In Italy the sale of Cannabis sativa with THC content up to 0,2% (and de facto tolerance up to 0,6%) it's legal. However, the same product also contains CBD, cannabidiol, with other properties and effects.

All this is enshrined in the Italian law number 242, approved in December 2016, which allows the production and marketing of the so-called cannabis light. The same law prevents imports of varieties not included in the European catalog, in order to avoid crossbreeding and hybrids, in particular of some varieties from Switzerland. This allows the use of cannabis in the food sector, cosmetic and textile.

At the same time though, recreational personal use is not allowed, garantendo così un controllo maggiore su questo prodotto tanto soggetto a dibattiti per la sua discussa pericolosità e efficacia. Medical cannabis instead, with a higher THC content, it can only be sold in pharmacies strictly under medical prescription. But let's talk about it and see what is known about cannabinoids so far.

 

The two cannabinoids most present in Cannabis sativa: CBD (cannabidiol) with positive effects on human health and THC (tetraidrocannabinolo) the most psychoactive substance in the plant,

 

Cannabis sativa contains several compounds, but the Δ-tetrahydrocannabinol (THC) it is the one with psychotropic effects, that is, capable of acting on the mind. THC has been identified in 1940, ma è stato sintetizzato chimicamente, isolated and characterized only in 1960. But cannabis contains beyond 60 cannabinoids, and many, such as cannabidiol -CBD-, can modulate the effect of THC.

Cannabinoids are typically lipophilic molecules, e inizialmente si pensava che attraversassero semplicemente le membrane cellulari. Only in 1990 the first cannabinoid receptor was identified, or the molecule that regulates their action on cells.

These receptors, mainly CB1 and CB2, they are the ones who are called into question when a cannabinol molecule enters our body. So what really happens after the stimulation depends on the location of the receptors, which determine the brain areas that will be more subject to the administration of substances.

The image shows the similarity between an Anandamide molecule, a sx, normally present in our brain, and a THC molecule, the cannabinol present in therapeutic cannabis. It is thanks to this similarity that the two molecules can interact with the same cannabinoid receptors, constitutively expressed on our neuronal cells.

But there are also endo-cannabinoids, or cannabinoids that we are able to self-produce, and which normally perform their function in our body, legando anch’essi i recettori CB1 e CB2. Il primo ad essere scoperto è l’anandamide, where "ananda" means "inner bliss", and it is the molecule also present in chocolate.

So never underestimate the powers of a dark chocolate bar!

La funzione principale degli endocannabinoidi è di regolare la neurotrasmissione, thus being able to influence different functions of our nervous system. Some research shows that cannabinoids increase the release of dopamine in the brain's reward center.

The development of neurons, and consequently the regulation of CB1 receptors, it follows some particularly delicate phases, especially during childhood and adolescence, periods in which there is a high synaptic plasticity: or the ability of neurons to form, creare connessioni e stabilizzarsi. Per questo l’utilizzo cronico di Marijuana negli adolescenti è associato a disturbi cognitive e deficit della memoria a breve termine. On the other hand, patients with post-traumatic disorders find the use of cannabis a fairly decisive cure.

It is now known that THC produces significant psychotropic effects and those who use it can experience panic attacks, anxiety and an increased heart rate with hyperventilation. But on the other hand, CBD is able to regulate the metabolism of THC.

Many studies to date highlight the usefulness of cannabis in treating symptoms thanks to its analgesic and calming properties. Experimental studies highlight its usefulness in the treatment of spasms and pain in patients with multiple sclerosis. Other therapeutic indications of cannabis concern the treatment of glaucoma, thanks to its antispasmodic and analgesic activity, the treatment of epilepsy, as an anticonvulsant, and to the treatment of Tourette's syndrome, grazie alla stimolazione dell’appetito e all’effetto rilassante.

 

Very recent and interesting is the discovery of a neuroprotective role of CBD, capable of stimulating the production of BDNF or neurotrophic factor, that is responsible for the regeneration and growth of neurons. Furthermore, a lot of research is looking for other applications for cannabis, such as the treatment of neurological diseases, for example Parkinson's and Alzheimer's, or Huntington's chorea, associated with a dysregulation in the presence of CB1 receptors in the striated nucleus.

The obstacles in ascertaining the effects of cannabis lie in finding an animal model suitable for studying the psychotropic effects of cannabinoids.

It should be emphasized that the anxiolytics currently available on the market, that compete with cannabis are drugs, obviously, with psychotropic effects. Benzodiazepines for example, which are administered as psychiatric drugs, they bind to GABA receptors, a neurotransmitter, limiting its action, and they are not without side effects.

Mentre i farmaci per curare il dolore cronico sono maggiormente analgesici oppioidi (also called narcotics), and morphine belongs to this class of drugs, methadone and codeine, all molecules that work by binding to receptors in the brain and thus blocking the sensation of pain.

Then, although the fight against illegal drugs is good and just, it is good to define what is drug and what is not. La cannabis light, or weakened, constitutes an interesting avenue for the discovery of new therapeutic approaches. Not to mention the advantages in growing cannabis: excellent for soil maintenance, and its use as a textile material and more. It is also important to remember that no cases of death from cannabis overdose have been reported so far.

As we study the biological and pharmacological properties of cannabis, different varieties of this plant could prove to be excellent candidates as suppliers of new drugs against certain diseases.

Whatever the future is, there are still many challenges to overcome before cannabinoids can be considered as drugs. But there are two issues: first of all it would not be a strange event for a revolutionary drug to be extracted from a plant (see morphine, painkiller, e chinina, antimalarico); second, prohibiting and banning it is certainly not the best solution.

 

Sources:

 

Carlini, E. A. (2004). The good and the bad effects of (−) trans-delta-9-tetrahydrocannabinol (Δ9-THC) on humans. Toxicon, 44(4), 461-467.

Baker, D., Pryce, G., Giovannoni, G., & Thompson, A. J. (2003). The therapeutic potential of cannabis. The Lancet Neurology, 2(5), 291-298.