Immunomodulatory effect of concentrated lime juice extract on activated human mononuclear cells

In this study, the in vitro immunomodulatory effect of concentrated juice o f Citrus aurantifolia cv. swingle (Lime) was investigated. Clarified fresh lime juice was concentrated by freeze-drying. After dialysis against phosph ate buffered saline and sterilization by a Millipore filter, it was used fo r further experiments. Immunogenic property of the CLJ extract was document ed by production of specific polyclonal antibodies in rabbits. The immunomo dulatory effect of the extract was tested in mitogen activated cultured mon onuclear cells. The culture results indicated that proliferation of phytohe magglutinin (PHA) activated mononuclear cells were significantly inhibited by 250 and 500 mug/ml of CLJ extract, whereas only 500 mug/ml of the extrac t could inhibit proliferation of staphylococcal protein A (SPA) activated r nononuclear cells (P < 0.05). The abrogation of this inhibitory effect of t he CLJ extract was noted by adding anti-CLJ antibody to the lymphocyte cult ure. Considering these data, it can be concluded that the CLJ extract posse sses immunomodulatory principles, which may mainly be due to the protein co mponents of the extract. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.