Evaluation of Toosendanin as a Botulinum Neurotoxin Antagonist

摘要

Toosendanin (TSN), a tetranortriterpenoid compound from the plant Melia toosendan, has been reported to protect rats and non-human primates from the lethal actions of botulinum neurotoxin A (BoNT/A). TSN was tested in isolated mouse phrenic nerve-hemidiaphragm preparations against BoNT serotypes A, B and E. When added prior to toxin, TSN was found to delay the onset of muscle paralysis with all 3 BoNT serotypes. TSN had little or no effect on BoNT- induced muscle paralysis when applied 30 min after BoNT. It is suggested that the antagonist activity of TSN may result from inhibition of BoNT translocation.