The hypolipidemic natural product Commiphora mukul and its component guggulsterone inhibit oxidative modification of LDL.

There is accumulating evidence that LDL oxidation is essential for atherogenesis, and that antioxidants that prevent this oxidation may either slow down or prevent atherogenesis. In the present study, we found that Commiphora mukul and its cholesterol-lowering component, guggulsterone, effectively inhibited LDL oxidation mediated by either catalytic copper ions, free radicals generated with the azo compound 2,2\u27-azobis-(2-amidinopropane)dihydrochloride (AAPH), soybean lipoxygenase enzymatically, or mouse peritoneal macrophages. This inhibition was assessed by the decrease in the following parameters describing LDL oxidation: conjugated dienes, relative electrophoretic mobility (REM), thiobarbituric acid reactive substances, lipid hydroperoxides, oxidation-specific immune epitopes as detected with a monoclonal antibody against oxidized LDL, and the accumulation of LDL derived cholesterol esters in mouse peritoneal macrophages. We concluded that C. mukul and its lipid-lowering component, guggulsterone, significantly inhibit LDL oxidation. The combination of antioxidant and lipid-lowering properties of C. mukul and guggulsterone makes them especially beneficial against atherogenesis

Peroxiredoxin 6 deficiency and atherosclerosis susceptibility in mice: significance of genetic background for assessing atherosclerosis.

Peroxiredoxin 6 (Prdx6; also called antioxidant protein 2, or Aop2) is a candidate gene for Ath1, a locus responsible for the respective susceptibility and resistance of mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) to diet-induced atherosclerosis. To evaluate if Prdx6 underlies Ath1, we compared the diet-induced atherosclerotic lesions in Prdx6 targeted mutant (Prdx6-/-) mice of different genetic backgrounds: B6, 129, and B6;129. PRDX6 protein and mRNA were expressed in normal and atherosclerotic aortas. B6;129 Prdx6-/- macrophages oxidized LDL significantly more than did controls. Plasma lipid hydroperoxide levels were higher in atherogenic diet-fed Prdx6-/- mice with B6;129 and B6 backgrounds than in controls. Prdx6-/- and controls in a 129 genetic background were equally lesion-resistant, and Prdx6-/- and controls in a B6 background were equally lesion-susceptible. In contrast, Prdx6-/- mice in a B6;129 background had significantly larger aortic root lesions than did littermate wild type controls. Therefore, although PRDX6 protein did not affect atherosclerosis susceptibility in either the resistant 129 background or the susceptible B6 background, it may inhibit atherosclerosis in backgrounds with mixed pro- and anti-atherogenic genes. Thus, genetic background plays an important role in modulating atherogenesis in targeted mutant mice. However, we think it is unlikely that Prdx6 underlies Ath1