Bamboo Culm Extract Downregulated Activation of NKT- and B- cells and Production of IL-6 in Pristane-Induced Lupus Mice

Lupus is characterized by immunoregulatory abnormalities between T- and B-cells leading to autoantibody production and multiorgan injuries. We investigated whether bamboo culm extract (BC) ameliorates aberrant activation of T cells and B cells and attenuate production of IL-6 in pristane-induced lupus mice. Lupus was induced by i.p. a single injection of 0.5 ml of pristane in female BALB/c mice, which, later about 4 months, were used as a lupus model. The pristane-induced lupus mice and healthy mice were injected i.p. with BC 5 μl/kg or PBS once a day for 3 weeks. These results demonstrated that BC significantly decreased levels of serum and BAL IL-6 and production of IL-6 by macrophages with/without LPS, and downregulated expression of NKT cell and CD86+ CD45R/B220+, but not CD80+CD45R/B220+ and CD69+CD4+ in the splenocytes in pristaneinduced lupus mice. Moreover, BC greatly increased Con A-stimulated production of IL-6, IL-10 and IFN-γ by splenocytes obtained from pristane-induced lupus mice. Therefore, our findings suggest that BC may ameliorate lupus pathogenesis in pristane-induced lupus mice via downregulation of aberrant activation of NKT cells and B cells and inhibition of production of IL-6.