title: Role of flavonoids on oxidative stress and mineral contents in the retinoic acid-induced bone loss model of rat.
abstract: OBJECTIVE
  Reactive oxygen species play a role in a number of degenerative conditions including osteoporosis. Flavonoids as phyto-oestrogens exert physiological effects against oxidative stress diseases. We developed a retinoic acid-induced bone loss model of rats to assess whether flavonoids and alendronate as positive control have role against oxidative stress and mineral contents in osteoporosis in vivo.
  
  
  METHODS
  Three-month-old female rats of the Y59 strain were given quercetin, chrysin, naringenin (100 mg kg(-1)) or alendronate (40 mg kg(-1), a positive control) immediately before retinoic acid treatment (80 mg kg(-1)) once daily for 14 days by a single intragastric (i.g.) application. In the second part of the study, we assessed the effect of those flavonoids on the skeletal system of healthy rats using single i.g. application on the respective flavonoids during 14 days. Twenty-four hours after the treatment, we analysed bone mineral density and the total content of bone calcium and phosphorus in the femur, the geometric and physical characteristics of thigh bones and lipid peroxidation and glutathione levels of liver and kidney cells.
  
  
  RESULTS
  All flavonoids improved the decrease in bone weight coefficient, the length and the diameter of the bone, the content of bone ash and calcium and phosphorus content induced by retinoic acid. Chrysin and quercetin showed promise as preventive agents. Flavonoids were superior to alendronate according to some criteria.
  
  
  CONCLUSIONS
  These results suggest that the dietary flavonoids could reduce retinoic acid-induced oxidative stress and bone loss and that flavonoids may be useful therapeutics for prevention of skeletal diseases.
authors.affiliation: Department of Animal Physiology, Faculty of Science, University of Zagreb, Rooseveltov Trg 6, 10000, Zagreb, Croatia, norsolic@yahoo.com.
authors.forename: Nada
authors.initials: N
authors.lastname: Oršolić
authors.forename: Eleonora
authors.initials: E
authors.lastname: Goluža
authors.forename: Domagoj
authors.initials: D
authors.lastname: Dikić
authors.forename: Duje
authors.initials: D
authors.lastname: Lisičić
authors.forename: Kristijan
authors.initials: K
authors.lastname: Sašilo
authors.forename: Edi
authors.initials: E
authors.lastname: Rođak
authors.forename: Zelko
authors.initials: Z
authors.lastname: Jeleč
authors.forename: Maja Vihnanek
authors.initials: MV
authors.lastname: Lazarus
authors.forename: Tatjana
authors.initials: T
authors.lastname: Orct
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D005269:Femur / Q000187:drug effects / Q000378:metabolism; D044950:Flavanones / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008903:Minerals / Q000378:metabolism; D010024:Osteoporosis / Q000139:chemically induced / Q000188:drug therapy; D018384:Oxidative Stress / Q000187:drug effects*; D010758:Phosphorus / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology; D051381:Rats; D014212:Tretinoin / Q000009:adverse effects*
chemical_list: D044950:Flavanones; D005419:Flavonoids; D008903:Minerals; D010758:Phosphorus; C043561:chrysin; D014212:Tretinoin; C028705:bone ash; D011794:Quercetin; C005273:naringenin; D002118:Calcium