Anti-staphylococcal activity of soilless cultivated cannabis across the whole vegetation cycle under various nutritional treatments in relation to cannabinoid content

Summary & key facts

Researchers tested alcohol extracts from cannabis plants grown without soil to see if they slow the growth of Staphylococcus aureus bacteria. All extracts slowed bacterial growth in lab dishes, and the strongest effects came from plants harvested between about week five and week thirteen. The main chemical found was THCA, and a related compound called THCVA cut bacterial growth by about three quarters. These results are promising for making new anti-staph drugs, but the tests were done in the lab on bacteria and not in people or animals yet.

Key facts:

• The study used ethanolic extracts, which means the researchers soaked cannabis plant parts in alcohol to pull out chemicals and then tested those extracts on bacteria in the lab.
• All the cannabis extracts tested slowed the growth of Staphylococcus aureus, including strains that are resistant to some antibiotics and strains that are sensitive.
• The strongest antibacterial activity came from plants harvested roughly between the 5th and 13th week of growth across different nutrient treatments.
• The minimum concentration that stopped bacterial growth in the most active extracts was about 30 to 60 micrograms per milliliter.
• Chemical analysis showed THCA was the most abundant cannabinoid in the extracts, and a related compound, THCVA, reduced bacterial growth by about 74 percent.
• The experiments were done in vitro, meaning in laboratory dishes, so these findings do not prove the extracts will work or be safe in people or animals yet.

Abstract

Antibiotic resistance in staphylococcal strains and its impact on public health and agriculture are global problems. The development of new anti-staphylococcal agents is an effective strategy for addressing the increasing incidence of bacterial resistance. In this study, ethanolic extracts of Cannabis sativa L. made from plant parts harvested during the whole vegetation cycle under various nutritional treatments were assessed for in vitro anti-staphylococcal effects. The results showed that all the cannabis extracts tested exhibited a certain degree of growth inhibition against bacterial strains of Staphylococcus aureus, including antibiotic-resistant and antibiotic-sensitive forms. The highest antibacterial activity of the extracts was observed from the 5th to the 13th week of plant growth across all the nutritional treatments tested, with minimum inhibitory concentrations ranging from 32 to 64 µg/mL. Using HPLC, Δ9-tetrahydrocannabinolic acid (THCA) was identified as the most abundant cannabinoid in the ethanolic extracts. A homolog of THCA, tetrahydrocannabivarinic acid (THCVA), reduced bacterial growth by 74%. These findings suggest that the cannabis extracts tested in this study can be used for the development of new anti-staphylococcal compounds with improved efficacy.

Topics

Allelopathy and phytotoxic interactions Plant Parasitism and Resistance Plant tissue culture and regeneration

Categories

Agricultural and Biological Sciences Life Sciences Plant Science

Tags

Antibiotic resistance Antibiotics Bacteria Bacterial growth Biology Cannabis Food science Genetics Medicine Microbiology Nutraceutical Psychiatry Staphylococcus Staphylococcus aureus

Substances

Cannabis