Antioxidant activity of cleomiscosins A and C isolated from Acer okamotoanum.
Phytochemical investigation of Acer okamotoanum leaf and twig led to the isolation of two coumarinolignans, cleomiscosin A (1) and cleomiscosin C (2). Here, we found that 2 dose-dependently inhibits LDL oxidation mediated by either catalytic copper ions (Cu2+) or free radicals generated with the azo compound 2,2'-azobis-(2-amidinopropane)dihydro-chloride (AAPH) with IC50s of 29.5 and 11.9 microM, respectively. By electrophoretic analysis, we also observed that 2 protects apolipoprotein B-100 (apoB-100) against Cu2+-induced fragmentation (65.3% inhibition at 5 microM). Furthermore, fluorescence analyses clearly indicated that both 1 and 2 protect against the oxidative modification of apoB-100 induced by either Cu2+ or HOCl (1, IC50s of 13.4 and 8.1 microM, respectively; 2, IC50s of 23.6 and 3.9 microM, respectively). These findings suggest that 1 and 2 could be beneficial in preventing LDL oxidation in atherosclerotic lesions.
Jin
WenYi
W
College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
Thuong
Phuong Thien
PT
Su
Nguyen Duy
ND
Min
Byung Sun
BS
Son
Kun Ho
KH
Chang
Hyeun Wook
HW
Kim
Hyun Pyo
HP
Kang
Sam Sik
SS
Sok
Dai Eun
DE
Bae
KiHwan
K
D031002:Acer / Q000737:chemistry*; D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology; D003374:Coumarins / Q000302:isolation & purification* / Q000494:pharmacology; D004146:Dioxanes / Q000302:isolation & purification* / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000378:metabolism; D010084:Oxidation-Reduction
D000975:Antioxidants; D003374:Coumarins; D004146:Dioxanes; D008077:Lipoproteins, LDL; C438427:cleomiscosin C; C041934:cleomiscosin A