MPO and colitis: Accordingly, it has been reported that activation of CB1 or CB2 with synthetic agonists protected from colitis [12,16] and that treatment with Δ9-tetrahydrocannabinol (THC), the main psychoactive constituent of Cannabis sativa, reduced TNBS-induced inflammation as well as myeloperoxidase (MPO) activity and motility disturbances in the in rat colon [17].