Product description
What is KPV?
KPV is a tripeptide composed of the amino acids lysine-proline-valine (Lys-Pro-Val), constituting the C-terminal fragment of the hormone α-melanocyte-stimulating hormone (α-MSH). This sequence corresponds to positions 11-13 of full-length α-MSH and has been identified as the region responsible for most of this neuropeptide’s anti-inflammatory properties, while lacking the broader hormonal effects associated with skin pigmentation.
α-MSH is a thirteen-amino-acid peptide that is a product of the proteolytic processing of proopiomelanocortin (POMC), exhibiting broad protective, anti-inflammatory, and antimicrobial actions. Studies have shown that the anti-inflammatory activity of α-MSH is mediated mainly by the three N-terminal amino acids, and that the KPV fragment retains - or even exceeds - the efficacy of the full-length peptide in inhibiting inflammatory processes.
Structurally, KPV is one of the smallest biologically active anti-inflammatory peptides, with a molecular weight of approximately 342 Da. Its simple structure and small molecular size allow for different routes of administration, including oral, topical, and injectable. Unlike many therapeutic peptides, KPV shows stability in the gastrointestinal tract, opening possibilities for oral applications.
KPV is attracting researchers’ attention because of its potential applications in the treatment of inflammatory bowel diseases (IBD), inflammatory skin conditions, and as an alternative to classic anti-inflammatory drugs with a lower risk of adverse effects. The peptide is a naturally occurring fragment of an endogenous hormone, suggesting a favorable safety profile.
Mechanism of action
Inhibition of the NF-κB pathway - The key mechanism of KPV’s anti-inflammatory action is inhibition of activation of the NF-κB transcription factor, a central regulator of pro-inflammatory gene expression. The peptide prevents degradation of the IκB-α inhibitor, blocks translocation of NF-κB to the cell nucleus, and reduces production of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6.
Transport via PepT1 - Studies have shown that the anti-inflammatory action of KPV is mediated by the di/tripeptide transporter PepT1 (hPepT1), rather than by melanocortin receptors. PepT1 is normally expressed in the small intestine and is induced in the colon during inflammatory bowel diseases. Transport of KPV into cells via PepT1 leads to intracellular accumulation of the peptide and inhibition of inflammatory signaling pathways.
Inhibition of the MAPK cascade - In addition to NF-κB, KPV also inhibits activation of MAP kinases (mitogen-activated protein kinases), which participate in transmission of pro-inflammatory signals. Dual inhibition of the NF-κB and MAPK pathways provides comprehensive anti-inflammatory action.
Reduction of cytokine secretion - KPV reduces secretion of pro-inflammatory cytokines by intestinal epithelial cells and immune cells. At nanomolar concentrations, the peptide effectively reduces production of IL-8 and other inflammatory mediators in cytokine-stimulated cells.
Melanocortin receptor-independent mechanism - Unlike full-length α-MSH, KPV does not bind to melanocortin receptors MC1R, MC3R, or MC5R and does not compete with α-MSH for these receptors. The anti-inflammatory action is preserved in mice with nonfunctional MC1R, confirming an alternative mechanism of action.
Directions for scientific research
Research on KPV focuses mainly on its potential application in inflammatory bowel diseases and inflammatory skin conditions.
Inflammatory bowel diseases (IBD)
In studies on mouse models of intestinal inflammation (DSS-induced colitis, TNBS-induced colitis), oral administration of KPV significantly reduced the severity of disease symptoms. The peptide reduced body-weight loss, myeloperoxidase activity in the colon, and histological signs of inflammation. In the study by Kannengiesser et al. (2008), KPV showed significant anti-inflammatory activity in two models of intestinal inflammation, and these effects were at least partly independent of MC1R signaling.
Molecular mechanisms in intestinal cells
Studies in human intestinal epithelial cells (Caco2-BBE, HT29-Cl.19A) showed that nanomolar concentrations of KPV inhibit activation of the NF-κB and MAPK signaling pathways and reduce secretion of pro-inflammatory cytokines. Dalmasso et al. (2008) confirmed that KPV is transported into cells by hPepT1 and that its anti-inflammatory action depends on expression of this transporter. Since PepT1 expression is elevated in intestinal inflammation, this creates the possibility of selective delivery of the peptide to sites affected by inflammation.
Nanoparticle delivery systems
Because of the potential degradation of the peptide in the gastrointestinal tract, advanced KPV delivery systems have been developed. Xiao et al. (2017) showed that hyaluronic acid-functionalized nanoparticles loaded with KPV effectively alleviate ulcerative colitis through targeted delivery to inflamed tissues and activated macrophages.
