in the future.

Throughout the talk, providing comic relief and energetic, hands on chemistry demonstrations were UCL chemist Andrea Sella and KCL material scientist Mark Miodownik. These two hopped from expounding the historical significance of hemp as a fibre, to explaining how cannabis plants protect themselves from insect pests, up to a small-scale demonstration of how they use liquid carbon dioxide to extract the cannabinoids. Several aphids were harmed in the making of this talk, although we’re reliably informed that they started it.

I’m told that last year at the festival this group’s talk on chocolate was very well received (all the more so for handing out free samples, which unsurprisingly wasn’t the case this year). I wasn’t there, but this year’s talk has certainly been my favourite so far. Andrea and Mark have a wonderful rapport, and can easily and entertainingly illustrate abstract chemical concepts. Clive and David obviously have tremendous experience in the pharmacology of marijuana, and together have enlightened me about the remarkable properties of this controversial plant.