purif ied protein fraction of garlic extract modulates cellular immune response against breast transplanted tumors in balb/c mice model

objective: garlic (allium sativum) has anti-inflammatory, anti-mutagenesis, and immunomodulatory properties that modulate anti-tumor immunity and inhibit tumor growth. in this study we have examined the effect of a protein fraction isolated from fresh garlic on anti-tumor response and intra-tumor lymphocyte infiltration. materials and methods: in this experimental study a protein fraction was purified from fresh garlic bulbs using ultra-filtration, followed by chromatofocusing, and sds-page analysis. anti-tumor activity was assessed by intra-tumor injection of the protein fraction and garlic extract, itself, into groups of 5 mice each. the percentage of peripheral blood and intra-tumor cd4+ and cd8+ cells were assessed by flow cytometry. unpaired student’s t test using the spss program was applied for all statistical analyses. results: garlic extract included different type of proteins with different molecular weight. one of protein’s fraction was immunomodeulator and was composed of three single polypeptides, with molecular masses of ~10-13 kda and different isoelectric points (pi). these molecules augmented the delayed type hypersensitivity (dth) response compared to the control group. intra-tumor injection of the fraction provoked a significant increase in the cd8+ subpopulation of t-lymphocytes, as well as a decrease in tumor size. the fraction increased peripheral blood cd8+ t-lymphocytes in treated animals. conclusion: the data confirms that protein fractions purified from fresh garlic bulbs augment cd8+ t-cell infiltration into the tumor site, inhibiting tumor growth more efficiently than garlic extract. these fi ndings provide a basis for further investigations on the purified polypeptide as a useful candidate for immunomodulation and tumor treatment.