No abstract

Cannabis saliva L. strains can be divided into a number of groups according to their content of the psychotropic phytocannabinoid delta-9-Tetrahydrocannabinol (THC) and of the non-psychotropic Cannabinoid Cannabidiol (CBD). Although the main focus has been on THC in the past, there is growing interest on strains rich in CBD. Strains with a ratio of CBD to THC above one and a content of THC of less than 1%, often legally limited to 0.3%, are commonly designed as hemp (industrial hemp or fiber-type Cannabis) in contrast to THCrich strains (drug-type Cannabis and marijuana), and are grown as outdoor cultures in many countries. Such strains contain CBD as the main cannabinoid in addition to numerous other phytosubstances that are in general not further characterized but known to have beneficial effects on health. They are used for the preparation of extracts and other products e.g., essential oils, teas or edibles and promoted as nutraceuticals in hemp shops and on the internet. These products are increasingly popular, and a number of countries allow the cultivation of strains poor in THC. THC and CBD but also many other phytosubstances in hemp in particular terpenes and flavonoids target the so called endocannabinoid system that regulates the homeostasis of vital processes. However, the chemical profile of hemp and derivatives is subject to a wide variability due to a number of factors such as the nature of cultivars, agroclimatic conditions and methods of preparation. Hemp strains and concentrates differ not only in their chemical composition but also in their physiological effects. This heterogeneity has led to conflicting results in clinical studies with Cannabis formulations in the past. The physiological effects of purified cannabinoids differ from those observed with extracts. Most products from outdoor cultures cannot be sufficiently standardized, and so are currently unsuitable as medications. They may however play an important role in complementary and integrative medicine. For future clinical studies it is important that only well characterized products are used.