Journal of Ethnopharmacology 77 (2001) 85 – 90 Immunomodulatory effect of concentrated lime juice extract on activated human mononuclear cells Marjan Gharagozloo, Abbas Ghaderi * Immunology Department, Medical School, Shiraz Uniersity of Medical Sciences, PO Box 71345 -1798, Shiraz, Iran Received 16 January 2001; received in revised form 8 May 2001; accepted 22 May 2001 Abstract In this study, the in vitro immunomodulatory effect of concentrated juice of Citrus aurantifolia cv. swingle (Lime) was investigated. Clarified fresh lime juice was concentrated by freeze-drying. After dialysis against phosphate buffered saline and sterilization by a Millipore filter, it was used for further experiments. Immunogenic property of the CLJ extract was documented by production of specific polyclonal antibodies in rabbits. The immunomodulatory effect of the extract was tested in mitogen activated cultured mononuclear cells. The culture results indicated that proliferation of phytohemagglutinin (PHA) activated mononuclear cells were significantly inhibited by 250 and 500 g/ml of CLJ extract, whereas only 500 g/ml of the extract could inhibit proliferation of staphylococcal protein A (SPA) activated mononuclear cells (P 0.05). The abrogation of this inhibitory effect of the CLJ extract was noted by adding anti-CLJ antibody to the lymphocyte culture. Considering these data, it can be concluded that the CLJ extract possesses immunomodulatory principles, which may mainly be due to the protein components of the extract. © 2001 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Immunomodulatory effect; Mononuclear cell proliferation; Citrus aurantifolia swingle; Lime juice www.elsevier.com/locate/jethpharm 1. Introduction Plants have always been a common recourse of the medicaments either in the form of traditional prepara- tions or as pure active principles. In every region, based on the climate and geographic conditions, spe- cial medicinal plants grow and many of them have unique medicinal properties in treatment of diseases. Several reports have clarified the anti-inflammatory and immunomodulatory properties of some medicinal plants cultivated in Iran such as Achillea talagonica, Biebersteinia multifida, Cichrorium intybus, Marticaria chamomilla, and Calendula officinalis (Rezaeipoor et al., 1999; Amirghofran et al., 2000; Farsam et al., 2000). Among the important cultivated plants in Iran are the Citrus species from Rutaceae family. Citrus fruits are known as familiar food and medicine, their therapeutic effectiveness in a variety of diseases has been suggested in traditional medicine (Chavallier, 1996). Some experiments provide evidences of anti- cancer, antidepressant, anti-inflammatory and antibac- terial properties of various Citrus juices and fragrance (Komori et al., 1995; Hollman et al., 1996; Kawaii et al., 1999; Rodrigues et al., 2000). For example, flavonoids, limonoids, and ascorbic acid are groups of citrus micronutrients, which are responsible for the anti-inflammatory and antitumor activities of citrus juice (Bennet et al., 1981; Lam and Hasegawa, 1989; Guthrie and Carroll, 1998; Samarineanu, 1998). How- ever, there are few reports about immunomodulatory effects of citrus juice macromolecules such as proteins. In the Rutaceae family, Citrus aurantifolia cv. swingle (Lime) is a plant which has been frequently cultivated in southern region of Iran during centuries (Ghahreman, 1988). Also, it has long been used in Iran for treatment of cold, asthma, infections, and joint pain. Therefore, in this study immunogenicity and immunomodulatory effect of concentrated lime juice (CLJ) extract on the proliferation of mitogen activated mononuclear cells were investigated. * Corresponding author. Fax: +98-711-233-4589. E-mail address: ghaderia@sums.ac.ir (A. Ghaderi). 0378-8741/01/$ - see front matter © 2001 Elsevier Science Ireland Ltd. All rights reserved. PII:S0378-8741(01)00269-0