Cannabis, weed, grass, hash… a striking variety of names used to describe this well-recognized drug illustrates its popularity. It may be smoked with tobacco, or using bongos in different forms, including hashish. Known for its recreational and medical uses, cannabis still seems to be an intriguing source of natural substances, of a remarkable potential in treating popular diseases. What if nature has hidden a clou to medical development between green leaves of herbs, like Cannabis sativa?
An enormous machinery of chemical synthesis present in plants has created a lot of compounds with potential medical use. Δ-9-tetrahydrocannabinol, for example, despite its difficult chemical name, covers a broad spectrum of action, including psychical and somatic effect of marijuana administration. Why current science is so interested in this widely-used drug, especially when it still remains illegal in a majority of countries? Let’s see.
First therapeutic use of Cannabis sativa plant dates back to 2737 BC, ancient China, with Shen Nong Cesar described as one of the pioneers of its triage. In European medicine, it emerged as a drug in 1839, in O’Shaughnessy’s treatise about antiemetic, appetite stimulating and analgesic properties of Cannabis. In XX century, THC became a key substance in invention of synthetic drugs, e.g. Nabilone and Dronabinnole. (click on the names to see BNF entries for those)
- feeling of relax,
- increased hunger and appetite stimulation,
- dryness in oral cavity,
- tachycardia (increased heart rate),
- sometimes accompanied with a feeling of increased skin temperature
A new kind of brain transmission?
After extensive research on cannabis, scientists discovered new, unknown brain receptors, called Cannabinoid receptor-1 and 2 (you may find them as ‘CB1’ and ‘CB2’ in the literature. In fact, please do explore your favourite application of those here). These intriguing proteins occurred to be engaged in a lot of neuronal, gastrointestinal, immunological processes. They even have been linked to pain modulation mechanisms. However, the evidence in many of these trials is controversial; often promising results in vitro do not give statistically significant results in real life measures. Some scientist reached a conclusion stating that there is indeed a new, cannabinoid “electrical line” in the CNS. It is said to have its own neurotransmitters, called endocannabinoids, and its own neuronal pathways.
Do we have Cannabis inside?
The answer to this, a bit odd, and quite funny question is: Yes. Our neurons have an ability to synthesize molecules very similar to these extracted from the cannabis plant. However, the resemblance is more connected with a spectrum of action exhibited by these compounds, rather than their chemical structure. Our “indigenous” THC is called Anandamide (AEA) and2-Arachidonyloglycerole, if you want to read up on these.
Presence of these constituents is confirmed in:
- Hippocampus (the main structure responsible for memory consolidation), where they seem to have some inhibitory influence in process of memorizing
- Human immune cells are rich in CB-2 receptors
- Dorsal horns of spinal cord, where the pain modulation effects of cannabinoids may be targeted.
- Gastrointestinal tract and Dorsal Vagal Complex (a vomit control centre)
Discovery of cannabinoid-mediated neuronal transmission has opened a new trail in pharmacology, resulting in a development of new drugs, e.g. appetite stimulation (Dronabinol, NIH referral for that purpose) vomit inhibition (Nabilone), and spasticity of muscles (Cannabidiole), they all are based on Cannabis sativa plant, commonly recognized as ‘weed’. It’s worth to notice that Marijuana has a lot of dark sides, too. These include worsening of short time memory, psychical and personality disorders, and obviously, disorganization of family and social life in a consequence of Cannabis overuse and addiction.