Reactive oxygen species scavenging activity of Du-zhong (Eucommia ulmoidesOliv.) and its active compounds

The biologically active compounds and free radical-/ or reactive oxygen;spe cies (ROS)-/scavenging effect of water extract from Du-zhong (WEDZ) were in vestigated. The WEDZ used included leaves, raw cortex, and roasted cortex. The hot water extract of Du-zhong leaves showed marked activity as a ROS sc avenger, and the scavenging effect was concentration dependent. The extract of roasted cortex exhibited a modest scavenging effect on ROS, while the e xtract of raw cortex had the weakest scavenging effect. The scavenging acti vity of WEDZ on ROS was correlated to its protocatechuic acid (PCA) content . The content of PCA in Du-zhong determined by HPLC followed the order of l eaves (17.17 mg/g) > roasted cortex (2.99 mg/g) > raw cortex (1.16 mg/g). T he inhibitory activity of leaf extract of Du-zhong was stronger than that o f PCA on the peroxidation of linoleic acid at the same concentration of 0.1 mg/mL. The results presented herein indicated that extract of Du-zhong cou ld possibly act asa prophylactic agent to prevent free radical-related dise ases.