Magalhães Ana S, Silva Branca M, Pereira José A, Andrade Paula B, Valentão Patrícia, Carvalho Márcia
CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, R. Carlos da Maia, 296, 4200-150 Porto, Portugal.
Food Chem Toxicol. 2009 Jun;47(6):1372-7. doi: 10.1016/j.fct.2009.03.017. Epub 2009 Mar 21.
The aim of this study was to determine the phenolic content and evaluate the antioxidant activity of quince (Cydonia oblonga) fruit. For this purpose, fruits were separated into pulps, peels and seeds and methanolic extracts were prepared. The phenolic profiles were determined by HPLC/UV and antioxidant properties were studied for their ability to quench the stable free radical 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and to inhibit the 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of human erythrocytes. The main phenolic compounds were 5-O-caffeoylquinic acid for pulp and peel (57% and 29%, respectively) and stellarin-2 for seed (18%). Total phenolics content was 2.5, 6.3 and 0.4g/kg of methanolic extract for pulp, peel and seed, respectively. Pulp and peel extracts showed similar DPPH free radical scavenging activities (EC(50) of 0.6 and 0.8 mg/ml, respectively), while seed extract presented much lower antioxidant potential (EC(50) of 12.2mg/ml). Under the oxidative action of AAPH, pulp and peel extracts showed significant protection of the erythrocyte membrane from hemolysis, in a time- and concentration-dependent manner. Seed extracts by themselves induced extensive hemolysis. These results indicate higher antioxidant activity for certain parts of quince fruit, namely pulp and peel, that may therefore represent accessible sources of natural antioxidants with potential application in nutritional/pharmaceutical fields, as preventive or therapeutic agents in diseases in which free radicals are implicated.
本研究的目的是测定温柏（Cydonia oblonga）果实的酚类含量并评估其抗氧化活性。为此，将果实分为果肉、果皮和种子，并制备了甲醇提取物。通过高效液相色谱/紫外检测法测定酚类成分，并研究其抗氧化特性，即淬灭稳定自由基2,2'-二苯基-1-苦基肼（DPPH）的能力以及抑制2,2'-偶氮二异丁脒盐酸盐（AAPH）诱导的人红细胞氧化溶血的能力。主要酚类化合物在果肉和果皮中分别为5-O-咖啡酰奎尼酸（分别占57%和29%），在种子中为星芒菌素-2（占18%）。果肉、果皮和种子的甲醇提取物中总酚含量分别为2.5、6.3和0.4 g/kg。果肉和果皮提取物表现出相似的DPPH自由基清除活性（EC(50)分别为0.6和0.8 mg/ml），而种子提取物的抗氧化潜力则低得多（EC(50)为12.2 mg/ml）。在AAPH的氧化作用下，果肉和果皮提取物对红细胞膜溶血表现出显著的保护作用，呈时间和浓度依赖性。种子提取物本身会导致广泛的溶血。这些结果表明，温柏果实的某些部分，即果肉和果皮，具有较高的抗氧化活性，因此可能是天然抗氧化剂的可获取来源，在营养/制药领域具有潜在应用价值，可作为涉及自由基的疾病的预防或治疗剂。
