Brandstetter S, Berthold C, Isnardy B, Solar S, Elmadfa I
Department of Nutritional Sciences, University of Vienna, Vienna, Austria.
Food Chem Toxicol. 2009 Sep;47(9):2230-5. doi: 10.1016/j.fct.2009.06.009. Epub 2009 Jun 9.
Ionizing radiation is known to stimulate the generation of oxygen radicals which destabilize organic molecules resulting in a decrease of the system's antioxidant potential. The Salmonella typhimurium (TA102) reverse mutation assay, co-incubated with t-BOOH and H(2)O(2), was used to assess the effects of gamma-irradiation (dose: 10kGy) on the antioxidant properties of sage, thyme, and oregano in chloroform and methanol extracts as well as in their mixture. In addition, measurements of the trolox equivalent antioxidative capacity (TEAC), total polyphenol content (TPC), and tocopherol equivalent (TE) were performed. For the methanol and mixed extracts, antioxidative properties in the S. typhimurium reverse mutation assay were only found when using an exogenous metabolic activation system. Generally, the greatest inhibition of mutagenicity was observed in the chloroform fractions of irradiated and of non-irradiated herbs. The relative antioxidant activities for the different herbs were as follows: TA102/t-BOOH, TEAC, TPC: thyme approximately oregano>sage. TA102/H(2)O(2): thyme approximately oregano approximately sage. TE: sage>thyme>oregano. For the majority of the investigated samples the impact of irradiation was insignificant. Therefore, gamma-irradiation at the doses tested seems to have little, if any, effect on the antioxidative capacity of the tested herbs.
已知电离辐射会刺激氧自由基的产生，这些自由基会使有机分子不稳定，导致系统抗氧化潜力下降。采用鼠伤寒沙门氏菌（TA102）回复突变试验，将其与叔丁基过氧化氢（t-BOOH）和过氧化氢（H₂O₂）共同孵育，以评估γ射线辐照（剂量：10千戈瑞）对迷迭香、百里香和牛至在氯仿和甲醇提取物及其混合物中的抗氧化性能的影响。此外，还进行了Trolox等效抗氧化能力（TEAC）、总多酚含量（TPC）和生育酚当量（TE）的测定。对于甲醇提取物和混合提取物，只有在使用外源性代谢活化系统时，才在鼠伤寒沙门氏菌回复突变试验中发现抗氧化性能。一般来说，在辐照和未辐照草药的氯仿馏分中观察到最大的致突变性抑制。不同草药的相对抗氧化活性如下：TA102/t-BOOH、TEAC、TPC：百里香≈牛至＞迷迭香。TA102/H₂O₂：百里香≈牛至≈迷迭香。TE：迷迭香＞百里香＞牛至。对于大多数研究样本，辐照的影响不显著。因此，在所测试的剂量下，γ射线辐照似乎对所测试草药的抗氧化能力影响很小（如果有影响的话）。
