Studies of chemical constituents and their antioxidant activities from Astragalus mongholicus Bunge.
OBJECTIVE
To evaluate the antioxidant activities of different chemical constituents from Astragalus mongholicus Bunge and their protection against xanthine (XA)/xanthine oxidase (XO)-induced toxicity in PC12 cells.


METHODS
The compounds of Astragalus mongholicus Bunge were isolated by chromatography and the structures were elucidated on the basis of spectral data interpretation. Their antioxidant activities were detected by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities in a cell-free system. Meanwhile, the effects against XA/XO-induced toxicity were assessed using MTT assay in PC12 cells.


RESULTS
Ten principal constituents were isolated and identified as formononetin (I), ononin (II), calycosin (III), calycosin-7-O-beta-D-glucoside (IV), 9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (V), adenosine (VI), pinitol (VII), daucosterol (VIII), beta-sitoster (IX) and saccharose (X) from Astragalus mongholicus Bunge. The compounds I, III, and IV scavenged DPPH free radicals in vitro. Formononetin and calycosin were found to inhibit XA/XO-induced cell injury significantly, with an estimated EC50 of 50 ng/mL.


CONCLUSIONS
Compound II, VI, and VII are first reported in this plant. Calycosin exhibits the most potent antioxidant activity both in the cell-free system and in the cell system.
Yu
De-Hong
DH
Department of Environment and Biology, Dalian University of Technology, Dalian 116024, Liaoning, China.
Bao
Yong-Ming
YM
Wei
Chao-Liang
CL
An
Li-Jia
LJ
D000818:Animals; D027883:Astragalus Plant / Q000737:chemistry; D027885:Astragalus propinquus; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology*; D005609:Free Radicals / Q000378:metabolism; D007529:Isoflavones / Q000737:chemistry / Q000494:pharmacology; D016716:PC12 Cells; D051381:Rats; D019820:Xanthine / Q000633:toxicity; D014969:Xanthine Oxidase / Q000633:toxicity
D004365:Drugs, Chinese Herbal; D016166:Free Radical Scavengers; D005609:Free Radicals; D007529:Isoflavones; D019820:Xanthine; C027492:Huang Qi; D014969:Xanthine Oxidase