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  • Author or Editor: G. Ozkan x
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In our study, the protective effects of vitamin E and Se (selenium) against cigarette smoke hazards on second-hand smoker (passive smoker) male mice (Balb/c) were investigated. Serum MDA levels in the smoke-exposed mice were found higher than serum MDA levels of control mice and Se- and vitamin E-treated mice. But, the MDA levels of smoke-exposed plus Se- and vitamin E-treated mice were found lower than MDA levels of smoke-exposed mice at the end of the three and five months. According to these results, application of vitamin E and Se, when given to smoke-exposed mice together, had an additive protective effect against cigarette smoke hazards (p<0.05). Vitamin E also had protective effect on formation of 8-OHdG in smoke-exposed mice. The serum 8-OHdG amounts of smoke-exposed plus vitamin E-treated mice were found low, but the serum 8-OHdG amounts of smoke-exposed mice were found high. Also 8-OHdG levels in the serum of the smoke-exposed mice were increased which occurs as a result of DNA oxidation (p<0.05). At the end of the three and five months, COMT (catechol-o-methyl transferase) activity of smoke-exposed mice livers were increased but, vitamin E and/or Se showed a significant protective effect on changing of COMT activity only at the end of the 5 months. Our results showed that MDA levels and 8-OHdG amounts were increased in the serum of smoke-exposed mice. On the other hand, vitamin E and Se had an additive protective effect against increasing MDA level. Also vitamin E had a protective effect against formation of 8-OHdG amounts and COMT activity alterations.

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In this study, the antibacterial and antioxidant activities of dried fruit extract of cranberry (gilaburu, Viburnum opulus) were determined. The total phenolic content was found to be 131.99±2.11 mg gallic acid equivalent (GAE) g-1 in the cranberry fruit extract (CFE). The antioxidant activity of the extract was found to be 315.50±8.2 mg g-1 in dried methanol extract. At 2, 5, 10 and 15% concentrations the extracts were tested for their antibacterial effects by using the agar diffusion method against ten bacteria, some of them pathogenic and some of them spoilage microorganisms. All bacteria were inhibited by 10 and 15% concentrations of the CFE. Methanol (control) had no inhibitory effect on all the tested bacteria. The most sensitive of the bacteria was A. hydrophila, whereas the most resistant bacterium was Y. enterocolitica.

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The aim of this study was to determine the changes in some physicochemical properties of olives (fruit weight, water content and oil content) and olive oils (total chlorophyll, carotenoid, pheophytin a, peroxide value and free acidity), and in the chemical properties (fatty acids, tocopherols, phenolics, oxidation stability and volatile profiles) of oils during ripening.Ripening indices (RI) of olive samples were 1.93 (unripe), 4.28 (ripe) and 5.89 (overripe). Most of the mentioned features changed with ripening. During ripening there was a sharp decrease in total chlorophyll, carotenoid and pheophytin a contents. An increase in oleic and linoleic acids and a decrease in palmitic acid were found in the fatty acid composition. Olive oils showed strong relations among oxidation stability, tocopherol content, total phenols content, and antiradical actvity of phenol extracts and these parameters decreased with maturation. Nevertheless, higher amounts of trans-2-hexenal were found in the oil from ripe olives than from unripe and overripe olives. On the other hand, the highest concentration of hexanal was found in the oil from overripe olives.In general, significant differences were observed in fruit weight, pigments, free acidity, fatty acid, tocopherol, and total phenolics contents, radical scavenger activity, oxidation stability, phenolic profile and volatile profile between the olive oils from the Gemlik cultivar at different stages of maturation.

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Acta Alimentaria
Authors: I. Tas, A.B. Yildirim, E. Ozkan, G.C. Ozyigitoglu, M.Z. Yavuz, and A.U. Turker

Lichens are a symbiotic relationship between a fungus and a photosynthetic partner. Chemical characterization and bioactive potentials (antiproliferative, antioxidant, and antibacterial) of five lichen species (Evernia prunastri, Platismatia glauca, Pseudevernia furfuracea, Ramalina fastigiata, and Ramalina farinacea) were assessed. Five lichen metabolites (usnic acid, atranorin, stictic acid, evernic acid, and fumarprotocetraric acid) were analyzed by HPLC-DAD. E. prunastri was noteworthy evernic acid source. Antiproliferative activity was evaluated using human breast adenocarcinoma (MCF-7) and human hepatocellular carcinoma (HepG2/C3A) cell lines. The strongest activity was observed for P. glauca against HepG2/C3A, while the only lichen species that induced cytotoxicity against MCF-7 cell line was P. furfuracea. The highest antioxidant activity was also obtained with P. furfuracea. E. prunastri and R. farinaceae had the highest phenolic and flavonoid contents, respectively. Antibacterial activities of the extracts were determined against ten pathogenic bacteria. The most effective antibacterial agent was methanol extract of R. fastigiata. Our findings have revealed the pharmaceutical potentials of tested lichen species.

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