In vitro immunomodulatory effects of an oleanolic acid-enriched extract of Ligustrum lucidum fruit (Ligustrum lucidum supercritical CO2 extract) on piglet immunocytes

This study was conducted to evaluate the in vitro immunomodulatory effects of supercritical CO2 Ligustrum lucidum extract (LLE) on the immune cells of piglets. The results showed that the LLE enhanced the proliferative activity of piglet blood lymphocytes and up-regulated the CD4(+) CD8(+) and CD4(+) CD8(-) cell populations. The LLE also regulated the expression of Th1- and Th2-related cytokines; elevated the levels of IL-2, IFN-gamma and TNF-alpha, which were produced by Th1 lymphocytes; and decreased the levels of IL-4 and IL-10, which were produced by Th2 lymphocytes. Furthermore, the LLE stimulated the NO secretion of lymphocytes. These results indicated that LLE might have potential immunomodulatory effects on the immune system of piglets and provided scientific and experimental foundations for the development of a new kind of LLE immune adjuvant in the pig production. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.