The results of a new study have found that molecules derived from naturally produced cannabinoids can help to fight inflammation.
The researchers, from the University of Illinois at Urbana-Champaign, report their findings in the journal PNAS.
Although the medicinal uses of cannabis, or marijuana, have been documented in records that go back 4,700 years, it was not until 1964 that we found out how it worked.
It was then that Israeli scientists Yechiel Gaoni and Raphael Mechoulam discovered the cannabinoid tetrahydrocannabinol (THC), the most active component in marijuana.
Since then, it has been shown that THC mimics a natural brain chemical, one of many "endocannabinoids" - that is, cannabinoids that are produced naturally in the body.
The body makes cannabinoids from foods that contain omega-3 and omega-6 fatty acids, such as eggs, meat, fish, and nuts.
Endocannabinoids are essential to health
It is now known that endocannabinoids, as well as the cell receptors that they bind to, are found throughout the body - such as in organs, the brain, glands, connective tissues, and the immune system - and that they play an important role in human health.
However, despite the fact that much has been discovered about their effects on the body, the detailed mechanisms through which cannabinoids interact with systems such as the immune system are not wholly understood.
Study leader Aditi Das, a professor of comparative biosciences and biochemistry at the University of Illinois, says that because they interact with the immune system, cannabinoids make attractive targets for anti-inflammatory drugs.
Cannabinoids exert their effects on cells by binding to surface proteins called cannabinoid receptors. These act as gatekeepers, only allowing entry to unique compounds with the right credentials.
'Powerful anti-inflammatory molecules'
Prof. Das says that there are two types of cannabinoid receptors in the human body. One type is found mainly in the nervous system, and the other type occurs mainly in the immune system.
"Some cannabinoids, such as THC in marijuana or endocannabinoids can bind to these receptors and elicit anti-inflammatory and anti-pain action," she explains.
By conducting experiments on human cells and animal tissue, the team discovered an enzyme pathway that converts omega-3-derived endocannabinoids into powerful anti-inflammatory molecules that bind predominantly to cannabinoid receptors in the immune system.
The researchers also discovered that the anti-inflammatory molecules, which are called omega-3 endocannabinoid epoxides, have other properties that influence blood vessel dilation and blood platelet aggregation.
They conclude that the identification of these new molecules "may aid in the development of therapeutics for neuroinflammatory and cerebrovascular diseases."
"This finding demonstrates how omega-3 fatty acids can produce some of the same medicinal qualities as marijuana, but without a psychotropic effect."
Prof. Aditi Das