School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.
Nat Prod Res. 2012;26(11):1050-3. doi: 10.1080/14786419.2010.551771. Epub 2011 Oct 7.
Five Radix Astragali (RA) extracts were prepared and their antioxidant activities were measured in vitro using ABTS [2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid diammonium salt)], DPPH · (1,1-diphenyl-2-picrylhydrazyl radical), reducing power, •O₂⁻ and •OH assays. Their chemical contents were then determined, including total phenolics, total flavonoids, total saponins and total sugars. The 1/IC₅₀ values of the various antioxidant assays were used to evaluate the level of antioxidant activity of the RA extracts (plot showing 1/IC₅₀ values vs. chemical contents), and the average R values (correlation coefficients) of total phenolics and total flavonoids were 0.762 and 0.638. In contrast, the average R values of the total saponins and total sugars were -0.0386 and -0.132, respectively. This large difference clearly demonstrates that the antioxidant effects of RA in vitro might be generally considered to be a result of the presence of phenolic compounds (including flavonoids) but not astragalosides and polysaccharides.
五种黄芪提取物被制备出来，并在体外使用 ABTS [2, 2'- 偶氮 -双(3-乙基苯并噻唑啉-6-磺酸)二铵盐]、DPPH·（1,1-二苯基-2-苦基肼自由基）、还原能力、•O₂⁻ 和 •OH 测定法来测量其抗氧化活性。然后测定它们的化学成分，包括总酚、总黄酮、总皂苷和总糖。用各种抗氧化测定的 1/IC₅₀ 值来评价 RA 提取物的抗氧化活性水平（显示 1/IC₅₀ 值与化学成分关系的图），总酚和总黄酮的平均 R 值（相关系数）分别为 0.762 和 0.638。相比之下，总皂苷和总糖的平均 R 值分别为-0.0386 和-0.132。这种巨大的差异清楚地表明，RA 在体外的抗氧化作用通常可以被认为是由于酚类化合物（包括类黄酮）的存在，而不是黄芪皂苷和多糖的存在。
