We have shown that oral corticotropin hormone (ACTH) decreased clinical score, inflammatory foci and T_eff IL-17 in fed and adoptive transferred recipient mice with experimental autoimmune encephalomyelitis (EAE). Therefore, we determined whether oral administration of ACTH had immunological and endocrinological effects and was safe in humans.

Three groups of three healthy adult volunteers were assayed for total serum ACTH, cortisol and a set of pro-inflammatory and counter-regulatory cytokines after ingested dose(s) of ACTH 4 IU (n=3), 41 IU (n=3), or 123 IU (n=3) over 5 days.

There were no safety issues during the trial. There was no increase in total ACTH levels after day 1 or day 5. There was no significant increase in total cortisol among the groups comparing day 1 to day 5. There were significant decreases in the inflammatory cytokine IL-1 and IL-17 secretion at day 6 compared to baseline with the 123 IU dose but not after the 4 IU and 41 IU doses.

These data provide evidence for the safety and an immunological effect of oral ACTH in humans. It is unknown if the change in IL-1 and IL-17 reflects a local GI-mediated effect or effects following systemic absorption of ACTH.