Inside the body with KPV

KPV corresponds to residues 11-13 of alpha-MSH, the 13-residue melanocortin derived from pro-opiomelanocortin, which is produced in the pituitary and other tissues. The C-terminal tripeptide was reported to keep anti-inflammatory activity in mice (Hiltz and Lipton, 1989) while lacking the pigmentary activity of the full hormone (Brzoska 2008). Whether endogenous KPV-length fragments have a physiological role in people is not established.[src][src][src]

Dalmasso et al. reported that KPV is taken up by PepT1 in human Caco2-BBE and HT29-Cl.19A epithelial cells and Jurkat T cells, in uptake and competition assays; the reported Km in Caco2-BBE cells was about 160 uM, which the authors describe as high affinity for this transporter. PepT1 is expressed in the small intestine and induced in the colon in inflammatory bowel disease. These are cell-culture and mouse findings; PepT1 uptake of KPV has not been demonstrated in people.[src]

In human cell lines stimulated with pro-inflammatory cytokines, nanomolar KPV inhibited activation of NF-kB and MAP-kinase pathways and reduced pro-inflammatory cytokine secretion (Dalmasso 2008). Earlier mouse work suggested KPV acts by inhibiting IL-1 beta functions (Getting 2003). The direct molecular target is unknown, as FDA's 2026 review also notes.[src][src][src]

KPV did not raise cAMP or inhibit cytokine release in macrophages, and its anti-migratory effect in mouse peritonitis was not blocked by an MC3/4 receptor antagonist. It remained active in MC1R-deficient (recessive yellow, e/e) mice, in peritonitis and in DSS colitis (Getting 2003; Kannengiesser 2008). This is why KPV is generally not classed with melanocortin receptor agonists such as bremelanotide, although the authors of the colitis study describe the independence from MC1R as at least partial.[src][src][src]

KPV added to drinking water reduced the incidence of DSS- and TNBS-induced colitis in mice, with lower pro-inflammatory cytokine mRNA (Dalmasso 2008). KPV also aided recovery in DSS and CD45RBhi transfer colitis (Kannengiesser 2008). It prevented tumour formation in a wild-type mouse model of colitis-associated cancer, but not in PepT1-knockout mice (Viennois 2016). Carrier-based oral delivery has been tested in mice (Xiao 2017). All findings are animal-only.[src][src][src][src]

Rodent wound-healing models have been reported, and Bohm and Luger (2019) proposed that KPV and KdPT are candidates for clinical study in cutaneous wounds and ulcers. FDA found no human data for the nominated topical uses (wound healing and inflammatory conditions such as psoriasis and eczema). In excised human skin, passive permeation was below the assay limit (0.01 ug/mL), and measurable delivery required microneedle pretreatment, iontophoresis (a small electric current) or both (Pawar 2017).[src][src][src]