The science behind Marijuana

31 March 2016

The first brief in this series considered the case of a couple being prosecuted for the production and use of marijuana. This brief focuses on the science effects of marijuana.

Introduction

Marijuana is known by many names such as Cannabis, Ganga, Hemp, Durban Poison and Swazi Gold, Cannabis. It has been used for a very long time. Archaeology dates it back to about 3000 BC. In Siberia charred seeds have been found inside burial mounds [1].

In 1970 the United States Federal Government classified marijuana as a Schedule I drug (a dangerous substance with no valid medical purpose and a high potential for abuse). It was classified in the same category as heroin [2]. However, in 23 States as well as the District of Columbia the use of marijuana is now legalised for some medical purposes and a majority of the Americans are in favour for legalization for recreational use [3]. Uruguay and Portugal have also changed its legislation in favour of legalising of marijuana [4]. Israel, Canada and the Netherlands have medical marijuana programs [5]. A number of other countries have taken the more liberalized view on marijuana.

The science behind marijuana

There are three main types of marijuana: Cannibis Sativa, Cannibis Indica and Cannabis Ruderalis. Cannibis is a dioceious plant in nature which means that it forms into distinct colonies of male and female plants [6].

Cannibis Sativa [7]:

This is the most common type of cannabis species and is a very large plant which can grow from anything between 2-6 meters in height. It does not have particularly dense foliage. The leaves of Sativa are delicate and have smooth seeds without any marbling or flecks. This type of Cannabis takes a long time to flower and is less affected by changes in light cycles. Sativa is usually found in India, Thailand, Nigeria, Mexico and Colombia.

Sativa it is usually dried, cured and processed into a low-moisture herb for consumption. Sativa is more commonly used for getting users high rather than stoned. What this means it that it has a more stimulating than calming effect. Sativa has a high THC [8] to CBN [9] ratio and is therefore less likely to be suggested for medicinal purposes. It has been used for Ayurvedic medicine.

It is worth distinguishing the uses of seeds, leaves and resin of the cannabis plant. A seed is produced by the genes used from both female and male plants, unless it is produced by a hermaphrodite plant (see below) [10]. The fairly hardy plant is grown from seed [11]. The leaf is the part that is usually dried and smoked or taken in other forms. Resin is formed from the trichomes which are little buds on the cannabis plant which protect of the plant from predators. It is used for hashish which uses the aromatic sugar like oil i.e the resin to make it [12].

Cannabis Indica [13]:

This type of cannabis is denser than Sativa and is much shorter than Sativa measuring between 1-3 meters tall. The foliage of the tree is lush and the leaves are rounder and more robust. These leaves are more jagged and angular in appearance. The flowering of the Indica plant is more rapid and the plant is more susceptible to changes in light that induce flowering. The Indica plant is commonly found in Nepal, Lebanon, Morocco and Afghanistan.

Compared to Sativa the Indica flowers and buds are much closer to each other and are very sticky and resinous. Indica is also usually used to make Hashish due to its high volume of resin. Indica is the type of cannabis that gives the effect of the stoned feel. This is due to the high amounts of CBN in the plant.

Cannabis Ruderalis [14]:

This is the least well known from of cannabis and is extremely short in relation to the other two types. It measures between 30-60 centimeters in height. Ruderalis has very thick foliage and very fast flowering cycle. Ruderalis is not very psychotropic and is used primarily as a genetic material by breeders and cultivators. This type of cannabis ensures that hybrids which flower early can be bred and cultivated.

Reproduction

Male cannabis plants [15]:

The male cannabis plant, once mature, flowers process occurs all across the plant. Short flower stalks known as racemes are formed on the base of the flower itself. As the flower opens the plant releases a load of airborne pollen which is then absorbed by the pistil [16] of female plant. This is how the fertilisation of a cannabis plant occurs and it is usually that the male plant has earlier sexual development.

Female Cannabis plants [17]

The female cannabis plants also produces racemes. The female plant has a combination of tiny pistils and calices [18]. In each of the calices there is an ovule which receives the pollen from the male plant. When the grains of pollen stick to the pistil stalk it then pushes into the calyx which then fertilizes the plant. The calyx itself is also the site where cannabis seeds grow after fertilisation.

Hermaphrodite Cannabis Plants [19]

This type of cannabis plants is rare. These plants have both male and female sex organs and therefore are able to fertilize themselves. This type of plant is useful for breeding. The pollen from this plant is useful. Some growers collect it because even though it is supposed to belong to the male part of reproduction, the pollen from this plant is female and will produce female flowers.

Hybrids [20]:

Hybrids results from the cross-pollination of the different types of cannabis. Hybrids mix different characteristics such as different flowering cycles, yield, CBN: THC ratio and disease resistance. The hybrids are basically a composition or combination of the positive characteristics of the different strains together.

Semsimilla [21]

This is the unpollinated female plant and it is used to produce more cannaboids and buds. This type of plant has more sugar, THC and much denser odorous flowers. It is ideal for the medicinal purposes, especially for those patients who are in need of the active ingredient.

Local types of Marijuana

There are predominantly three different strains grown locally, these are Swazi Skunk, Durban Poison and Rooibaard. Swazi Skunk [22] is derived from breeders in Swaziland and has been exclusively inbred. It is the Sativa type of marijuana and has a very potent seedless bud with a strong cigar odour. Swazi skunk is essentially a Sativa Strain. This variety grows between 4-6 feet indoors and up to 14 feet outdoors. The height depends on the conditions and growing time. There are a lot of branches with extensive large, slim leaves and compact sticky buds covered in hair and visible resin glands.

