Visualization of tyrosinase activity in melanoma cells by a BODIPY-based fluorescent probe

2011 ◽  
Vol 47 (47) ◽  
pp. 12640 ◽  
Author(s):  
Tae-Il Kim ◽  
Jihye Park ◽  
Seonhwa Park ◽  
Yongdoo Choi ◽  
Youngmi Kim
2017 ◽  
Vol 53 (81) ◽  
pp. 11213-11216 ◽  
Author(s):  
Kondapa Naidu Bobba ◽  
Miae Won ◽  
Inseob Shim ◽  
Nithya Velusamy ◽  
Zhigang Yang ◽  
...  

A two-photon fluorescent probe (Tyro-1) can validate intracellular tyrosinase activity, and H2O2induced upregulated tyrosinase in melanoma cells.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 674
Author(s):  
Shilpi Goenka ◽  
Francis Johnson ◽  
Sanford R. Simon

Skin hyperpigmentation disorders arise due to excessive production of the macromolecular pigment melanin catalyzed by the enzyme tyrosinase. Recently, the therapeutic use of curcumin for inhibiting tyrosinase activity and production of melanin have been recognized, but poor stability and solubility have limited its use, which has inspired synthesis of curcumin analogs. Here, we investigated four novel chemically modified curcumin (CMC) derivatives (CMC2.14, CMC2.5, CMC2.23 and CMC2.24) and compared them to the parent compound curcumin (PC) for inhibition of in vitro tyrosinase activity using two substrates for monophenolase and diphenolase activities of the enzyme and for diminution of cellular melanogenesis. Enzyme kinetics were analyzed using Lineweaver-Burk and Dixon plots and nonlinear curve-fitting to determine the mechanism for tyrosinase inhibition. Copper chelating activity, using pyrocatechol violet dye indicator assay, and antioxidant activity, using a DPPH radical scavenging assay, were also conducted. Next, the capacity of these derivatives to inhibit tyrosinase-catalyzed melanogenesis was studied in B16F10 mouse melanoma cells and the mechanisms of inhibition were elucidated. Inhibition mechanisms were studied by measuring intracellular tyrosinase activity, cell-free and intracellular α-glucosidase enzyme activity, and effects on MITF protein level and cAMP maturation factor. Our results showed that CMC2.24 showed the greatest efficacy as a tyrosinase inhibitor of all the CMCs and was better than PC as well as a popular tyrosinase inhibitor-kojic acid. Both CMC2.24 and CMC2.23 inhibited tyrosinase enzyme activity by a mixed mode of inhibition with a predominant competitive mode. In addition, CMC2.24 as well as CMC2.23 showed a comparable robust efficacy in inhibiting melanogenesis in cultured melanocytes. Furthermore, after removal of CMC2.24 or CMC2.23 from the medium, we could demonstrate a partial recovery of the suppressed intracellular tyrosinase activity in the melanocytes. Our results provide a proof-of-principle for the novel use of the CMCs that shows them to be far superior to the parent compound, curcumin, for skin depigmentation.


2018 ◽  
Vol 18 (7) ◽  
pp. 1064-1069 ◽  
Author(s):  
Seyed H. Hashemi-Shahri ◽  
Alireza Golshan ◽  
Seyed A. Mohajeri ◽  
Javad Baharara ◽  
Elaheh Amini ◽  
...  

Background: Crocus sativus (Iridaceae) has been traditionally used in the Iranian folk medicine and as a culinary additive. Major components of the plant that are responsible for biological properties are saffranal, crocin, picrocrocin and crocetin. Although the level of crocetin is not high, some of the important activities of saffron such as antioxidant activity have been attributed to crocetin. Objective: In the present study, we investigated the effects of crocetin on melanogenesis in B16 melanoma cells. Methods: The effect of crocetin on intracellular and mushroom tyrosinase activity and the content of melanin was evaluated spectrophotometrically. Tyrosinase and Microphthalmia-Associated Transcription Factor (MITF) protein levels were compared between Crocetin-treated and control cells after western blot analysis. The antioxidative activity of crocetin was also investigated. Results: Crocetin could inhibit mushroom tyrosinase activity and lower the amount of melanin in B16 melanoma cells. Protein levels of tyrosinase and MITF were also decreased by crocetin. Crocetin also showed antioxidant activity and depleted cellular Reactive Oxygen Species (ROS) content but had no cytotoxicity in alamarBlue® assay. Conclusion: Taken together, decreased tyrosinase activity, melanin content, tyrosinase and MITF proteins levels, and ROS production showed the inhibition of melanogenesis in B16F10 cells by crocetin. Hence, crocetin could be suggested as a potential dermatological whitening agent in skin care products.


2018 ◽  
Vol 13 (5) ◽  
pp. 1934578X1801300
Author(s):  
Shuo Liu ◽  
Zhen Zhao ◽  
Zhijun Huo ◽  
Zhiru Xu ◽  
Yan Zhong ◽  
...  

The Osmanthus fragrans flower (OFF) is commonly used as an additive for tea in China and as a traditional medicine to treat dysentery, asthma and hepatitis. In the current study, we have acquired the aqueous extract of the dried OFF (OFFE) and determined its enriched acteoside contents. However, whether OFFE and acteoside can modulate melanogenesis and pigmentation has yet to be determined. We here provide novel data revealing that OFFE and acteoside inhibit melanogenesis induced by α-MSH in B16 melanoma cells via the MITF-tyrosinase signaling pathway. Treatment with α-MSH (1μM) enhanced melanin levels and tyrosinase activity, up-regulated the mRNA levels of MITF and tyrosinase and increased the dendritic number in B16 melanoma cells, effects all being intervened by OFFE and acteoside. Of interest, OFFE and acteoside showed no direct inhibition of tyrosinase activity as revealed by our ex vivo tyrosinase activity assay. In addition, OFFE produced a depigmenting action on UVB-induced hyperpigmentation in guinea pigs, as shown by the improved skin brightness and the decreased melanin staining. Our data have demonstrated that OFFE can alter melanogenesis via modulating the MITF-tyrosinase signaling thereby leading to its depigmenting action in the in vivo model. OFFE could be a substitute for acteoside as a promising skin-whitening agent.


2019 ◽  
Vol 20 (19) ◽  
pp. 4785
Author(s):  
Junya Azumi ◽  
Tomoya Takeda ◽  
Yasuhiro Shimada ◽  
Hisashi Aso ◽  
Takashi Nakamura

The organogermanium compound 3-(trihydroxygermyl)propanoic acid (THGP) has various biological activities. We previously reported that THGP forms a complex with cis-diol structures. L-3,4-Dihydroxyphenylalanine (L-DOPA), a precursor of melanin, contains a cis-diol structure in its catechol skeleton, and excessive melanin production causes skin darkening and staining. Thus, the cosmetic field is investigating substances that suppress melanin production. In this study, we investigated whether THGP inhibits melanin synthesis via the formation of a complex with L-DOPA using mushroom tyrosinase and B16 4A5 melanoma cells. The ability of THGP to interact with L-DOPA was analyzed by 1H-NMR, and the influence of THGP and/or kojic acid on melanin synthesis was investigated. We also examined the effect of THGP on cytotoxicity, tyrosinase activity, and gene expression and found that THGP interacted with L-DOPA, a precursor of melanin with a cis-diol structure. The results also showed that THGP inhibited melanin synthesis, exerted a synergistic effect with kojic acid, and did not affect tyrosinase activity or gene expression. These results suggest that THGP is a useful substrate that functions as an inhibitor of melanogenesis and that its effect is enhanced by combination with kojic acid.


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