Aim of this study is to evaluate protective impact of Astaxanthin (AST) on rats with experimental brain injury induced with Cadmium (Cd). 32 male Wistar albino rats were divided into four groups as Control, Cadmium, Astaxanthin (AST), Cadmium (Cd)+Astaxanthin (AST). Rat brain tissues were obtained at the end of 30 th day. Malondialdehyde (MDA), glutathione (GSH) levels and superoxide dismutase (SOD) enzyme activities were measured in brain homogenates and histopathological examination was performed. MDA levels were improvement in cadmium administered group (p<0.01) as well as Cd+AST administered group (p<0.05) compared to control group. In addition a substantial reduction Cd+AST group was observed compared to cadmium administered group (p<0.01). GSH level shows a decrease in Cd and Cd+AST groups compared to control (p<0.05). SOD enzyme activity was found significantly lower in Cd and Cd+AST groups compared to control (p<0.01). In addition, increase of SOD in Cd+AST group compared to cadmium group was also found significant (p<0.05). Histopathological findings in the cerebral cortex and hippocampus were different between groups. In the control and AST administered groups, normal histological structure was observed in the brain, while severe lesions were seen in the Cd administered group and in the Cd+AST group only mild degenerative lesions were observed.As a result, elevated MDA level due to Cd administration was attenuated with AST administration. Decreased GSH level and SOD enzyme activity due to Cd administration was increased with AST administration. In addition, AST administration decreased histopathological lesions. Consequently, it is thought that AST may be used for protection against brain oxidative damage due to Cd.Keywords: Astaxanthin, cadmium, oxidative stress.ÖZET: Bu çalışmada, ratlarda kadmiyum (Cd), ile meydana gelen beyin hasarını önlemede astaksantinin (AST), koruyucu etkisinin değerlendirilmesi amaçlandı. 32 adet Winstar albino cinsi rat kontol, Kadmiyum (Cd), Astaksantin (AST), Kadmiyum (Cd)+Astaksantin (AST), olmak üzere dört gruba ayrıldı. 30. Günün sonunda rat beyin dokuları alındı. Beyin doku homojenatında malondialdehit (MDA), Glutatyon (GSH) seviyeleri ve süperoksitdismutaz (SOD) enzim aktivitesi ölçülerek, histopatolojik inceleme yapıldı. Beyin dokusu MDA, düzeyleri değerlendirildiğinde kontrol grubu ile kıyaslandığında Cd uygulaması yapılan grupta (p<0,01) ve yine Cd+AST uygulanan grupta artış (p<0,05) olduğu belirlendi. Cd uygulaması yapılan gruba oranla Cd+AST grubunda görülen azalmanın istatistiksel olarak önemli olduğu belirlenmişdir (p<0,01). GSH düzeyleri değerlendirildiğinde, Cd ve Cd+AST grupları, kontrol grubu ile kıyaslandığında gruplar arasında istatistiksel olarak azalışın olduğu belirlendi (p<0,05). SOD enzim aktivitesi değerlendirildiğinde ise Cd ve Cd+AST gruplarında, kontrol grubuna kıyasla görülen azalışın (p<0,01) istatistiksel olarak önemli olduğu, Cd grubuna oranla, Cd+AST uygulaması yapılan grupta SOD düzeyinde görülen artışın önemli olduğu belirlendi (p<0,05). Hi...