Durban Poison is one of the very few unadultered sativas which is currently sold locally. It has been described as an original landrace strain [23]. A Landrace strain is a local variety of cannabis that has adapted to the environment of its geographic location [24].

Rooibaard also known as Swazi Red is the third of the local brands and is also a landrace strain. It belongs to the Sativa type of marijuana. It is brownish green with red hairs and smells very earthy and herbal [25]. The effect of this strain is a ‘head high’ and will have a person lost in their racing thoughts [26].

Studies showing the physical effects of cannabis

A study conducted by Dr Manuel Guzman [27] investigated whether cannaboids can cure cancer. The active components of cannabis and their derivatives are useful in exerting palliative effects in cancer patients in preventing nausea, vomiting and pain by stimulating appetite [28]. These compounds inhibit the growth of tumour cells in laboratory animals such as mice and rats [29]. At the moment there is no solid evidence to prove that cannabinoids –whether natural or synthetic- can effectively treat cancer in patients, although research is ongoing around the world [30]. To date all the research done on cannaboids and curing of cancer has been using cancer cells which have been grown in a lab or in infected animals.

The following are some of the effects cited by the study of cannabis on the cancer cells [31]:

- Triggering of apoptosis (death of cancer cells)

- Inhibiting cells from dividing

- Preventing new blood vessels from growing into tumour

- Reducing the metastasized rate of the cells by stopping cells from moving or invading neighbouring tissue.

- Speeding up autophagy (the cell’s internal waste disposal system).

The study concluded that cannaboids are efficacious to at least treat some types of cancer in a laboratory setting. Phase 1 clinical trials to tests the efficacy of cannaboids on humans have begun [32].

Although we are awaiting the results of these studies relating to cancer we have had evidence of other studies which show that cannabis is useful for other diseases such as multiple sclerosis, arthritis, severe nausea and seizures [33].

Clinical studies are difficult to conduct on marijuana as there are a series of barriers such as research funds are limited and regulation is heavy[34]. It has been stated that Marijuana is useful predominantly for relief of symptoms as opposed to cure. [35].

A study conducted by the Medical Research Council (MRC) [36] conducted a survey of findings on the medicinal use of cannaboids. The results of this study were similar to that conducted by Guzman in that the medicinal use of cannaboids was found to [37]:

- Alleviate nausea and vomiting due to chemotherapy

- Stimulate appetite in HIV/AIDS patients

- Chronic pain

- Spasticity due to MS paraplegia

- Glaucoma

This is not a closed list and the evidence given by the trial participants for each category was rated. There was moderate evidence used to support the use of cannaboids in the treatment of chronic pain. There was moderate evidence supplied that the use of cannaboids reduces the spasticity in Multiple Sclerosis patients [38].

The study furthermore revealed that there existed very low evidence to suggest that cannaboids reduce the nausea and vomiting of in HIV infected patients and that it reduces the intra ocular pressure in patients with glaucoma [39].

In some countries there have been medicines containing cannaboids. These medicines are dronabinol, nabilone capsules and oral nabiximol sprays [40].

There needs to be more studies conducted to prove that cannabis is efficacious to patients who use it if the decriminalisation is to occur for marijuana. Extraction from plants, quality standardization, dosage and use will all be issues.

Recreational use

The social harms of smoking, eating, drinking or inhaling [41] of marijuana could include dropping out of school, legal issues and delinquency to name a few. Those who become dependent on it become less motivated, could go into depression etc. [42]

The physical harm of marijuana use is that the THC in the marijuana over activates certain brain receptors. This results in altered sense, changes in mood, impaired body movement, difficulty with thinking and problem solving as well as impaired memory and learning [43]. Breathing illnesses, possible harm to a foetus’s brain in pregnant users, hallucinations and paranoia are also other physical harms caused by the smoking of marijuana [44].

There are long term and short term effects of marijuana [45]. The short term effects of marijuana are as follows and are not limited to this list:

- Sensory distortion

- Panic

- Anxiety

- Poor coordination of movement

- Lowered reaction time

- After an initial “up,” the user feels sleepy or depressed 

- Increased heartbeat (and risk of heart attack

The long term effects of marijuana are as follows:

- Reduced resistance to common illnesses (colds, bronchitis, etc.)

- Suppression of the immune system

- Growth disorders

- Increase of abnormally structured cells in the body

- Reduction of male sex hormones

- Rapid destruction of lung fibers and lesions (injuries) to the brain could be permanent

- Reduced sexual capacity

- Study difficulties: reduced ability to learn and retain information

- Apathy, drowsiness, lack of motivation

- Personality and mood changes

- Inability to understand things clearly

Even though the following harms have been cited this does not detract from the use of other recreational drugs. In terms of harm to self and harm to others, cannabis has been rated as number eight on a list, and less harmful than either alcohol or tobacco. It imposes more harm on the user than to others [46].

It is a choice of the user in the case of marijuana as to subject them to the risk of such a drug. However marijuana, unlike other drugs, mostly gives the user a high or stoned feeling. The majority of users just want to sit down on the couch and “chill”. It does not create aggression. If legalised, it can have great benefits for recreational users and patients who use it for medical purposes.

Conclusion

Marijuana is not the serious threat that most governments want us to believe. There are legalized drugs that cause more harm than marijuana, such as alcohol and tobacco. One estimate is that over 158 million people around the world use marijuana [47]. There are social and physical side effects, particularly among adolescents and pregnant women [48]. But, the science shows that marijuana can be mixed in various quantities to achieve a certain desired result. Legalizing and regulation is preferable to a black market.

Issued Arvitha Doodnath, Legal Researcher, Helen Suzman Foundation, 31 March 2016