ABSTRACT
A polysaccharide fraction from Solanum nigrum, SN-ppF3 was shown previously to have an immunomodulatory activity where it could possibly be used to enhance the host immune response in fighting cancer. The non-toxic SN-ppF3 was fed orally to breast tumor bearing-mice with concentrations of 250 and 500mg/kg for 10days. During the treatment period, size of the tumor and weight of the mice were monitored. At the end of the treatment, blood, tumor, spleen and thymus were harvested for physiological and immunological analyses. After the treatment, the tumor volume and tumor weight were significantly inhibited by 65% and 40%, respectively. Based on the histological observation, the treatment of SN-ppF3 resulted in the disruption of tumor cells morphology. The increase in infiltrating T cells, NK cells and macrophages were observed in tumor tissues of the treated mice, which partly explained the higher apoptosis tumor cells observed in the treated mice. Moreover, the level of TNF-α, IFN-γ and IL-4 were elevated, while the level of IL-6 was decreased significantly, in serum of the treated mice. These results suggested that tumor suppression mechanisms observed in SN-ppF3-treated mice were most probably due through enhancing the host immune response.
Subject(s)
Immunomodulation/drug effects , Mammary Neoplasms, Experimental/drug therapy , Mammary Neoplasms, Experimental/immunology , Polysaccharides/therapeutic use , Solanum nigrum/chemistry , Animals , Body Weight/drug effects , Cell Death/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Chemical Fractionation , Cytokines/metabolism , Disease Progression , Female , Fluorescent Antibody Technique , In Situ Nick-End Labeling , Killer Cells, Natural/drug effects , Killer Cells, Natural/immunology , Mammary Neoplasms, Experimental/pathology , Mice, Inbred BALB C , Polysaccharides/pharmacology , Spectroscopy, Fourier Transform Infrared , Staining and LabelingABSTRACT
The polysaccharide fraction from Solanum nigrum Linne has been shown to have antitumor activity by enhancing the CD4+/CD8+ ratio of the T-lymphocyte subpopulation. In this study, we analyzed a polysaccharide extract of S. nigrum to determine its modulating effects on RAW 264.7 murine macrophage cells since macrophages play a key role in inducing both innate and adaptive immune responses. Crude polysaccharide was extracted from the stem of S. nigrum and subjected to ion-exchange chromatography to partially purify the extract. Five polysaccharide fractions were then subjected to a cytotoxicity assay and a nitric oxide production assay. To further analyze the ability of the fractionated polysaccharide extract to activate macrophages, the phagocytosis activity and cytokine production were also measured. The polysaccharide fractions were not cytotoxic, but all of the fractions induced nitric oxide in RAW 264.7 cells. Of the five fractions tested, SN-ppF3 was the least toxic and also induced the greatest amount of nitric oxide, which was comparable to the inducible nitric oxide synthase expression detected in the cell lysate. This fraction also significantly induced phagocytosis activity and stimulated the production of tumor necrosis factor-α and interleukin-6. Our study showed that fraction SN-ppF3 could classically activate macrophages. Macrophage induction may be the manner in which polysaccharides from S. nigrum are able to prevent tumor growth.
