Sarov Prize - Basic Studies
DO MICROBES SMOKE DOPE?

Plenty of documentation is available on the effects of cannabis and cannabinoids on the physiology of the human body and on several illness. However, very little is documented on the effect of cannabinoids on microbes.

We have tested effects of several derivatives of synthetic cannabinoids and extracts on several bacteria. Tested agents: HU-210, synthetic cannabinoid, 100-800 times more potent than THC, displays multiple effects in eukaryotes which dependent on a selective agonistic activity at CB1/CB2 cannabinoid receptors. HU-308 is a cannabinoid that also acts as a cannabinoid agonist. It is highly selective for the CB2 receptor.

We tested the microbial effects of the cannabinoids on variety of bacterial properties, using several bacterial models in planktonic and biofilm environments.

All tested cannabinoids had an antibacterial effect. We have further investigated if those agents have any other effects on bacteria but below the MIC. We found that HU-210 had an effect on several characteristic properties of the V. harveyi. It affects biofilm formation, gene expression and motility. Those effects are mediated by altering the bacteria cross-talk (quorum sensing) cascade. The anti quorum sensing effect was specifically on the AI-2 cascade which is the universal pathway of quorum sensing. HU-210 has an antibiofilm activity on Pseudomonas aeruginosa resulting in an increase metabolic activity probably due to environmental stress. However, it affects the structure of the biofilm formed by the Pseudomonas. HU-210 was found to have a killing effect on Streptococcus mutans and Listeria Monocytogenes.

HU-308 was found to have an effect on quorum sensing of V. harveyi. However this effect was less profound than the effect of the HU-210.

These results are indication that synthetic cannabinoids may act as a novel non-classic anti-bacterial agent for treatment of infection diseases. This effect is structure dependence.

Acknowledgment: Partially funded-Israeli Agriculture Ministry