Abstract Background: Ischemia/reperfusion (I/R) is a pivotal mechanism of organ injury during clinical stetting for example for cardiopulmonary bypasses. The generation of reactive oxygen species (ROS) during I/R induces oxidative stress that promotes endothelial dysfunction, DNA dissociation and local inflammation. In turn, those processes induce cytokine release, resulting in damage to cellular structures and cell death. One of the major psychoactive compounds of Cannabis is delta-9-tetrahydrocannabinol (ΔΔ99-THC), which is known as an anti-inflammatory mediator. Our research aimed to test if ΔΔ99-THC may be protective in the treatment of cardiovascular system dysfunction arising from I/R heart injury. Methods: Two experimental models were used: isolated rat hearts perfused with the...