Study Finds Cannabis Extracts Inhibit MRSA
- The study by the University of Limpopo found that methanol and distilled-water extracts from two high-CBD hemp strains of Cannabis sativa, Futura 75 and CBD Carmagnola, inhibited methicillin-resistant Staphylococcus aureus (MRSA) but showed no antimicrobial activity against other tested drug-resistant microorganisms.
- Methanol extracts were more effective than distilled-water extracts, with the CBD Carmagnola methanol extract showing the strongest antibacterial activity, having a minimum inhibitory concentration (MIC) of 3.13 mg/mL and minimum bactericidal concentration (MBC) of 6.25 mg/mL against MRSA.
- Phytochemical analysis revealed the presence of saponins, tannins, and flavonoids in all extracts, while terpenoids and steroids were found only in methanol extracts, which may contribute to the antibacterial effects observed.
- The researchers suggest these findings provide a foundation for further investigation into cannabis-derived compounds as potential topical treatments for MRSA infections and recommend additional studies to isolate active components and test against more drug-resistant pathogens.
A new study found that extracts from two cannabis strains inhibited methicillin-resistant Staphylococcus aureus (MRSA), with researchers saying the findings could provide a foundation for developing new treatments targeting the drug-resistant bacteria.
The study, published in the South African Journal of Botany, was conducted by researchers at the University of Limpopo in South Africa. Researchers examined two Cannabis sativa strains, Futura 75 and CBD Carmagnola, both high-CBD hemp varieties, to determine their antimicrobial activity against multidrug-resistant microorganisms.
Researchers prepared methanol and distilled-water extracts from the plants and tested them against MRSA, Enterococcus faecium, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. The microorganisms were clinical isolates obtained from the National Health Laboratory Service in South Africa.
The cannabis extracts inhibited MRSA but did not demonstrate detectable antimicrobial activity against the other four microorganisms tested. Both methanol and distilled-water extracts inhibited MRSA at higher concentrations, although the methanol extracts generally produced greater inhibition.
At a concentration of 100 milligrams per milliliter, the methanol extract from Futura 75 produced an average MRSA inhibition zone of 27.67 millimeters, while the CBD Carmagnola extract produced a 23.33-millimeter zone. At 50 milligrams per milliliter, the respective inhibition zones were 17.33 and 20.33 millimeters.
Researchers also measured the minimum inhibitory concentration (MIC), or the lowest concentration capable of preventing visible bacterial growth, and the minimum bactericidal concentration (MBC), which reflects the concentration needed to kill the bacteria.
The strongest results came from the CBD Carmagnola methanol extract, which had an MIC of 3.13 milligrams per milliliter and an MBC of 6.25 milligrams per milliliter. The Futura 75 methanol extract had an MIC and MBC of 12.5 milligrams per milliliter. Distilled-water extracts were less potent, with MBC values of 100 milligrams per milliliter for Futura 75 and 50 milligrams per milliliter for CBD Carmagnola.
Although methanol extracts generally performed better, researchers found no statistically significant differences between the two strains for either the methanol or distilled-water extracts. Preliminary phytochemical testing found saponins, tannins and flavonoids in all extracts, while terpenoids and steroids were detected only in the methanol extracts.
The authors said the findings demonstrate the in vitro inhibitory potential of cannabis extracts against MRSA and could serve as a starting point for research into topical treatments for MRSA skin infections. They called for additional studies to isolate and quantify individual compounds, examine how they work and test a broader range of cannabis strains and drug-resistant pathogens.