Abstract In the present study the acute and subacute antidiabetic activities of the ethanolic extract of Vitis vinifera L. leaves were investigated. The acute effect was studied on the normoglycaemic, glucose hyperglycaemic and streptozotocin-induced d iabetic rats; and the subacute effect was studied on same diabetic rats for 15 days. The blood glucose levels were measured by using blood glucose measuring strips based on glucose-oxidase method. After the subacute administration, the antioxidant activity of the extracts was investigated on the liver, kidney and the heart tissues of the experimental animals by measuring the tissue GSH and MDA levels. All of the antioxidant parameters were compared with the diabetic control group. According to the obtained data, the ethanolic extract of V. vinifera leaves at 250 mg/kg dose was found to possess a high antidiabetic and antioxidant activity. Mainly condensed tannins and flavonoids were suggested to contribute in the activities. Özet Bu çalismada Vitis vinifera L. yapraklarinin etanolik ekstresinin akut ve subakut aktivitesi incelenmistir. Akut etkinin degerlendirilebilmesi için normoglisemik, glukoz hiperglisemik ve streptozotosin ile diyabet olusturulmus siçanlar kullanilmistir. Subakut etki ise 15 gün boyunca streptozotosin ile diyabet olusturulmus siçanlar üzerinde incelenmistir. Kan glukoz seviyeleri kan glikoz test çubuklari kullanilarak glukoz oksidaz metodu ile ölçülmüstür. Subakut uygulama sonrasi ekstrelerin antioksidan aktiviteleri karaciger, böbrek ve kalp dokularinin GSH ve MDA seviyeleri ölçülerek degerlendirilmistir. Antioksidan parametrelerin hepsi diyabetik kontrol grubu ile karsilastirilmistir. V. vinifera yapraklarinin etanol ekstresi 250 mg/kg dozda antidiyabetik ve antioksidan aktivite göstermistir. Aktiviteden baslica kondanse tanenlerin ve flavonoitlerin sorumlu oldugu düsünülmektedir.

Keywords: Vitis vinifera, antidiabetic, hypoglycaemia, antioxidant, lipid peroxidation, MDA, GSH