quarta-feira, 5 de dezembro de 2007

Mais parabenos, menos festa.

O abstract que se segue faz referimento a um trabalho da Universidade de Franche Comté, Besançon, sobre a capacidade de penetração nos extratos cutâneos dos parabenos.
Para quem ainda não está habituado com o nome, basta dar uma checadinha nos produtos cosméticos e de higiene pessoal que vocês têm nas suas casas. Se achar nos ingredientes coisas como metilparabeno, butil, etil, etc...parabeno, então é disso mesmo que se trata. Eles são conservantes e dos mais difusos no mercado.
Então, boa leitura!

El Hussein S, Muret P, Berard M, Makki S, Humbert P. Assessment of principal parabens used in cosmetics after their passage through human epidermis-dermis layers (ex-vivo study).Exp Dermatol. 2007 Oct;16(10):830-6.

Concern is continuously raised about the safety of parabens which are present in most of the cosmetic preparations. In this investigation, methyl-, ethyl-, propyl- and butyl paraben (MP, EP, PP, BP), in a commercial cosmetic lotion, were deposited on human skin fragments, collected after surgical operations. Permeated parabens were determined after their passage through human epidermis-dermis layers, fixed on Franz diffusion cells. Bovine serum albumin (3%) was employed as receptor fluid. Then, parabens were assessed by liquid chromatography. The objective of this research was to determine the permeation of these molecules through human epidermis-dermis layers, and their possible passage to body tissues and/or accumulation in skin layers. Two groups of experiments were performed. In the first experimental group (G1), unique doses of the cosmetic were deposited on skin fragments fixed on Franz cells (n = 6), at time 0 h, followed with different withdrawn times of the receptor fluid at 12, 24 and 36 h. G1 results demonstrated that parabens penetration was influenced by their lipophilicity: more lipophilic the parabens were (BP > PP > EP > MP), less they crossed the skin layers (BP < PP < EP < MP). The second experimental group (G2) was constituted of three equal deposits on each Franz cell (n = 6) at different hour times 0, 12 and 24 h followed with three withdrawn times of the receptor fluid at 12, 24 and 36 h. The G2 results indicated that investigated parabens had significant increasing permeations in skin layers. This situation provokes the accumulation of these molecules which were considered by some authors as the cause of skin toxicities and carcinogenicity.

Nenhum comentário: