Effects of Hydroquinone on Cytoskeletal Organization and Intracellular Transport in Cultured Xenopus laevis Melanophores and Fibroblasts

Abstract

Hydroquinone is used as a skin-lightening agent, it is also present in different chemical products and cigarette smoke. It is believed to inhibit melanin production in melanocytes by inhibiting the key enzyme tyrosinase. In the present study, we show that hydroquinone had severe effects on microtubules and actin filaments in cultured Xenopus laevis melanophores as studied by immunohistochemistry. It affected the intracellular transport of melanosomes, induced bundling of microtubules and disassembly of actin filaments at 10 and 50 μM, and at 100 μM proper adhesion to the substrate was lost. Effects occurred at lower concentrations than what previously has been stated to be cytotoxic, and the results show that tyrosinase is not the only cellular target. The cytoskeleton is of utmost importance for the function of all cells and across species. Our data has therefore to be considered in the discussions about the use of hydroquinone for bleaching of skin.

Rapid color change in fish and amphibians – function, regulation, and emerging applications

“…Pharmaceuticals and different toxins can affect pigmentation, and many substances are offered on the market to either increase or decrease pigmentation. One example of the latter is hydroquinone, a skin‐lightening agent, which we recently have shown not only to affect intracellular transport of melanosomes in X. laevis melanophores (Aspengren et al., ) but also to induce bundling of microtubules and disassembly of actin filaments at lower concentrations than what previously has been stated as cytotoxic. This means that we are increasing the amount of substances in the environment that may pose threats to water supplies and that might affect fish and frog coloration, thereby affecting their ability to avoid predators or to communicate.…”

“…Image analysis by light microscopy reveals important morphological data. Microtubules and actin filaments are evolutionary well conserved proteins (due to their important roles in eukaryotic cells) and using immunocytochemistry together with optical detection of pigment transport (Aspengren et al., , ; Hedberg and Wallin, ) predictions can be drawn about possible toxicological effects even in other cells and species. Such studies are preferentially made on aggregated cells because melanosomes quench the fluorescence signals from stained microtubules and actin filaments.…”

In Vitro Study of the Effects of Five Chemically Modified Tetracycline (CMT) Analogs on Human Epidermal Melanogenesis: Potential as Novel Anti-Melanogenic Agents

“…The reorganization of filamentous actin (F-actin) and subsequent dendritic development plays a crucial role in cellular morphological alterations and the transfer of melanin [43,44]. Treatment of melanophores with the commercial anti-melanogenic drug HQ was shown to lower the formation of actin filaments [45]. Moreover, CMT-1 has been shown to lower F-actin filament amounts in osteoclasts, resulting in reduced podosome formation and adhesion of bone cell osteoclasts [46].…”

Assessing Colouration in Ichthyology: Insights from the Melanophore Index Perspective

“…Melanophores, the most prevalent and studied chromatophores, are integral to vertebrate dorsal pigmentation [25]. These dendritic-shaped cells extend pigmented projections, known as melanosomes, parallel to the skin's plane [26,27].…”