A new mechanism for Cannabidiol in regulating the one-carbon cycle and methionine levels in Dictyostelium and in mammalian epilepsy models

Background and Purpose: Epidiolex, a form of highly purified cannabidiol (CBD) derived from Cannabis plants has demonstrated seizure control activity in patients with Dravet syndrome, without a fully elucidated mechanism of action. We have employed an unbiased approach to investigate this mechanism at a cellular level. Experimental Approach: We use a tractable biomedical model organism, Dictyostelium, to identify protein controlling the effect of CBD and characterize this mechanism. We then translate these results to a Dravet Syndrome mouse model and an acute in vitro seizure model. Key Results: CBD activity is partially dependent upon the mitochondrial glycine cleavage system component, GcvH1 in Dictyostelium, orthologous to the human GCSH protein, which is functionally linked to folate one-carbon metabolism (FOCM). Analysis of FOCM components identified a mechanism for CBD in directly inhibiting methionine synthesis. Analysis of brain tissue from a Dravet syndrome mouse model also showed drastically altered levels of one-carbon components including methionine, and an in vitro rat seizure model showed an elevated level of methionine that is attenuated following CBD treatment. Conclusions and Implications: Our results suggest a novel mechanism for CBD in the regulating methionine levels, and identify altered one-carbon metabolism in Dravet syndrome and seizure activity. voltage-dependent anion selective channel proteins, VDAC1.