Treating idiopathic thrombocytopenic purpura with comprising extracts of Astragalus membranaceus

A composition comprising a purified extract of the roots of Astragalus membranaceus, wherein the extract comprises:

• an arabinose:galactose ratio greater than 4.0:1 to 5.0:1;
• from about 5% to about 10% rhamnose;
• from about 15% to about 20% galactose;
• from about 10% to about 20% galacturonic acid;
• not more than 2% by weight protein, and,
• from about 10% to about 15% glucose;
• wherein,
• the extract is prepared using a first process that includes isolating a crude extract from Astragalus membranaceus and mildly treating the crude extract with an acid, the mildly treating including applying the acid to the crude extract at a concentration ranging from about 0.05M to about 0.5M, at a temperature ranging from about 15° C. to 25° C., and for a time ranging from about 1 hour to about 24 hours, wherein the temperature and time for applying the acid are selected to obtain the arabinose:galactose ratio, the galactose content, the glucose content, and a high yield;
• and,
• the extract is substantially higher in yield than an extract of the Astragalus membranaceus produced using a second process that includes applying the acid to the crude extract at a temperature and time selected to obtain an arabinose:galactose ratio of less than 3.5:1, 20%-35% galactose, and less than about 10% glucose.