The administration of an alpha-MSH analogue reduces the serum release of IL-1 alpha and TNF alpha induced by the injection of a sublethal dose of lipopolysaccharides in the BALB/c mouse.
The injection of alpha-MSH or of one of its analogues ([Nle4-D.Phe7] alpha-MSH4-10) reduced, in vivo, the release of two cytokines (IL-1 alpha and TNF alpha) involved in inflammation. The inflammatory state was induced in BALB/c mice by intraperitoneal injection of a sublethal dose of lipopolysaccharides (LPS). The assay of these cytokines by ELISA showed a reduction of 20% with alpha-MSH and between 30 and 60% with the alpha-MSH analogue. The alpha-MSH or the analogue was administered in one of two ways: intravenously or subcutaneously. The most efficient method seemed to be the subcutaneous one because it improved the activity 10,000 times more than the intravenous method. Moreover, the analogue induced a regression of mortality in the animals treated by the intravenous method. Our results show that alpha-MSH and one of its analogues inhibit IL-1 alpha and TNF alpha, and can be used as anti-inflammatory molecules.