Effects of wheat antioxidants on oxygen diffusion-concentration products in liposomes and mRNA levels of HMG-CoA reductase and cholesterol 7alpha-hydroxylase in primary rat hepatocytes.
Three wheat antioxidant fractions were investigated for their potential effects on oxygen diffusion-concentration products in liposomes prepared with egg yolk phosphatidycholine (yolk PC) and rat liver PC (liver PC), using the electron spin resonance (ESR) oximetry method with 2,2'-azobis(2-aminopropane) dihydrochloride (AAPH) and 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN) as radical generators. Both water-soluble wheat antioxidant (WWA) and the second lipophilic antioxidant (LWA2) fractions were able to inhibit oxygen diffusion-concentration product induced by either AAPH or AMVN. The first lipophilic wheat antioxidant (LWA1) fraction only showed antioxidant activity in yolk PC liposomes with AAPH as the radical initiator but had pro-oxidant activity under other testing conditions. Both liposome composition and radical initiator altered the antioxidative properties of WWA, LWA1, and LWA2. WWA also showed the strongest DPPH(*) scavenging capacity on a per grain weight basis. HPLC analysis showed that WWA had a much higher level of total phenolic acids, which may partially explain their antioxidant properties. In addition, wheat antioxidants significantly down-regulated the mRNA of HMG-CoA reductase, the key enzyme for cholesterol biosynthesis, and up-regulated the mRNA of cholesterol 7alpha-hydroxylase (CYP7A1), the key enzyme for cholesterol metabolism, in primary rat hepatocytes. These data indicated the potential of wheat antioxidants in reducing the risk of atherosclerosis through multimechanisms.
Department of Nutrition and Food Science, University of Maryland, College Park, Maryland 20742, USA.
Zhihong
Z
Cheng
Huiping
H
Zhou
Marla
M
Luther
Jun-Jie
JJ
Yin
Liangli Lucy
LL
Yu
D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D050197:Atherosclerosis / Q000378:metabolism / Q000517:prevention & control; D002478:Cells, Cultured; D002645:Chickens; D002784:Cholesterol / Q000378:metabolism; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics* / Q000378:metabolism; D004058:Diffusion; D015870:Gene Expression / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D062385:Hydroxybenzoates / Q000032:analysis; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics* / Q000378:metabolism; D008081:Liposomes / Q000302:isolation & purification / Q000378:metabolism*; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D014908:Triticum / Q000378:metabolism*
D000975:Antioxidants; D062385:Hydroxybenzoates; D008081:Liposomes; D010936:Plant Extracts; D012333:RNA, Messenger; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases; D002790:Cholesterol 7-alpha-Hydroxylase; C017616:phenolic acid; D010100:Oxygen