INFLUENCE OF MELATONIN ON HaCaT CELL PROLIFERATION MEASURED BY MEANS OF ATP BIOLUMINESCENCE AND FLUOROMETRIC ASSAYS
The epiphysial hormone melatonin is characterized by many pharmacological effects in biological systems. In vitro-investigations to characterize the growth of spontaneously immortal human HaCaT-keratinocytes (Deutsches Krebsforschungszentrum, Heidelberg, Germany) influenced by melatonin were performed by Nickel et al.1 Evaluation of the cytotoxic effects after application of different substances was assessed by the DNA-synthesis rate which was determined by BrdU – insertion. The decrease of the DNA synthesis rate could be shown after treatment of keratinocytes with melatonin in high concentrations (1 nM). However, low concentrations of melatonin ( 10 μM -1 nM ) caused an increase of BrdU – insertion after 24h. The research laboratory of the Department of Dermatology (Friedrich-Schiller-University of Jena) found the inhibitory as well as the stimulating effects of melatonin depend on its concentration for growth of hair. A stimulation of hair growth could be detected in concentrations between 10 and 40 μmol in comparison to William's E medium. The maximum of the stimulating effect was found at 30 μmol.2 The aim of the present study was to determine the optimal melatonin doses for increasing HaCaT cell proliferation…
