| Isoflavones, mainly genistein from soybean, has gained attention for various bioactive properties in cancers, cardiovascular disease, atherosclerosis, etc. Besides soybean, kudzu roots, commonly used in traditional Chinese medicine, is also known to be a rich source of isoflavonoids.; Isoflavones and isoflavone glycosides were isolated from ethyl acetate and n-butanol fractions of kudzu roots and formononetin-7-O-glucoside (ononin) from kudzu root was identified for the first time.; The antioxidative, anticancer and antiinflammatory activities of 5 major isoflavones, including puerarin, daidzin, daidzein, genistein and biochanin A, were assayed by (1) three different antioxidant activity methods; (2) the arachidonic acid modulation activity assay in intact HT-29 colon cancer cell; (3) the arachidonic acid inhibition activity test in the RAW 264.7 murine macrophage cell; and (4) NO formation inhibitory activity assay using RAW 264.7 murine macrophage cell.; Puerarin and daidzin showed stronger antioxidant activity in the DPPH free radical scavenging assay. However, the aglycones displayed stronger antioxidant activities than the glycosides in the ferric thiocyanate assay and lipoxygenase assay. The antioxidant activities of 5 compounds in one test did not correlate with activity results in other tests.; Aglycones had better inhibition activity both in the arachidonic acid release and in NO formation. Higher hydrophilicity and the greater molecular weight of isoflavone glycosides seems to lead to poor absorption, which accounts for their low inhibitory effects on arachidonic acid release and NO production.; Biochanin A demonstrated the highest inhibitory activity (70%) in arachidonic acid release in the HT 29 colon cancer cell at a concentration of 50 μM. In addition, biochanin A exhibited distinctive suppression both in arachidonic acid release and NO formation in the RAW 264.7 murine macrophage cell. It can be suggested that the methoxyl group in biochanin A contributes to its high absorption into cells. In addition, the C-5 hydroxyl group may be another possible factor contributing the highest suppression activity of biochanin A in arachidonic acid release and NO formation.; The present results indicate that isoflavones and isoflavone glycosides from kudzu roots are possible modulators in arachidonic acid release and NO production, as well as inhibitors of lipid oxidation. |
