Is genistein neuroprotective in traumatic brain injury?

The concerns about negative consequences of estrogen therapy have led to introduce other strategies to obtain estrogen's benefits in the brain. The present study tests the hypothesis that a major isoflavone of soy; genistein with estrogen-like activity can be neuroprotective in traumatic brain injury (TBI). The male Wistar rats were randomly divided to four groups: sham, TBI, vehicle and genistein. The TBI was induced by Marmarou method. The brain edema and the disruption of blood-brain-barrier (BBB) were evaluated 48 h post-TBI. Genistein (15 mg/kg) or dimethyl sulfoxide (DMSO) was injected i.p., twice after TBI. The intracranial pressure (ICP), the motor performance, and the beam-walk task (WB) were determined before trauma, on trauma day (D0), and first (D1) and second (D2) days post-TBI. Genistein inhibited a development of brain edema and a BBB permeability in TBI animals. An increase of ICP and a defect in motor and WB performance were showed following TBI, in all times evaluated. An increase of ICP induced by TBI was suppressed by genistein on D1 and D2 times. Genistein improved a motor disorder induced by TBI, on D1 and D2 times. Also an increase of traversal time in WB task was suppressed by genistein in TBI animals, on D1 and D2 times. The results of this study demonstrated that genistein can be neuroprotective in TBI. Genistein inhibited the disruption of BBB, the brain edema and the increase of ICP, and the disturbance of neurobehavioral performance in TBI.