These immune cells have been shown to decrease production of immune-related chemical signals (e.g., cytokines) or undergo apoptosis as a consequence of CB2 agonism by CBN.
[6] While some phytocannabinoids have been shown to interact with nociceptive and immune-related signaling via transient receptor potential channels (e.g., TRPV1 and TRPM8), there is currently limited evidence to suggest that CBN acts in this way.
[6][13] In preclinical rodent studies, CBN, anandamide and other CB1 agonists have demonstrated inhibitory effects on GI motility, reversible via CB1R blockade (i.e., antagonism).
This concept describes a widely reported but poorly-understood synergistic effect of certain cannabinoids when phytocannabinoids are coadministered with other naturally-occurring chemical compounds in the cannabis plant (e.g., flavonoids, terpenoids, alkaloids).
Exogenous (plant-derived) phytocannabinoids are identified with an asterisk while remaining chemicals represent well-known endocannabinoids (i.e., endogenously produced cannabinoid receptor ligands).
In the brain, the canonical mechanism of CB1 receptor activation is a form of short-term synaptic plasticity initiated via retrograde signaling of endogenous CB1 agonists such as 2AG or AEA (two primary endocannabinoids).
Other examples of compounds in this group include dibenzopyran derivatives such as Δ9-THC, well-known for underlying the subjective "high" experienced by cannabis users, as well as Δ8-THC, and their synthetic analogs.
In contrast, endogenously produced cannabinoids (i.e., endocannabinoids), which also exert effects through CB agonism, are considered eicosanoids, distinguished by notable differences in chemical structure.
According to the 2018 Farm Bill,[25] extracts from the Cannabis sativa L. plant, including CBN, are legal under US federal law as long as they have a delta-9 Tetrahydrocannabinol (THC) concentration of 0.3% or less.
Although reports are limited, CBN-A has also been measured at very low levels in the cannabis plant, thought to have formed via hydrolyzation of THC-A (see Phytocannabinoid Biosynthesis diagram, below).