Cannabidiol Protects Human Skin Keratinocytes from Hydrogen-Peroxide-Induced Oxidative Stress via Modulation of the Caspase-1-IL-1β Axis.

Preclinical and clinical studies support cannabidiol (CBD)'s antioxidant and anti-inflammatory effects, which are linked to its skin protective effects, but there have been limited mechanistic studies reported. Herein we evaluated CBD's protective effects against hydrogen peroxide (H2O2)-induced oxidative stress in human keratinocyte HaCaT cells and explored its possible mechanism(s) of action. CBD (10 μM) protected HaCaT cells by alleviating H2O2 (200 μM)-induced cytotoxicity (by 11.3%) and reactive oxygen species (total- and mitochondrial-derived). Several NLRP3 inflammasome-related genes including CASP1 and IL1B were identified as potential molecular targets for CBD's antioxidant effects by multiplexed gene and network pharmacology analyses. CBD treatment down-regulated the mRNA expression levels of CASP1 and IL1B (by 32.9 and 51.0%, respectively) and reduced IL-1β level (by 16.2%) in H2O2-stimulated HaCaT cells. Furthermore, CBD inhibited the activity of caspase-1 enzyme (by 15.7%) via direct binding to caspase-1 protein, which was supported by data from a biophysical binding assay (surface plasmon resonance) and a computational docking experiment. In addition, CBD mitigated H2O2-induced pyroptosis (capase-1-mediated cell death) and apoptosis by 23.6 and 44.0%, respectively. The findings from the current study suggest that CBD exerts protective effects in human keratinocytes via the modulation of the caspase-1-IL-1β axis, supporting its potential skin health applications.