The Therapeutic Effectiveness of Full Spectrum Hemp Oil Using a Chronic Neuropathic Pain Model

Abstract

Background: Few models exist that can control for placebo and expectancy effects commonly observed in clinical trials measuring ‘Cannabis’ pharmacodynamics. We used the Foramen Rotundum Inflammatory Constriction Trigeminal Infraorbital Nerve injury (FRICT-ION) model to measure the effect of “full-spectrum” whole plant extracted hemp oil on chronic neuropathic pain sensitivity in mice. Methods: Male BALBc mice were submitted to the FRICT-ION chronic neuropathic pain model with oral insertion through an incision in the buccal/cheek crease of 3 mm of chromic gut suture (4-0). The suture, wedged along the V2 trigeminal nerve branch, creates a continuous irritation that develops into secondary mechanical hypersensitivity on the snout. Von Frey filament stimuli on the mouse whisker pad was used to assess the mechanical pain threshold from 0–6 h following dosing among animals (n = 6) exposed to 5 μL of whole plant extracted hemp oil combined with a peanut butter vehicle (0.138 mg/kg), the vehicle alone (n = 3) 7 weeks post-surgery, or a naïve control condition (n = 3). Results: Mechanical allodynia was alleviated within 1 h (d = 2.50, p < 0.001) with a peak reversal effect at 4 h (d = 7.21, p < 0.001) and remained significant throughout the 6 h observation window. There was no threshold change on contralateral whisker pad after hemp oil administration, demonstrating the localization of anesthetic response to affected areas. Conclusion: Future research should focus on how whole plant extracted hemp oil affects multi-sensory and cognitive-attentional systems that process pain.

Cannabidiol for Pain Treatment: Focus on Pharmacology and Mechanism of Action

“…Furthermore, glycine currents in dorsal horn neurons in spinal cord slices from neuropathic rats were enhanced by cannabinoids [ 66 ]. In a mouse chronic neuropathic pain model involving foramen rotundum inflammatory constriction trigeminal infraorbital nerve injury, CBD administered orally in a peanut butter vehicle alleviated mechanical allodynia within 1 h and remained significant through 6 h [ 67 ]. CBD effectiveness was also demonstrated in a chronic constriction injury (CCI) animal model of neuropathic pain.…”

Pain-related behavioral and electrophysiological actions of dynorphin A (1-17)

“…Mechanical hypersensitivity was tested on the hindpaw, with von Frey filament stimulation at baseline and weekly thereafter as has been previously established with the 'updown method' of analysis. [15][16][17][18][19][20] Experimenter was blinded to treatment groups. Mice were allowed to acclimate for 30 minutes in the room prior to testing.…”

Single-Dose P2 X4R Single-Chain Fragment Variable Antibody Permanently Reverses Chronic Pain in Male Mice

“…Hypersensitivity persists indefinitely in the FRICT-ION model, thus the model is suitable for assessing pain-like responses equivalent to the timeframe of chronic clinical pain (Montera & Westlund, 2020). Mechanical hypersensitivity was tested on the whiskerpad, the innervation territory of the infraorbital nerve, with von Frey filament stimulation at baseline and weekly thereafter as we have reported previously [32,[72][73][74][75]. Reflexive responses to mechanical stimuli applied with graded von Frey filaments was tested weekly.…”