CBD Promotes Structural and Functional Epithelial Restoration and Alleviates Inflammation in a Mouse Model of...

Background: Interstitial cystitis (IC) is a debilitating lower urinary tract condition characterised by chronic inflammation of the bladder. As the aetiology remains unknown, current treatments are symptomatic, aiming to reduce inflammation and pain. Cannabidiol (CBD), the most common cannabinoid in industrial Cannabis sativa (hemp), is one of the most important pharmacologically active cannabinoids used in medicine due to its anti-inflammatory and antioxidant effects without psychoactive properties. While other cannabinoids have shown beneficial effects in animal models of IC, the impact of CBD on the urinary bladder and overall animal well-being has not been elucidated. Methods: Using a cyclophosphamide (CYP)-induced mouse model of IC, we investigated the effects of intraperitoneally administered CBD on bladder structure, function, inflammation, and animal behaviour. A multimodal approach was applied, including light and electron microscopy, immunolabeling, qPCR, transepithelial electrical resistance (TEER) measurements, behavioural testing, and monitoring of animals. Results: CBD treatment promoted the restoration of damaged urothelial structure and improved the integrity of the blood-urine barrier. Additionally, CBD exerted an anti-inflammatory effect, reducing oedema and infiltration of inflammatory cells in the bladder wall with chronic cystitis. Finally, the increased burrowing activity of CBD-treated mice suggests a benefit of CBD on overall well-being. Conclusions: Our findings suggest that CBD has a beneficial effect on the inflamed urinary bladder and could potentially serve as an adjunct treatment for patients with IC in the future.