Cannabidiol (CBD) is one of at least 60 active cannabinoids identified in cannabis.
It is a major constituent of the Hemp plant, accounting for up to 40% of the plant’s extract, as a non-psychotropic phytocannabinoid.
CBD is considered to have a wider scope of medical applications than tetrahydrocannabinol (THC)
In November 2007, researchers at the California Pacific Medical Center reported that CBD shows promise for controlling the spread of metastatic breast cancer.
In vitro CBD down-regulates, or “turns off”, the activity of ID1, the gene responsible for tumor metastasis in breast and other types of cancers, including the particularly aggressive triple negative breast cancer.
The researchers in September 2012 said they hope to start human trials soon.
Cannabidiol has been shown to inhibit cancer cell growth with low potency in non-cancer cells. Although the inhibitory mechanism is not yet fully understood, Ligresti et al. suggest that “cannabidiol exerts its effects on these cells through a combination of mechanisms that include either direct or indirect activation of CB2 and TRPV1 receptors, and induction of oxidative stress, all contributing to induce apoptosis.”
Non-intoxicating cannabinoids, including cannabidiol (CBD) and other more pronounced CB2 agonists such as cannabinol (CBN, an immunosuppressant), are now seen as promising candidates for anti-tumor drugs since they experimentally reduce the size of in-vivo xenografts, for example gliomas.
Combinations of submaximal THC doses and CBD have both been successfully applied to greatly increase in-vitro efficacy of temozolomide in glioblastoma multiforme cell lines.
CBD likely exerts its effects through the induction of apoptosis by Reactive oxygen species.
Non-psychoactive cannabinoids can be administered at much higher doses without the well-known side effects that are sometimes associated with the drop-out rate in trials involving psychoactive cannabinoids.
A team of researchers from the University of California at Irvine proposed in February 2013 that CBD’s anti-malignant effect by way of apoptosis may be due to its potential action on “mutant p53 proteins in cancer cells,” due to cannabidiol’s chemo-physical similarity to stictic acid, a promising anti-cancer compound found in some species of lichens that acts on the aforementioned proteins.
The University biologists, chemists and computer scientists “identified an elusive pocket on the surface of the p53 protein that can be targeted by cancer-fighting drugs”