Cannabinoids may cause antitumor effects by various mechanisms, including induction of cell death, inhibition of cell growth, and inhibition of tumor angiogenesis invasion and metastasis.[9-12] Two reviews summarize the molecular mechanisms of action of cannabinoids as antitumor agents.[13,14] Cannabinoids appear to kill tumor cells but do not affect their nontransformed counterparts and may even protect them from cell death. For example, these compounds have been shown to induce apoptosis in glioma cells in culture and induce regression of glioma tumors in mice and rats, while they protect normal glial cells of astroglial and oligodendroglial lineages from apoptosis mediated by the CB1 receptor.
The use of Cannabis for seed oil (Fig. 36) began at least 3 millennia ago. Hempseed oil is a drying oil, formerly used in paints and varnishes and in the manufacture of soap. Present cultivation of oilseed hemp is not competitive with linseed for production of oil for manufacturing, or to sunflower and canola for edible vegetable oil. However, as noted below, there are remarkable dietary advantages to hempseed oil, which accordingly has good potential for penetrating the salad oil market, and for use in a very wide variety of food products. There is also good potential for hemp oil in cosmetics and skin-care products.
Industrial hemp is marketed a fiber, as a seed, or as a dual-purpose crop. Although detailed market information for hemp ins not readily available, estimates from Vote Hemp show that the total retail value of hemp products in the U.S. in 2017 was $820 million. This includes food and body products, clothing, auto parts, building materials, and other products.
In early June, I met with Penny Pennington Howard, a mother of three, who lives in Carrollton, Texas, about 25 minutes outside of Dallas. Posted in the glass of her front door are two signs you can’t quite make out from the sidewalk: one asking visitors not to smoke, as oxygen treatments are in use; the other a yellow diamond informing guests this is the home of a special needs child. Penny welcomed me inside, out of the glare of the sun, and led me through her living room into her kitchen, where her kids were gathered for lunch. Seth, then eight months old, was plucking cereal off the tray of his highchair, while Lily, seven, was darting back and forth between the countertop and table. Harper, a blond five-year-old with hot pink toenails, was reclining in her “tomato chair,” a molded plastic seat with straps to help keep her steady.
Medical cannabis (or medical marijuana) refers to the use of cannabis and its constituent cannabinoids, to treat disease or improve symptoms. Cannabis is used to reduce nausea and vomiting during chemotherapy, to improve appetite in people with HIV/AIDS, and to treat chronic pain and muscle spasms. Cannabinoids are under preliminary research for their potential to affect stroke.
There have been ten clinical trials on the use of inhaled Cannabis in cancer patients that can be divided into two groups. In one group, four small studies assessed antiemetic activity but each explored a different patient population and chemotherapy regimen. One study demonstrated no effect, the second study showed a positive effect versus placebo, the report of the third study did not provide enough information to characterize the overall outcome as positive or neutral. Consequently, there are insufficient data to provide an overall level of evidence assessment for the use of Cannabis for chemotherapy-induced N/V. Apparently, there are no published controlled clinical trials on the use of inhaled Cannabis for other cancer-related or cancer treatment–related symptoms.
That leaves those touting CBD’s effectiveness pointing primarily to research in mice and petri dishes. There, CBD (sometimes combined with small amounts of THC) has shown promise for helping pain, neurological conditions like anxiety and PTSD, and the immune system—and therefore potentially arthritis, diabetes, multiple sclerosis, cancer, and more.
In 2017, the cultivated area for hemp in the Prairie provinces include Saskatchewan with more than 56,000 acres (23,000 ha), Alberta with 45,000 acres (18,000 ha), and Manitoba with 30,000 acres (12,000 ha). Canadian hemp is cultivated mostly for its food value as hulled hemp seeds, hemp oils and hemp protein powders, with only a small fraction devoted to production of hemp fiber used for construction and insulation.
A mixture of fiberglass, hemp fiber, kenaf, and flax has been used since 2002 to make composite panels for automobiles. The choice of which bast fiber to use is primarily based on cost and availability. Various car makers are beginning to use hemp in their cars, including Audi, BMW, Ford, GM, Chrysler, Honda, Iveco, Lotus, Mercedes, Mitsubishi, Porsche, Saturn, Volkswagen and Volvo. For example, the Lotus Eco Elise and the Mercedes C-Class both contain hemp (up to 20 kg in each car in the case of the latter).
Hemp’s greatest obstacle is its association with psychoactive cannabis, despite the important distinction that hemp contains only nominal amounts (no more than 0.3%) of the psychoactive ingredient, tetrahydrocannabinol (THC). Although the U.S. is the largest importer of hemp products according to the Hemp Business Journal (a New Frontier Data subsidiary), hemp itself has struggled to gain social acceptance in the country and elsewhere. For instance, current U.S. legislation only permits universities and states performing agricultural or academic research to cultivate hemp. However, the 2018 Farm Bill currently in Congress would grant hemp full legalization across the nation. Passage of this bill would be a key step in promoting public acceptance in the U.S. and elsewhere, allowing the country to participate in the rapidly growing global hemp market.
