KPV

Source: PubChem

Source: PubChem

As far back as 1984, research in rabbits revealed that KPV is a powerful anti-inflammatory and fever reducer (anti-pyretic). In this setting, however, KPV had lower potency than the full alpha-MSH molecule. This suggested to scientists at the time that KPV was lacking some portion of the alpha-MSH molecule necessary for full anti-pyretic activity[5]. What ensued was decades of research investigating various modified forms of alpha-MSH.

The difference in potency has been found to be minimal, at best, as the majority of anti-inflammatory effects of alpha-MSH are, in fact, due to the KPV section. What is interesting, however, is that the parent molecule appears to be better at suppressing late-stage inflammatory reaction. In the case of contact dermatitis, for instance, alpha-MSH does a better job of preventing an allergic inflammatory response at 2 weeks post initial exposure. This suggests that alpha-MSH may be affecting some aspect of immune modulation that is separate from the immediate inflammatory response[7]. Work is still being done to determine what this process is.

Source: PubChem

Source: Wiley Online Library

It is also important to note that the anti-inflammatory effects of KPV appear to be mediated through a different mechanism than those of alpha-MSH. Whereas alpha-MSH binds to specific melanocortin receptors, KPV does not. Evidence of this comes from mouse studies in which blocking MC3/4 receptors, which mediate the anti-inflammatory effects of alpha-MSH, has no impact on the anti-inflammatory effects of KPV. Specifically, blocking these receptors does not block the leukocyte migration effects induced by KPV[16].