Supercritical carbon dioxide extraction of Aloe emodin and barbaloin from Aloe vera L. leaves and their in-vitro cytotoxic activity

ABSTRACT

Aloe emodin and barbaloin, isolated as the active principles of the medicinal plant Aloe vera L., were extracted by supercritical fluid extraction [SFE] and analyzed by high performance liquid chromatography [HPLC]. With optimized operating conditions for SFE, Aloe emodin and barbaloin were quantitatively extracted from A. vera leaves within 20 minutes at a flow rate of 0.3 ml/min, temperature and pressure at 40 °C and 3200 Psi respectively with the addition of 1 ml of methanol as a modifier. Separation of Aloe emodin and barbaloin, in a pure form, from the SFE extract was achieved using a semi-preparative column. The cytotoxic activity of both aloe emodin and barbaloin were evaluated using the in-vitro MTT colorimetric assay. Aloe emodin showed a cytotoxic activity on two human colon cancer cells lines [DLD-1 and HT-29] with IC[50] 8.94 and 10.78 micro M respectively, while barbaloin had no effect