Biological activity of liposomal vanillin.
This article presents a study of vanillin encapsulation inside multilamellar liposomes, with emphasis on the evaluation of antioxidant activity, the hemolytic effect, and the antisickling properties of these products. Egg phosphatidylcholine-cholesterol and egg phosphatidylcholine-cholesterol-1-O-decylglycerol liposomes were prepared by mechanical dispersion, all with vanillin included. Vesicles were characterized by determination of encapsulation efficiency and vanillin retention capacity. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The hemolytic effect of liposomes was also evaluated by spectrophotometry, as well as the antisickling activity by the Huck test using optical microscopy. Results showed that the lipid composition of liposomes did not significantly affect the encapsulation efficiency. Stable vesicles were obtained with a high retention percentage of vanillin. Liposomes exhibited a high capture of the DPPH radical compared to free vanillin and 1-O-decylglycerol (C10) in solution. Vesicles caused no significant hemolisys in normal erythrocytes, nor in those coming from patients with sickle cell anemia. Vanillin encapsulated in liposomes retained its antisickling activity, with a greater effect for C10-containing vesicles. Our results show that vanillin encapsulation in liposomes is a way to enhance the pharmacologic properties of this molecule using a suitable vehicle.