Can Soy Diet be Protective in Severe and Diffuse Traumatic Brain Injury?

Abstract

Our previous studies have demonstrated that estrogen is protective in traumatic brain injury (TBI). However, concerns about negative consequences of estrogen therapy have led to find other strategies to obtain estrogen's benefits in the brain, including the use of a soy diet. This study was designed to determine whether a soy diet is protective in TBI. The male Albino N-Mary rats received either a soy-free diet (SFD) or soy diet (SD) from weaning to adulthood. The SFD and SD rats were separately divided to two groups of sham and TBI (n= 18 in each group). The diffuse and severe brain injury was induced by Marmarou method. The disruption of Blood brain-barrier (BBB) was evaluated 48 h post-TBI. The intracranial pressure (ICP), the neurologic outcome, and the beam-walk task (WB) were determined before trauma, on trauma day (D0), and first (D1) and second (D2) days post-TBI. Evans blue dye was significantly high in the SFD + TBI group vs. other groups. The ICP was significantly high in the SFD + TBI group in all times evaluated, and in the SD + TBI group on D1 and D2, however lower than that in the former group. The neurologic outcome score was significantly low in the SFD + TBI group vs. the sham groups in all times. Also the traversal time in WB task was significantly high in the SFD + TBI group not the SD + TBI group, vs. the sham groups in all times, however significant difference of distance traveled was shown only on trauma day. The results of this study demonstrate that soy diet can prevent the disruption of BBB, and attenuate the elevation of ICP, and the disturbance of vestibulomotor and neurologic performance in TBI.

Pharmacotherapeutic potential of soy isoflavones in neurological disorders

“…The assessment of vestibulomotor function by performing the Beam-walk (BW) task showed that soy diet prevented traversal time increase and it is concluded that the brain edema reduction followed by the ICP reduction might play a role. 115 Another study conducted by Soltani et al on male Wistar rats introduced genistein as a neuroprotective agent that helped blood-brain barrier (BBB) permeability, suppressed increase of ICP and lowered the brain edema development. According to this study, brain water content increased in TBI group compared to the control group.…”