Neuroprotective antioxidant effect of sex steroid hormones in traumatic brain injury.

The aim of the present study was to evaluate the effect of different doses of sex steroid hormones on brain edema, BBB permeability, brain antioxidant enzyme activity, and MDA level after traumatic brain injury (TBI) in ovarectomized (OVX) rats. Female rats were divided into six (One sham and 5 TBI) groups including: vehicle, estrogen in physiologic (33.3 μg/kg) and pharmacologic (1mg/kg) doses, progesterone in physiologic (1.7 mg/kg) and pharmacological doses (8mg/kg). The results showed that compared to vehicle group, estrogen and progesterone groups showed significantly lower brain water content (P<0.001). Evans blue content was significantly lower in both estrogen doses and in progesterone physiologic dose (P<0.001). Evans blue content was significantly higher in progesterone pharmacologic dose (P<0.001). Superoxide dismutase (SOD) activity was significantly higher in estrogen and progesterone pharmacologic doses (P<0.001). Glutathione peroxidase (GPx) activity was significantly lower in estrogen physiologic dose (P<0.001). It was concluded that the neuroprotective effect of different doses of sex steroid hormones after TBI, may be mediated by changes in oxidant agent activity.