Antimicrobial + cosmetic peptides

Category: immune_innate

Overview

Two functional categories. (1) Antimicrobial peptides (AMPs) — cathelicidin (LL-37) + defensins as innate immune effectors; pore formation in bacterial membranes; some research-stage as antibiotic adjuncts. KPV (lysine-proline-valine, α-MSH fragment) — anti-inflammatory peptide; topical IBD + dermatitis claim. Larazotide — zonulin antagonist; restores intestinal tight junctions; phase 3 celiac disease. (2) Cosmetic peptides — argireline (acetyl hexapeptide-3) is a SNAP-25 fragment that competitively inhibits SNARE complex → blunts muscle contraction → "topical Botox" mechanism (modest signal). Matrixyl (palmitoyl pentapeptide-4) → procollagen + hyaluronic acid synthesis upregulation. SNAP-8 / SNAP-29 — argireline analogs.

Organ Systems

• integumentary
• immune-hematologic

Pathway Steps

1. membrane-disruption-or-receptor-signal → antimicrobial-or-cosmetic-effect — via AMPs disrupt bacterial membranes; cosmetic peptides modulate cellular signaling pathways. Bioactive peptides act by two broad mechanisms: cationic antimicrobial peptides (LL-37, defensins) disrupt negatively charged microbial membranes, while signaling “cosmetic” peptides (matrikines like palmitoyl pentapeptide) act as receptor ligands that stimulate collagen synthesis. The same chemical class thus serves either host defense or skin-remodeling roles.

Known Modulators

• ll 37 (inhibitor) — bacterial membrane disruption + immune modulation. human cathelicidin; broad-spectrum AMP; psoriasis + rosacea pathophysiology contributor
• kpv (inhibitor) — NF-κB / α-MSH-fragment anti-inflammatory. C-terminal tripeptide of α-MSH; topical/oral anti-inflammatory; IBD + psoriasis research
• larazotide (inhibitor) — zonulin / tight-junction regulation. octapeptide; phase 3 celiac disease (CeDLara); restores intestinal tight junctions
• argireline (inhibitor) — SNAP-25 / SNARE complex. acetyl hexapeptide-3; topical "Botox-like" cosmetic; modest effect at supraphysiological concentrations
• matrixyl (activator) — fibroblast collagen synthesis. palmitoyl pentapeptide-4; cosmetic topical; procollagen + GAG production claims
• snap 8 (inhibitor) — SNARE complex (argireline derivative). acetyl octapeptide-3; modified argireline; cosmetic
• snap 29 (inhibitor) — SNARE complex regulatory protein (research). distinct from cosmetic SNAP peptides; SNARE-trafficking research molecule
• tbp 4 (activator) — tubulin polymerization-related peptide (research). research peptide; mechanism + indication not well established
• follistatin 344 (inhibitor) — myostatin + activin. follistatin variant; muscle-growth claims via myostatin neutralization; research-stage

References

• PMID 15703760