Maria Del Carmen Velazquez Pereda

Effect of green Coffea arabica L. seed oil on extracellular matrix components and water-channel expression in in vitro and ex vivo human skin models

Background  Green Coffea arabica L. seed oil is being widely used in cosmetic formulations, although its effects on human skin cells are not clear and most observations are unpublished.

Neuroimmunomodulatory compound for sensitive skin care: in vitro and clinical assessment.

Background  The pathophysiology of sensitive skin consists of an inflammatory reaction resulting from the abnormal penetration in the skin of potentially irritating substances, which occurs due to skin barrier dysfunction and changes in the production of local neuromediators.

Expression of differential genes involved in the maintenance of water balance in human skin by Piptadenia colubrina extract

Background  Hydration and integrity of the stratum corneum (SC) is an important determinant of skin appearance, metabolism, mechanical properties, and barrier function. The presence of aquaglyceroporins and envelope proteins are crucial to provide greater corneocyte cohesion to keep water and other moisturizers in the skin.

Photoprotective and antioxidant effects of Rhubarb: inhibitory action on tyrosinase and tyrosine kinase activities and TNF-α, IL-1α and α-MSH production in human melanocytes

BackgroundExposure to ultraviolet (UV) radiation causes various forms of acute and chronic skin damage, including immunosuppression, inflammation, premature aging and photodamage. Furthermore, it induces the generation of reactive oxygen species, produces proinflammatory cytokines and melanocyte-stimulating hormone (MSH) and increases tyrosinase activity. The aim of this study was to evaluate the potential photoprotective effects of Rheum rhaponticum L. rhizome extract on human UV-stimulated melanocytes.MethodsThe effects of Rheum rhaponticum rhizome extract on tyrosine kinase activity, and on interleukin-1α (IL-1α), tumour necrosis factor α (TNF-α), and α-MSH production in human epidermal melanocytes were evaluated under UV-stimulated and non-stimulated conditions. Antioxidant activity was evaluated by lipid peroxidation and 1,1-dyphenyl-2-picryl-hydrazyl (DPPH) assays, while anti-tyrosinase activity was evaluated by the mushroom tyrosinase method.ResultsRheum rhaponticum L. rhizome extract showed in vitro antioxidant properties against lipid peroxidation, free radical scavenging and anti-tyrosinase activities, and inhibited the production of IL-1α, TNF-α, α-MSH, and tyrosine kinase activity in melanocytes subjected to UV radiation.ConclusionsThese results support the inclusion of Rheum rhaponticum L. rhizome extract into cosmetic, sunscreen and skin care products for the prevention or reduction of photodamage.

Effects of a Brazilian herbal compound as a cosmetic eyecare for periorbital hyperchromia (''dark circles'')

Background  Evidence suggests that periorbital hyperchromia (dark circles) occurs mainly as a consequence of postinflammatory hemodynamic congestion producing a typical bruising aspect on the lower eyelids.

Effects of Coccoloba uvifera L. on UV-stimulated melanocytes

Background: Exposure to ultraviolet (UV) radiation induces generation of reactive oxygen species, production of proinflammatory cytokines and melanocyte‐stimulating hormone (MSH) as well as increase in tyrosinase activity. The potential photoprotective effects of Coccoloba uvifera extract (CUE) were evaluated in UV‐stimulated melanocytes.

Antiageing Mechanisms of a Standardized Supercritical CO2 Preparation of Black Jack (Bidens pilosa L.) in Human Fibroblasts and Skin Fragments

The use of topical retinoids to treat skin disorders and ageing can induce local reactions, while oral retinoids are potent teratogens and produce several unwanted effects. This way, efforts to explore complementary care resources should be supported. Based on this, we evaluate the antiageing effects of a supercritical CO2 extract from Bidens pilosa L. (BPE-CO2A) containing a standardized multicomponent mixture of phytol, linolenic, palmitic, linoleic, and oleic acids. BPE-CO2A was assessed for its effects on human dermal fibroblasts (TGF-β1 and FGF levels using ELISA; collagen, elastin, and glycosaminoglycan by colorimetric assays, and mRNA expression of RXR, RAR, and EGFr by qRT-PCR) and human skin fragments (RAR, RXR, collagen, elastin, and glycosaminoglycan by immunohistochemical analysis). Levels of extracellular matrix elements, TGF-β1 and FGF, and EGFr gene expression were significantly increased by BPE-CO2A. The modulation of RXR and RAR was positively demonstrated after the treatment with BPE-CO2A or phytol, a component of BPE-CO2A. The effects produced by BPE-CO2A were similar to or better than those produced by retinol and retinoic acid. The ability to stimulate extracellular matrix elements, increase growth factors, and modulate retinoid and rexinoid receptors provides a basis for the development of preparation containing BPE-CO2A as an antiageing/skin-repair agent.

Preliminary safety assessment of C–8 xylitol monoester and xylitol phosphate esters

Most of the cosmetic compounds with preservative properties available in the market pose some risks concerning safety, such as the possibility of causing sensitization. Due to the fact that there are few options, the proper development of new molecules with this purpose is needed. Xylitol is a natural sugar, and the antimicrobial properties of xylitol‐derived compounds have already been described in the literature. C‐8 xylitol monoester and xylitol phosphate esters may be useful for the development of skincare products. As an initial screen for safety of chemicals, the combination of in silico methods and in vitro testing can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal and human testing. This study was designed to evaluate the safety of C‐8 xylitol monoester and xylitol phosphate esters regarding carcinogenicity, mutagenicity, skin and eye irritation/corrosion and sensitization through alternative methods.