Bot 380: Cannabis

How is Cannabis one of the worlds oldest economic plants?

• In the 18th and 19th centuries plantations were established in Missouri, Mississippi and Kentucky

• George Washington grew it in his garden!

• Moved worldwide

What is hemp used for?

• Plant stems: source of fiber, used in rope and canvas cloth

• Seeds: rich in oil, low in psychoactive chemicals, used in soaps, lamp oil and as a paint base

How are the roots vs stems of cannabis used medicinally?

• Leaves and seeds: pain relief, sleep induction, soothing agent for sleep disorders

• Root: gout, ground up and mixed with oil and butter and used as a salve to treat burns

What are the three kinds of cannabis we discuss?

• Cannabis sativa = psychoactive, invigorating and uplifting cerebral effects. Note Cannabis sativa L = hemp

• Cannabis indica = physically sedating, relaxing. Annotated by French naturalist Jean-Baptiste

• Cannabis ruderalis = Rare. Annotated by Russian Botanist D.E Janischevisky.

How many cannabinoids are found in Cannabis? how many are THCs?

114 in Cannabis, 11 are THCs

What class of compounds are cannabinoids?

• Lipid soluble phenolic compounds 

• Also referred to as Terpenophenolics

What is a key feature of cannabis which modifies metabolite content during flower maturation?

Trichomes

What is Nabilone?

Nabilone is a synthetic cannabinoid which mimics THC; it has therapeutic uses for pain relief and anti-nasea

What are the 3 approaches to harvesting cannabinoids?

1. Resin harvesting

2. Harvesting plants with unfertilized flowers

3. Harvesting remaining plant material aside from tops

How is resin harvested from cannabis?

• Several methods; evolved in India

• Pure resin is removed from surfaces of young leaves and flowers; this is very potent and has a high THC content of 7 - 14%

• Called Charas in India and Hashish everywhere else

Why are ufertilized flowers harvested for cannabinoids?

• Male plants are removed before pollen production; female plants are not fertilized → they continue to produce cannabinoids. After fertilization synthesis would decline.

• The female plant then shunts energy into seed production

• Plant material is then dried

What is the THC content of unfertilized flower cannabis?

High grade 4-8% THC content

What is the unferilized flower of cannabis also called?

• Called Ganja in India, Sinsemilla in Mexico and Marijuana in the USA and the rest of the world

What does low grade THC cannabis look like?

• Dried and ground into a powder; Low grade <1% THC content

• Often added to drinks or candies. 

• Used during religious festivals; Holi

• Added to milkshakes

When was THC first isolated?

In 1964 THC was isolated and synthesized

How is THC metabolized when smoked?

• THC is rapidly absorbed into the bloodstream

• First reaches the brain, then redistributed to the rest of the body

• THC is metabolized in the liver

What are the physiological effects of cannabis on the CNS?

• Alters electrical properties of nerve membranes

• Alters turnover rates of serotonin and dopamine

• Affects prostaglandins synthesis

Different derivatives have different binding rates*

What are the ‘optimum effects’ of cannabis?

• Initial effects = mild tension or anxiety

• Followed by pleasant feeling of well being

• User can become introspective and tranquil

• Can experience rapid mood changes; moments of hilarity followed by periods of contemplative silence

What is the dose difference between euphoria and the hallucinogenic effect of cannabis?

Euphoria = 25-50 ug / kilo body weight THC

Hallucinogenic effect = 200-250 ug / kilo body weight THC

What are the two cannabis receptors and their respective characteristics?

CB1 receptors = THC

• Found primarily in the brain and CNS

• Varies with location of brain; highest in basal ganglia

CB2 receptors = CBD

• Found primarily in the PNS organs and immune cells

• Glial cells, spleen, bones and skin

What are the endocannabinoids we discus?

Anandamide

2-Arachidonoylglycerol = 2-AG

What is anadamide?

An endocannabinoid which is an essential fatty acid neurotransmitter derived from the non oxidative metabolism of archidonic acid

What is 2-Arachidonoylglycerol ?

2nd highest endocannabinoid

Endogenous agonist of CB1 receptor

Formed from arachadonic acid + glycerol

High levels across CNS

High in bovine and human milk

How are endocannabinoids formed?

• ECs are formed within neurons and other cell types via multiple biosynthetic pathways

• Not stored, but produced on demand

T/F Ms patiens are deficent in endocannabnoids?

True

Endocannabinoids are deficient in lesions in the motor centres as seen in MS

What is the MOA of cannabinoids?

1. Action potentials are transmitted along the axon to the terminal end feet

2. Presynaptic nt release

3. The action potential is transmitted along neuronal pathways

4. As a consequence of post synaptic depolarization or nt receptor signalling endocannabinoids are released and diffuse across the synapse to bind the presynaptic CB1 receptors

5. These inhibit further nt release

What are the three kinds of glandular trichomes?

Sessile, bulbous and stalked

What metabolic pathways create cannaiboids?

MEP pathway