b-Caryophyllene Inhibits Monoacylglycerol Lipase Activity and Increases 2-Arachidonoyl Glycerol Levels In Vivo: A New Mechanism of Endocannabinoid-Mediated Analgesia?
Authors
Jost Klawitter,1 Wiebke Weissenborn,1 Iuliia Gvon,1 Mackenzie Walz, Jelena Klawitter, Matthew Jackson, Cristina Sempio, Sonja L. Joksimovic, Touraj Shokati, Ingo Just, Uwe Christians, and Slobodan M. Todorovic
Published
November 8, 2023
Abstract
The mechanisms of β-caryophyllene (BCP)-induced analgesia are not well studied. Here, we tested the efficacy of BCP in an acute postsurgical pain model and evaluated its effect on the endocannabinoid system. Rats were treated with vehicle and 10, 25, 50, and 75 mg/kg BCP. Paw withdrawal responses to mechanical stimuli were evaluated using an electronic von Frey anesthesiometer. Endocannabinoids, including 2-arachidonoylglycerol (2-AG), were also evaluated in plasma and tissues using high-performance liquid chromatography-tandem mass spectrometry. Monoacylglycerol lipase (MAGL) activity was evaluated in vitro as well as ex vivo. We observed a dose-dependent and time-dependent alleviation of hyperalgesia in incised paws up to 85% of the baseline value at 30 minutes after administration of BCP. We also observed dose-dependent increases in the 2-AG levels of about threefold after administration of BCP as compared with vehicle controls. Incubations of spinal cord tissue homogenates from BCP-treated rats with isotope-labeled 2-arachidonoylglycerol-d8 revealed a reduced formation of the isotope-labeled MAGL product 2-AG-d8 as compared with vehicle controls, indicating MAGL enzyme inhibition. In vitro MAGL enzyme activity assessment using 2-AG as the substrate revealed an IC50 of 15.8 µM for MAGL inhibition using BCP. These data showed that BCP inhibits MAGL activity in vitro and in vivo, causing 2-AG levels to rise. Since the endocannabinoid 2-AG is a CB1 and CB2 receptor agonist, we propose that 2-AG–mediated cannabinoid receptor activation contributes to BCP’s mechanism of analgesia.
Citations
Klawitter, J., Weissenborn, W., Gvon, I., Walz, M., Klawitter, J., Jackson, M., … & Todorovic, S. M. (2024). β-Caryophyllene inhibits monoacylglycerol lipase activity and increases 2-arachidonoyl glycerol levels in vivo: a new mechanism of endocannabinoid-mediated analgesia?. Molecular Pharmacology, 105(2), 75-83.