To elucidate the anti-inflammatory mechanisms involved, we investigated the effects of atractylenolide III (ATL-III) on cytokine expression, extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38 mitogen-activated protein kinase (p38), C-Jun-N-terminal protein kinase1/2 (JNK1/2) and nuclear factor-κB (NF-κB) pathways in lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophages. Macrophages were incubated with various concentrations (0, 25, 50, 100 μM) of ATL-III and/or LPS (1 μg/mL) for 24 h. The production of nitric oxide (NO) was determined by the Greiss reagent. The production of tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2) and interleukin 6 (IL-6) was determined by enzyme-linked immunosorbent assay (ELISA). Furthermore, macrophages were treated with ATL-III (0, 25, 100 μM) for 1 h and then stimulated by LPS. NF-κB, p38, JNK1/2 and ERK1/2 were determined by western blotting. We found ATL-III showed no inhibitory effect on cell proliferation at concentrations ranging from 1 μM to 100 μM. In addition, ATL-III decreased the release of NO, TNF-α, PGE2 and IL-6 in a dose-dependent manner and showed statistically significant at concentrations of 50 μM and 100 μM as well as cyclooxygenase-2 (COX-2) expression. Furthermore, ATL-III suppressed the transcriptional activity of NF-κB. ATL-III also inhibited the activation of ERK1/2, p38 and JNK1/2 in LPS-treated macrophages and showed statistically significant at concentrations of 25 μM and 100 μM. These data suggest that ATL-III shows an anti-inflammatory effect by suppressing the release of NO, PGE2, TNF-α and IL-6 related to the NF-κB- and MAPK-signaling pathways.

Context: Atractylodes macrocephala Koidz is a traditional herb. Atractylodes macrocephalaon polysaccharides (AMP) have been found to enhance immunity and improve heart function. However, the mechanisms of the immunomodulatory effect have not been investigated. Objective: We examined whether AMP activated macrophages and explored the mechanisms of activation. Materials and methods: AMP was prepared and evaluated its immunomodulatory activity (25, 50, 100, and 200 lg/mL) by detecting the phagocytosis and the production of tumor necrosis factor-a (TNF-a), IFN-c, and nitric oxide (NO) in RAW264.7 macrophages. Furthermore, the role of nuclear factor-kB (NF-kB) pathway was examined in regulating TNF-a and NO production. Results: The phagocytosis of macrophages was enhanced by AMP in a dose-dependent manner and the maximal phagocytosis of macrophages occurred at concentrations of 100 and 200 lg/mL. NO, TNF-a, and IFN-c release was also found to be dose dependent by increasing concentrations of AMP and reached the peak at a concentration of 200 lg/mL. In addition, AMP induced inhibitor kappaB (IkB) degradation and the activation of NF-kB by p65 nuclear translocation, and then the activation of NF-kB in nucleus peaked at a concentration of 200 lg/ mL. Besides, NF-kB-specific inhibitor pyrrolidine dithiocarbamate (PDTC) decreased AMP-induced NO and TNF-a production. Discussion and conclusion: These data suggest that AMP may modulate macrophage activities by stimulating NF-kB or activating NF-kB-dependent mechanisms.