PHYTOCANNABINOID BETA-CARYOPHYLLENE MODULATES INFECTION AND INFLAMMATION IN IN VITRO AND MURINE MODELS OF URINARY TRACT INFECTION

Abstract

Urinary tract infections (UTIs) are common infections, placing significant burdens on both patients and the healthcare system. Though antibiotics usually clear UTIs, they do not address pain and inflammation. The terpene, beta-caryophyllene (beta-C) is a specific agonist of cannabinoid type 2 receptor (CB2R) and can modulate bladder inflammation and pain. Beta-C also has known anti-bacterial activity. We hypothesized that beta-C can modulate bacterial burden, pain, and inflammation in a murine model of UTI. We hypothesized that some of these effects are mediated via the bladder urothelium. Using a murine model of lipopolysaccharide-induced bladder inflammation, we determined via intravital microscopy that beta-C reduces leukocyte adhesion within inflamed bladder venules. We further investigated these effects in a murine model of UTI, with BALB/c mice infected with uropathogenic E. coli CFT073. At the 6-hour timepoint, bacterial burden was variable and animals exhibited low levels of local and systemic inflammation. At the 24-hour timepoint, beta-C treatment significantly reduced bacterial burden in the bladder tissue and urine, and decreased leukocyte adhesion in bladder venules. At both timepoints, beta-C treatment reduced signs of non-evoked, but not evoked pain, as assessed by behavioral scoring and von Frey aesthesiometry. At 72-hour timepoint, most of the animals cleared the infection, though signs of non-evoked pain persisted. Preliminary studies with a bladder cancer cell line were not amenable for our experimental treatment, therefore we employed a primary human bladder epithelial cell line for our in vitro studies. Using a gentamicin protection assay, we observed a significant decrease in internalized bacteria secondary to beta-C treatment. Furthermore, we identified CB2R expression as early as 1 hour following induction of infection by both Western blot and fluorescent microscopy. In summary, we demonstrated anti-bacterial, anti-nociceptive, and anti-inflammatory effects of beta-C in the context of experimental UTI. Therefore, beta-C represents a promising potential adjunct therapy for the management of UTI in humans.