Methyl 4-(ss-D-glucopyranosyloxy)-3-hydroxy-5-methoxybenzoate, isolated from Sanguisorba officinalis, inhibits CpG-DNA-induced inflammation

Purpose: To evaluate the anti-inflammatory effect of methyl-4-(ss-D-glucopyranosyloxy)-3-hydroxy-5-methoxybenzoate (comp-1) on immune cells. Methods: Comp-1 was isolated from Sanguisorba officinalis. After treating with comp-1, cell viability and levels of pro-inflammatory cytokines were assessed utilizing MTT assay and ELISA, respectively. Besides, the effects of comp-1 on nuclear factor kappa B (NF-kappa B), mitogen-activated protein kinase (MAPK), and iNOS were determined using western blotting. Moreover, nitric oxide production was assessed using the Griess reagent. Results: Treatment of dendritic cells (DCs) with CpG DNA upregulated cytokine expression. Comp-1 markedly downregulated the expressions of IL-12 p40, IL-6, and TNF-alpha, with 50% inhibitory concentrations (IC50) of 1.077 +/- 0.04 (p < 0.01), 0.28 +/- 0.01 (p < 0.01), and 0.79 +/- 0.02 mu M (p < 0.01), respectively. Treatment of DCs with CpG DNA upregulated NF-kappa B and MAPK activation. However, pretreatment of the cells with Comp-1 suppressed CpG DNA-induced NF-kappa B and MAPK activation. Moreover, comp-1 exhibited a strong anti-inflammatory effect by inhibiting nitric oxide production and iNOS expression. Conclusion: These results reveal that comp-1 has significant anti-inflammatory effect on immune cells.