Inhibition of 12- and 15- lipoxygenase activities and protection of human and tilapia low density lipoprotein oxidation by I-Tiao-Gung (Glycine tomentella)

• Published in: Lipids Vol. 40; no. 11; pp. 1171 - 1177
• Main Authors: Chen, T.Y, Shiao, M.S, Pan, B.S
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer‐Verlag 01-11-2005; Springer Nature B.V
• Subjects: Animals; antioxidant activity; Cells, Cultured; Cyclooxygenase 2; Drugs, Chinese Herbal - pharmacology; enzyme activity; Ethanol; Glycine tomentella; Herbal medicine; human health; Humans; Lipoproteins, LDL - metabolism; lipoxygenase; Lipoxygenase Inhibitors; low density lipoprotein; medicinal plants; Membrane Proteins - antagonists & inhibitors; Oxidation; Oxidation-Reduction - drug effects; plant extracts; prostaglandin synthase; Tilapia; tilapia (common name)
• ISSN: 0024-4201; 1558-9307
• DOI: 10.1007/s11745-005-1482-1

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 μg/mL GT‐E was similar to that with 2.0 μM (ca. 0.5 μg/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 μg/mL, respectively, whereas the IC50 values for nordihydroguaiaretic acid (NDGA) on 5‐, 12‐, and 15‐LOX were 2.3, 1.6, and 1.7 μg/mL, respectively. The IC50 value for cyclooxygenase‐2 (COX‐2) inhibition by GT‐E was 42.0 μg/mL, whereas the IC50 value by indomethacin as a positive control was 0.61 μg/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.