Cannabigerolic acid showed anticonvulsant effects in Dravet syndrome mice but had proconvulsant effects at high doses in another seizure model | Research

The takeaway

CBGA, a precursor cannabinoid, reduced seizures in Dravet syndrome mice and potentiated clobazam, but showed proconvulsant effects in a different seizure model and at high doses.

Pediatric neurologists, parents using artisanal cannabis for epilepsy, and drug developers working on cannabinoid-based seizure treatments.

CBGA: anticonvulsant in Dravet model, proconvulsant in 6-Hz model

What the researchers found

Screening identified CBGA, CBDVA, and CBGVA as novel anticonvulsants. CBGA was most potent and potentiated clobazam against both heat-induced and spontaneous seizures in Scn1a+/- (Dravet) mice. However, CBGA was proconvulsant in the 6-Hz threshold test and a high dose increased spontaneous seizure frequency. CBGA interacted with GPR55, TRPV1, and GABA-A receptors.

Why it matters

Artisanal cannabis products for childhood epilepsy often contain phytocannabinoids beyond CBD. Identifying which compounds help and which may actually worsen certain seizure types is critical for safe product development.

The numbers in context

CBGA, CBDVA, and CBGVA identified as anticonvulsant. CBGA potentiated clobazam in Dravet model. CBGA proconvulsant in 6-Hz test. High-dose CBGA increased spontaneous seizure frequency. CBGA interacted with GPR55, TRPV1, GABA-A receptors.

How the study worked

Scn1a+/- mouse model of Dravet syndrome tested against hyperthermia-induced and spontaneous seizures. MES and 6-Hz threshold models also used. Pharmacological profiling across multiple epilepsy-relevant targets (GPR55, TRPV1, GABA-A receptors).

What this study cannot tell us

Mouse models may not predict human responses. The proconvulsant effects at higher doses raise safety concerns. Only one genetic model of epilepsy (Scn1a+/-) was tested. Drug interactions with clobazam could be pharmacokinetic rather than pharmacodynamic.

How to read the evidence

Thorough preclinical characterization across multiple seizure models, but the dual effect profile complicates translation.

When this study was published

2021 animal study. Important safety finding for cannabis products used in childhood epilepsy.

The bigger picture

The dual anticonvulsant/proconvulsant profile of CBGA depending on the seizure type and dose is a cautionary finding for the development of cannabis-based epilepsy treatments beyond CBD.

Questions still open

Can the therapeutic window of CBGA be defined to avoid proconvulsant effects? Would CBGA be safer in combination with other cannabinoids? Do the multi-target interactions of CBGA create unpredictable effects across seizure types?

Common questions

What is CBGA?

Cannabigerolic acid (CBGA) is a precursor molecule in cannabis from which THC, CBD, and other cannabinoids are biosynthesized. It is found in raw cannabis products and some artisanal preparations.

Is CBGA safe for epilepsy?

It showed anticonvulsant effects in a Dravet syndrome model but proconvulsant effects in another seizure model and at high doses. This mixed profile means careful dosing and seizure-type consideration would be essential.

Read the original research

Cannabigerolic acid, a major biosynthetic precursor molecule in cannabis, exhibits divergent effects on seizures in mouse models of epilepsy.

British journal of pharmacology, 178(24), 4826-4841

View on PubMed ↗Publisher’s paper ↗

Citation

Anderson, Lyndsey L; Heblinski, Marika; Absalom, Nathan L; Hawkins, Nicole A; Bowen, Michael T; Benson, Melissa J; Zhang, Fan; Bahceci, Dilara; Doohan, Peter T; Chebib, Mary; McGregor, Iain S; Kearney, Jennifer A; Arnold, Jonathon C. (2021). Cannabigerolic acid, a major biosynthetic precursor molecule in cannabis, exhibits divergent effects on seizures in mouse models of epilepsy.. British journal of pharmacology, 178(24), 4826-4841. https://doi.org/10.1111/bph.15661