A team of Spanish researchers has succeeded in isolating the beneficial properties of cannabis's main psychoactive component. The results of this research, published in the journal PLOS Biology, represent a significant step forward in developing drugs that do not have the undesirable side effects of this drug, while still retaining all its benefits. "We have discovered a new mechanism of action of THC that allows us to separate the negative effects of cannabis from its beneficial ones," Dr. Patricia Robledo, one of the authors of this research, told eldiario.es.<\/p>\n
Marijuana has been studied for several years due to its various properties that are useful from a medical perspective. Among the different chemical components of cannabis, called cannabinoids, one of the most widely used is tetrahydrocannabinol, better known as THC. \u201cIt has a wide range of effects and its therapeutic potential is enormous,\u201d says Robledo, a researcher at Pompeu Fabra University and the Hospital del Mar Medical Research Institute.<\/p>\n
The problem lies in its adverse effects.<\/p>\n
Among other properties, this compound has analgesic effects, so it is being studied as a possible way to alleviate chronic pain caused by some diseases, such as multiple sclerosis or fibromyalgia. Furthermore, there are also studies that link THC to a reduction in the growth of certain tumors. However, despite the \u201cgreat interest in developing cannabis therapies, the problem lies in its undesirable effects, especially when used long-term,\u201d says Robledo.<\/p>\n
THC is the main psychoactive component of marijuana and has various adverse effects, such as memory loss, altered senses, fatigue, etc. Thanks to this study, researchers have been able to identify the brain receptors that are related to some of these negative effects, such as memory loss.<\/p>\n
The receptors found in the brain can be free or bind with other receptors to form complexes called heteromers. During the research, investigators discovered that one of the receptors that cannabis typically acts upon, called CB1, is commonly associated with another receptor related to memory function, called 5-HT2a. By analyzing the action of these receptors in mice, the researchers found that the resulting heteromeric complex is responsible for some of THC's harmful effects. "We have discovered that this population of heteromers is what is mediating the unwanted effects of cannabis, which in this case correspond to memory impairment," says Robledo.<\/p>\n
This result will help make THC more widely accepted.<\/strong><\/p>\n Furthermore, Robledo emphasizes that this heteromer is not related to other beneficial effects of THC, such as its analgesic effects. \u201cWe have identified a therapeutic target that allows us to dissociate the harmful effects from the beneficial ones, so that by breaking down these specific heteromers we would reduce the unwanted effect,\u201d she asserts. For the researcher, the result is promising, and although she acknowledges that \u201cwe must be cautious when extrapolating the results obtained with mice,\u201d she believes that this finding \u201ccan help make the therapeutic use of THC more widely accepted.\u201d.<\/p>\n To demonstrate that these complex receptors are linked to memory loss, researchers used mice with a reduced number of 5-HT2a receptors (either pharmacologically or through genetic modification). The study authors observed that THC did not cause memory loss in these mice, unlike in mice with a normal population of these receptors. Furthermore, they also confirmed that THC retained its analgesic properties in both cases.<\/p>\n To test the mice's memory, researchers used what are called behavioral paradigms. The animals were trained to recognize a series of objects in a maze. Once the mice were trained, they were given a dose of THC. The next day, the animals returned to the maze, but this time one of the objects had been replaced with a new one. The mice with the reduced number of receptors spent less time on the old objects and more time inspecting the new one. This reaction indicates that these mice were able to remember the objects and only reacted to the new one, spending more time inspecting it. However, the mice without the reduced number of receptors spent the same amount of time inspecting each of the objects, indicating that they did not remember any of them.<\/p>\n