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Quantification of Hypopigmentation Activity In Vitro
Published on: March 6, 2019
A simple and novel colorimetric assay for tyrosinase and inhibitor screening using 3,3',5,5'-tetramethylbenzidine as
Cuihua Lei1, Xian-En Zhao2, Jing Sun3
1Shandong Provincial Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu City, Shandong Province 273165, China.
Abstract:
A novel colorimetric method for the detection of tyrosinase (TYR) and its inhibitor by taking utilization of Ag+-3,3',5,5'-tetramethylbenzidine (TMB) detection system has been proposed. Ag+ could oxidize TMB to oxidized TMB (oxTMB) and induce a blue color solution corresponding to an absorption peak centered at 652nm. The addition of dopamine (DA) could cause the reduction of oxTMB which resulted in the fading of the blue color and a decrease of the absorbance at 652nm. However, in the presence of TYR, DA could be oxidized to dopaquinone, which inhibited the reduction of oxTMB by DA, resulting in a blue color recovery and an increase of the absorbance at 652nm. Based on this finding, we propose a method to quantitatively detect TYR activity with the help of UV-vis spectroscopy. The developed assay is highly sensitive with a low detection limit of 0.010U/mL. More importantly, this method is fairly simple and inexpensive without the use of complicated nanomaterials. In addition, it constructs a useful platform for TYR inhibitor screening.
