Due to the ease of administration, relatively high safety profile and its low cost and ready availability, the hormone progesterone (PROG) and its metabolites should be considered as a viable treatment option for traumatic brain injuries (TBI), according to a clinical perspective published in this month's American Journal of Roentgenology.
Donald Stein, PhD, and colleagues at the department of emergency medicine at Emory University in Atlanta, found that the administration of PROG--a naturally occurring hormone found in both males and females that can protect damaged cells in the central and peripheral nervous systems--can allow for the reduction of edema, or swelling levels after TBI; the significant reduction of the area of necrotic cell death in different models of cerebral ischemia; the improvement of behavioral outcomes; and the protection of neurons distal to the injury that would normally die.
Considered primarily a female sex hormone involved in regulating pregnancy, current research has been conducted to demonstrate that PROG may potentially serve many purposes in terms of brain injuries, as the hormone can cross the blood-brain barrier, explained the researchers.
“In pregnant females, progesterone levels increase more than 10-fold and remain high throughout gestation of the fetus,” said the researchers. “It is our contention that progesterone's mechanisms of action have evolved primarily to protect the developing fetus against oxidative stress and immune–inflammatory rejection reactions."
"It also appears to play a critical role in neuronal–glial signaling and normal neuronal development," Stein and his colleagues wrote. "Many of the processes of central nervous system repair recapitulate the steps taking place during development, and this is why we think that progesterone may also show promise in the treatment of traumatic and degenerative disorders of the brain and the central nervous system.”
The hormone was recently tested in two phase 2 clinical trials for traumatic brain injury and is slated to begin a phase 3 trial this month.
“PROG should be considered a viable treatment option — especially because, in brain injury, so little else is currently available,” concluded Stein.