RESUMEN
OBJECTIVES: The immunomodulatory effect of ginger, Zingiber officinale (Zingiberaceae), sage, Salvia officinalis (Lamiaceae) and clove, Syzygium aromaticum (Myrtaceae), essential oils were evaluated by studying humor- and cell-mediated immune responses. METHODS: Essential oils were administered to mice (once a day, orally, for a week) previously immunized with sheep red blood cells (SRBCs). KEY FINDINGS: Clove essential oil increased the total white blood cell (WBC) count and enhanced the delayed-type hypersensitivity (DTH) response in mice. Moreover, it restored cellular and humoral immune responses in cyclophosphamide-immunosuppressed mice in a dose-dependent manner. Ginger essential oil recovered the humoral immune response in immunosuppressed mice. Contrary to the ginger essential oil response, sage essential oil did not show any immunomodulatory activity. CONCLUSIONS: Our findings establish that the immunostimulatory activity found in mice treated with clove essential oil is due to improvement in humor- and cell-mediated immune response mechanisms.