Cannabidiol-induced apoptosis in primary lymphocytes is associated with oxidative stress-dependent activation of caspase-8.
We recently reported that cannabidiol (CBD) exhibited a generalized suppressive effect on T-cell functional activities in splenocytes directly exposed to CBD in vitro or isolated from CBD-administered mice. To investigate the potential mechanisms of CBD effects on T cells, we characterized the pro-apoptotic effect of CBD on primary lymphocytes. The apoptosis of splenocytes was markedly enhanced following CBD exposure in a time- and concentration-dependent manner, as evidenced by nuclear hypodiploidity and DNA strand breaks. Exposure of splenocytes to CBD elicited an early production of reactive oxygen species (ROS) with the peak response at 1 h post CBD treatment. In parallel with the ROS production, a gradual diminishment in the cellular glutathione (GSH) content was detected in CBD-treated splenocytes. Both CBD-mediated ROS production and GSH diminishment were remarkably attenuated by the presence of N-acetyl-L-cysteine (NAC), a thiol antioxidant. In addition, CBD treatment significantly stimulated the activation of caspase-8, which was abrogated in the presence of NAC or GSH. Pretreatment of splenocytes with a cell-permeable inhibitor for caspase-8 significantly attenuated, in a concentration-dependent manner, CBD-mediated apoptosis, but not ROS production. Collectively, the present study demonstrated that the apoptotic effect of CBD in primary lymphocytes is closely associated with oxidative stress-dependent activation of caspase-8.
Wu
Hsin-Ying
HY
Department of Veterinary Medicine, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei, Taiwan 106, ROC.
Chu
Rea-Min
RM
Wang
Chia-Chi
CC
Lee
Chi-Ya
CY
Lin
Shu-Hong
SH
Jan
Tong-Rong
TR
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002185:Cannabidiol / Q000494:pharmacology*; D053181:Caspase 8 / Q000096:biosynthesis*; D061945:Caspase Inhibitors; D002467:Cell Nucleus / Q000187:drug effects / Q000473:pathology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D007155:Immunologic Factors / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013154:Spleen / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology
D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D007155:Immunologic Factors; D017382:Reactive Oxygen Species; D002185:Cannabidiol; D053181:Caspase 8; D005978:Glutathione; D000111:Acetylcysteine