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 findings provide a basis for further investigations on the purified polypeptide as a useful candidate for immunomodulation and tumor treatment.