Tobacco Smoke Found Guilty In Skin Pigmentation

We all know that cigarette smoke is notoriously carcinogenic and a culpable instigator behind so many health issues. But the latest discovery that science has made against the nicotine-laced fumes is that they promote pigmentation. In simple words, tobacco clouds turn radiant milky complexion into ashy dark skin tone.

According to a study published in the journal of International Investigative Dermatology smoking tobacco was linked directly with inducing skin pigmentation.

Researchers cultured human epidermal melanocytes in vitro — When cultured with tobacco smoke extract: Pigment cells (melanocytes) grew to a large size and produced more melanin. For comparison and control some melanocytes were irradiated with UVB light (another cause of pigmentation), and a similar production of melanin was observed. However the morphology of melanocytes was unaltered.

Melanocyte activity was estimated by measuring Microphthalmia-associated transcription factor (MITF) expressions by real-time PCR (Polymerase Chain Reaction). MITF expressions were significantly and dose-dependently increased by tobacco smoke extract (similarly to increased doses of UVB).

The Wnt/β-catenin signaling pathway seemed to mediate these melanocyte activations by tobacco smoke, because β-catenin expressions were increased only by tobacco smoke and not by UVB irradiations. Another important finding that these results indicate is that UVB-induced melaninogenesis might be mediated by another pathway, for example the α-MSH or the SCF/c-kit pathway.

Immunocytochemical studies also revealed that tobacco activated melanocytes actively expressed the aryl hydrocarbon receptors (AHR) around their nuclear membrane. Scientists also noted that this tobacco smoke induced MITF activation was inhibited by RNA silencing of the aryl hydrocarbon receptors.

This is not the first study that links the effects of smoking on pigment producing melanocytes. In the past many studies have established the correlation of lip and gum pigmentation with tobacco smoke. But the interesting thing about this current study is that it has precisely shown us the pathways of pigment production and exact measurements of pigment produced in response to tobacco smoke, while comparing nicotine-smoke induced pigmentation to UV induced pigmentation.

Source Of Information: Tobacco smoke induced skin pigmentation is mediated by the Wnt/β-catenin pathway and the aryl hydrocarbon receptor signaling. International Investigative Dermatology (IID) 2013 – Edinburgh, United Kingdom - M Nakamura, Y Ueda, T Furuhashi and A Morita Department of Geriatric and Environmental Dermatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.