Uso do resíduo industrial do sisal (Agave sisalana Perrine) em produtos cosméticos sustentáveis com atividades antioxidante e fotoprotetora

Abstract

Sisal is the main hard fiber produced in the world. In the chemical composition of the Agave sisalana residue, carbohydrates, saponins and phenolic compounds are found, which are used in the cosmetic industry with antioxidant and photoprotective activities. This work aimed to develop a multifunctional formulation with antioxidant and photoprotective activities from the industrial residue of A. sisalana. An ultrasonic extraction of the solid plant material was performed, varying the concentrations of the extracting agent (50% ethanol/water (v/v), 80% ethanol/water (v/v) and 100% ethanol). The extract with the highest yield was chemically characterized and evaluated for in vitro antioxidant activity. Ten photoprotective formulations were prepared varying the component concentrations and the shear time. The A. sisalana extract at a concentration of 1.0% was incorporated into the most stable formulations and their preliminary and accelerated stability was evaluated and the emulsions were investigated for safety. The photoprotective formulations containing or not the extract that were stable after 90 days, had their in vivo Sun Protection Factor, UVA Protection Factor, critical wavelength, and protection against visible and blue light determined. Ultrasound extraction using 50% ethanol/water (EH 50) as extractor vehicle showed the best yield. The extract exhibited a good concentration of phenolic compounds and showed in vitro antioxidant activity at different stages of the oxidative cascade. Emulsions without and with 1.0% A. sisalana extract remained stable for 90 days, presenting a desirable rheological behavior for a cosmetic for topical use: pseudoplastic and thixotropic. The emulsion containing A. sisalana extract proved to be safe after clinical studies. It was verified that the addition of the extract to the photoprotective formulation statistically increased the SPF when compared to the formulation without the extract with protection against UVA radiation, critical wavelength, absorption of visible and blue light and they fit in with the requirements of current legislation for sunscreens. In view of the results presented, the solid residue of A. sisalana can be indicated as a component of photoprotective and antioxidant cosmetic formulations.