Farombi E Olatunde, Ogundipe Oluyemisi O, Samuel Uhunwangho E, Adeyanju Mary A, Olarenwaju Moody J
Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine University of Ibadan, Ibadan, Nigeria.
Phytother Res. 2003 Aug;17(7):713-6. doi: 10.1002/ptr.1050.
The antioxidant activities of the leaf and root extracts of Alchornea laxiflora, a plant used locally for the preservation of food items in Nigeria, were evaluated using the ferric thiocyanate method, horseradish peroxidase catalysed oxidation of 2,2 azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), beta-carotene linoleate model system and Fe(2+)/ascorbate/H(2)O(2)-induced rat liver microsomal lipid peroxidation. The crude hexane root (HR), methanol root (MR), methanol leaf (ML) and hexane leaf (HL) extracts from A. laxiflora were tested for antioxidant activities. Antioxidant activity decreased in the following order: HR (76.4%), MR (63%), ML (40%) and HL (38%) at a concentration of 0.05% v/v. The antioxidant activity of HR compared to that of butylated hydroxyanisole (BHA) (80%), a standard antioxidant. The total antioxidant activity (TAA) of the crude extracts suggests that activity is highest in the HR compared with the others. The TAA value was estimated to be 8.0 measured as mm of vitamin C equivalent. Six column chromatographic fractions (FI-FVI) from HR showed antioxidant activity to varying extents in the beta-carotene model system in the order of FII > FI > FVI > FIII > FIV > FV. FII exhibited the highest antioxidant activity in all model systems utilized, it recorded a higher antioxidant activity than BHA and quercetin in the beta-carotene linoleate and Fe(2+)/ascorbate/H(2)O(2). TLC analysis of fraction II revealed the presence of terpenoid compounds (radiant green coloration with 2,4 dinitrophenylhydrazine). Our results suggest that A. laxiflora contains potent natural antioxidants and may therefore be relevant in the preservation of lipid food products, which are prone to oxidation and rancidity.
对尼日利亚当地用于食品保存的植物疏花山麻杆的叶和根提取物的抗氧化活性进行了评估，采用硫氰酸铁法、辣根过氧化物酶催化氧化2,2 - 联氮 - 双 -（3 - 乙基苯并噻唑啉 - 6 - 磺酸）（ABTS）、β - 胡萝卜素亚油酸酯模型系统以及Fe(2 +)/抗坏血酸/H(2)O(2)诱导的大鼠肝微粒体脂质过氧化。对疏花山麻杆的粗己烷根提取物（HR）、甲醇根提取物（MR）、甲醇叶提取物（ML）和己烷叶提取物（HL）进行了抗氧化活性测试。在浓度为0.05% v/v时，抗氧化活性按以下顺序降低：HR（76.4%）、MR（63%）、ML（40%）和HL（38%）。HR的抗氧化活性与标准抗氧化剂丁基羟基茴香醚（BHA）（80%）相比。粗提取物的总抗氧化活性（TAA）表明，HR中的活性最高。TAA值估计为8.0，以维生素C当量的毫米数衡量。HR的六个柱色谱馏分（FI - FVI）在β - 胡萝卜素模型系统中显示出不同程度的抗氧化活性，顺序为FII > FI > FVI > FIII > FIV > FV。FII在所有使用的模型系统中表现出最高的抗氧化活性，在β - 胡萝卜素亚油酸酯和Fe(2 +)/抗坏血酸/H(2)O(2)中，其抗氧化活性高于BHA和槲皮素。馏分II的TLC分析显示存在萜类化合物（与2,4 - 二硝基苯肼呈亮绿色）。我们的结果表明，疏花山麻杆含有有效的天然抗氧化剂，因此可能与易氧化和酸败的脂质食品的保存有关。
