Authors:İ. Gülçin, Ş. Beydemir, ?.G. Şat, and Ö.İ. Küfrevioğlu
In present study, water extract of cornelian cherry (Cornus mas L.) (WECM) was studied for antioxidant properties. The antioxidant properties of WECM were evaluated using different antioxidant tests, including reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. These properties may be the major reason for the inhibition of lipid peroxidation. The concentration of 20, 40 and 60 µg ml-1 of WECM showed 75.8, 93.4 and 97.5% inhibition on peroxidation of linoleic acid emulsion, respectively. On the other hand, 60 µg ml-1 of standard antioxidants such as BHA, BHT and a-tocopherol exhibited 96.5, 99.2 and 61.1% inhibition on peroxidation of linoleic acid emulsion, respectively. In addition, the WECM had effective reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities at the same concentrations (20, 40, and 60 µg ml-1). Those various antioxidant activities were compared to reference antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and a -tocopherol. In addition, total phenolic compounds in the WECM were determinedas gallic acid equivalent.
Authors:Ş. Aras-Hisar, O. Hisar, Ş. Beydemir, I. Gülçin, and T. Yanik
Considering that the excessive usage of vitamin E causes hypervitaminosis and thus reduces blood erythrocyte concentrations, therefore it is worth studying how its pharmacological dosage affects the activity of carbonic anhydrase (CA) enzyme found in erythrocytes of rainbow trout (Oncorhynchus mykiss) in vitro and in vivo. Vitamin E inhibited CA enzyme and the IC50 value of the vitamin was 0.039 mM in vitro. Similarly, it was seen that vitamin E inhibited CA enzyme activity after the first hour following vitamin E injections in vivo. The activities of CA in groups of trout given vitamin E injection were measured at 1, 3 and 5 h and the corresponding activities were found to be 772.7 ± 290.5 (P < 0.05), 1286.4 ± 378.2 and 1005.7 ± 436.1 enzyme units (EU) g Hb-1. The difference over the control was significant (P < 0.05) in the first hour and insignificant at 3 and 5 h (P ? 0.05). The activity of CA in the control, which did not contain vitamin E, was determined as 1597.7 ± 429.0 EU g Hb-1.