KPV

Three amino acids are enough: lysine, proline and valine form the tripeptide KPV, which sits at the C-terminal end of alpha-melanocyte-stimulating hormone. From the hormone it inherits the anti-inflammatory action but not the pigment formation. That makes KPV one of the best-characterised anti-inflammatory peptides in the literature and at the same time a mechanistically very reduced tool.

How it works:

• In preclinical studies KPV suppresses the activation of NF-kB, a master transcription factor of the inflammatory cascade. Downstream, cytokines such as TNF-alpha, IL-1 and IL-6 fall.
• It does not bind the classical melanocortin receptors to any relevant degree. In a mouse peritonitis model it slowed leukocyte migration without raising cAMP, which argues against a receptor route. The action therefore appears to start inside the cell.
• It enters the cell through the peptide transporter PepT1, found in intestinal epithelial and immune cells. There KPV blocked NF-kB and MAP kinase signals already at nanomolar concentrations.

KPV has been studied most thoroughly in models of long-running gut inflammation, inflamed skin and atopic dermatitis. In two mouse colitis models body weight recovered faster under KPV and the tissue carried fewer inflammatory infiltrates, even in animals lacking a working MC1 receptor; oral dosing likewise reduced intestinal inflammation. A 2008 review in Endocrine Reviews places KPV next to the related tripeptide KdPT.

We list KPV strictly as a research compound. What you read here places the evidence in context and is not a guide to use.

KPV is regarded in the studies as low in side effects, which fits its structure: short, quickly broken down and without relevant binding to the classical melanocortin receptors through which alpha-MSH itself acts. A few points are still worth knowing:

• Injection site: mild redness or tenderness is the most common local observation with subcutaneous dosing.
• Intervention in inflammatory pathways: damping NF-kB and lowering cytokines is an active intervention in immune regulation.
• Origin of the data: the evidence is extensive but comes almost entirely from cell and animal models. Robust long-term data in humans are missing, and what the colitis models show cannot simply be transferred to other questions.

This summary is no substitute for medical advice.

• PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation - 2008 paper on uptake via PepT1 and the effect in two colitis models.
• Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease - 2008 mouse study, including animals without a working MC1 receptor.
• Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides - 2003 peritonitis model: leukocytes slowed, cAMP unchanged.