title: Long-term cysteine fortification impacts cysteine/glutathione homeostasis and food intake in ageing rats.
abstract: OBJECTIVE
  Healthy ageing is associated with higher levels of glutathione. The study aimed to determine whether long-term dietary fortification with cysteine increases cysteine and glutathione pools, thus alleviating age-associated low-grade inflammation and resulting in global physiological benefits.
  
  
  METHODS
  The effect of a 14-week dietary fortification with cysteine was studied in non-inflamed (NI, healthy at baseline) and in spontaneously age-related low-grade inflamed (LGI, prefrail at baseline) 21-month-old rats. Fifty-seven NI rats and 14 LGI rats received cysteine-supplemented diet (4.0 g/kg of free cysteine added to the standard diet containing 2.8 g/kg cysteine). Fifty-six NI rats and 16 LGI rats received a control alanine-supplemented diet.
  
  
  RESULTS
  Cysteine fortification in NI rats increased free cysteine (P < 0.0001) and glutathione (P < 0.03) in the liver and the small intestine. In LGI rats, cysteine fortification increased total non-protein cysteine (P < 0.0007) and free cysteine (P < 0.03) in plasma, and free cysteine (P < 0.02) and glutathione (P < 0.01) in liver. Food intake decreased over time in alanine-fed rats (r² = 0.73, P = 0.0002), whereas it was constant in cysteine-fed rats (r² = 0.02, P = 0.68). Cysteine fortification did not affect inflammatory markers, mortality, body weight loss, or tissue masses.
  
  
  CONCLUSIONS
  Doubling the dietary intake of cysteine in old rats increased cysteine and glutathione pools in selected tissues. Additionally, it alleviated the age-related decline in food intake. Further validation of these effects in the elderly population suffering from age-related anorexia would suggest a useful therapeutic approach to the problem.
authors.affiliation: Department of Nutrition and Health, Nestlé Research Center, 10000, Lausanne 26, Switzerland.
authors.forename: Karine
authors.initials: K
authors.lastname: Vidal
authors.forename: Denis
authors.initials: D
authors.lastname: Breuillé
authors.forename: Patrick
authors.initials: P
authors.lastname: Serrant
authors.forename: Philippe
authors.initials: P
authors.lastname: Denis
authors.forename: Françoise
authors.initials: F
authors.lastname: Glomot
authors.forename: Fabienne
authors.initials: F
authors.lastname: Béchereau
authors.forename: Isabelle
authors.initials: I
authors.lastname: Papet
mesh_terms: D000375:Aging; D000818:Animals; D000855:Anorexia / Q000097:blood / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use; D000975:Antioxidants / Q000009:adverse effects / Q000378:metabolism / Q000627:therapeutic use*; D001069:Appetite Regulation; D003545:Cysteine / Q000009:adverse effects / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use*; D019587:Dietary Supplements / Q000009:adverse effects; D002149:Energy Intake; D004751:Enteritis / Q000097:blood / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D005978:Glutathione / Q000378:metabolism*; D006505:Hepatitis / Q000097:blood / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D006706:Homeostasis; D018836:Inflammation Mediators / Q000097:blood / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism; D007421:Intestine, Small / Q000276:immunology / Q000378:metabolism; D008099:Liver / Q000276:immunology / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress; D017208:Rats, Wistar
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D018836:Inflammation Mediators; D005978:Glutathione; D003545:Cysteine