Kazuomi Sato1, Masaru Toriyama. 1. Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, 422-8529, Japan. w6611007@ipc.shizuoka.ac.jp
Abstract
BACKGROUND: Increased production and accumulation of melanin leads to various hyperpigmentation disorders. Melanin synthesis is regulated by melanogenic proteins such as tyrosinase, tyrosinase-related protein (TRP)-1 and -2, and their transcription factors. OBJECTIVE: In this study, we assessed the effects of PQQ on melanogenic protein expression of murine B16 melanoma cells. METHODS: We assessed melanin production of PQQ-treated B16 melanoma cells. Furthermore, we investigated the effect of PQQ on the activity of melanogenic enzymes and their expression using Western blot and semi-quantitative RT-PCR analyses. RESULTS: In the present study, PQQ inhibited melanin synthesis in cultured melanoma cells stimulated by either alpha-melanocyte stimulating hormone (alpha-MSH) or 3-isobutyl-1-methylxanthine (IBMX). To elucidate the mechanism of the effect of PQQ on melanogenesis, we performed Western blotting for melanogenic proteins, such as tyrosinase, TRP-1, and TRP-2. PQQ inhibited tyrosinase expression, however, it did not inhibit TRP-2 expression. Used as the stimulant for melanogenesis, both alpha-MSH and IBMX gave the same results for melanogenic protein expression. Semi-quantitative RT-PCR analysis showed that the depigmentation effect of PQQ might be due to the inhibition of tyrosinase gene transcription but not the inhibition of microphthalmia-associated transcription factor (Mitf). CONCLUSION: This report indicates that PQQ is a possible anti-melanogenic agent and might be effective against hyperpigmentation disorders.
BACKGROUND: Increased production and accumulation of melanin leads to various hyperpigmentation disorders. Melanin synthesis is regulated by melanogenic proteins such as tyrosinase, tyrosinase-related protein (TRP)-1 and -2, and their transcription factors. OBJECTIVE: In this study, we assessed the effects of PQQ on melanogenic protein expression of murine B16 melanoma cells. METHODS: We assessed melanin production of PQQ-treated B16 melanoma cells. Furthermore, we investigated the effect of PQQ on the activity of melanogenic enzymes and their expression using Western blot and semi-quantitative RT-PCR analyses. RESULTS: In the present study, PQQ inhibited melanin synthesis in cultured melanoma cells stimulated by either alpha-melanocyte stimulating hormone (alpha-MSH) or 3-isobutyl-1-methylxanthine (IBMX). To elucidate the mechanism of the effect of PQQ on melanogenesis, we performed Western blotting for melanogenic proteins, such as tyrosinase, TRP-1, and TRP-2. PQQ inhibited tyrosinase expression, however, it did not inhibit TRP-2 expression. Used as the stimulant for melanogenesis, both alpha-MSH and IBMX gave the same results for melanogenic protein expression. Semi-quantitative RT-PCR analysis showed that the depigmentation effect of PQQ might be due to the inhibition of tyrosinase gene transcription but not the inhibition of microphthalmia-associated transcription factor (Mitf). CONCLUSION: This report indicates that PQQ is a possible anti-melanogenic agent and might be effective against hyperpigmentation disorders.