Photometry

How are In Vitro Testing Methods Used for Cosmetics?

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With the growing distaste and outright bans of animal testing of cosmetic products, more and more cosmetics companies are turning to in vitro testing. Let’s take a closer look at the nature of in vitro testing and the opportunities it offers for cosmetics brands and manufacturers.

Behavior of the two circulating androgens testosterone and DHEA and their main intracellular metabolites in an androgen-sensitive sebocyte cell line.

Androgens are known to strongly regulate the sebaceous gland. Relationships with testosterone have been reported and little is known about the role of DHEA. We showed that the most potent intracellular androgen metabolite, dihydrotestosterone (DHT), induced AR translocation, specific transcripts such as ras-related dexamethasone induced 1 (RASD1) and lipogenesis/lipid storage. We used these parameters to assess the behaviour and activity of the two main circulating androgens TESTO and DHEA, in comparison with DHT, in this model.

Innate immunity activation of sebocyte cells by living bacteria. Evidence of a potential immunosuppressive effect of DHT.

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Acne is a skin pathology targeting the pilosebaceous unit…sebum hypersecretion and bacterial infection. We studied the effects of living bacteria on the induction of an innate immune response in a sebocyte cell line.

Pharmacological effects of anti-androgens and other compounds in an androgen-sensitive sebocyte cell line.

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We analysed the activity of reference anti-androgens (Finasteride, Dutasteride, Cyproterone acetate), at the level of their potential targets (5-alpha-reductase, AR translocation, induced transcripts) and in a functional lipid accumulation assay. We also evaluated this androgen-induced lipid accumulation assay as a potential pharmacological tool to detect potential inhibitors from both androgenic and non-androgenic origins.

Androgens activate lipogenesis through an AKT-independent mTOR pathway stimulation and a limitation of autophagy in an androgen-sensitive sebocyte cell line.

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Androgens are key regulators of sebaceous function... A link between mTOR and androgen signaling has previously been reported...as well as a link between these processes and lipid synthesis...Here we aimed at confirming that DHT-induced lipid synthesis/accumulation is at least in part dependent on mTOR activation in the SEBO662AR cell line and that the autophagic process is consequently modified by the androgenic treatment.
in vitro and ex vivo assays: skin protection and immune defense system

Pollution and epigenetics: Histone H3 modifications in keratinocytes after exposure to urban dust and Benzo(a)pyrene

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In this work, human epidermal keratinocytes were used to study the effects of urban dust and benzo(a)pyrene on the epigenetic pattern of the histone H3 protein. The assay was then used to screen a series of plant extracts in order to find cosmetic actives to protect the skin against air pollution.
Dog Skin - Epidermal Cornification Proteins

Pseudomonas aeruginosa flagellum is critical for invasion, cutaneous persistence and induction of inflammatory response of skin epidermis

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Pseudomonas aeruginosa, an opportunistic pathogen involved in skin and lung diseases, possesses numerous virulence factors, including type 2 and 3 secretion systems (T2SS and T3SS) and its flagellum, whose functions remain poorly known during cutaneous infection.

Anti-inflammatory activity of CKC-containing cationic emulsion eye drop vehicles

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Preservative-free cationic emulsion-based artificial tears (ATs) or drug vehicles are innovative eye drop formulations with tear film stabilization and drug delivery properties, and valuable in vivo anti-inflammatory and wound healing properties.

New Biological Activities of Lythrum salicaria L.

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The perennial and widespread herb Lythrum salicaria L., also called purple loosestrife, is a plant that is traditionally used in European medicine.
lipid

Acne vulgaris: physiopathology and cell mechanisms

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Acne Vulgaris is a chronic inflammatory pathology located in the region of the pilosebaceous follicle. It occurs following a high production of sebum linked to hormonal (androgynous) or environmental (pollution) malfunctioning and to the colonization of the pilosebaceous follicle by certain bacteria (P. acnes). QIMA Life Sciences has developed a panel of innovative assays to discover and evaluate compounds for the treatment of acne.

Physiology and functions of the sebaceous gland

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The sebaceous gland is an organ located in the dermis. Its role is to synthesise and secrete sebum which is a component of the hydrolipidic film. The purpose of sebum is to protect the skin from external aggression and dehydration. Sebum also maintains the suppleness of the skin and hair.

Hair: Follicle, Associated Structures and Growth

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Hair follicles are skin adnexa which are able to regenerate in a complete, autonomous, cyclic and asynchronous manner. The histological analysis of the pilosebaceous unit reveals a three-element organization: the epithelial compartment, the mesenchymal compartment and the sebaceous gland.
Skin care complex

A Compensating Skin Care Complex Containing Pro-xylane in Menopausal Women: Results from a Multicentre, Evaluator-blinded, Randomized Study

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In addition to the natural process of skin aging, the skin of women is significantly impacted during and after menopause.

New biological effects of Aphloïol

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In the present study, we identified new properties of Aphloïol (syn. mangiferin) in improving skin barrier function, especially by promoting keratinocyte differentiation, synthesis of transmembrane glycoprotein and lipid neosynthesis.
skin photoaging irradiations

in vitro modeling of skin photoaging: development of evaluation tools for cosmetics

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Development of in vitro models skin for better understand the modifications during photo-aging induced by repetitive UV exposure.
ageing reconstructed epidermis

Development of a new model of reconstructed aged skin useful to study antiageing effects of cosmetic compounds

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The development of new anti-ageing products needs performant in vitro models mimicking morphological changes and physiological modifications appearing during skin ageing. In order to have access to a simple model mimicking the epidermis ageing but in relation with a normal dermis, we have developed a new in vitro model of reconstructed skin comprising an aged epidermis covering a reconstructed dermis built with collagen and normal (young) fibroblasts.
Rab11

Rab11a Is Essential for Lamellar Body Biogenesis in the Human

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Most of the skin barrier function is attributable to the outermost layer of the epidermis, the stratum corneum, which is composed of flattened, anucleated cells called corneocytes surrounded by a lipid-enriched lamellar matrix.

Androgens induce sebaceous differentiation in sebocyte cells expressing a stable functional androgen receptor

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In order to study the impact of active androgens in sebocytes, we constructed a stable human sebocyte cell line derived from SEBO662 [17] constitutively expressing a fully functional AR. In these SEBO662 AR+ cells, dihydrotestosterone (DHT) induced AR nuclear translocation and the strong modulation of a set of transcripts (RASD1, GREB1...) known to be androgen-sensitive in other androgenic cells and tissues.