Article by Henry Fountain

published in the New York Times on 5 September 2008 under the title Marijuana Ingredient May Fight Bacteria

Italian and English researchers have discovered that the main active component of marijuana - tetrahydrocannabinol or THC - and its compounds promise to be excellent antibacterial agents, in particular against those microbial strains that until now had proved resistant to numerous classes of drugs.

It has been known for decades that Cannabis sativa has antibacterial properties. Experiments conducted in the 1950s had tested the effectiveness of various marijuana-based preparations against certain types of infections - particularly cutaneous infections - but at that time the researchers managed to understand little of the chemical composition of marijuana.

The current research by Giovanni Appendino and his colleagues at the University of Eastern Piedmont, published in The Journal of Natural Products, examined the antibacterial activity of the five most common cannabinoids. All have proven effective against usually very resistant bacterial strains, although, understandably, the researchers suggest that non-psychotropic cannabinoids may prove more useful in the future for other uses.

The researchers say they still don't know how cannabinoids work or whether they can be effective, because systemic antibiotics require much more research and experimentation than has been done so far. But the compounds could prove to be useful as local agents against methicillin-resistant Staphylococcus aureus (MRSA), to prevent the microbes from forming colonies on the skin.