Panpen Diawpanich, Papavadee Klongpityapong, Sukitaya Veeranondha, and Patricia Watts

pp. 603 - 609

Abstract

Media components may affect the activities of cultured cells. In this study, tyrosinase activity was evaluated by using B16-F10 mouse melanoma cell lines (B16-F10) and primary human melanocytes cultured in different media. An optical density measurement and a L-dopa reaction assay were used as the determination of the tyrosinase activity. The study of B16-F10 found the optical density to be 2010, 2246 and 2961 in cells cultured in RPMI Medium 1640 (RPMI1640), Minimum Essential Medium (MEM) and Dulbecco’s Modified Eagle Medium (DMEM), respectively. Moreover, compared
to RPMI 1640 and MEM, DMEM showed the darkest color of melanin formation in culture media and in cells after the L-dopa reaction assay. Addition of kojic acid showed a significant inhibitory effect on tyrosinase activity in all media. Whereas MCDB153 showed no significant effect on human melanocytes, DMEM caused a dramatic increase in tyrosinase
activity after 4 days of cultivation. Addition of kojic acid showed a significant tyrosinase inhibitory effect in DMEM only. Furthermore, an active ingredient in green tea, epigallocathechin gallate (EGCG) could inhibit tyrosinase activity in both B16-F10 and human melanocytes cultured in DMEM. In summary, these results suggest that DMEM is a suitable medium
that provides high detection sensitivity in a tyrosinase inhibition assay.