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A Trial of Sulforaphane in Autism

Despite intensive research efforts, neither prevention nor treatment of underlying mechanisms in autism is possible. In a published study, Dr. Zimmerman and colleagues confirmed anecdotal observations that behavioral symptoms in autistic children improve during episodes of fever. The cellular mechanisms underlying the effects of fever in autism remain to be clarified, however it is likely that heat shock proteins are involved. Dr. Zimmerman and his group hypothesized that in autism, enhancement of under-expressed genes and induction of the cellular stress response proteome, including heat shock proteins, will occur in response to treatment with sulforaphane. Mounting evidence shows that sulforaphane, a derivative of cruciferous vegetables (and therefore of low toxicity), defends cells against stresses by upregulating a network of cytoprotective genes that defend against oxidation, inflammation and mitochondrial dysfunction. All of these processes have been described in autism, in which multiple genes appear to be involved, with mutations that are not lethal but cause marked dysfunction, especially in the central nervous system. To date, specific gene mutations account for only 10-15% of patients with autism. Positive effects of fever occur in from 38 to 83% of patients with autism. Sulforaphane, as both oral and topical broccoli sprout extracts, penetrates the CNS and is well tolerated. It has been shown to be bioavailable to nerve cells and accumulates in the brain with various routes of administration. Dr. Zimmerman and his group undertook a Phase I/II study of sulforaphane in 45 young adult males with autism, 13-30 years of age. They measured a core feature of autistic spectrum disorders: social communication deficits. Cellular effects of sulforaphane was measured in lymphocytes during treatment. The trial’s primary objectives were to answer whether treatment administered within a specified dose range is safe, treatment administered within a specified dose range is well tolerated by young autistic males, there is evidence of a measurable effect on behavioral symptoms, there is evidence that treatment within the specified range has observable activity affecting social communication, and key cellular biomarkers support the hypothesized mechanism.