The cultivation of hemp in the EU is heavily weighted toward fiber production over oilseed production. In 1999, the EU produced about 27,000 t of hemp fiber, but only about 6,200 t of hemp seeds, mostly in France, and 90% of this was used as animal feed (Karus et al. 2000). The seeds (Fig. 33) have traditionally been employed as bird and poultry feed, but feeding the entire seeds to livestock has been considered to be a poor investment because of the high cost involved (although subsidization in Europe allows such usage, especially in France where hemp seeds are not legally permitted in human food). As pointed out later, higher yield and better harvesting practices may make whole hempseed an economical livestock feed. Moreover, seed cake left after expressing the oil is an excellent feed. Efforts are underway in Europe to add value in the form of processed products for hemp, especially cosmetics and food but, as noted below, the North American market is already quite advanced in oilseed applications.
Jump up ^ Fusar-Poli, Paolo; Crippa, José A.; Bhattacharyya, Sagnik; Borgwardt, Stefan J.; Allen, Paul; Martin-Santos, Rocio; Seal, Marc; Surguladze, Simon A.; O'Carrol, Colin; Atakan, Zerrin; Zuardi, Antonio W.; McGuire, Philip K. (2009). "Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing". Archives of General Psychiatry. 66 (1): 95–105. doi:10.1001/archgenpsychiatry.2008.519. PMID 19124693.
The arrival of Epidiolex is unlikely to erase the unregulated CBD market, however. For one, Epidiolex has been studied only in connection with a small number of epileptic conditions. If and when Epidiolex makes its way to drug stores, it will be approved only for the treatment of Dravet Syndrome and Lennox-Gastaut Syndrome, two rare forms of catastrophic epilepsy. People like me, with comparatively mild Janz Syndrome, and people like Harper, with extremely rare conditions like CDKL5, may still be out of luck.
In modern times, the Rastafari movement has embraced Cannabis as a sacrament. Elders of the Ethiopian Zion Coptic Church, a religious movement founded in the United States in 1975 with no ties to either Ethiopia or the Coptic Church, consider Cannabis to be the Eucharist, claiming it as an oral tradition from Ethiopia dating back to the time of Christ. Like the Rastafari, some modern Gnostic Christian sects have asserted that Cannabis is the Tree of Life. Other organized religions founded in the 20th century that treat Cannabis as a sacrament are the THC Ministry, Cantheism, the Cannabis Assembly and the Church of Cognizance. Rastafarians tend to be among the biggest consumers of modern Cannabis use.
Cannabis use for medicinal purposes dates back at least 3,000 years.[1-5] It was introduced into Western medicine in 1839 by W.B. O’Shaughnessy, a surgeon who learned of its medicinal properties while working in India for the British East India Company. Its use was promoted for reported analgesic, sedative, anti-inflammatory, antispasmodic, and anticonvulsant effects.
It is clear that there is a culture of idealistic believers in hemp in North America, and that there is great determination to establish the industry. As history has demonstrated, unbridled enthusiasm for largely untested new crops touted as gold mines sometimes leads to disaster. The attempt to raise silk in the US is probably the most egregious example. In 1826 a Congressional report that recommended the preparation of a practical manual on the industry resulted in a contagious desire to plant mulberries for silk production, with the eventual collapse of the industry, the loss of fortunes, and a legacy of “Mulberry Streets” in the US (Chapter 2, Bailey 1898). In the early 1980s in Minnesota, Jerusalem artichoke was touted as a fuel, a feed, a food, and a sugar crop. Unfortunately there was no market for the new “wonder crop” and hundreds of farmers lost about $20 million (Paarlberg 1990). The level of “hype” associated with industrial hemp is far more than has been observed before for other new crops (Pinfold Consulting 1998). Probably more so than any plant in living memory, hemp attracts people to attempt its cultivation without first acquiring a realistic appreciation of the possible pitfalls. American presidents George Washington and Thomas Jefferson encouraged the cultivation of hemp, but both lost money trying to grow it. Sadly in Canada in 1999 numerous farmers contracted to grow half of Canada’s crop area for hemp for the American-based Consolidated Growers and Processors, and with the collapse of the firm were left holding very large amounts of unmarketable grain and baled hemp straw. This has represented a most untimely setback for a fledgling industry, but at least has had a sobering effect on investing in hemp. In this section we emphasize why producers should exercise caution before getting into hemp.
Fig. 8. Scanning electron micrographs of the abaxial surface of a perigonal bract (which envelops the fruit). These bracts are the most intoxicating part of the plant, and may contain 20% THC, dry weight. The resin is synthesized both in stalked and sessile glands. Multicellular secretory glands (of phallic appearance), some broken stalks of these (note cellular appearance), and unicellular cystolith hairs (claw-like structures) are pictured. Fig. 9. Some important cannabinoids of cannabis resin. D9-THC (delta-9 tetrahydrocannabinol) is the chief intoxicant chemical and predominates in intoxicant strains, while the isomer D8-THC is usually present in no more than trace amounts. CBD (cannabidiol) is the chief non-intoxicant chemical, and predominates in non-intoxicant strains; it has sedative effects. The non-intoxicant CBN (cannabinol) is a frequent degradation or oxidation product. The non-intoxicant cannabichromene (CBC) is typically found in trace amounts in intoxicant strains. The non-intoxicant cannabigerol (CBG) is considered to be a precursor of the other cannbinoids (see Fig. 10).
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.