A stopped spectrophotometric assay for the dopa oxidase activity of tyrosinase

Winder, Alison J.

doi:10.1016/0165-022x(94)90014-0

Cited by 35 publications

(40 citation statements)

References 24 publications

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“…The cells were treated with α-MSH (1 μM) alone or with α-MSH plus 50 and 100 μg/ml concentrations of extracts, arbutin or ascorbic acid for 72 h. Cellular tyrosinase and DOPAquinone activities were measured as described previously [7,17,18] with the following modifications. The effects of extracts on tyrosinase activity and DOPAquione content inhibition were assessed as percentages of those observed in controls treated with vehicle DMSO (0.1% final volume).…”

Section: Cellular Tyrosinase Activity and Dopaquinone Contentmentioning

confidence: 99%

Antioxidant and Antimelanogenic Behaviors of Paeonia suffruticosa

Ding

Chou

Lin

et al. 2011

Plant Foods Hum Nutr

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Antioxidant properties of eight Paeonia suffruticosa (Ps) extracts (Ps-1 to Ps-8) were evaluated. The respective half maximally effective concentration (EC(50)) values of Ps-1 ~ 8 were 10.0, 9.8, 63.6, >100, 3.8, 85.1, 6.9, and 0.7 μg/ml for 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) radical scavenging efficiency and 22.9, 11.4, 53.1, >100, 7.5, 97.6, 43.7, 4.2 μg/ml for 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS·(+)) radical scavenging capacity. The Ps-8 exhibited high free radical scavenging capacity, ion-chelating ability, reducing power, and inhibition of lipid peroxidation, which may have been attributable to its abundant phenolic and flavonoid content. In Hs68 and B16 cells treated with 100 μg/ml Ps-1, Ps-3, Ps-4 and Ps-6, expressions of toxic activities were lower than those in cells treated with arbutin and ascorbic acid. The antimelanogenesis properties were also tested in B16 cells. Extract Ps-1, and particularly extract Ps-6, considerably inhibited cellular tyrosinase and 3,4-dihydroxyphenylalanine (DOPA) oxidase activity and also reduced melanin content in B16 cells by down-expression of melanocortin-1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related proteins-1 (TRP-1). The results suggest that P. suffruticosa extracts have antioxidant and antimelanogenesis activities with potential applications in cosmetic materials or food additives.

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Section: Cellular Tyrosinase Activity and Dopaquinone Contentmentioning

confidence: 99%

Antioxidant and Antimelanogenic Behaviors of Paeonia suffruticosa

Ding

Chou

Lin

et al. 2011

Plant Foods Hum Nutr

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“…Cells were harvested by trypsinisation on day 5, then tyrosinase (DOPA oxidase) activity was determined by the 3-methyl-2-benzothiazolinone hydrazone method, in which dopaquinone, formed by the oxidation of DOPA by tyrosinase, is quenched by 3-methyl-2-benzothiazolinone hydrazone and the resulting complex is determined spectrophotometrically at 508 nm [15,23]. The activity is then divided by the cellular protein concentration determined with the Bradford assay [24].…”

Section: Methodsmentioning

confidence: 99%

The Potential Depigmenting Activity of Retinaldehyde

Sorg

Kasraee²,

Salomon³

et al. 2013

Dermatology

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Background: Retinoids have been reported to exert depigmenting activity. Unlike most depigmenting agents that target tyrosinase, they are not phenolic agents and may act via different mechanisms. Objectives: We analysed the properties of retinaldehyde (RAL), a precursor of retinoic acid (RA), as a skin-lightening agent in various models. Methods: The viability and the depigmenting properties of RAL were assessed in murine melanocytes, in human reconstructed epidermis, and in mice and guinea pigs. The melanin content and cytotoxicity were assessed in melanocytes; in 3-dimensional models, the melanin concentration and the number of active melanocytes were determined. Results: RAL was taken up by melanocytes and mostly metabolised to retinol and retinyl esters, and to a lesser extent to RA. RAL decreased the melanin concentration of guinea pig ears and mouse tails by 54 and 74%, respectively, and decreased the number of active melanocytes by 42 and 77%, respectively. In reconstructed epidermis the melanin concentration was increased by 52%, whereas the number of active melanocytes decreased by 44%. Conclusion: RAL exerts a significant depigmenting activity with a mode of action that looks different from that of RA. Our data suggest a skin-lightening effect related to a melanolytic action (i.e. a decrease in melanin concentration, whatever the mechanism) rather than to melanocytotoxicity, besides other still unknown actions of RAL on melanocytes.

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“…Cells were harvested by trypsinisation at day 5, then tyrosinase (DOPA oxidase) activity was determined by the 3-methyl-2-benzothiazolinone hydrazone (MBTH) method, in which dopaquinone, formed through the oxidation of DOPA by tyrosinase, is quenched by MBTH and the resulting complex is determined spectrophotometrically at 508 nm [11,17]. The activity is then divided by the cellular protein concentration determined with the Bradford assay [18].…”

Section: Methodsmentioning

confidence: 99%

The Combination of a Retinoid, a Phenolic Agent and an Antioxidant Improves Tolerance while Retaining an Optimal Depigmenting Action in Reconstructed Epidermis

et al. 2013

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Background: Cutaneous pigmented lesions urge the need to find safe and effective treatments to lighten the skin. Objective: The aim of this study was to combine a retinoid (retinaldehyde), a new phenolic agent (4-(1-phenylethyl)-resorcinol) and a proreducing agent (δ-tocopheryl-β-D-glucopyranoside) to achieve synergistic actions for skin lightening. Methods: The tolerance profile and the depigmenting properties of these agents were assessed in murine keratinocyte and melanocyte cell lines, as well as in a 3-dimensional model of reconstructed epidermis. Results: Retinaldehyde and 4-(1-phenylethyl)-resorcinol induced a significant decrease of tissue viability in reconstructed epidermis, but this cytotoxicity was prevented by the addition of δ-tocopheryl-β-D-glucopyranoside. The combination of the three agents was, however, efficient in decreasing the specific melanin content and the density of active melanocytes. Conclusion: A combination of various chemicals acting via different mechanisms allows a decrease in the toxicity of each compound alone while retaining optimal skin-lightening properties.

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A stopped spectrophotometric assay for the dopa oxidase activity of tyrosinase

Cited by 35 publications

References 24 publications

Antioxidant and Antimelanogenic Behaviors of Paeonia suffruticosa

Antioxidant and Antimelanogenic Behaviors of Paeonia suffruticosa

The Potential Depigmenting Activity of Retinaldehyde

The Combination of a Retinoid, a Phenolic Agent and an Antioxidant Improves Tolerance while Retaining an Optimal Depigmenting Action in Reconstructed Epidermis

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