Cannabidiol Attenuates Methamphetamine-Induced Cardiac Inflammatory Response and Necrosis through The PKA/CREB Signaling Pathway

Methamphetamine (MA) abuse is a major global public health problem, with cardiovascular issues becoming an increasingly recognized complication. Cannabidiol (CBD) has gained recent attention, due to its various pharmacological properties. However, whether CBD has therapeutic effects on MA-induced cardiotoxicity remains unknown. In the present study, we investigated whether CBD has a protective or therapeutic effect on MA-induced cardiac damage in rats via the protein kinase A (PKA)/cyclic adenosine monophosphate response element-binding (CREB) signaling pathway. Thirty rats were randomly divided into five groups. The rats were administered MA by intraperitoneal injection (IP) once a day for 4 weeks, with CBD (40 or 80 mg/kg, IP) treatment 1 h prior to the MA injections. Body and heart weights were measured, and morphological changes were determined using hematoxylin & eosin and Masson’s trichrome staining. The serum levels of interleukin-6 (IL-6) and IL-10 were detected using enzyme linked immunosorbent assay (ELISA) kits. The protein expression levels of PKA, phospho-PKA (p-PKA), CREB, phospho-CREB (p-CREB) and cardiac troponin I (cTnI) in the myocardium were detected by western blot analysis. Results showed that the heart-to-body weight ratio increased significantly following MA administration but decreased with CBD treatment. Chronic administration of MA resulted in a cardiac inflammatory response and progressive development of fibrosis, while CBD treatment attenuated these lesions in a dose-dependent manner. MA administration increased IL-6 but decreased IL-10 levels, which were reversed by CBD pretreatment. Moreover, MA significantly increased the cTnI level, but this was decreased by CBD treatment at 80 mg/kg. The protein expression levels of PKA, p-PKA, CREB, and p-CREB increased following MA administration, but significantly decreased with CBD treatment. Overall, these results indicate that chronic MA administration leads to cardiotoxicity, including cardiac inflammatory response, fibrosis, and myocardial necrosis, but these effects can be attenuated by CBD pretreatment. Our research suggests a potential application of CBD for MA-induced cardiotoxicity, which may attenuate inflammatory response and necrosis through the PKA/CREB signaling pathway.