No abstract

Peptides of synthesis are a very new strategy in cosmetic science and technology for at least two reasons: (1) they are small molecules, easily penetrable in the skin and (2) they are able to induce a very specific action, because all skin cells (keratinocytes, fibroblasts, nervous cells) have membrane receptors for peptides. This group of cosmeceutics includes the botox-like peptides, represented by acetyl hexapeptide 3 (Argireline) and pentapeptid-3 (Leuphasyl). The latter is less known and has been less studied. This substance inhibits the neuromuscular synapses in the mimic muscles, acting as enkephalins. It links the enkephalin receptor to nervous cells, thereby modulating the release of acetylcholine in synaptic space. This cellular activity will be translated in vivo in a relaxation of the muscle and a reduction of expression wrinkles. The aim of our study is to evaluate the optimal concentration of Leuphasyl for skin application at the mimic muscle level, the efficiency and the safety of this peptide. We formulated three emulsions of different concentrations (0.5%, 1%, 2%) which were applied to the skin, at the level of mimic muscles (1) at the eyebrows zone (above the corrugator supercilii muscle) and (2) at the periorbital zone (above the orbicularis oculi muscle). We evaluated the regression of the wrinkles between the eyebrows using an imagistic method: pro-derm Analyser. The study is of interest to discussions concerning how to apply these kinds of cosmetic products at the mimic muscle skin level and not at the level of the wrinkles.

No abstract

Finding non-invasive skin depigmenting agentsrepresent an important goal of cosmetic research and industry. It is now admited that Tyrosinase inhibitor substances could be the most efficient molecules in this field because Tyrosinase is the key enzyme in the melanogenesis process. In the pathology of macular skin hyperpigmentations it can mention aesthetic problems such as: melasma gravidarum, pigmentation of aged skin, photosensibilisation, hepatic disfunctions and post-inflammatory residual pigmentation. The aim of the study was to find out if the Lavandula essential oil has depigmenting properties on human skin, having as theoretical premise its tyrosinase-blocking effect, previously reported in literature for some plant species. By using gas chromatograph coupled with mass spectrometer (GC/MS), a pharmaceutical cream preparation, a protocol of exploration on volunteers (including criteria) and a mexameter, we have highlighted the composition of a sample of Lavandula angustifolia essential oil (LEO) and its depigmenting effect on skin melanic macula. The results highlightes that the main compounds identified were linalool (26.783%), terpinen-4-ol (22.143%) and 3-carene(21.668%), Terpinen-4-ol is represented as the possible active compound in tyrosinase inhibition. Our dermocosmetic assay shows that the depigmenting effect of Lavandula angustifolia oil is effective after 2 months of daily topical treatement, when the melanine average value (measured by the mexameter) decreases more than a third from the innitial value. The study remarks that Lavandula angustifolia essential oil (LEO) in daily cutaneous pharmaceutical form application, during two month, reduces the intensity of spot skin melanin, exprimed through mexametric values.Keywords: Lavandula angustifolia L.; tyrosinase inhibitor; melanic skin macula.

No abstract