Researchers have detected cannabidiol (CBD) in Trema micranthum blume (Jamaican nettletree), a shrub native to South America, which is generally considered a weed. While this valuable bioactive compound was thought to exist only in cannabis, its presence in another plant offers a new avenue for medical use, and it doesn’t contain tetrahydrocannabinol (THC), the psychoactive substance that renders cannabis illegal in many countries.
Cannabis has been used in traditional medicine for centuries to alleviate various ailments, such as chronic pain and respiratory conditions. Its bioactive properties come from three main cannabinoids: tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN). In modern medicine, CBD is increasingly used in the treatment of epilepsy, anxiety, depression, and chronic pain. Antibacterial properties have also been reported in clinical trials targeting antibiotic-resistant bacteria.
Trema belongs to the same family as cannabis (Cannabaceae) and is commonly used in traditional Oriental medicine as an anti-infective and antipyretic (fever-reducing) agent. Researchers from the Federal University of Rio de Janeiro (UFRJ) have detected CBD in Trema micranthum blume, a taxon native to South America. Given the wide distribution of the plant, this discovery could potentially improve the availability of CBD and reduce dependence on cannabis.
A Variety Without THC
T. micranthum blume is a shrub that primarily grows in the tropical dry seasons of South America. It has been traditionally undervalued in modern medicine and is mainly collected for livestock or biofuel production. Phytochemical analysis of the plant’s fruits and flowers has shown that it could be used as an alternative to cannabis.
Although Brazilian experts have not yet published their results, researchers previously detected significant amounts of CBD, as well as other cannabinoids (THC and CBN), in a related variety (T. orientalis) found in Thailand. This 2021 study was the first to detect CBD in a plant other than cannabis. It showed that whole plant extracts could stop the growth of Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, even at concentrations as low as 31.25 to 125 µg/ml of CBD. These are types of bacteria that are known to be resistant to antibiotics. Active compounds can be extracted from nearly all parts of the plant, from berries to bark to flowers.
The South American indigenous variety, according to Brazilian researchers, does not contain THC. This could potentially circumvent legal obstacles related to the use of this type of plant. Due to its psychoactive nature, THC causes the euphoric feeling that consumers experience, making it illegal for consumption and production in many nations. For medical use, the legal THC concentration is limited to 0.2% in Brazil and 0.3% in the United States and Europe. Additionally, the use of CBD extracted from cannabis is restricted to certain medical conditions in Brazil, such as childhood and adolescent epilepsy. In other parts of the world, its use is somewhat less restricted. Some people use it, for example, to alleviate chemotherapy side effects or to complement treatment for chronic pain.
“In the case of the Brazilian plant, this would not be a problem, as it does not contain THC. There would also be no legal restrictions on cultivation, as it can be planted at will,” explains the study’s lead author, Rodrigo Moura Neto, from UFRJ. “In fact, it is already widespread throughout Brazil. It would be a more accessible and less expensive source to obtain cannabidiol,” he adds. Its exploitation could also contribute to the ecological control of this fast-growing and potentially invasive plant.
Moura Neto plans to assemble a team of biologists to map out the most effective methods for extracting CBD from T. micranthum blume. In vitro tests will also be conducted in about six months to determine if the compound has the same bioactive effects as those extracted from cannabis.