Immunostimulatory and anticancer activities of polysaccharides extracted from traditional anticancer Chinese medicinal herbs

Background and Objective: It is evident from the scientific literature that plant and mushroom polysaccharides possess significant antioxidant, immunomodulatory and anticancer activities. Sixteen traditional Chinese anticancer herbs were evaluated for the immunomodulatory and anticancer potential of their polysaccharides. This study also aimed to correlate the bioactivities of these polysaccharides with their monosaccharide composition and to identify the best herbs for further detailed studies. Methods: Polysaccharides were extracted from the selected traditional Chinese medicinal (TCM) herbs and their biological activities examined. The antioxidant activities were examined using DPPH∙ scavenging, ABTS∙+ scavenging and iron chelating assays. The immunomodulatory properties of the polysaccharides were determined by evaluating their capacity to activate mouse macrophages (RAW 264.7) to produce the cytokines, namely, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The anticancer activities of the polysaccharides were determined against five human cancer cell lines. Cell viabilities were evaluated by the MTT test to assess the toxicities of these polysaccharides. The total sugar content and the monosaccharide composition of the polysaccharides were determined with a view to correlate their bioactivities with chemical constituents. All data were analyzed using ANOVA and Duncan’s multiple range methods. Results: The polysaccharides isolated from Artemisia annua L., Lobelia chinensis Lour, Amauroderma rugosum (Blume and T. nees), Artemisia scoparia Waldst. and Kit, Artemisia vulgaris L., Curcuma aromatic Salisb, Rheum palmatum L. and Cyperusrotundus Blanco showed significant anticancer, immunomodulatory and antioxidant activities with low toxicity. The results suggested that the polysaccharides extracted from A. annua, L. chinensis, A. rugosum and S. suberectus have strong potential for immunotherapy and hence suitable candidates for cancer treatment. Conclusion: Polysaccharides from several herbs were found to exhibit significant antioxidant, immunostimulatory and anticancer activities. The results demonstrated that, A. annua, L. chinensis and A. rugosum and S. suberectus are highly suitable herbs for the discovery of anticancer polysaccharides.