Pentapeptide-18

Pentapeptide-18 Related Research

1.Introduction to Enkephalins and Design Rationale

Enkephalins are opioid peptides that function as neurotransmitters in the central nervous system and have diverse effects, including modulation of pain perception and mood.

Pentapeptide-18 was developed to simulate the action of these endogenous neuropeptides.

The second amino acid of Pentapeptide-18 is D-alanine, while in endogenous enkephalin this position is occupied by glycine (Gly).

The use of this unnatural D-amino acid confers enhanced stability to the peptide, e.g., resistance to degradation by proteases (in particular aminopeptidases) in vivo.

This alteration increases the half-life of Pentapeptide-18 in the skin and therefore provides for longer-lasting efficacy.

2.Mechanism of Action

The mode of action of Pentapeptide-18 is to target the enkephalin receptor on the cell membrane of neuron cells.

It activates inhibitory G proteins (Gi) upon binding, which triggers an intracellular signaling cascade that inhibits the voltage-gated calcium channel and opens potassium channels.

The blockade of calcium influx directly suppresses synaptic vesicle fusion with the plasma membrane and the release of acetylcholine.

The neurotransmitter responsible for muscle contraction at the neuromuscular junction is acetylcholine.

Its reduced release results in decreased excitability of the neurons, which lessens the intensity of muscle contractions and eases dynamic lines that are caused by facial movements.

3.Clinical Studies on Efficacy

A clinical comparison of a cream containing 0.05 percent Pentapeptide-18 and another containing Acetyl Hexapeptide-3 (Argireline) was conducted on 43 female volunteers.

After 28 days of use, the Pentapeptide-18-only group had an average decrease in wrinkle depth of 11.64%.

It shares a similar outcome with acetyl hexapeptide-8 (Argireline), but acts via a distinct mechanism.

The combination of both has increasing effects for anti-wrinkle activity.

The wrinkle reduction rate was 25–47% when it was formulated to contain 5% acetyl hexapeptide-8 (branded as Argirelox®).

A further open-label study was carried out (20 volunteers) testing a higher concentration (2%) formulation of Pentapeptide-18.

After 28 days of continuous use, silicone impression assessments showed a 35% decrease in wrinkle depth on the forehead and a 28% decrease in crow’s feet wrinkles around the eyes⁴.

4.Modern Applications and Summary

Pentapeptide-18 is a chemically modified derivative of enkephalin, a well-recognized active ingredient in modern anti-age skincare.

It is primarily added as an anti-wrinkle active to serums, lotions, creams and masks for a more youthful appearance that combats the effects of muscle contraction.