title: Melatonin supplementation therapy as a potent alternative to ERT in ovariectomized rats.
abstract: OBJECTIVE
  To evaluate the efficacy of melatonin supplementation therapy as an alternative to estrogen replacement therapy in an ovariectomized rat model and to assess diabetogenic metabolic dysregulation caused by estrogen deficiency in postmenopausal individuals.
  
  
  METHODS
  Ovariectomized adult Wistar rats were treated with either estrogen/progesterone, melatonin or a combination of estrogen and melatonin. Body weight gain, feed efficiency, serum glucose, insulin, glucose tolerance and insulin response, serum and tissue lipids, tissue glycogen contents and activities of glycogen phosphorylase and glucose-6-phosphatase were analyzed in all the experimental groups.
  
  
  RESULTS
  Ovariectomized animals showed increased body weight gain, feed efficiency, fasting insulin resistance, greater area under curve for the glucose tolerance test, higher serum and tissue lipids and reduced glycogen content and insulin sensitivity. A low dose of melatonin was more efficient than estrogen in reversing all the ovariectomy-induced changes. The combination of estrogen + melatonin was found to be best in correcting glycemic dysregulation while high doses of melatonin could effectively regulate dyslipidemia.
  
  
  CONCLUSIONS
  The present study provides strong evidence for melatonin supplementation therapy to be more potent and effective in comparison to estrogen replacement therapy due to its single-handed ability to revert all the ovariectomy-induced changes. No reported side-effect or long-term effect of melatonin, against the known effects of estrogen replacement therapy, make it more attractive as a candidate to treat postmenopausal symptoms.
authors.affiliation: Division of Metabolic Endocrinology, Department of Zoology, Faculty of Science, The M.S. University of Baroda, Vadodara, Gujarat, India.
authors.forename: D
authors.initials: D
authors.lastname: Baxi
authors.forename: P K
authors.initials: PK
authors.lastname: Singh
authors.forename: K
authors.initials: K
authors.lastname: Vachhrajani
authors.forename: A V
authors.initials: AV
authors.lastname: Ramachandran
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology; D015914:Estrogen Replacement Therapy / Q000379:methods*; D004967:Estrogens / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D005951:Glucose Tolerance Test; D005952:Glucose-6-Phosphatase / Q000032:analysis; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D008055:Lipids / Q000032:analysis*; D008550:Melatonin / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D010052:Ovariectomy; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001786:Blood Glucose; D004967:Estrogens; D007328:Insulin; D008055:Lipids; D011374:Progesterone; D004958:Estradiol; D005952:Glucose-6-Phosphatase; D008550:Melatonin