title: Antioxidant capacity responsible for a hypocholesterolemia is independent of dietary cholesterol in adult rats fed rice protein.
abstract: Dietary cholesterol and aging are major risk factors to accelerate oxidation process for developing hypercholesterolemia. The major aim of this study is to elucidate the effects of rice protein on cholesterol level and oxidative stress in adult rats fed with and without cholesterol. After 2 weeks of feeding, hepatic and plasma contents of cholesterol, reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA) and protein carbonyl (PCO) were measured. In liver, total antioxidative capacity (T-AOC), activities of antioxidant enzymes (total superoxide dismutase, T-SOD; catalase, CAT), glutathione metabolizing enzyme activities and gene expression levels (γ-glutamylcysteine synthetase, γ-GCS; glutathione reductase, GR; glutathione peroxidase, GPx) were determined. Under cholesterol-free/enriched dietary condition, T-AOC, activities of T-SOD and CAT, glutathione metabolism related enzymes' activities and mRNA levels (γ-GCS, GR and GPx) were effectively stimulated by rice proteins as compared to caseins. Compared with caseins, rice proteins significantly increased hepatic and plasma GSH contents, whereas hepatic and plasma accumulations of MDA, PCO and GSSG were significantly reduced by rice protein-feedings. As a result, the marked reductions of cholesterol in the plasma and in the liver were observed in adult rats fed rice proteins with and without cholesterol. The present study demonstrates that the hypocholesterolemic effect of rice protein is attributable to inducing antioxidative response and depressing oxidative damage in adult rats fed cholesterol-free/enriched diets. Results suggest that the antioxidant capability involved in the hypocholesterolemic action exerted by rice protein is independent of dietary cholesterol during adult period.
authors.affiliation: Department of Food Science, School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, China.
authors.forename: Jixiang
authors.initials: J
authors.lastname: Cai
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Hong-Juan
authors.initials: HJ
authors.lastname: He
authors.forename: Tong
authors.initials: T
authors.lastname: Xu
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Liu
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.forename: Qiao-Hong
authors.initials: QH
authors.lastname: Liu
authors.forename: Ming-Hao
authors.initials: MH
authors.lastname: Nie
mesh_terms: D000821:Animal Feed; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001483:Base Sequence; D001835:Body Weight; D002784:Cholesterol / Q000097:blood* / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000008:administration & dosage*; D017931:DNA Primers; D005247:Feeding Behavior; D005978:Glutathione / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D012275:Oryza; D010940:Plant Proteins / Q000008:administration & dosage*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000975:Antioxidants; D002791:Cholesterol, Dietary; D017931:DNA Primers; D010940:Plant Proteins; D012333:RNA, Messenger; D008315:Malondialdehyde; D002784:Cholesterol; D005978:Glutathione
keywords: Adult rats; Antioxidative response; CAS; CAS-C; CAT; Cholesterol; Cys; Enzyme activity; GPx; GR; GSH; GSSG; Gene expression; Glu; Gly; MDA; Met; PCO; RP; RP-C; Rice protein; SAAs; T-AOC; T-GSH; T-SOD; TC; casein; catalase; cholesterol-supplemented casein; cholesterol-supplemented rice protein; cysteine; glutamate; glutathione peroxidase; glutathione reductase; glycine; malondialdehyde; methionine; oxidized glutathione; protein carbonyl; reduced glutathione; rice protein; sulfur amino acids; total antioxidative capacity; total cholesterol; total glutathione; total superoxide dismutase; γ-GCS; γ-glutamylcysteine synthetase