Assessing the influence of various factors on antioxidant activity of medicinal herbs

摘要

The purposes of this study were: (1) to assess the antioxidant activity of fifteen medicinal plantsusing CUPRAC method, and (2) to highlight similarities or differences between results for the antioxidantactivity estimated by FRAP and CUPRAC (cupric ion reducing antioxidant capacity) methods. Themedicinal herbs have been purchased from the local market. The antioxidant activity of medicinal plantsby CUPRAC method ranged from 34.20 μmol of Trolox equivalents /g (Urtica dioica) and 512,48 μmolof Trolox equivalents /g (Melissae Folium). The antioxidant capacity values after the CUPRAC methodhave been very high compared to those determined by FRAP method. The six herbs which recorded thehighest antioxidant capacity by FRAP method are also found in the group of plants with very highantioxidant activity according with the CUPRAC method. In both cases the lowest antioxidant activitywas assessed for Urtica dioica. Also, the last four positions were occupied by the same plants(Chelidonium majus, Capsella bursa pastoris, Valeriana officinalis and Urtica dioica) both for FRAPmethod and for the CUPRAC method. The hierarchies of medicinal plants, according to their antioxidantactivities, were different for the two methods of measuring, respectively CUPRAC and FRAP.