a highly pure sub-fraction of shallot extract with potent in vitro anti-angiogenic activity

abstract 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.