and stored at 0 C. The dried extracts were redissolved in water at a suitable concentration for the different assays. ORAC Assay The assay was based on that of Ou et al. (17). The dried sample extracts were dissolved in water and tested at concentrations of 12.5, 25, 50 and 100 mg extract/l in triplicate. Briefly, 20 ml of sample or Trolox was incubated with 10 ml 75 nM fluorescein and 170 ml 17 mM AAPH in a total volume of 200 ml. All ORAC analyses were performed at 37 C with an excitation wavelength of 485 nm and emission wavelength of 535 nm. The area under the fluorescence decay curve for FL (AUC) was calculated by point-to-point integra- tion. The decrease in fluorescence was followed at 1 min intervals for 35 min. The protective effect of an antiox- idant was measured by comparing the AUC of the sample with that of a known antioxidant, Trolox, a water-soluble analogue of Vitamin E. The final ORAC values were expressed as micromole Trolox Equivalents per gram dried herb (mmol TE/g). Each sample was tested at four concentrations in triplicate. The results were expressed as mean (SD 5 10%). Results ORAC Value of 45 Chinese Herbs In this assay, 45 Chinese herbs that regulate the blood circulation were analyzed for antioxidant activity (Table 1 and Table 2). The results showed that they had a wide range of antioxidant activity. The herbs Table 1. Antioxidant activity of first 10 herbs with high ORAC value and together with their classification by flavor, nature and function Latin Binomial ORAC (mmol TE/g)y Spatholobus suberectus 1990 Sanguisorba officinalis 1940 Agrimonia pilosa 1440 Artemisia anomala Salvia miltiorrhiza Sophora japonica Nelumbo nucifera Crataegus pinnatifida Lycopus lucidus Artemisia argyi 1400 1320 1300 1300 1240 1220 1150 bitter, sweet bitter, sour bitter, sour bitter bitter bitter bitter neutral sour, sweet warm bitter, pungent warm pungent, bitter warm warm cold neutral warm cold cool 2 1 1 2 2 1 1 2 2 1 ymmol TE/g, micromoles Trolox equivalent per gram dried herb. z,x, The flavor, nature and function are according to Chinese Pharmacopoeia (2005). The flavor, nature and function is according to Dictionary of Traditional Chinese Herb (28). Flavorz Naturex Function Curcuma wenyujin eCAM 2008;5(4) 431 with the highest antioxidant activity were Spatholobus suberectus vine (1990 mmol TE/g) and Sanguisorba officinalis root (1940 mmol TE/g). There was a 50-fold difference in antioxidant capacity between Spatholobus suberectus vine (1990 mmol TE/g) and Ziziphus jujuba fruit (40 mmol TE/g). ORAC Value Comparison of Herbs with Different Natures, Flavors and Functions Herbs with bitter flavor had a higher ORAC value than other flavors (Table 3). The average ORAC value of herbs with bitter and/or sour flavor was 856 mmol TE/g, four times higher than herbs with sweet and/or pungent flavor (213 mmol TE/g) (P50.01). Ten herbs had an Table 2. ORAC value of 35 herbs yCarbonized medicine involves heating a drug to the point that the outer layer is burned black and the inner part brown/partly carbonized. zSteamed medicines are heated with vapour. Latin Binomial Platycladus orientalis Drynaria fortunei Bochmeria nivea Gleditsia sinensis Cirsium japomicum Cirsium setosum Arnebia euchroma Rheum palmatum (steamedz) Vaccaria segetalis Imperata cylindrica Typha angustifolia Commiphora molmol Angelica sinensis Scrophularia ningpoensis Rehmannia glutinosa Boswellia carterii Ziziphus jujuba ORAC (mmol TE/g) 940 700 640 570 400 370 320 270 200 140 130 120 96 78 77 65 49 40 Latin Binomial Polygonum multiflorum Paeonia lactiflora Rubia cordifolia Paeonia suffruticosa Carthamus tinctorius Paeonia lactiflora Zingiber officinale (carbonizedy) Sparganium stoloniferum Curcuma phaeocaulis Ligusticum chuanxiong Corydalis yanhusuo Bletilla striata Prunus persica Rehmannia glutinosa (steamedz) Panax notoginseng Curcuma wenyujin Cyathula officinalis ORAC (mmol TE/g) 790 680 640 470 370 350 280 260 170 130 130 100 85 77 75 54 43