Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The improved method presented here for localizing monophenoloxidase activity of tyrosinase (E.C. 1.14.18.1) after electrophoresis is based on the transfer of electrons from the monophenolic substrate, tyrosine methyl ester, to an artificial acceptor, phenazine methosulfate, and subsequent reduction of nitro blue tetrazolium into a violet formazan. This method is rapid, sensitive and versatile compared to the standard method. The electron transferred from monophenol can be accepted directly by nitro blue tetrazolium; although the background of the gel is clear, the sensitivity is decreased. The monophenol-PMS-NBT method is suitable for both plant and animal samples. This method can also be used for histochemical demonstration of monophenoloxidase activity.
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PMID:Demonstration of monophenoloxidase activity of tyrosinase after electrophoresis. 171 63

To examine the possibility of luteolin as a whitening agent, we measured antioxidant activity using DPPH assay, NBT/XO assay and intracellular ROS scavengning assay and depigmenting activity using tyrosinase assay, alpha-MSH-induced melanin production in B-16 cells. Luteolin showed dose-dependent anti-oxidant activity in DPPH, NBT/XO and intracellular ROS assay. Also, luteolin directly inhibited xanthine oxidase activity in a dose-dependent manner. Although luteolin did not directly inhibit tyrosinase activity, it dose-dependently inhibited both tyrosinase activity and melanin production in B16 melanoma cells stimulated by 1 microM alpha-MSH. Luteolin dose-dependently inhibited cAMP levels in B16 melanoma cells stimulated by 1 microM alpha-MSH and 1 microM forskolin, which suggest that luteolin directly inhibits adenyl cyclase in B16 melanoma cells. Therefore, these results suggest that whitening activity of luteolin may be due to the inhibition of adenyl cyclase involved in the signal pathway of alpha-MSH in B16 melanoma cells.
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PMID:Whitening activity of luteolin related to the inhibition of cAMP pathway in alpha-MSH-stimulated B16 melanoma cells. 1880 60