A Highly Pure Sub-Fraction of Shallot Extract With Potent in vitro Anti-Angiogenic Activity

Our previous studies showed that various extracts of Persian shallot (Allium hirtifolium) have anti- angiogenic effects. This study has been undertaken to isolate and identify the major effective anti- angiogeneic sub-fraction of shallot. After preparation of the 50% hydroalcoholic extract of shallot bulbs, the extract was successively fractionated into n- hexane, ethyl acetate, n- butanol and aqueous fractions. Anti-angiogenesis activity of fractions was examined by in vitro angiogenesis assay. The ethyl acetate fraction which had the most anti-angiogenesis activity was further fractionated to four sub- fractions by thin layer chromatography (TLC), silica gel column chromatography and then analyzed by High Performance TLC (HPTLC) with ethyl acetate-methanol- water as the solvent system. Our results showed that one of the four sub- fractions, as the major band in HPTLC, had the most anti- angiogenic activity. Purification and characterization of the major anti- angiogenic compound/compounds of shallot's extract may constitute one means by which diets rich in shallot confer protection against cancer and finally introduce new agents with pharmacological activities in shallot as a potential candidate in cancer therapy.