EMG to investigate the in-vivo myorelaxant effect of anti-wrinkle compound

Newsletter # 89



Animal models


Argireline (acetyl hexapeptide-8) is a peptide fragment of plasma membrane protein SNAP-25, a molecular target for botulinum toxin. Argireline is considered as a safe anti-wrinkle alternative to the injection of botulinum toxin despite its lower potency. To our best knowledge, there was no preclinical studies that demonstrate the myorelaxing effect of Argireline in muscles involved in gait and walk.

In the below graph, Neurofit measured the depression of gastrocnemius Compound Muscle Action Potential (CMAP) by intramuscular (i.m.) Argireline in the rat.
This supports the myorelaxing effect of this anti-wrinkle compound in muscle other than those of the face and may therefore open a new therapeutic avenue for indications such as the treatment of hypertonia.





  • Argireline was found to reduce in a dose-dependent manner the electrical response of the injected muscle (gastrocnemius) in the rat. The peak of effect of Argireline was observed between 2-3 days post-injection.
    The measure of CMAP amplitude is the technique implemented herein and allows the estimation of the number of activated muscle fibers following the stimulation of the nerve

  • The measure of CMAP amplitude is the technique implemented herein and allows the estimation of the number of activated muscle fibers following the stimulation of the nerve.

    To see further our capabilities to evaluate the myorelaxing effect of drugs of interest in the context of spasticity or hypertonia, visit the following link : spasticity.


NEUROFIT offers a range of validated in vitro and in vivo screening tests for psychiatry and neurology.

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