Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye
Tezin Onay Tarihi: 2007
Öğrenci: NİZAMETTİN ÖZDOĞAN
Danışman: NURSEN ÇORUH
Özet:This study was designed to investigate the cytotoxic and antioxidative properties of Aesculus hippocastanum L. (A. hippocastanum) bark extracts. Dried and powdered barks were extracted in ethanol, methanol, water and ethylacetate at a ratio of 1:6 (w/v). Antioxidative capacity of each extract (ethanol, methanol, water and ethylacetate) were determined by their ability to scavenge 1, 1 -diphenyl-2-picryl-hydrazyl radical (DPPH). Effective concentration (EC50) values were calculated as 0.010 mg/mL 0.011 mg/mL, 0.009 and 0.019 mg/mL, respectively for ethanol, methanol, ethylacetate and aqueous extracts. The highest DPPH radical scavenging activity was demonstrated by ethyl acetate among the four bark extracts of A. hippocastanum. Nevertheless, methanol extract was preferred for the separation, identification and further quantification of ıts phenolic compounds using HPLC method. Analytical and semipreparative HPLC methods were applied to qualify and quantify the isolates. Human Myeloid Leukemia (HL - 60) cell line was used as a model system for the proliferation studies. HL - 60 cells were cultured in the presence of various concentrations (0 to 100 g/mL) of methanol bark extract and, also, with the various concentrations of standard esculetin. HL-60 cell viability was examined by tryphan blue and the metabolism of tetrazolium salt XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) -carbonyl]-2H-tetrazolium hydroxide). XTT effective dose (ED50) values for the proliferation studies of methanol extract and standard esculetin were calculated as 56.18 g/mL and 21.23 g/mL, respectively. These results suggested that A. hippocastanum methanol bark extract and esculetin could be considered as a potent antioxidant and cytotoxic agent.