Cannabis

Cannabis is a common plant in every tropical and warm area of the world. It's native to Central Asia but has spread all over the world illegally cultivated mainly in North and South America, the Caribbean and southwest Asia.

It is generally classified as Cannabaceae, which is a family composed of Cannabis and Humulus, the genus of Hops. And it is believed that there are three species: C. indica; C. ruderalia; and C. sativa.

Cannabis plants can be either male or female (dioecious) but the female ones are the best cannabinoids producers.

It is traditionally believed that only the plants containing flowers and fruits and cannabis leaves contain big amounts of psychoactive substances (THC - Tetrahydrocannabinol).

There are different ways in which cannabis is processed in order to be used as a drug: marijuana, hashish, hashish oil and Kif.

• Marijuana is a green, brown, or gray mixture of dried, shredded leaves, stems, seeds, and flowers of the hemp plant. It is swallowed or smoked in tightly rolled cigarettes (called joints) or small brass bowled pipes. Street names are: blunt, dope, ganja, grass, herb, joints, Mary Jane, pot, reefer, sinsemilla, skunk, weed

• Hashish is processed marijuana into a concentrated "brick" form. As a result, it contains a higher concentration of THC than unprocessed marijuana. Hashish is found in many colors, ranging from gold to black, typically smoked in a pipe or a water pipe, often combined with marijuana.

Hashish is a resin, obtained from the top leaves of the plant. But even though cannabis plants grow all over the world, most hashish comes from the Near East and other parts of Southern Asia where it has been used for thousands of years. Hashish consists of the THC-rich resinous material of the cannabis plant, which is collected, dried, and then compressed into a variety of forms, such as balls, cakes, or cookie-like sheets. Pieces are then broken off, placed in pipes and smoked.

The fact that hashish is more THC concentrated does not necessarily mean that it's always stronger or of higher quality than marijuana. Certain strains of high quality marijuana may be more potent then certain strains of low quality hashish. Most hashish imported into the United States has been diluted/cut by dealers making it very difficult to obtain high quality hashish.

Street names for hashish are: boom, chronic, gangster, hash, hemp, bammer, gold stamp, afagani, black, shish, blondie, brick, kief, kif, kaff, khaf, Kuti.

• Hashish Oil: “ The term hash oil is used by illicit drug users and dealers, but is a misnomer in suggesting any resemblance to hashish. Hash oil is produced by extracting the cannabinoids from plant material with a solvent. The color and odor of the resulting extract will vary, depending on the type of solvent used. Current samples of hash oil, a viscous liquid ranging from amber to dark brown in colour, average about 15 percent THC. In terms of its psychoactive effect, a drop or two of this liquid on a cigarette is equal to a single "joint" of marijuana.” – (DEA- US Drug Enforcement Administration; http://www.usdoj.gov/dea/concern/hashish_oil.html )

• Kif: is the Moroccan word for marihuana. It is a clean product of cannabis where almost all of the seeds and stem has been removed. Although kif is more readily available and cheaper in Morocco , much more kif is smoked than in the U.S. but much less is actually ingested. The practice of inhaling but not holding the breath might decrease significantly the amount of active principle absorbed. Combination of kif with tobacco would also decrease the amount of cannabis actually ingested

The following chart compares the THC levels in the three typical forms of cannabis:

Marijuana	0.5 – 5 %
Resin	2 – 10 %
Oil	10 – 30%

Marijuana is the most commonly used illicit drug. At least one-third of Americans have used marijuana sometime in their lives.

Its effects are euphoria, slowed thinking and reaction time, confusion, impaired balance and coordination /cough, frequent respiratory infections; impaired memory and learning; increased heart rate, anxiety; panic attacks; tolerance, addiction.

The three most important cannabinoids in forensic Sciences are: Tetra-hydro-cannabinol, cannabinol, cannabidiol (both cannabinol and cannabidiol aren't psychoactive).

The natural brain cannabinoid anandamide functions as a neurotransmitter . Neurotransmitters are chemical messenger molecules that carry signals between neurons.

A neuron has two ends - the axon and the dendrite . A pattern of electrical excitement travels down a neuron from the dendrite to the axon. The axon releases neurotransmitter molecules into the synapse , the space between the axon of one neuron and the dendrite of another neuron. The neurotransmitter molecules travel across the synapse to the receptor molecules on the dendrite of the other neuron.

If the transmitter molecules don't fit the receptors on the dendrite, then nothing happens. But if the neurotransmitter molecules fit or "bind to" the receptor molecules, then that dendrite is excited. A pattern of electrical excitement propagates down that neuron to its axon, where the process of transmitter release and receptor capture repeats itself.

