Oxidative stress is thought to play a key role in macrophage foam cell formation which is the hallmark of the early atherosclerotic lesion. 1,2) Oxidative stress is associated with lipid peroxidation in lipoproteins and in arterial cells, including macrophages.3,4) These "oxidized macrophages" are characterized by increased peroxide levels, decreased glutathione content, and increased capability to oxidize lowdensity lipoprotein. 5,6) These properties of the cells increase their capability to accumulate cholesterol and to form macrophage foam cells. 7,8) Antioxidants can reduce the cellular oxidative stress by inhibiting the formation of superoxide anions, and by detoxification of reactive oxygen species/reactive nitrogen species through upregulation of cellular defense mechanisms, such as superoxide dismutase, catalase, or glutathione peroxidase. 9,10) Naturally occurring antioxidants in plants are classified as vitamins, phenolic compounds, tannins, volatile compounds and so on. Among them, herbs have received much attention as preventive medicines and ingredients in a variety of processed foods because they have beneficial health effects such as antioxidant and antibacterial activity.11) In recent years, polysaccharides from plant origin have also emerged as a relevant class of bioactive natural products and the great advances have been made in chemical and biological studies of natural polysaccharides as new safe plant-based health foods.
12-15)Angelica sinensis (OLIV.) DIELS is a herbaceous perennial plant mainly distributed in the northwest of China. The root is variously called Dang Gui or Dong Quai. It has been traditionally applied to the treatment of gynecological disorders (e.g., menstrual disorders, amenorrhea, dysmenorrhea, anemia, premenstrual syndrome, menopause) for thousands of years in Asia. 16,17) It was first introduced into the West in 1899 by Merck in the form of a liquid extract named "Eumenol" and was presently marketed in the United States as a dietary supplement, with numerous products being marketed worldwide. 18,19) In recent years, it was also reported that the polysaccharide extracts from A. sinensis possessed significant immunomodulatory activity. 20) However, it is not known whether A. sinensis polysaccharides have any direct antioxidant effects and more detailed work is needed on the elucidation of the sugar composition and antioxidant activities of active polysaccharides.In the present study, we isolated and purified three A. sinensis polysaccharide fractions (APFs), designed as APF1, APF2 and APF3 from the roots of A. sinensis and the antioxidant activities of APFs against hydrogen peroxide (H 2 O 2 )-mediated oxidative stress were evaluated in isolated mouse peritoneal macrophages. Furthermore, the sugar composition in APFs was also characterized by high-performance capillary electrophoresis (HPCE). Sciences, Shaanxi Normal University; Xi'an 710062, China: and b Faculty of Pharmaceutical Sciences, Fourth Military Medical University; Xi'an 710032, China. Received March 30, ...
