[Inhibitory effect of isorhamnetin and hesperidin on the oxidation of high-density lipoproteins (HDL) induced by Cu2+].
OBJECTIVE
To test the inhibitory effect of isorhamnetin and hesperidin on the HDL oxidation induced by Cu2+.


METHODS
The serum HDL was isolated by the one step density gradient ultracentrifugation. The HDL oxidation was induced by Cu2+ in vitro for different length of periods. Isorhamnetin and hesperidin at 5 micromol/L, respectively, were added 3 h before the copper oxidation. The oxidation of HDL was measured by the levels of absorbance at 234 nm (A234), relative electrophoretic mobility (REM), thiobarbituric acid reactive substances (TBARS) and protein carbonyls content.


RESULTS
(1) A234, REM, TBARS and protein carbonyls formation increased gradually after 2, 4, 6, 8, 12 and 24 h of HDL oxidation induced by CU2+ without treatment with isorhamnetin or hesperidin. (2) With the treatment of isorhamnetin or hesperidin, the kinetic changes of A234, REM, TBARS and protein carbonyls formation delayed 2-6 h and 2-4 h, respectively. Compared with the controls, the A234, REM, TBARS and protein carbonyls formation were reduced by 16.3%-46.9% (P < 0.001), 0.6%-25.2% (P < 0.05), 9.2%-28.4% (P < 0.01) and 11.6%-45.2% (P < 0.001) by isorhamnetin and by 1.5%-30.0%, 1.4%-13.3%, 6.6%-18.8% (P < 0.05) and 14.4%-62.0% (P < 0.001) by hesperidin, respectively.


CONCLUSIONS
Both isorhamnetin and hesperidin inhibit the oxidation of HDL, but isorhamnetin functions stronger.
Liu
Rui
R
Division of Peptides Related with Human Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China.
Meng
Fang
F
Bai
Huai
H
Liu
Yu
Y
Liu
Bing-wen
BW
D003300:Copper / Q000494:pharmacology*; D044948:Flavonols / Q000494:pharmacology*; D006569:Hesperidin / Q000494:pharmacology*; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism*; D010084:Oxidation-Reduction; D011794:Quercetin / Q000031:analogs & derivatives
D044948:Flavonols; D008075:Lipoproteins, HDL; C047368:3-methylquercetin; D003300:Copper; D011794:Quercetin; D006569:Hesperidin