Isoescin IB, isolated from horse chestnut tree seeds, is an isomer of Escin IB. Isoescin IB and Escin IB are the chief active ingredients in escin^[1]. In Vitro: β-Escin (mainly consisting of escin Ia and escin Ib) is the major active ingredient in horse chestnut seeds extracts. β-escin can inhibit proliferation and/or induce apoptosis in various types of cancer cells including A549 cell, HT-29 cell, HCC cell, OVCAR3 cell and H-Ras 5RP7 cell. β-escin may be useful as a chemopreventive agent, especially for tumors associated with an inflammatory response^[1].
As the minor component of escin, α-escin (mainly consisting of isoescin Ia and isoescin Ib) exhibits lower bioactivity^[1].