Effect of vaporized Cannabidiol (CBD) on neuropathic pain and its potential implication for development of chronic lung inflammation in rats

BACKGROUND: Cannabidiol (CBD) use in e-cigarettes is increasing, and its vaping involves using CBD in conjunction with other chemical additives such as propylene glycol (PG), vegetable glycerin (VG) and food flavorings, which help vaporize the CBD and enhance the vaping experience. Chronic neuropathic pain is challenging to treat with current medications, and there is growing interest in the use of medical cannabis for this condition. While the effects of vaping CBD could be beneficial for people with neuropathic pain, the potential detrimental effects on the lungs after continued exposure are not fully known. Whereas acute respiratory failure has been associated with vaping Cannabis, this study was undertaken to assess effects of CBD vaping on lung pathology and analgesic effectiveness in rats with sciatic nerve chronic constriction injury and examine potential mechanisms underlying the pathophysiology associated with CBD vaping. METHODS: We used an in-house designed and assembled prototype of an automated vaping exposure system that enables precise quantitation of vaping for in-vivo exposure of rats with neuropathic pain. RESULTS: Our results showed that CBD vapor exposure significantly alleviated pain, and modulation of cytokines and the NLRP3 (NOD-like receptor family, pyrin domain-containing 3) inflammasome pathway may underlie the CBD-induced effects in lung tissue, thereby affecting lung pathophysiology. Further, exposure to chemical additives like PGVG (Propylene Glycol and Vegetable Glycerin) resulted in a substantial inflammatory response indicating that these substances are by no means safe additives in e-cigarettes. CONCLUSIONS: Thus, while CBD vaping may be beneficial in the management of neuropathic pain, it may cause substantial lung injury by promoting significant inflammatory changes in the lung.