Antioxidant activity of 45 Chinese herbs and the relationship with their TCM characteristics.

Here, 45 Chinese herbs that regulate blood circulation were analyzed for antioxidant activity using the oxygen radical absorbance capacity (ORAC) assay. A recent publication by Ou et al. identified a close relationship between in vitro antioxidant activity and classification of Chinese herbs as yin or yang. The 45 Chinese herbs in this study could be assigned the traditional characteristics of natures (cold, cool, hot and warm), flavors (pungent, sweet, sour, bitter and salty) and functions (arresting bleeding, promoting blood flow to relieve stasis, nourishing blood and clearing away heat from blood). These characteristics are generalized according to the theory of yin and yang. We identified a broad range, 40-1990 micromol Trolox Equivalent/g herbs, of antioxidant activity in water extracts. There was no significant correlation between ORAC values and natures or functions of the herbs. There was a significant relationship between flavors and ORAC values. Bitter and/or sour herbs had the highest ORAC values, pungent and/or sweet herbs the lowest. Other flavors had intermediate values. Flavors also correspond with the yin/yang relationship and our results are supportive of the earlier publication. We reported for the first time antioxidant properties of many Chinese herbs. High antioxidant herbs were identified as Spatholobus suberectus vine (1990 micromol TE/g), Sanguisorba officinalis root (1940 micromol TE/g), Agrimonia pilosa herb (1440 micromol TE/g), Artemisia anomala herb (1400 micromol TE/g), Salvia miltiorrhiza root (1320 micromol TE/g) and Nelembo nucifera leaf (1300 micromol TE/g). Antioxidant capacity appears to correlate with the flavors of herbs identified within the formal TCM classification system and may be a useful guide in describing their utility and biochemical mechanism of action.