Inhibitory Effect of Isorhapontigenin on Copper-Mediated Peroxidation of Human Low-Density Lipoprotein in vitro

Abstract

Abstract: Aim To study the effect of Isorhapontigenin (Iso) on copper-mediated peroxidation of human low-density lipoprotein (LDL) and on the toxicity of oxidized LDL (ox-LDL) to mouse macrophages in vitro. Methods Human LDL from sera of normal lipidemic donors was separated by sequential ultracentrifugation.The separated human LDL 1 mg·mL^-1 in phosphate buffer saline, pH 7.4, was incubated with cupric sulfate (10 μmol·L^-1) at 37 °C for 10 h in the presence or absence of various concentrations of Iso.Malondialdehyde (MDA) formation, vitamin E consumption, electrophoretic mobility of LDL, mitochondrial membrane potential of mouse peritoneal macrophages, phagocytosis of neutral red, and release of nitric oxide (NO) from macrophages were determined by various methods. Results Iso 1-100 μmol·L^-1 significantly inhibited the increase of MDA formation, vitamin E consumption and electrophoretic mobility of LDL induced by Cu²⁺ in a concentration-dependent manner.The injury of the mitochondrial membrane potential of mouse peritoneal macrophages due to incubation with ox-LDL (0.1 mg·mL^-1) at 37 °C for 12 h was markedly protected by 10 μmol·L^-1 Iso. After pretreatment of the macrophages with 10 μmol·L^-1 of Iso and then exposure to ox-LDL for 4 h, the reduction of phagocytosis of neutral red and release of NO in response to lipopolysaccharide (LPS) stimulation were significantly prevented. Conclusion Iso has protective action against Cu²⁺ mediated LDL peroxidation and ox-LDL induced toxicity to macrophages in vitro.

Key words: isorhapontigenin, isorhapontigenin, low-density lipoprotein, low-density lipoprotein, oxidized low-density lipoprotein, oxidized low-density lipoprotein, macrophages, macrophages, phagocytosis, phagocytosis, mitochondrial membrane potential, mitochondrial membrane potential

CLC Number:

R963

R972.6

Supporting:

FANG Ya-nan, LIN Mao, LIU Geng-tao^*. Inhibitory Effect of Isorhapontigenin on Copper-Mediated Peroxidation of Human Low-Density Lipoprotein in vitro[J]. .

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