Browsing by Author "Dawbaa, Sam"
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Publication Investigation of antioxidant ability of grape seeds extract to prevent oxidatively induced dna damage by gas chromatography-tandem mass spectrometry(2018) Aybastier, Önder; Dawbaa, Sam; Demir, Cevdet; AYBASTIER, ÖNDER; Dawbaa, Sam; DEMİR, CEVDET; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü; 0000-0003-1508-0181; 0000-0002-9381-0410; 0000-0002-0380-1992; 0000-0001-7001-0739; AFR-1890-2022; ABA-2005-2020; KRQ-0516-2024; X-4621-2018Phenolic compounds have been studied elaborately for their efficacy to improve health and to protect against a wide variety of diseases. Herein this study, different analysis methods were implemented to evaluate the antioxidant properties of catechin and cyanidin using their standard substances and as they found in the grape seeds extracts. Total phenol contents were 107.39 +/- 8.94 mg GAE/g dw of grape seeds for grape seed extract (GSE) and 218.32 +/- 10.66 mg GAE/g dw of grape seeds for acid-hydrolyzed grape seed extract (AcGSE). The extracts were analyzed by HPLC-DAD system and the results showed the presence of catechin, gallic acid, chlorogenic acid and ellagic acid in the processed methanolic extract and cyanidin, gallic acid and ellagic acid in the processed acidified methanolic extract. The protective abilities of catechin and cyanidin were tested against the oxidation of DNA. The results showed that cyanidin has better protection of DNA against oxidation than catechin. GSE and AcGSE were revealed to inhibit the oxidatively induced DNA damage. GSE decreased about 57% of damage caused by the Fenton control sample. This study could show new aspects of the antioxidant profiles of cyanidin and catechin.Item Investigation of antioxidant ability of grape seeds extract to prevent oxidatively induced DNA damage by gas chromatography-tandem mass spectrometry(Elsevier, 2018-01-01) Aybastıer, Önder; Dawbaa, Sam; Demir, Cevdet; Uludağ Üniversitesi/Fen - Edebiyat Fakültesi/Kimya Bölümü.; 0000-0002-0380-1992; 0000-0001-7001-0739; 0000-0003-1508-0181; X-4621-2018; DUQ-8689-2022; DTQ-5753-2022; 35344478800; 55697616600; 7003565902Phenolic compounds have been studied elaborately for their efficacy to improve health and to protect against a wide variety of diseases. Herein this study, different analysis methods were implemented to evaluate the antioxidant properties of catechin and cyanidin using their standard substances and as they found in the grape seeds extracts. Total phenol contents were 107.39 +/- 8.94 mg GAE/g dw of grape seeds for grape seed extract (GSE) and 218.32 +/- 10.66 mg GAE/g dw of grape seeds for acid-hydrolyzed grape seed extract (AcGSE). The extracts were analyzed by HPLC-DAD system and the results showed the presence of catechin, gallic acid, chlorogenic acid and ellagic acid in the processed methanolic extract and cyanidin, gallic acid and ellagic acid in the processed acidified methanolic extract. The protective abilities of catechin and cyanidin were tested against the oxidation of DNA. The results showed that cyanidin has better protection of DNA against oxidation than catechin. GSE and AcGSE were revealed to inhibit the oxidatively induced DNA damage. GSE decreased about 57% of damage caused by the Fenton control sample. This study could show new aspects of the antioxidant profiles of cyanidin and catechin.Item Quantification of DNA damage products by gas chromatography tandem mass spectrometry in lung cell lines and prevention effect of thyme antioxidants on oxidative induced DNA damage(Elsevier, 2018-01-16) Ulukaya, Engin; Aybastıer, Önder; Dawbaa, Sam; Demir, Cevdet; Akgün, Oğuzhan; Arı, Ferda; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü.; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Biyoloji Bölümü.; 0000-0002-0380-1992; 0000-0001-7001-0739; 0000-0002-9381-0410; 0000-0002-8410-1786; 0000-0002-6729-7908; X-4621-2018; AFR-1890-2022; A-5608-2019; AAG-7012-2021; 35344478800; 55697616600; 7003565902; 57194269996; 24376085300Lung cancer has a high treatment cost and poor prognosis in comparison to other types of cancers. This work was involved in studying oxidative DNA base damage inhibition. Accordingly, standard carvacrol, thymol, thymoquinone with water and water-methanol extract of thyme (Origanum vulgare L. subsp. hirtum (link.) Ietswaart), thyme oil and thyme water were prepared and investigated for their efficacy to inhibit DNA oxidative damage formed by H2O2 in malignant lung cells (A549). The antioxidant capacity by ABTS assay was 271.73 +/- 11.45 mg trolox equivalent/mL for thyme oil. HPLC analysis was carried out to determine the contents of different thyme extracts, results showing the presence of carvacrol, thymol, protocatechuic acid, caffeic acid, epicatechin and rosmarinic acid in water and water-methanol extracts while only carvacrol and thymol were found in thyme oil and thyme water. After DNA isolation from the cultured cells, the formed