Sildenafil (Viagra®) down regulates cytokines and prevents demyelination in a cuprizone-induced MS mouse model

► Sildenafil effects on cerebellum were studied in a multiple sclerosis mice model. ► CPZ increased GFAP and Iba-1 expression, and sildenafil inhibited this effect. ► Sildenafil had an anti-inflammatory effect, decreasing cytokines/COX-2 levels. ► Sildenafil inhibited CPZ-induced demyelination in the cerebellum. ► The data suggest a beneficial effect of PDE5 inhibition in CNS injury.