title: Effect of polyphenol-rich extract from walnut on diet-induced hypertriglyceridemia in mice via enhancement of fatty acid oxidation in the liver.
abstract: The kernel pellicles of walnut are rich in ellagitannins with antioxidative activity. A polyphenol-rich extract from walnuts (WP, 45% polyphenol) was prepared and evaluated for its hypolipidemic effect in high fat diet fed mice. Oral administration of WP (100 and 200 mg/kg) significantly reduced liver weight and liver and serum triglycerides (TG). Hepatic beta-oxidation in cytosol, including peroxisome, was enhanced by WP (50-200 mg/kg). mRNA expressions of hepatic peroxisome proliferator-activated receptor (PPAR) alpha and acyl coenzyme A oxidase (ACOX) 1 were enhanced by WP (50-200 mg/kg). With respect to the hypotriglyceridemic mechanism of WP, it suppressed neither olive oil induced serum TG elevation in mice nor oleic acid induced TG accumulation in HepG2 cells. On the other hand, mRNA expressions of PPARalpha, ACOX1, and carnitine palmitoyltransferase (CPT) 1A in HepG2 cells were significantly enhanced by addition of WP (100 microg/mL). Moreover, tellimagrandin I, a polyphenolic constituent in WP, enhanced ACOX1 expression at 1-100 microg/mL. In conclusion, WP was found to possess hypotriglyceridemic activity via enhancement of peroxisomal fatty acid beta-oxidation in the liver. These results suggest that tellimagrandin I is involved in the hypotriglyceridemic mechanism of WP.
authors.affiliation: Research and Development Division, Oryza Oil and Fat Chemical Company, Ltd., 1 Numata, Kitagata-cho, Ichinomiya, Aichi 493-8001, Japan. kaihatsu@mri.biglobe.ne.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimoda
authors.forename: Junji
authors.initials: J
authors.lastname: Tanaka
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukuda
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ito
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hatano
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage / Q000009:adverse effects; D004195:Disease Models, Animal; D005227:Fatty Acids / Q000378:metabolism*; D005419:Flavonoids / Q000008:administration & dosage*; D015870:Gene Expression / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D015228:Hypertriglyceridemia / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism*; D031324:Juglans / Q000737:chemistry*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D010084:Oxidation-Reduction; D047492:Peroxisome Proliferator-Activated Receptors / Q000235:genetics / Q000378:metabolism; D010636:Phenols / Q000008:administration & dosage*; D010936:Plant Extracts / Q000008:administration & dosage*; D059808:Polyphenols; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D005419:Flavonoids; D047492:Peroxisome Proliferator-Activated Receptors; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D014280:Triglycerides