D-Limonene modulates T lymphocyte activity and viability

D-Limonene, a cyclic terpene that is a major component of several plant essential oils, is used widely as an additive in perfumes, soaps, foods and beverages, and has also been shown to possess chemopreventative and chemotherapeutic activity. A limited number of studies have been conducted investigating the effect of D-limonene on immune system function. We show that D-limonene and its metabolites limonene-1-2-diol and perillic acid inhibit the production by CD3(+)CD4(+) T cells of IFN-gamma, IL-2, TNF-alpha, IL-4 and IL-13, and the production by CD3(+)CD8(+) T cells of IFN-gamma, IL-2, and TNF-alpha. Additionally, the upregulation of CD25, CD69 and CD40L by activated T lymphocytes is modulated by D-limonene, limonene-1-2-diol and perillic acid treatment. Furthermore, high concentrations of D-limonene, limonene-1-2-diol and perillic acid induce T lymphocyte cell death. These data suggest that D-limonene possesses immunomodulatory activity that must be considered when utilizing the compound for therapeutic or commercial purposes. (c) 2012 Elsevier Inc. All rights reserved.