Erigeron annuus flower absolute prolongs botulinum neurotoxin A-induced muscle paralysis and inhibits neurotransmitter release-linked responses.

This study aimed to determine the effects of Erigeron annuus (L.) Pers. (EAP) flower absolute (EAPFAb) on neurotransmitter release-blocking events and muscle paralysis induced by botulinum neurotoxin type A (BoNT/A). For this study, EAPFAb was extracted from EAP flowers by solvent extraction and its composition was determined by GC/MS. Neurotransmitter release and SNARE protein expression were examined in PC12 cells by ELISA and immunoblotting. Rat hind limbs were tested for muscle paralysis. EAPFAb contained 23 components and prolonged the duration of BoNT/A-induced rat hind limb muscle paralysis. EAPFAb reduced neurotransmitter release induced by elevated extracellular potassium levels and attenuated SNARE protein expression in PC12 cells. These findings demonstrate that EAPFAb prolongs BoNT/A-induced muscle paralysis action, probably by inhibiting releases of neurotransmitters that are regulated by SNARE proteins in neural cells. EAPFAb may be a promising material for prolonging BoNT/A action.