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Rosmarinic acid (RA), which has multiple bioactive properties, might be a useful agent for protecting central nervous system against age related alterations. In this context, the purpose of the present study was to investigate possible protective effects of RA on mismatch negativity (MMN) component of auditory event-related potentials (AERPs) as an indicator of auditory discrimination and echoic memory in the ovariectomized (OVX) rats injected with D-galactose combined with neurochemical and histological analyses. Ninety female Wistar rats were randomly divided into six groups: sham control (5); RA-treated (R); OVX (O); OVX + RA-treated (OR); OVX+ D-galactose-treated (OD); OVX+ D-galactose + RA treated (ODR). Eight weeks later, MMN responses were recorded using the oddball condition. An amplitude reduction of some components of AERPs was observed due to ovariectomy with or without D-galactose administiration and these reduction patterns were diverse for different electrode locations. MMN amplitudes were significantly lower over temporal and right frontal locations in the o and OD groups versus the S and R groups, which was accompanied by increased thiobarbituric acid reactive substances (TBARS) and hydroxy-2-nonenal (4-HNE) levels. RA treatment significantly increased AERP/MMN amplitudes and lowered the TBARS/4-HNE levels in the OR and ODR groups versus the 0 and OD groups, respectively. Our findings support the potential benefit of RA in the prevention of auditory distortion related to the estrogen deficiency and D-galactose administration at least partly by antioxidant actions. (C) 2017 Elsevier B.V. All rights reserved.

The purpose of the present study was to investigate the duration effects of 2100-MHz electromagnetic field (EMF) on visual evoked potentials (VEPs) and to assess lipid peroxidation (LPO), nitric oxide (NO) production and antioxidant status of EMF exposed rats. Rats were randomized to following groups: Sham rats (S1 and S10) and rats exposed to 2100-MHz EMF (El and E10) for 2 h/day for 1 or 10 weeks, respectively. At the end of experimental periods, VEPs were recorded under anesthesia. Brain thiobarbituric acid reactive substances (TBARS) and 4-hydroxy-2-nonenal (4-HNE) levels were significantly decreased in the El whereas increased in the E10 compared with their control groups. While brain catalase (CAT), glutathione peroxidase (GSH-Px) activities and NO and glutathione (GSH) levels were significantly increased in the El, reduction of superoxide dismutase (SOD) activity was detected in the same group compared with the Si. Conversely, decreased CAT, GSH-Px activities and NO levels were observed in the E10 compared with the S10. Latencies of all VEP components were shortened in the El compared with the Si, whereas latencies of all VEP components, except P1, were prolonged in the E10 compared with the S10. There was a positive correlation between all VEP latencies and brain TBARS and 4-HNE values. Consequently, it could be concluded that different effects of EMFs on VEPs depend on exposure duration. In addition, our results indicated that short-term EMF could provide protective effects, while long-term EMF could have an adverse effect on VEPs and oxidant/antioxidant status. (C) 2016 Elsevier B.V. All rights reserved.