Durmuş, M; Yilmaz, HR; Uz, E; Özçelik, N
Aim: This study was performed to determine the effect of caffeic acid phenethyl ester (CAPE) treatment on levels of malondialdehyde (MDA) and nitric oxide (NO) and activities of antioxidant enzymes in retinas of streptozotocin (STZ)-induced diabetic rats. Materials and Methods: Twenty-seven rats were enrolled and divided into three groups: group 1: nondiabetic rats as control (n = 9); group 2: STZ-induced, untreated diabetic rats (n = 8); and group 3: STZ-induced, CAPE-treated diabetic rats (n = 10). Levels of MDA and NO and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in retinal tissues were analyzed. Results: In retinas of untreated diabetic rats, levels of MDA and NO and the activity of GSH-Px were significantly increased (P = 0.001, P = 0.0001, P = 0.0001, respectively), while the SOD activity was significantly decreased (P = 0.021) when compared to the control group. GSH-Px activity in the CAPE-treated diabetic group was markedly higher than that of the control group (P = 0.0001). MDA and NO levels were lower (P = 0.005, P = 0.001, respectively) and SOD activity was higher in the CAPE-treated diabetic group compared to the untreated diabetic group (P = 0.016). Conclusions: It can be concluded that nitrosative and oxidative stress is increased in the diabetic retina. CAPE treatment inhibits lipid peroxidation and NO overproduction and regulates SOD enzyme activities in diabetic rat retinas while it has no effects on GSH-Px activity. (English) [ABSTRACT FROM AUTHOR] Amaç: Bu çalişma, streptozotocin (STZ) ile diyabet oluşturulmuş siçanlarda, kafeik asit fenetil ester (CAPE) tedavisinin retinadaki malondialdehit (MDA), nitrik oksit (NO) düzeyleri ve antioksidan enzim aktiviteleri üzerine etkilerini araştirmak üzere yapildi. Yöntem ve Gereç: Yirmiyedi siçan çalişmaya alindi ve üç gruba ayrildi: grup 1: diyabetik olmayan siçanlar (kontrol grubu) (N = 9); grup 2: STZ uygulanmiş-tedavi uygulanmamiş siçanlar (N = 8); grup 3: STZ uygulanmiş ve CAPE tedavisi verilmiş siçanlar (N = 10). Bütün gruplarin retinalarinda, MDA ve NO düzeyleri, superoksit dismutaz (SOD) ve glutatyon peroksidaz (GSH-Px) enzim aktiviteleri analiz edildi. Bulgular: Kontrol grubu ile kiyaslandiğinda, tedavi uygulanmamiş diyabetik siçanlarda MDA ve NO düzeyleri ve GSH-Px aktivitesi artmiş ( sirasiyla P = 0.001, P = 0.0001, P = 0.0001), buna karşilik SOD aktivitesi önemli ölçüde azalmiş olarak bulundu (P = 0.021). GSH-Px aktivitesi CAPE tedavisi uygulanmiş diyabetik siçanlarda, kontrol grubuna göre belirgin ölçüde yüksekti (P = 0.0001). CAPE tedavisi uygulanmiş diyabetik siçanlarda, tedavi edilmemiş olanlara nazaran MDA ve NO düzeyleri azalmiş (sirasiyla P = 0.005, P = 0.001), SOD aktivitesi artmişti (P = 0.016). Sonuç: STZ ile diyabet oluşturulmuş siçanlarda MDA ve NO düzeyleri ve GSH-Px aktivitesi artmişti, CAPE tedavisi ile GSH-Px dişindakiler azalmaktaydi. SOD aktivitesi diyabetik grupta azalmişken, CAPE tedavisi ile artmaktaydi. (Turkish) [ABSTRACT FROM AUTHOR] Copyright of Turkish Journal of Medical Sciences is the property of Scientific and Technical Research Council of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)