State-dependent cannabidiol interactions with fentanyl-bound mouse μ-opioid receptor conformations: a three-state molecular dynamics study

A recent study has revealed that cannabidiol (CBD), a primary constituent of cannabis products, interacts differently with fentanyl (FEN) binding across various conformations of the mu opioid receptor (MOR1) in mice. The researchers conducted molecular dynamics simulations on systems containing FEN alone or FEN+CBD in three distinct MOR1 conformations: active-like 5C1M, inactive-like 4DKL, and a modeled Morph50 intermediate.

They analyzed three independently seeded 200 ns trajectories per model and condition, resulting in a total of 18 trajectories. The study found that CBD's effects on FEN binding were strongly dependent on the specific MOR1 conformation. While corrected intracellular TM3 to TM6 analyses differentiated between the expected active-like, intermediate, and inactive-like backgrounds, a CBD-associated shift that was consistent across all geometric definitions and all three replicates was not identified.

The authors conclude that their descriptive results support the idea of receptor-state-dependent CBD-FEN-MOR1 interactions, but also highlight the limited inferential power of the limited number of trajectories used in the study (three per condition).