Caco‑2 Monolayer Permeability and Stability of Chamaelirium luteum (False Unicorn) Open-Chain Steroidal Saponins

Herbal
medicines, although significant components of health care
for much of the global populace, are still far less stringently regulated
than conventional pharmaceuticals. Safety and efficacy concerns arise
because of the limited information regarding many of the phytochemicals
present in herbal medicines. Chamaelirium luteum (false unicorn) is an indigenous American herb marketed for “women’s
issues”. Recently, the potential bioactives, a new class of
open-chain steroidal saponins, have been fully characterized and preliminary
bioactivity assays have been performed. The present study utilized
the Caco-2 cell monolayer model to evaluate metabolic vulnerability
and potential bioavailability of eight saponins and sapogenins from
false unicorn. No compound metabolism was detected in Caco-2 cell
homogenate. One sapogenin, helogenin, exhibited low-to-moderate permeability
across the monolayers. Three saponinschamaeliroside A, heloside
A, and 6-dehydrochamaeliroside Awere found to have moderate
permeability. Transport studies indicated active transport of these
saponins. In contrast, all saponins with more than two sugar units
exhibited low permeability.