Actividad Fotoprotectora In Vitro de los Extractos de Parmelina tiliace.

Abstract

Due to the capacity of lichens to synthesize compounds when exposed to sun radiation, it has been posible to obtain a dry extract from which many sub extracts such as hexane, ethyl acetate, chloroform and ethanol are obtained in order to evaluate their capacity to be used as UVB filters, since the UV index in Ecuador is clearly increasing, so there is an important amount of UVB radiation affecting the population, this can cause adverse effects on health. The dry extract was disolved in each one of the solvents at different concentrations, for example: 20ppm, 200ppm, and 2000ppm; in addition octylmethoxycinnamate and Pamidate were used as control. The UVB radiation-induced cell death was carried out with the use of Escherichia coli ATCC ( 29522) strain to analyze the photoprotecting capacity as well as Mansur equation for the in vitro sun protection factor determination. The number of Escherichia coli colony forming units which survived after being exposed to the UVB radiation were transformed into values of area under the curve during a four-hour trial period. The ethanol sub extract showed a higher photoprotecting effect related to the other sub extracts at the proposed concentrations. At 2000ppm the hexane, ethyl acetate, and chloroform showed a photoprotecting effect which is comparable to the controls. The sun protection factor at 200ppm was 1.98, 7.79, 9.17 and 12.07 for hexane, ethyl acetate, chloroform and ethanol sub extracts respectively. It is worth nothing that both the photoprotecting effect and the FPS increase proportionally to the concentration each sub extract has.