oxidative induced DNA damage products were analysed using GC-MS/MS. It was proven that the antioxidants in the cell culture media have succeeded to inhibit oxidative DNA base damage. Thymoquinone was shown to be the best protectant antioxidant among other antioxidants against the formation of oxidative DNA damage, whereas water-methanol extract of thyme was the best among the plant-sourced samples. Thymoquinone and thyme water-methanol extract were investigated for their efficacy on cultured healthy lung cells (BEAS-2B), and it was proven that they are efficient in protection against the oxidation of DNA of healthy lung cells too.Item Rutin ve izokuersitrin antioksidanların DNA oksidasyonuna karşı etkilerin incelenmesi(Uludağ Üniversitesi, 2017-05-09) Dawbaa, Sam; Şahin, Saliha; Uludağ Üniversitesi/Fen Bilimleri Enstitüsü/Kimya Anabilim Dalı.Oksidatif stres, DNA hasarının en önemli nedenlerinden biri olarak kabul edilir ve kanser oluşumu, mutasyon, yaşlanma gibi bir dizi ara süreç yoluyla hücre ölümüne neden olur. Bitki ve meyve gibi doğal kaynaklar, hücrelerin genetik materyalini oksidasyona karşı korumak için kullanılabilecek antioksidan maddeleri içerirler. Bu çalışmada, Vitis vinifera (alfons)'un sürgünlerinde bulunan antioksidan maddeler ekstrakte edilerek oksidasyon sonucu oluşan DNA hasar ürünlerinin oluşumu üzerine etkisi GC-MS/MS ile tayin edilmiştir. Ayrıca, Folin-Ciocalteau ve CHROMAC yöntemleri kullanılarak ekstraktın toplam fenol içeriği ve antioksidan kapasitesi belirlenmiştir. Toplam fenol değeri 7,83 ± 0,08 mg GAE/g taze ağırlık ve antioksidan kapasitesi 8,17 ± 0,49 mg TE/g taze ağırlık olarak tayin edilmiştir. Bitki ekstraktının HPLC-DAD ile yapılan nitel analiz sonucu ekstraktın içinde rutin ve izokuersitrin olmak üzere iki flavonoid glikozitin ve klorojenik asitin bulunduğunu ortaya koymuştur. DNA oksidasyon ürünlerinin belirlenmesi, farklı konsantrasyonlarda standart rutin ve izokuersitrin çözeltileri ile ekstraktın oksidatif stres altında buzağı timus DNA'sına uyguladıktan sonra gerçekleştirilmiştir. On sekiz DNA oksidasyon ürünü yüksek duyarlılıkla GC-MS/MS kullanılarak tayin edilmiştir. Sonuçlar, oksidatif strese karşı koruyucu bir madde olarak Vitis vinifera (alfons) sürgününün ekstraktı kullanıldığında, DNA oksidasyon ürünlerinin miktarında önemli bir azalma olduğunu göstermiştir. Sonuç olarak, V. vinifera (tür: alfons)'un sürgünlerinin iyi bir antioksidan aktiviteye sahip olduğu belirlenmiştir. Bu nedenle, günlük sağlıklı yiyecek listesinin bir parçası olarak kullanılması önerilebilir.Item Ultrasensitive determination of DNA oxidation products by gas chromatography-tandem mass spectrometry and the role of antioxidants in the prevention of oxidative damage(Elsevier, 2017-03-14) Dawbaa, Sam; Aybastıer, Önder; Demir, Cevdet; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü.; 0000-0003-1508-0181; 0000-0002-0380-1992; 0000-0002-9381-0410; 0000-0001-7001-0739; AFR-1890-2022; ABA-2005-2020; X-4621-2018; 55697616600; 35344478800; 7003565902Oxidative stress is considered as one of the significant causes of DNA damage which in turn contributes to cell death through a series of intermediate processes such as cancer formation, mutation, and aging. Natural sources such as plant and fruit products have provided us with interesting substances of antioxidant activity that could be recruited in protecting the genetic materials of the cells. This study is an effort to discover some of those antioxidants effects in their standard and natural forms by performing an ultra sensitive determination of the products of DNA oxidation using GC-MS/MS. Experiments were used to determine the direct antioxidant activity of the substances contained in the tendrils of Vitis vinifera (var. alphonse) by extracting them and achieving Folin-Ciocalteau and CHROMAC analyses to determine the total phenolic content (TPC) and the antioxidant capacity of the extract, respectively; results revealed a phenolic content of 11.39 +/- 0.30 mg Gallic Acid Equivalent (GAE)/g of the plant's fresh weight (FW) by Folin-Ciocalteau and 8.17 +/- 0.49 mg Trolox Equivalent (TE)/g FW by CHROMAC assays. The qualitative analysis of the plant extract by HPLC-DAD technique revealed that two flavonoid glycosides namely rutin and isoquercitrin in addition to chlorogenic acid were contained in the extract. The determination of the DNA oxidation products was performed after putting DNA, rutin and isoquercitrin standard samples with different concentration, and the extract's sample under oxidative stress. Eighteen DNA oxidation products were traced using GC-MS/MS with ultra-sensitivity and the experiments proved a significant decrease in the concentration of the DNA oxidation products when the extract was used as a protectant against the oxidative stress. It is believed by conclusion that the extract of V. vinifera's (var. alphonse) tendrils has a good antioxidant activity; hence it is recommended to be used as a part of the daily healthy food list if possible.