by IAN STEADMAN
An example of a mouse macrophage reaching out to absorb to particles (possibly pathogens)magnaram/Flickr/CC BY-SA 2.0
The chemical compound in cannabis, THC, appears to be able to damage and weaken the most common strain of the HIV virus.
Before you light up a spliff, though, this is only a preliminary result reached under laboratory conditions, and further research will be needed.
THC, or tetrahydrocannabinol, is the main psychoactive ingredient in cannabis — it’s the chemical that gets the user stoned. Synthetic versions of it have been developed for research purposes, and it’s this that was used to attack the HIV-1 virus, which represents the vast majority (more than 90 percent) of all HIV types.
The way it works is by interaction with the cannabinoid type-2 (CB2) receptor in white blood cells, specifically the macrophages. Macrophages are one of many types of white blood cell in humans. While the main cells, the lymphocytes, do the bulk of the work in fighting infection by tracking down and destroying germs with antibodies, macrophages form a kind of backup part of the immune system — attracted to damaged cells, they surround and engulf them while also alerting lymphocytes of new dangers.