Effect of TLR4 antagonist LPS-RS on TNF production by monocyte/macrophages activated with Clerodendrum polysaccharide fraction CSP-AU1. Human PBMCs (Panel A) or MonoMac-6 cells (Panel B) were pretreated with indicated concentrations LPS-RS for 30 min, followed by treatment with media (negative control, ●), CSP-AU1 (250 μg/ml, ○), or LPS (200 ng/ml, □) for 24 hr, and extracellular TNF was quantified by ELISA. Values are the mean ± S.D. of triplicate samples from one experiment, which is representative of three independent experiments. Statistically significant differences (* p<0.05) between PBS-treated cells and cells treated with the indicated concentrations of LPS-RS plus fraction CSP-AU1 or LPS are indicated.