Neuroprotective Effect of Ginseng against Alteration of Calcium Binding Proteins Immunoreactivity in the Mice Hippocampus after Radiofrequency Exposure

Calcium binding proteins (CaBPs) such as calbindin D28-k, parvalbumin, and calretinin are able to bind Ca(2+) with high affinity. Changes in Ca(2+) concentrations via CaBPs can disturb Ca(2+) homeostasis. Brain damage can be induced by the prolonged electromagnetic field (EMF) exposure with loss of interacellular Ca(2+) balance. The present study investigated the radioprotective effect of ginseng in regard to CaBPs immunoreactivity (IR) in the hippocampus through immunohistochemistry after one-month exposure at 1.6 SAR value by comparing sham control with exposed and ginseng-treated exposed groups separately. Loss of dendritic arborization was noted with the CaBPs in the Cornu Ammonis areas as well as a decrease of staining intensity of the granule cells in the dentate gyrus after exposure while no loss was observed in the ginseng-treated group. A significant difference in the relative mean density was noted between control and exposed groups but was nonsignificant in the ginseng-treated group. Decrease in CaBP IR with changes in the neuronal staining as observed in the exposed group would affect the hippocampal trisynaptic circuit by alteration of the Ca(2+) concentration which could be prevented by ginseng. Hence, ginseng could contribute as a radioprotective agent against EMF exposure, contributing to the maintenance of Ca(2+) homeostasis by preventing impairment of intracellular Ca(2+) levels in the hippocampus.