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

► A Ligustrum lucidum supercritical CO2 extract (LLE) has been produced in our lab. ► The LLE enhanced the proliferative activity of piglet blood lymphocytes in vitro. ► The LLE up-regulated the CD4+ CD8+ and CD4+ CD8- cell populations of piglet in vitro. ► The LLE up-regulated the Th1/Th2 arms of piglet in vitro. ► The LLE stimulated the NO secretion of piglet blood monocytes in vitro.