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.