Chaouche Tarik Mohammed, Haddouchi Farah, Ksouri Riadh, Atik-Bekkara Fouzia
Laboratory of Natural Products, Department of Biology, Faculty of Sciences, Abou Bekr Belkaïd University, Tlemcen, Algeria.
Laboratory of Natural Products, Department of Biology, Faculty of Sciences, Abou Bekr Belkaïd University, Tlemcen, Algeria.
J Chin Med Assoc. 2014 Jun;77(6):302-7. doi: 10.1016/j.jcma.2014.01.009. Epub 2014 Mar 7.
Phytochemicals are found in abundance at different levels in many medicinal plants. It is important to measure the total phenolic compounds correctly in such medicinal plants, the better to assess their antioxidant capacity.
Our study sought to evaluate the total phenolic, flavonoid, and tannin contents of three Algerian medicinal plants: Echium pycnanthum Pomel, Haloxylon articulatum Boiss, and Solenostemma oleifolium Bull. & Bruce. We employed six different testing methods to help ascertain whether these compounds have an antioxidant capacity, including total antioxidant capacity, 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid(+), β-carotene, reducing, and chelating assays.
Our study showed that these medicinal plants exhibited significantly different total polyphenol contents varying from 27.3 ± 2.1 mg to 120.3 ± 5.6 mg gallic acid equivalents/g dry weight. The phenolic content in H. articulatum was superior to those in E. pycnanthum and S. oleifolium. The same tendency was observed for the relative amounts of flavonoids and condensed tannins in the three medicinal plants. The antioxidant activities varied greatly among the different plants used in this study. Indeed, H. articulatum shoots exhibited the strongest antioxidant activity, with the lowest IC50 (6.3 ± 0.25 μg/mL) and EC50 (0.21 ± 0.01 mg/mL) values for 1,1-diphenyl-2-picrylhydrazyl and iron reducing tests, respectively. In addition, the superiority of this plant was more marked as compared to positive controls. Strong and positive correlations were found between phenolic classes and antioxidant activities with a correlation coefficient reaching R ≥ 0.99.
This investigation confirmed that several medicinal herbs from South Algeria possess high in vitro antioxidant potency. Overall, our results can be considered very promising in the continuing effort to utilize plant species successfully for medicinal purposes in humans, providing further justification for the hypothesis that phenolic compounds in these plants can provide substantial antioxidant activity.
许多药用植物中不同程度地富含植物化学物质。正确测定此类药用植物中的总酚类化合物，对于更好地评估其抗氧化能力至关重要。
我们的研究旨在评估三种阿尔及利亚药用植物的总酚、黄酮和单宁含量，这三种植物分别是：多花蓝蓟（Echium pycnanthum Pomel）、盐生假木贼（Haloxylon articulatum Boiss）和油叶白前（Solenostemma oleifolium Bull. & Bruce）。我们采用了六种不同的测试方法来帮助确定这些化合物是否具有抗氧化能力，包括总抗氧化能力、1,1 - 二苯基 - 2 - 苦基肼自由基（DPPH）、2,2'-联氮 - 双 - 3 - 乙基苯并噻唑啉 - 6 - 磺酸（ABTS）、β - 胡萝卜素、还原能力和螯合能力测定。
我们的研究表明，这些药用植物的总多酚含量差异显著，范围从27.3±2.1毫克到120.3±5.6毫克没食子酸当量/克干重。盐生假木贼中的酚类含量高于多花蓝蓟和油叶白前。这三种药用植物中的黄酮类和缩合单宁的相对含量也呈现相同趋势。本研究中使用的不同植物的抗氧化活性差异很大。事实上，盐生假木贼的嫩枝表现出最强的抗氧化活性，在DPPH和铁还原能力测试中，其IC50（6.3±0.25微克/毫升）和EC50（0.21±0.01毫克/毫升）值最低。此外，与阳性对照相比，这种植物的优势更为明显。酚类物质类别与抗氧化活性之间存在强正相关，相关系数达到R≥0.99。
本研究证实，来自阿尔及利亚南部的几种药草具有较高的体外抗氧化能力。总体而言，我们的结果对于持续成功地将植物物种用于人类医学目的的努力而言非常有前景，为这些植物中的酚类化合物可提供大量抗氧化活性这一假设提供了进一步的依据。
