Antimicrobial effects of alpha-MSH peptides.
Cutuli. M M; Cristiani. S S; Lipton. J M JM; Catania. A A
Key Findings
- Alpha‑MSH (1‑13) and its KPV fragment inhibit growth of Staphylococcus aureus and Candida albicans in vitro.
- Antimicrobial activity is seen at picomolar concentrations, within physiological ranges.
- The killing effect involves increased cellular cAMP; blocking cAMP partially reduces the antimicrobial action.
- KPV does not impair, and may enhance, neutrophil‑mediated killing of these pathogens.
Practical Outcomes
- For self‑experimenters, KPV could be explored as a low‑dose supplement to support innate immunity, especially when inflammation and infection co‑occur. However, optimal dosing, safety, and real‑world efficacy are not established, so any trial should start with very small amounts and monitor for side effects.
Summary
The short peptide KPV (the last three amino acids of alpha‑melanocyte‑stimulating hormone) can kill common germs like Staph bacteria and Candida yeast at very low, naturally‑occurring levels. It works by raising cellular cAMP and even helps immune cells kill these microbes better. While the study is in lab dishes, it hints that taking KPV could add an antimicrobial boost alongside its anti‑inflammatory effects.
Abstract
The presence of the ancient anti-inflammatory peptide alpha-melanocyte-stimulating hormone [alpha-MSH (1-13), SYSMEHFRWGKPV] in barrier organs such as gut and skin suggests a role in the nonspecific (innate) host defense. alpha-MSH and and its carboxy-terminal tripeptide (11-13, KPV) were determined to have antimicrobial influences against two major and representative pathogens: Staphylococcus aureus and Candida albicans. alpha-MSH peptides significantly inhibited S. aureus colony formation and reversed the enhancing effect of urokinase on colony formation. Antimicrobial effects occurred over a broad range of concentrations including the physiological (picomolar) range. Small concentrations of alpha-MSH peptides likewise reduced viability and germ tube formation of the yeast C. albicans. Antimicrobial influences of alpha-MSH peptides could be mediated by their capacity to increase cellular cAMP. Indeed, this messenger was significantly augmented in peptide-treated yeast and the potent adenylyl cyclase inhibitor dideoxyadenosine (ddAdo) partly reversed the killing activity of alpha-MSH peptides. Reduced killing of pathogens is a detrimental consequence of therapy with anti-inflammatory drugs. Because alpha-MSH has potent anti-inflammatory effects we determined influences of alpha-MSH on C. albicans and S. aureus killing by human neutrophils. alpha-MSH peptides did not reduce killing but rather enhanced it, likely as a consequence of the direct antimicrobial activity. alpha-MSH peptides that combine antipyretic, anti-inflammatory, and antimicrobial effects could be useful in treatment of disorders in which infection and inflammation coexist.
Study Information
pubmed
2000
2000-02-01T00:00:00.000Z
10.1002/jlb.67.2.233
136
35