Cannabidivarin’s Pain-Related Effects Changed Between Two Mouse Tests
Cannabidivarin, or CBDV, showed different effects when given alone in hotplate and formalin experiments. The difference matters when a broad claim that a cannabis constituent relieves pain is based on one laboratory assay.
Several kinds of evidence were combined
The study examined CBDV binding to the inflammatory signaling protein MD2, cellular responses to inflammatory stimulation, computational models and behavior in adult male mice. Protein and cell findings are in-vitro evidence; the behavioral experiments were animal evidence. Neither is a patient outcome.
A positive interaction did not mean every test was positive
CBDV enhanced and prolonged morphine-related antinociception in the hotplate experiment, while CBDV alone did not show an analgesic effect in that assay. In the formalin experiment, CBDV alone reduced nociceptive behavior in both measured phases. Repeated-treatment experiments also supported attenuation of morphine tolerance.
The assays asked different questions
Hotplate testing measures a response to noxious heat. Formalin produces a different sequence of tissue-injury-related behaviors. A null result in one assay and a positive result in another need not be contradictory. They narrow the circumstances under which the compound changed behavior.
Binding does not finish the clinical argument
Direct MD2-binding and inflammatory-signaling results supported a proposed mechanism, but the authors acknowledged other possible targets. Small animal groups, injected dosing and formulation limitations constrain translation. CBDV is a distinct constituent from CBD and THC; these results cannot be reassigned to either compound, a retail cannabis mixture or an individual patient’s opioid regimen.
Related analysis: A THC–Oxycodone Pain Signal Came With a Separate Reward Signal in Mice.
Primary research
Cannabidivarin alleviates neuroinflammation by targeting TLR4 co-receptor MD2 and improves morphine-mediated analgesia. Frontiers in immunology (2022). DOI: 10.3389/fimmu.2022.929222.
