In the present study, we examined the effect of phytoestrogenic isoflavones daidzein and genistein on glucose toxicity-induced cardiac mechanical malfunction simulating diabetic cardiomyopathy.
Matrix-assisted laser desorption ionization (MALDI) mass spectrometry of the final pigment provided evidence for homologous series of DHICA oligomers, while chemical analysis allowed an estimate of 2:1 DHICA/DHI-derived units in the polymer, with a substantial proportion of intact o -diphenolic functions.
Melanin Biosynthesis in Cryptococcus neoformans
Skin pigmentation results from melanin synthesis by melanocytes and is enhanced by exposure to UV radiation. Melanin is responsible for determining our skin color, and it plays an important role in protecting the skin cells from UV radiation. In melanin synthesis, there is a crucial enzyme called tyrosinase that catalyzes chemical reactions: amino acid tyrosine to melanin. Therefore, mutation of the tyrosinase gene causes albinism.
Phenylalanine supplement for depression, side effects
Fig. 1. Upper left: We used mouse melanoma to investigate the effect of aspirin on melanogenesis. Upper right: Acetylsalicylic acid (aspirin) is a white and crystalline solid. Lower: Effect of aspirin on melanin production. Aspirin strongly inhibits melanogenesis.
Color Genes - ESPCR & IFPCS
Genistein supplementation improves endothelial dysfunction induced by oophorectomy in rats and reduces infarct size in an experimental model of myocardial ischaemia-reperfusion injury.
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Conversely, 5,6-dihydroxyindole inhibits the oxidation oftyrosine to dopa, so that the relative concentrations of tyrosine and5,6-dihydroxyindole within the mammalian pigment cell are capable ofregulating melanogenesis in a previously unrecognized fashion.
Amino Acid Derivatives: Catecholamine, …
Tyrosinase, purified from murine melanomas and the skins of brownmice, has now been shown to catalyze a third reaction in mammalianmelanogenesis, namely the conversion of 5,6-dihydroxyindole tomelanochrome.
Nitric Oxide Synthesis and Function
In this study, we used the α-melanocyte stimulating hormone (α-MSH) to induce melanogenesis of melanoma. Thus, melanoma appears as UV-irradiated cells. In the presence of α-MSH, melanin content of cells was significantly increased. On the other hand, melanin content of cells that treated with aspirin was dramatically decreased. In the next step, we focused on the microphthalmia-associated transcription factor (Mitf) that is an important factor of melanin synthesis. Once activated, Mitf promotes gene transcription by binding the promoter region of tyrosinase gene. Interestingly, aspirin inhibited the Mitf gene at the transcriptional level. The fact that suppression of Mitf gene imply that aspirin depresses the tyrosinase gene and the subsequent inhibition of melanogenesis. Furthermore, we investigated the effect of aspirin on the extracellular signal regulated kinase (ERK) pathway. ERK plays an important role in cellular processes such as survival, proliferation, cell cycle progression and melanin synthesis. Activated ERK can phosphorylate Mitf, which causes degradation of the Mitf, and this process also brings about inhibition of melanin synthesis. Surprisingly, our result demonstrated that aspirin activated the ERK and it is also a leading cause of inhibition of melanogenesis. Taken together, our results suggest that aspirin can inhibit melanin synthesis that is caused by both inhibition of the Mitf gene expression and ERK activation.