In vitro effect of CWE on LPS-induced TNF-α expression in macrophages. A: Peritoneal macrophages were treated with CWE for 24 h in the absence or presence of LPS. CWE was added 1 h before LPS stimulation. Supernatants were collected and cytokine levels were measured by ELISA. * P <0.05 compared with non-treated cells. B: Peritoneal macrophages were pretreated with CWE for 1 h and then stimulated with LPS for 4 h. Total RNA was prepared and realtime RT-PCR was performed. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as an internal control. * P <0.05 compared with cells treated with LPS only. Data are expressed as the mean ± SD of four independent experiments.