Inhibition of 12- and 15-lipoxygenase activities and protection of human and tilapia low density lipoprotein oxidation by I-Tiao-Gung (Glycine tomentella).
I-Tiao-Gung, Glycine tomentella, has been used extensively as a traditional herbal medicine to relieve physical pain, but its bioactivity has not been studied systematically. Ninety-five percent ethanol extracts of G. tomentella (GT-E) showed antioxidant activity in human plasma by prolonging the lag phase (+Tlag) of Cu2+-induced LDL oxidation and were dose dependent. The +Tlag of LDL combined with 3.2 microg/mL GT-E was similar to that with 2.0 microM (ca. 0.5 microg/mL) Trolox. A similar inhibitory effect was found toward tilapia plasma LDL. In addition, GT-E inhibited tilapia thrombocyte (nucleated platelet) 5-, 12-, and 15-lipoxygenase (LOX). The IC50 values were 0.43, 0.72, and 0.42 microg/mL, respectively, whereas the IC50 values for nordihydroguaiaretic acid (NDGA) on 5-, 12-, and 15-LOX were 2.3, 1.6, and 1.7 microg/mL, respectively. The IC50 value for cyclooxygenase-2 (COX-2) inhibition by GT-E was 42.0 microg/mL, whereas the IC50 value by indomethacin as a positive control was 0.61 microLg/mL. The prevention of LDL oxidation and the dual inhibition of LOX and COX-2 are indicative of the possible roles of I-Tiao-Gung in antiatherosclerosis and anti-inflammation.
Chen
Tsui-Yao
TY
Food Science Department, National Taiwan Ocean University, Keelung, Taiwan, 202, Republic of China.
Shiao
Ming-Shi
MS
Pan
Bonnie Sun
BS
D000818:Animals; D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins / Q000037:antagonists & inhibitors; D010084:Oxidation-Reduction / Q000187:drug effects; D017210:Tilapia
D004365:Drugs, Chinese Herbal; D008077:Lipoproteins, LDL; D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human