Effects of the monoacylglycerol lipase inhibitor JZL184 on chickens infected with avian pathogenic Escherichia coli O78: A preliminary pharmacokinetic and infection study.

The endocannabinoid (eCB) system modulates the degree of injury caused by inflammation, while enhancing the activity of phagocytes that promote resolution of inflammation and tissue repair. In-vitro studies with the monoacylglycerol lipase (MAGL) inhibitor JZL184 have suggested that increased eCB signaling might enhance the ability of the host immune system to clear invading pathogens. Although the neurochemical effects of JZL184 on the eCB system in rodents are well-known, its immuneregulating effects are less clear, especially in chickens. The primary objective of this study was to explore whether modulating the eCB system affects immune responses in chickens. To do this, we administered JZL184 [10 and 40 mg/kg body weight (BW), intraperitoneal injection] into chickens prior to a challenge with avian pathogenic Escherichia coli (APEC) O78. Bacteria were isolated from livers, blood, air sacs, and hearts at 8, 28, and 56 h post-infection and the gross lesions in air sacs, livers, and hearts were also examined. Serum levels of JZL184 were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), which indicated that the drug was distributed systemically. The number of birds positive for airsacculitis after APEC O78 challenge was marginally higher in groups treated with JZL184 than in the control group (P = 0.064). Rather than augmenting host defense and enhancing pathogen clearance, these results suggested that JZL184 might have immunosuppressive effects that exacerbated APEC O78 infection in chickens.