Function
While Epitalon is reported to increase lifespan and reduce tumor incidence in animals, and to influence differentiation of neural and mesenchymal stem cells; is studied as an epigenetic regulatory peptide36, Snap-8 is a cosmetic peptide studied for reducing wrinkle depth by inhibiting synaptic vesicle fusion and subsequent muscle contraction in facial expression muscles5060.
Mechanism
While Epitalon works as a synthetic tetrapeptide, Ala-Glu-Asp-Gly (AEDG), that has been shown to bind histones and modulate gene expression and chromatin state, with reported effects on pineal function, neurogenesis, and longevity in animal models36, Snap-8 is acetyl octapeptide-3 (Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2), an extended analog of Argireline derived from the N-terminal region of SNAP-25 that competes with native SNAP-25 for binding to syntaxin-1, forming a non-functional SNARE complex and reducing neurotransmitter release5060.