Cannabidiol attenuates methamphetamine-induced oxidative neurotoxicity via regulating transient receptor potential vanilloid type 1.

BACKGROUND

The prevalence of methamphetamine (METH) abuse has significantly escalated in many regions worldwide. Despite this increase, the complexity of neurotoxicity associated with METH is inadequately understood. Cannabidiol (CBD), a non-addictive plant ingredient in cannabis, has been used in preclinical and clinical studies for treating various neuropsychiatric disorders, but the mechanism by which CBD exerts therapeutic effects is still unclear.

PURPOSE: This work aims to explore the mechanism of transient receptor potential vanilloid type 1 (TRPV1) mediates oxidative neurotoxicity in the context of METH exposure and reveal the therapeutic target of CBD for METH-induced oxidative neurotoxicity.

RESULTS

In the hippocampus and medial prefrontal cortex of METH users, overactivation of TRPV1, intracellular Ca2+ overload, increased oxidative stress, and elevated apoptosis were observed compared to control individuals. Molecular docking and surface plasmon resonance (SPR) detection results indicated that CBD binds to human TRPV1. In addition, METH induced Ca2+ influx, oxidative stress, cell damage, and TRPV1 activation in HT-22 cells, which were mitigated by TRPV1 knockdown or CBD pretreatment. CBD pretreatment also blocked TRPV1 agonist capsaicin-induced Ca2+ influx, oxidative stress, cell damage, and TRPV1 activation in HT-22 cells. Furthermore, METH triggered stereotyped behavior, spatial memory impairment, TRPV1 activation, Ca2+ overload, apoptosis, and oxidative stress in the hippocampus, which were attenuated by CBD pretreatment in mice. Finally, hippocampal TRPV1 knockdown reduced METH-induced stereotyped behavior and spatial memory impairment in mice, blocked METH-induced apoptosis and oxidative stress in the hippocampus of mice.

CONCLUSION

METH induces oxidative neurotoxicity via activating TRPV1-dependent Ca2+ influx, oxidative stress, and apoptosis, while CBD inhibits METH-induced oxidative neurotoxicity by regulating TRPV1. This study establishes CBD as a therapeutic intervention for METH use disorders.