Effects of femtomolar doses of DM on TNF-α production in the serum. Mice were pre-treated with or without 1 ng/kg of DM 30 minutes before LPS/GalN (20 μg/600 mg/kg, i.p.). The level of TNF-α was determined at 1, 2, and 3 hours post-injection by TNF-α ELISA kit. Data show mean ± SEM of total 10 mice from at least 3 independent experiments. *P < 0.05, post hoc analysis by Bonferroni t-test, indicates significant different from the LPS/GalN alone group.