Actions of the dual FAAH/MAGL inhibitor JZL195 in a murine inflammatory pain model. (301)
The analgesic efficacy of cannabinoids in chronic pain models is thought to be limited by side-effects. It has been proposed that this might be overcome by using agents which indirectly activate the endocannabinoid system. We directly compared the analgesic versus side-effects profile of the dual FAAH/MAGL inhibitor JZL195 to that of a pan-cannabinoid receptor agonist WIN55212 in an inflammatory pain model. Systemic injections of a range of doses of JZL195 and WIN55212 were performed 1 – 2 days following intraplantar injection of CFA in C57BL/6 mice. Mechanical allodynia and thermal hyperalgesia were measured with von Frey hairs and a Hargreaves device. Motor co-ordination, catalepsy and locomotor activity were measured with the rotarod, bar test and low light open field. JZL195 and WIN55212 both reduced mechanical allodynia and produced cannabinoid-like catalepsy and sedation in a dose dependent manner. Unlike WIN55212, JZL195 reduced allodynia at doses below those at which side-effects were observed. JZL195, displayed a threefold greater therapeutic index than WIN55212. The effects of JZL195 and WIN55212 were abolished by co-application with the CB1 antagonist AM251. The CB2 antagonist also reduced the JZL anti-allodynia, and reversed the WIN55212 anti-allodynia. These findings suggest that the dual FAAH/MAGL inhibitor JZL195 displays a greater therapeutic index than a pan cannabinoid receptor agonist in an inflammatory pain model. Thus, dual FAAH/MAGL inhibition has the potential to alleviate inflammatory pain without the side-effects associated with cannabinoids.