Neuroprotective effect of cannabidiol, a non‐psychoactive component fromCannabis sativa, on β‐amyloid‐induced toxicity in PC12 cells

Abstract
Alzheimer's disease is widely held to be associated with oxidative stress due, in part, to the membrane action of β‐amyloid peptide aggregates.Here, we studied the effect of cannabidiol, a major non‐psychoactive component of the marijuana plant (Cannabis sativa) on β‐amyloid peptide‐induced toxicity in cultured rat pheocromocytoma PC12 cells. Following exposure of cells to β‐amyloid peptide (1 µg/mL), a marked reduction in cell survival was observed. This effect was associated with increased reactive oxygen species (ROS) production and lipid peroxidation, as well as caspase 3 (a key enzyme in the apoptosis cell‐signalling cascade) appearance, DNA fragmentation and increased intracellular calcium. Treatment of the cells with cannabidiol (10−7−10−4m) prior to β‐amyloid peptide exposure significantly elevated cell survival while it decreased ROS production, lipid peroxidation, caspase 3 levels, DNA fragmentation and intracellular calcium. Our results indicate that cannabidiol exerts a combination of neuroprotective, anti‐oxidative and anti‐apoptotic effects against β‐amyloid peptide toxicity, and that inhibition of caspase 3 appearance from its inactive precursor, pro‐caspase 3, by cannabidiol is involved in the signalling pathway for this neuroprotection.