SUPERCRITICAL CARBON DIOXIDE EXTRACTION OF ALOE EMODIN AND BARBALOIN FROM ALOE VERA L. LEAVES AND THEIR IN-VITRO CYTOTOXIC ACTIVITY

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 IC50 8.94 and 10.78 μM respectively, while barbaloin had no effect.