Antileishmanial activity of fucosterol recovered from Lessonia vadosa Searles (Lessoniaceae) by SFE, PSE and CPC

摘要

Fucosterol, a triterpene derivative encountered in several alga species, provides a wide range of biological activities, such as protection against metabolic syndrome, or against UV-induced skin damage. We describe here the comparison of extraction by supercritical fluid (SFE) and pressurized solvent (PSE) of the brown alga Lessonia vadosa mainly abundant in the coastal water of Patagonia, followed by the isolation of fucosterol, using centrifugal partition chromatography (CPC), in association with HPLC-UV quantification. After collection, the seaweed was dried, ground and extracted either by PSE or by SFE under various conditions. The yield and the content in fucosterol of each extract were determined by HPLC-UV. Optimization of a biphasic solvent system and K-D calculation led to the isolation of pure fucosterol with high recovery rate. Extraction by SFE using CO2 at 180 bar and 50 degrees C with 20 to 30 % of cellulose as modifier and CPC purification by cyclohexane/acetone/methanol/water 10/1/10/1 with lower layer as mobile phase led to the best results in terms of yield, purity, time and solvent consumption. Natural and semisynthetic steroid derivatives have been previously shown to be potential drug candidates against parasitic diseases including leishmaniasis. In this context fucosterol was evaluated and demonstrated noticeable antileishmanial activity (IC50 < 10 mu M) against intracellular amastigotes with limited or no cytotoxicity in host cell macrophages. These results make this compound a valuable starting scaffold for pharmacomodulation. Adaptation of the procedure by slight modifications of the extraction and/or isolation conditions could permit the exploitation of other alga species as raw material. Since SFE and CPC are available for pilot and batch production, this work may serve as a model for further scale-up and industrial development. (C) 2014 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.