Immunomodulatory activity of polysaccharides from Brassica rapa by activating Akt/NF-κB signaling.

Objective: To investigate the immunomodulatory activity of polysaccharides from the roots of Brassica rapa. Methods: The crude polysaccharide from roots of B. rapa (BRP) was extracted and purified to further investigate the active fraction of BRT for inducing macrophage phagocytosis. Results: Effects on RAW264.7 cells demonstrated that BRP behaved better phagocytic capacity and had potent immunomodulatory activity, including increasing production of nitric oxide (NO), tumor necrosis factor α (TNFα) and upregulating mRNA levels of inducible NO synthase (iNOS) and TNFα. Furthermore, modulation of macrophage by BRP was indicated to be mediated via the activation of Akt and nuclear factor-kappa B (NF-κB). Conclusion: The beneficial effects of BRP could be used as an immunotherapeutic adjuvant in treatment of inflammatory diseases.

Polysaccharides of Brassica rapa L. attenuate tumor growth via shifting macrophages to M1-like phenotype.

Macrophages are the major tumor-infiltrating leukocytes, and tumor-associated macrophages (TAM) play a critical role in cancer-related inflammation since they show alternative polarization to M1 (tumor-inhibited macrophages) or M2 (tumor-promoted macrophages) phenotype. Brassica rapa L. (B. rapa) has been clinically proven to have anti-tumor and immunity-enhancing activity, and the polysaccharides of B. rapa (BRP) have been reported to have an immunoregulatory effect on macrophages. In this study, we focus on macrophage polarization to investigate the mechanism of anti-tumor response of BRP in vivo and in vitro. We found that BRP improved the expression of M1 markers, including iNOS, COX-2, HLA-DR, CD11b and M1-related cytokines. The expression of M2 markers Arg-1, CD206 and CD163 induced by IL-4 were inhibited by BRP treatment, resulting in the inhibition of tumor growth both in vivo and in co-culture experiments in vitro. The activation of STAT signaling pathway were significantly regulated by BRP, which are important signals in TAM polarization. Overall, the results indicated that BRP has anti-tumor effect through mediating macrophage polarization.

[Microbial transformation of glycyrrhetinic acid by Cunninghamella blakesleeana].

A study on the microbial transformation of glycyrrhetinic acid (GA) was conducted by a fungus, Cunninghamella blakesleeana CGMCC 3.970 systematically. After incubation with the cell cultures of C. blakesleeana CGMCC 3.970 at 25 degrees C for 7 days on a rotary shaker operating at 135 r x min(-1), GA was converted into one major product and five minor products. The products were extracted and purified by solvent extraction, macroporous adsorbent resin, silica gel column chromatography, and semi-preparative RP-HPLC chromatography. Their structures were identified as 3-oxo-15α-hydroxy-18ß-glycyrrhetinic acid(1), 3-oxo-15ß-hydroxy-18ß-glycyrrhetinic acid (2), 7ß,15α-dihydroxy-18ß-glycyrrhetinic acid (3), 3-oxo-7ß, 15α-dihydroxy-18ß-glycyrrhetinic acid (4), 7ß-hydroxy-18ß-glycyrrhetinic acid(5) and 15α-hydroxy-18ß-glycyrrhetinic acid(6) by the analyses of MS, 1H-NMR and 13C-NMR spectroscopic data respectively. Among them, 2 was a new compound. These results suggest that C. blakesleeana CGMCC 3.970 has the capability of selective ketonization and hydroxylation for GA. [Key words] glycyrrhetinic acid; Cunninghamella blakesleeana CGMCC 3. 970; microbial transformation