[The role of melatonin in lipid peroxidation in healthy subjects].
Melatonin is naturally occurring hormone, synthesized in the pineal gland of the vertebrates. There were reports that it has an antioxidative properties connected with scavenging of reactive oxygen species. The aim of the study is to investigate the changes in the blood antioxidative activity and in lipid peroxidation after oral administration of small doses of melatonin. Melatonin was given for 2 weeks and the estimation of lenght of hormone therapy effect was carried out.


METHODS
Venous blood was obtained from healthy volunteers (n = 20; 12 women and 8 men, aged 42 +/- 2), who were treated with 3 mg melatonin per day. Blood was obtained before melatonin adminstration, on 7 and on 14th day of melatonin treatment, and on 10th day after last melatonin administration. The antioxidative properties were examined by FRAP method (ferric reducing ability of plasma) and concentration of lipids' peroxidation products were examined by reaction with thiobarbituric acid (TBARS).


RESULTS
The higest plasma antioxidant activity was observed after 14 days of melatonin treatment and that increased level was maintained for the next 10 days after last dose of melatonin. The TBARS plasma concentrations reached the lowest level after 14 days of melatonin treatment and stayed the low level for 10 days after last dose of melatonin.


CONCLUSIONS
It was estimated that oral administration of melatonin increases the plasma antioxidative properties and parallely decreases the process of lipids peroxidation. The biochemical changes were still observed on the 10th day of the end of melatonin treatment.
Goraca
Anna
A
Uniwersytet Medyczny w Lodzi, Katedra Fizjologii Doświadczalnej i Klinicznej, Zakład Fizjologii Układu Krazenia. agoraca@zdn.am.lodz.pl
Cieśla
Włodzimierz
W
D000284:Administration, Oral; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008550:Melatonin / Q000008:administration & dosage* / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis / Q000378:metabolism
D000975:Antioxidants; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D008550:Melatonin