OBJECTIVE:To investigate antioxidant effects of different extract parts from Aquilaria sinensis leaves. METH-ODS:A. sinensis leaves were extracted by reflux extraction with petroleum ether,ethyl acetate,absolutely ethanol,water to obtain corresponding parts (AGP,AGE,AGA and AGW parts). The ability of different extracts eliminating ABTS+ free radical,DPPH free radical and O2-free radical and reducing Cu2+ were investigated. IC50 was also calculated. Vitamin C(VC)was used as positive control in above tests. RESULTS:Those parts eliminated above free radicals and reduced Cu2+ in concentration-dependant manner, among which maximal elimination rate of AGA and AGW parts to ABTS+ free radical were 100% and 81.07%(IC50=14.89,23.12 mg/L)and higher than that of VC(88%);those of other parts were less than 50%. The maximal elimination rate of AGA parts to DPPH free radical was 67.74%(IC50=47.96 mg/L),but still lower than that of VC(91.44%);the elimination rates of other parts were all weak and lower than 40%. The maximal elimination rates of AGA and AGW parts to O2-free radical were 67.79% and 61.79%(IC50=393.01,421.04 mg/L),but still lower than that of VC(88%);the elimination rates of other parts were all lower than 33%. The maximal reduction percentage of AGP,AGE,AGA and AGW parts to Cu2+ were all higher than 50%(IC50=55.99, 40.27,25.44,31.06 mg/L,respectively),but still lower than that of VC (100%). CONCLUSIONS:Different extract parts from A. sinensis leaves have antioxidant activity in vitro,and that of AGA is the strongest.

Asthma is a common chronic respiratory disease characterized by repeated attacks and prolonged illness.Traditional Chinese medicine believes that the formation of Sugen is the core pathogenesis of repeated asthma attacks.By tracing the origin of Sug-en theory,summarizing the connotation of ancient asthma Sugen theory and the innovative understanding of modern medical scholars on asthma Sugen,this paper explores the potential connection between the traditional Chinese medicine Sugen theory and the pathogenesis of modern asthma,in order to provide new ideas and methods for the treatment and research of asthma.