Pre-clinical evaluation of the efficacy of combined THC and CBDA to treat nausea, pain and anxiety in veterinary medicine

点击翻译按钮获取中文摘要

The cannabis plant has been used to treat nausea, pain and anxiety for thousand of years. However, it wasn't until the 1960's that scientists at the Hebrew University of Jerusalem discovered the psychoactive ingredient in cannabis, delta-9-tetrahydrocannabinol (THC) and other non-psychoactive cannabinoids, cannabidiol (CBD) and cannabidiolic acid (CBDA) in the plant. It is now known that the cannabis plant contains over 60 chemicals that have closely related structures, called cannabinoids, but the only mood altering consititutent is THC. Recent pre-clinical research using rat models of nausea has revealed that both THC and CBD are highly effective in reducing toxin-induced acute nausea and anticipatory nausea (as seen in chemotherapy patients when they return to the treatment clinic). They are also both effective in reducing inflammatory pain. THC produces a dose-dependent effect in animal models of anxiety-like behaviour, with low doses reducing anxiety and high doses increasing anxiety. CBD reduces anxiety across doses in animal models and has been shown to reverse the anxiety produced by high doses of THC. Most recently, the acidic precursor to CBD, CBDA that is in the plant before it is heated, has been found to be nearly 1000 times more potent than CBD in reducing acute and anticipatory nausea in animal models, without showing any effect on general motor activity level; therefore, CBDA may have considerable therapeutic potential in treating nausea in veterinary medicine. However, CBDA has not been evaluated for its effect on inflammatory pain or on anxiety. The therapeutic potential of combined ratios of THC and CBDA have not been systematically evaluated. The present studies aim to evaluate combined ratios of THC and CBDA (as well as each compound separately) in their ability to suppress acute and anticipatory nausea, inflammatory pain and anxiety in rodent models. These studies may potentially provide the pre-clinical evidence for the development of veterinary medicines to test in future clinical trials with companion animals.