title: Dietary proanthocyanidins modulate melatonin levels in plasma and the expression pattern of clock genes in the hypothalamus of rats.
abstract: METHODS
  Circadian rhythms allow organisms to anticipate and adapt to environmental changes, and food components can adjust internal rhythms. Proanthocyanidins improve cardiovascular risk factors that exhibit circadian oscillations. Therefore, the aim of the current study was to determine whether proanthocyanidins can modulate body rhythms.
  
  
  RESULTS
  Male Wistar rats were orally gavaged with 250 mg grape seed proanthocyanidin extract (GSPE)/kg body weight at zeitgeber time (ZT) 0 (light on). Phenotypic biorhythm was evaluated by measuring the concentration of plasma melatonin and metabolites, using MNR-metabolomics, at several ZT. Remarkably, GSPE treatment maintained nocturnal melatonin levels at ZT3 and altered the oscillations of some metabolites in plasma. Quantification of expression of clock-core (Clock, Bmal1, Per2, Rorα, Rev-erbα) and clock-controlled (Nampt) genes in the hypothalamus by RT-PCR showed that this phenotypic alteration was concomitant with the modulation of the expression pattern of Bmal1 and Nampt. However, GSPE did not modulate the nocturnal expression of clock genes when administered at ZT12 (light off).
  
  
  CONCLUSIONS
  PAs could have chronobiological properties, although their activity depends largely on the time of administration.
authors: Department of Biochemistry and Biotechnology, Nutrigenomic Research Group, Universitat Rovira i Virgili, Tarragona, Spain.
authors: Aleix
authors: A
authors: Ribas-Latre
authors: Josep M
authors: JM
authors: Del Bas
authors: Laura
authors: L
authors: Baselga-Escudero
authors: Ester
authors: E
authors: Casanova
authors: Anna
authors: A
authors: Arola-Arnal
authors: Maria-Josepa
authors: MJ
authors: Salvadó
authors: Lluís
authors: L
authors: Arola
authors: Cinta
authors: C
authors: Bladé
mesh_terms: D056930:ARNTL Transcription Factors / Q000235:genetics; D000596:Amino Acids / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D056926:CLOCK Proteins / Q000235:genetics*; D002940:Circadian Rhythm; D016207:Cytokines / Q000235:genetics; D056604:Grape Seed Extract / Q000008:administration & dosage*; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000097:blood*; D054409:Nicotinamide Phosphoribosyltransferase / Q000235:genetics; D044945:Proanthocyanidins / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D056930:ARNTL Transcription Factors; D000596:Amino Acids; C000598703:Arntl protein, rat; D001786:Blood Glucose; D016207:Cytokines; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D044945:Proanthocyanidins; D056926:CLOCK Proteins; D054409:Nicotinamide Phosphoribosyltransferase; C504970:nicotinamide phosphoribosyltransferase, rat; D008550:Melatonin
keywords: BMAL1; Flavonoids; Melatonin; Metabolomics; Xenohormesis