Open Access Research article

Vaccination prepartum enhances the beneficial effects of melatonin on the immune response and reduces platelet responsiveness in sheep

Sergio Regodón1, Asunción Ramos1, María P Míguez2, Antonio Carrillo-Vico3, Juan A Rosado4 and Isaac Jardín4*

Author Affiliations

1 Department of Animal Medicine, University of Extremadura, 10003, Cáceres, Spain

2 Department of Animal Health, University of Extremadura, 10003, Cáceres, Spain

3 Deparment of Medical Biochemistry and Molecular Biology, University of Sevilla School of Medicine, 41004, Sevilla, Spain

4 Department of Physiology (Cell Physiology Research Group), University of Extremadura, 10003, Cáceres, Spain

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BMC Veterinary Research 2012, 8:84  doi:10.1186/1746-6148-8-84

Published: 20 June 2012



Melatonin regulates several physiological processes and its powerful action as antioxidant has been widely reported. Melatonin acts modulating the immune system, showing a protective effect on the cardiovascular system and improving vaccine administration as an adjuvant-like agent. Here, we have investigated the role of melatonin as an adjuvant of the Clostridium perfringens vaccine in prepartum sheep and whether melatonin modulates platelet physiology during peripartum.


The experiments were carried out in peripartum sheep from a farm located in an area of Mediterranean-type ecosystem. Plasma melatonin levels were determined by ELISA and sheep platelet aggregation was monitored using an aggregometer. Here we demonstrated for the first time that plasma melatonin concentration were higher in pregnant (125 pg/mL) than in non-pregnant sheep (15 pg/mL; P < 0.05). Administration of melatonin prepartum did not significantly modify platelet function but significantly improved the immune response to vaccination against C. perfringens.


Administration of melatonin as an adjuvant provides a significant improvement in the immune response to vaccine administration prepartum against C. perfringens.

Clostridium perfringens; Immune response to vaccination; Melatonine; Platelet aggregation; Pregnant sheep