Kilani-Jaziri Soumaya, Neffati Aicha, Limem Ilef, Boubaker Jihed, Skandrani Ines, Sghair Mohamed Ben, Bouhlel Ines, Bhouri Wissem, Mariotte Anne Marie, Ghedira Kamel, Dijoux Franca Marie-Genviève, Chekir-Ghedira Leila
Unité de Pharmacognosie/Biologie Moléculaire 99/UR/07-03, Faculté de Pharmacie, Rue Avicenne, Monastir, Tunisia.
Chem Biol Interact. 2009 Sep 14;181(1):85-94. doi: 10.1016/j.cbi.2009.04.014. Epub 2009 May 14.
A Total Oligomers Flavonoids (TOFs) and ethyl acetate extracts of Cyperus rotundus were analyzed, in vitro, for their antioxidant activity using several biochemical assays: the xanthine (X)/xanthine oxidase (XO), the lipid peroxidation induced by H(2)O(2) in K562 human chronic myelogenous leukemia cells and the DNA damage in pKS plasmid DNA assay induced by H(2)O(2)/UV-photolysis and for their apoptotic effect. TOF and ethyl acetate extracts were found to be efficient in inhibiting xanthine oxidase with IC(50) values of 240 and 185 microg/ml and superoxide anion with IC(50) values of 150 and 215 microg/ml, respectively. Also, all the extracts tested were effective in reducing the production of thiobarbituric acid reactive substances (TBARS) and were able to protect against H(2)O(2)/UV-photolysis induced DNA damage. The highest activity, measured as equivalents of MDA concentration, was observed in the ethyl acetate extract (MDA=2.04 nM). In addition, the data suggest that only TOF enriched extract exerts growth inhibition on K562 cells through apoptosis induction. Therefore, these extracts were subjected to further separation by chromatographic methods. Thus, three major compounds (catechin, afzelechin and galloyl quinic acid) were isolated from the TOF enriched extract and five major compounds (luteolin, ferulic acid, quercetin, 3-hydroxy, 4-methoxy-benzoic acid and 6,7-dimethoxycoumarin) from ethyl acetate extract. Their structures were determined by spectroscopic data analysis and comparison with the literature. In addition, we evaluate the biological activities of the catechin, ferulic acid and luteolin. This investigation has revealed that the luteolin was the most active in reducing the production of TBARS (MDA=1.5 nM), inhibiting significantly the proliferation of K562 cells (IC(50)=25 microg/ml) and protecting against H(2)O(2)/UV-photolysis induced DNA damage. In conclusion, the study reveals that the ability of C. rotundus to inhibit the enzyme xanthine oxidase (XO), the lipid peroxidation and to exert apoptotic effect, may explain possible mechanisms by which C. rotundus exhibits its health benefits.
对香附子的总寡聚体类黄酮（TOFs）和乙酸乙酯提取物进行了体外分析，使用多种生化测定方法检测其抗氧化活性：黄嘌呤（X）/黄嘌呤氧化酶（XO）法、H₂O₂诱导的K562人慢性粒细胞白血病细胞中的脂质过氧化以及H₂O₂/紫外线光解诱导的pKS质粒DNA测定中的DNA损伤，并检测其凋亡作用。发现TOF和乙酸乙酯提取物能有效抑制黄嘌呤氧化酶，IC₅₀值分别为240和185微克/毫升，对超氧阴离子的IC₅₀值分别为150和215微克/毫升。此外，所有测试提取物均能有效降低硫代巴比妥酸反应性物质（TBARS）的产生，并能保护细胞免受H₂O₂/紫外线光解诱导的DNA损伤。以丙二醛（MDA）浓度当量衡量，乙酸乙酯提取物的活性最高（MDA = 2.04纳摩尔）。此外，数据表明只有富含TOF的提取物通过诱导凋亡对K562细胞发挥生长抑制作用。因此，对这些提取物采用色谱方法进行进一步分离。由此，从富含TOF的提取物中分离出三种主要化合物（儿茶素、阿夫儿茶素和没食子酰奎宁酸），从乙酸乙酯提取物中分离出五种主要化合物（木犀草素、阿魏酸、槲皮素、3 - 羟基 - 4 - 甲氧基苯甲酸和6,7 - 二甲氧基香豆素）。通过光谱数据分析并与文献对比确定了它们的结构。此外，我们评估了儿茶素、阿魏酸和木犀草素的生物活性。这项研究表明，木犀草素在降低TBARS产生（MDA = 1.5纳摩尔）、显著抑制K562细胞增殖（IC₅₀ = 25微克/毫升）以及保护细胞免受H₂O₂/紫外线光解诱导的DNA损伤方面活性最高。总之，该研究表明香附子抑制黄嘌呤氧化酶（XO）、脂质过氧化以及发挥凋亡作用的能力，可能解释了香附子展现其健康益处的潜在机制。
