TY - JOUR
T1 - Inhibitory effects of Du-zhong (Eucommia ulmoides Oliv.) against low-density lipoprotein oxidative modification
AU - Yen, Gow Chin
AU - Hsieh, Chiu Luan
PY - 2002/6/11
Y1 - 2002/6/11
N2 - This study presents the effects of water extracts from leaves, raw cortex, and roasted cortex of Du-zhong (Eucommia ulmoides Oliv.) on the oxidative modification of human low-density lipoprotein (LDL) induced by copper ion (Cu2+). Through determination of the formation of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (CD), as well as relative electrophoretic mobility (REM), all extracts of Du-zhong were found to possess inhibitory effects on the oxidative modification of LDL induced by Cu2+. The leaf extract had the most significant inhibitory effect. The ethyl acetate extract from leaf extract of Du-zhong was separated into six bands by preparative TLC. Band 2 (Rf=0.40), which was most inhibitory against LDL oxidative modification, was analyzed by HPLC; a single, main peak was collected and further examined using NMR and MS. The antioxidant compound thus identified was protocatechuic acid (PCA). At a concentration of 10 μg/ml, PCA showed a stronger inhibitory effect against LDL oxidative modification induced by Cu2+ than did Du-zhong extracts or ascorbic acid at the same concentration. The results suggest that, in leaf extract of Du-zhong, PCA could be a major source of the inhibitory effect against LDL oxidative modification induced by Cu2+.
AB - This study presents the effects of water extracts from leaves, raw cortex, and roasted cortex of Du-zhong (Eucommia ulmoides Oliv.) on the oxidative modification of human low-density lipoprotein (LDL) induced by copper ion (Cu2+). Through determination of the formation of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (CD), as well as relative electrophoretic mobility (REM), all extracts of Du-zhong were found to possess inhibitory effects on the oxidative modification of LDL induced by Cu2+. The leaf extract had the most significant inhibitory effect. The ethyl acetate extract from leaf extract of Du-zhong was separated into six bands by preparative TLC. Band 2 (Rf=0.40), which was most inhibitory against LDL oxidative modification, was analyzed by HPLC; a single, main peak was collected and further examined using NMR and MS. The antioxidant compound thus identified was protocatechuic acid (PCA). At a concentration of 10 μg/ml, PCA showed a stronger inhibitory effect against LDL oxidative modification induced by Cu2+ than did Du-zhong extracts or ascorbic acid at the same concentration. The results suggest that, in leaf extract of Du-zhong, PCA could be a major source of the inhibitory effect against LDL oxidative modification induced by Cu2+.
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U2 - 10.1016/S0308-8146(01)00379-X
DO - 10.1016/S0308-8146(01)00379-X
M3 - Article
AN - SCOPUS:0036262467
VL - 77
SP - 449
EP - 456
JO - Food Chemistry
JF - Food Chemistry
SN - 0308-8146
IS - 4
ER -