Melatonin, as an adjuvant-like agent, enhances platelet responsiveness.

Melatonin exerts immunomodulatory actions that enhance the magnitude and quality of immune responses specific for certain antigens; this has raised the possibility of using melatonin to design novel vaccine adjuvant systems. The present study investigated the effect of subcutaneous slow-release melatonin implants and subcutaneous melatonin injections on the responsiveness of circulating platelets in sheep after vaccination against Dichelobacter nodosus (A1 and C serotypes), the bacterium that causes ovine footrot, a major cause of lameness in sheep. The experiments were carried out in sheep from a farm located in an area of Mediterranean-type ecosystem.

Melatonin enhances the immune response to vaccination against A1 and C strains of Dichelobacter nodosus.

Melatonin has been shown to exert immunomodulatory properties with broad application in veterinary medicine. Here we have investigated the effect of exogenous melatonin in the improvement of the immune response to administration of an immune-preparation of two stumps of A1 and C strains of Dichelobacter nodosus in sheep. Subcutaneous administration of melatonin enhanced plasma levels of melatonin from days 42 to 120.