The neurotransmitter serotonin is believed to regulate mood, sleep and learning, and abnormalities in the production of serotonin are believed to be at the root of serious depressive disorders. Prozac works to relieve severe depression by blocking the natural removal of excess serotonin from the spaces between neurons in the brain.

Norepinephine and epinephrine regulate how the heart and vital functions respond to stress. The powerful neurotranmistter dopamine regulates the "reward system" of well being, among other things, and abnormalities in dopamine production in the brain are believed to lie behind Parkinson's disease (not enough dopamine) and schizophrenia (far too much of it)

Another class of neurotransmitters includes GABA, glutamate, glycine and aspartate. Opiates act both as hormones in the endocrine sysyem and as neurotransmitters in the central nervous system. Heroin addiction is believed to happen because the opiate system is very strongly tied to the powerful dopamine system, and heroin binds quite effectively to the natural opiate receptor system.

The brain cannabinoid receptors are called the CB1 receptors. The relative binding density for cannabinoids in the brain has been measured.

The primary regions where cannabinoids bind in the human brain are known as the basal ganglia . The basal ganglia are believed to control unconscious muscle movements. The basal ganglia consist of:

The next region where cannabinoids bind is known as the limbic system . The limbic system believed to be involved in integrating memories and strong emotions such as rage, lust and fear. The limbic system consists of:

Cannabinoids also bind in the cerebellum, the part of the brain that controls balance and the planning of motion. Finally, there is weak cannabinoid binding throughout the cerebral cortex.

Cannabinoids act in general as inhibitory neurotransmitters, meaning that they inhibit processes that other neurotransmitters can stimulate. This is probably why cannabinoids are such effective anti-spasmodic agents. Cannabinoid receptors are very rich in the areas of the brain that control muscle spasms.

In 1991 it was shown that the properties of the cannabinoid receptors in the brain were not irreversibly altered in monkeys given chronic doses of THC and marijuana. This toxicology study shows that marijuana is not a neurotoxin.

A useful tool in the study of a neuroreceptor system is some molecule that prevents the neurotransmitter from binding to the receptor. That way you can figure out what the natural neurotransmitter does by watching what happens when it can't do it any more. A molecule that does this is called a receptor antagonist .

For THC, the cannabinoid synthesized by cannabis sativa and indica, and andandamide, the cannabinoid synthesized in the central nervous systems of most animals on Earth, the receptor antagonist is called SR141716. SR141716 is like "anti-marijuana" -- it enhances the same memory functions that the natural brain cannabinoid anandamide and THC inhibit through the cannabinoid receptor.

SR141716 improves short term memory in rodents by blocking the CB1 cannabinoid receptor from binding to andandamide, not just THC. But anandamide is made by the brain naturally. Why would the brain be making a chemical -- andandamide -- that seems to inhibit short-term memory?
This question is partly answered by the effect of SR141716 on the sleep cycles of rats. SR141716 administered to rats interrupts their sleep cycles, causing a deficit in both short-wave and REM sleep. This research indicates that cannabinoids are important in the brain's regulation of the sleeping process .

The cost of improving short-term memory by blocking cannabinoids from the brain is deficient and delayed slow-wave and REM sleep. In studying marijuana, we have learned something important about the brain. Inhibition of short-term memory-related processes occurring ion the hippocampus might be necessary for a healthy sleep cycle.

A small amount of herbal material is placed on a filter paper and some drops of petroleum ether are added in order to extract the different components. Once the solvent has evaporated the sample is thrown away and the reagent dissolved in distilled water 1% and added. Then it is exposed to ammoniac vapour observing how it turns into purple red. This result is the combination of colours of the different cannabinoids, THC (red) and CBD (yellow) and CBN (violet).

It is important to note that tobacco doesn't interfere or react with the reagent.

Take either a small amount of the material to be analyzed or the extract from the petroleum ether. Add 2 mlof Solution A and agitate for 1 minute. Then add solution B and wait 10 minutes. It will appear to be purple blue that after adding reagent C will become violet.

It will be necessary silicagel G with f-254 fluorescence. As solvents there are various different options but based on experience it is recommended the use of

petroleum ether – ethylic ether (80:20) or benzene - hexane – diethylamine (75:30:5)

The developing reagent is Fast Blue B in distilled water 1% and the following exposure to ammoniac vapour. (Detection limit < 0.5 ug).

Detector: flame ionization detector ( hydrogen, 30 ml per minute, air 300 to 450ml per minute)

Work conditions: Injector's temperature 270ºC, Oven temperature 240-260ºC; detector temperature: 300ºC

Internal Standard: n-tetradekane or other adequate alkanes or adrosterone-a-ene-3,17-dion, dibencilftalate or colestane.