Hyperpigmentation spots are a common skin condition in people over the age of 40. Whether they are concentrated on the face, hands or décolletage, they can prove to be bothersome. Scientific studies have identified a signalling pathway potentially involved in the hyperpigmentation process. Let's delve into this in this article.
The WNT pathway, a new lead in hyperpigmentation.
Summary
Published on June 14, 2023, updated on February 22, 2024, by Manon, Scientific Editor — 4 min of reading
What is hyperpigmentation?
Thehyperpigmentation is the medical term used to describe a localised and uneven pigmentation disorder of the epidermis resulting from an irregular production of melanin by the skin, the pigment responsible for skin colouration produced by melanocytes. Depending on the causes, there are different types of brown spots.
The melasma or pregnancy mask: Following hormonal fluctuations, brown spots often appear on the forehead, cheeks, or lips. They typically form during pregnancy, or when taking a medication that affects the hormonal system.
The age spots : These brown spots occur on the areas most exposed to the sun's UV rays, namely the back of the hands, the face, the décolletage and the back. They are the result of the photo-ageing of the skin.
Thepost-inflammatory hyperpigmentation : These spots occur following an inflammation.
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Is the WNT/β-catenin signalling pathway linked to hyperpigmentation?
In recent years, researchers have turned to the WNT/β-catenin signalling pathway to find alternatives aimed at reducing hyperpigmentation spots. This has allowed them to find a link between the WNT/β-catenin signalling pathway and melanogenesis.
The WNT/β-catenin signalling pathway: what are we talking about?
The Microphthalmia-associated transcription factor (MITF) acts as a primary regulator of the development, function, and survival of melanocytes by modulating various differentiation and cell cycle progression genes. It operates as a regulator of melanin synthesis by controlling the expression of tyrosinase, an enzyme that converts tyrosine into melanin. The β-catenin can directly interact with the MITF protein itself, and then activate the specific target genes of MITF.
WNT/β-catenin pathway and pigmentation spots: what does the study say?
This scientific study has highlighted the link between the WNT/β-catenin signalling pathway and the appearance of pigmented spots. Indeed, a chemical compound, cardamom, was found to inhibit the accumulation of melanin by inhibiting the WNT/β-catenin signalling pathway. To achieve this, cardamom promoted the degradation of intracellular β-catenin, thereby repressing the expression of MITF and tyrosinase. The activated WNT/β-catenin signalling pathway is thus responsible for an excessive production of melanin, which leads to hyperpigmented spots. Compounds that inhibit the WNT/β-catenin signalling pathway, such as cardamom, pave the way for new research, as they could potentially constitute interesting depigmenting agents.
Source
CHO M. & al. Cardamonin suppresses melanogenesis by inhibition of WNT/β-catenin signaling. Biochemical and Biophysical Research Communications (2009).