Wound healing and inflammatory skin conditions
Studies suggest potential applications of KPV in wound healing and the treatment of inflammatory skin conditions such as eczema, psoriasis, and atopic dermatitis. The peptide may accelerate re-epithelialization and reduce inflammation at the site of tissue damage.
Scientific context
KPV belongs to the melanocortin peptide family, which also includes:
- α-MSH - full-length hormone, precursor of KPV, with anti-inflammatory and pigmenting activity
- ACTH - adrenocorticotropic hormone, also a product of POMC
- K(D)PT - a related tripeptide with similar anti-inflammatory properties
Compared with full-length α-MSH, KPV offers several potential advantages as a therapeutic candidate:
- Simplicity - smaller molecule, easier to synthesize and formulate
- Selectivity - preserves anti-inflammatory action without affecting pigmentation
- Stability - shows stability in gastrointestinal tract conditions
- Bioavailability - can be administered orally thanks to transport via PepT1
KPV differs from classic anti-inflammatory drugs (NSAIDs, corticosteroids) in its mechanism of action and potentially more favorable safety profile. As a naturally occurring fragment of an endogenous hormone, the peptide is unlikely to cause the typical adverse effects associated with long-term anti-inflammatory therapy, such as adrenal suppression, osteoporosis, or risk of gastrointestinal bleeding.
Safety profile in studies
General tolerance - In preclinical studies, KPV showed a very favorable safety profile. As a small, naturally occurring fragment of α-MSH, the peptide is generally well tolerated and does not cause systemic complications typical of stronger immunosuppressive drugs.
Oral tolerance - Animal studies show stability of KPV in the gastrointestinal tract without toxic effects at typical research doses.
Topical safety - Cream and gel preparations for topical use did not cause significant irritation or local adverse reactions.
Injectable use - No serious systemic toxicity was observed in preclinical studies even at relatively high doses (mg/kg).
No immunosuppression - Unlike corticosteroids, KPV regulates inflammation without suppressing immune function, reducing the risk of long-term complications such as adrenal suppression, tissue breakdown, or increased infection risk.
Regulatory status - KPV is not approved by the FDA or other major regulatory agencies for clinical use. The peptide remains in the stage of preclinical and early clinical research. The FDA has considered KPV in the context of compounding substances, expressing concerns about the immunogenicity of synthetic peptides and impurities.
Bibliography – the latest scientific research
- Dalmasso G et al. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology. 2008;134(1):166-178. PubMed
- Kannengiesser K et al. Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflamm Bowel Dis. 2008;14(3):324-331. PubMed
- Xiao B et al. Orally Targeted Delivery of Tripeptide KPV via Hyaluronic Acid-Functionalized Nanoparticles Efficiently Alleviates Ulcerative Colitis. Mol Ther. 2017;25(7):1628-1640. PMC
- Böhm M et al. α-MSH related peptides: a new class of anti-inflammatory and immunomodulating drugs. Ann Rheum Dis. 2007;66 Suppl 3:iii52-55. PMC
- Luger TA et al. New insights into the functions of alpha-MSH and related peptides in the immune system. Ann N Y Acad Sci. 2003;994:133-140. PubMed
- Viennois E et al. Critical role of PepT1 in promoting colitis-associated cancer and therapeutic benefits of the anti-inflammatory PepT1-mediated tripeptide KPV in a murine model. Cell Mol Gastroenterol Hepatol. 2016;2(3):340-357. PubMed
- Laroui H et al. Drug-loaded nanoparticles targeted to the colon with polysaccharide hydrogel reduce colitis in a mouse model. Gastroenterology. 2010;138(3):843-853. PubMed
- Land SC. Inhibition of cellular and systemic inflammation cues in human bronchial epithelial cells by melanocortin-related peptides: mechanism of KPV action and a role for MC3R agonists. Int J Physiol Pathophysiol Pharmacol. 2012;4(2):59-73. PubMed
- Brzoska T et al. α-Melanocyte-stimulating hormone and related tripeptides: biochemistry, antiinflammatory and protective effects in vitro and in vivo, and future perspectives for the treatment of immune-mediated inflammatory diseases. Endocr Rev. 2008;29(5):581-602. PubMed
- Cutuli M et al. Antimicrobial effects of alpha-MSH peptides. J Leukoc Biol. 2000;67(2):233-239. PubMed
