Effects of Extract from Brassica rapa L. Capsule on the Maturation and Function of Dendritic Cells

Abstract: Traditional uyghur medicine Brassica rapa L. has been used as tonic for lung and kidney and has a variety of efficacies， such as anti-aging and anti-radiation. It has been used to treat cough， chronic bronchitis and asthma. However， its effects on the regulation of the immune system， especially the maturation and function of dendritic cell (DC)， need to be investigated. DCs were induced from C57BL/6 bone marrow (BM) in the presence of murine granulocyte-macrophage colony stimulating factor (GM-CSF). On day 7， BM-DCs were treated with different doses of Brassica rapa L. Capsule extract (BRCE) according to polysaccharide concentrations (0.01， 0.1， 0.5， 1 mg/mL). DCs treated with lipopolysaccharides (LPS) were used as positive control. The expression of costimulatory molecules and the secretion of cytokines were detected by flow cytometry and ELISA， respectively. The function of DC was determined by mixed lymphocyte reaction (MLR). The results showed that BRCE containing 1 mg/mL polysaccharide had no toxic effect on DC survival. The expressions of co-stimulatory molecules (CD40，CD80 and CD86) were up-regulated by BRCE treatment in a dose-dependent manner， and the levels of cytokines (IL-12p40， IL-6， IL-1β and TNF-α) were also increased and arrived at the maximum in DCs treated with 0.1 mg/mL BRCE. MLR results suggested that BRCE dose-dependently enhanced the ability of DC to stimulate allogeneic T cell proliferation. We further observed that BRCE promoted the proliferation of splenocytes， and the proportions of DCs and B cells were significantly increased by BRCE treatment. These results show that BRCE not only enhances the maturation， cytokine production and function of DC， but also stimulates DC and B cell proliferation， suggesting that BRCE has the immunostimulatory potential through regulating the activating status of DCs.

CSTR: 32200.14.cjcb.2015.09.0013