Cannabidiolic acid (CBDA) and CBDA-rich extracts modulatory effects on voltage-dependent NaV1.2 sodium channels

Cannabidiolic acid (CBDA), the acidic precursor of cannabidiol (CBD), is increasingly recognized for its therapeutic potential, particularly within full-spectrum Cannabis sativa extracts. However, the molecular mechanisms underlying its biological activity remain poorly characterized.

In this study we investigated the electrophysiological effects of purified CBDA and a CBDA-rich ethanolic extract on human voltage-gated sodium channels (NaV1.2), a clinically relevant molecular target in epilepsy.

CBDA significantly reduced NaV1.2 currents with a low-micromolar IC₅₀ of 1.4 ± 0.3 µM, without altering activation voltage-dependence. CBDA also stabilized the channel's inactivated state, evidenced by a hyperpolarizing shift in steady-state inactivation, slowing recovery from inactivation, and inducing a pronounced use-dependent blockade. Notably, the CBDA-rich extract reproduced these effects but elicited markedly stronger inhibition than purified CBDA. To identify contributors to this enhanced activity, we evaluated two main components of the extract: the essential oil fraction and neutral CBD. Neither fraction altered channel activation, and only the low CBD concentration present in the extract induced a significant shift in inactivation.

These findings establish NaV1.2 as a molecular target for CBDA-mediated pharmacology, provide a biophysical rationale for the enhanced anticonvulsant activity reported for CBDA-enriched cannabis preparations relative to isolated constituents, and support the further preclinical evaluation of defined cannabis chemotypes as multi-component pharmacological agents for neuronal sodium channelopathies.