The effect of Delta(8)-THC on experimental autoimmune encephalomyeliti
s (EAE) was examined. Delta(8)-THC is an analogue of Delta(9)-THC, the
psychoactive component of marijuana. It is more stable and less psych
otropic than Delta(9)-THC and like the latter it binds to the brain ca
nnabinoid receptor. Two strains of rats were inoculated for EAE, and D
elta(8)-THC (40 mg/kg) was administered for up to 21 days. Delta(8)-TH
C significantly reduced the incidence and severity of neurological def
icit in both rat strains. The beneficial influence of Delta(8)-THC onl
y occurred on oral administration and not with parenteral injection. S
erum corticosterone levels were twofold elevated in rats with EAE chro
nically treated with Delta(8)-THC. These results suggest that suppress
ion of EAE by cannabinoids may be related to their effect on corticost
erone secretion.