HU-211, a Nonpsychotropic Cannabinoid, Produces Short- and Long-Term Neuroprotection after Optic Nerve Axotomy

HU-211 is a novel synthetic analog of tetrahydrocannabinol that was recently shown in animal models to be nonpsychotropic. In this study we show that HU-211 can potentially be used as a neuroprotective compound in the CNS. Using a calibrated crush injury of adult rat optic nerve, we show that HU-211 can reduce injury-induced metabolic and electrophysiological deficits. Energy metabolism was monitored by measuring the intramitochondrial nicotine-amine adenine dinucleotide redox state hourly for 6 h after injury and treatment. Electrophysiological activity was assessed by compound action potential and visual evoked potential response. Beneficial effects were dose-dependent, being optimal at 7 mg/kg, administered intraperitoneally. The time window during which treatment was effective was found to be from the time of injury for at least 5 h, with treatment most effective at the time of injury. These results strongly suggest that HU-211, given immediately after CNS injury at the optimal dosage, may possess neuroprotective activities.