Etudier l'Hyperpigmentation Post-inflammatoire (HPI) chez l'homme (Pour les professionnels)

Postinflammatory hyperpigmentation (PIH) is a common problem in darker skin types and happens after injury or inflammatory dermatoses such as acne vulgaris. The authors sought to create a reproductible model in humans after inducing PIH on the trunk with trichloracetic acid 35% (TCA 35%) and comparing it with PIH induced by truncal acne. 4 patients…

Le soja pour dépigmenter la peau (Pour les professionnels)

Soy contains antioxydants calles isoflavones. The 2 main ones are genistein and daizedine. In this study, the authors studied 7,3’,4’-Trihydroxyisoflavone (7,3’,4’-THIF), a metabolite of daidzedine would have a depigmenting effect Contrarily to daizedine, 7,3’,4’-THIF inhibits the extracellular and intracellular production of melanin by B16F10 cells (induced by α-melanocyte-stimulating hormone (MSH)) (7,3’,4’-THIF),  abolished the expression of…

Trouver des nouveaux agents dépigmentants: comprendre les voies de régulation pour conceptualiser des nouveaux traitements (Pour les professionnels)

The authors constructed the molecular regulatory network of melanogenesis by focusing on 2 pathways: paracrine factor-mediated signaling pathway Microphthalmia-associated transcription factor-related pathway By reviewing the literature, the authors established a “Boolean network model” that describes the dynamical characteristics of the network: Molecules which would decrease pigmentation: CREB, MITF protein, MITF active, GSK3B, CAMP, AC, PKA,…

Les lentigos solaires (taches de soleil, taches de vieillesse) et la consommation de graisses (Pour les professionnels)

Solar lentigo (sunspots, liver spots) are early seborrheic keratosis and are found in many individuals starting 45-50 years old. They are the result of sun exposure (photodamage). The goal of this study is to investigate the link between fat intake and the severity of solra lentigo. The study was done in 279 women: The severity…

Le Tabagisme favorise la pigmentation cutanée: pourquoi ? (Pour les professionnels)

Smoking tobacco is known for inducing skin pigmentation. In vitro the authors cultures human epidermal melanocytes. When cultured with tobacco smoke extract: Pigment cells (melanocytes) grew to a large size and produced more melanin. Some melanocytes were irradiated with UVB light (another cause of pigmentation), and a similar production of melanin was observed. However the…

Le Traitement du mélasma de triple combinaison (cortisone – vitamine A – hydroquinone) est loin de marcher toujours (Pour les professionnels)

Triple Combination Creams (Triluma) In Melasma (Hydroquinone, Fluocinolone, Tretinoin) Don’t Always Work. Triple combination creams are considered to be the gold standard in the treatment of melasma (chloasma, pregnancy mask). As a general rule, topical treatments work best when the location of the pigment is superficial. On the other hand,  treatment with light sources are…

Comprendre l'origine des cernes (Pour les professionnels)

Peri-orbital dark circles (DUEC) are a cosmetic concern worldwide and numerous causes and risk factors have been advocated as playing a role: allergy atopic dermatitis blood stasis structural shadowing effects a thinner epidermis/dermis under the eye. Questionnaires were given to 495 Brazilian women and the severity of DUEC was evaluated by a dermatologist. Hyperspectral image…

Vitiligo: Quelquechose qui "cloche" aux niveau des mitochondries (usines a énergie de toute cellule humaine) (Pour les professionnels)

Although still poorly understood, theories to the etiology of vitiligo are emerging. One of them is mitochondrial  dysfunctioning which would lead to oxydative stress and destruction of the melanocytes (pigment cells, unable to renew themselves). More precisely an increased Cyclosporin A-dependent ROS production, associated with a loss of membrane potential (Δψm), and defective Complex I…