The direct effects of NAC on TNF-α and IL-10 levels of untreated and LPS-treated THP-1 macrophages. A reduction of TNF-α and IL-10 levels was observed with NAC treatment for both untreated and LPS-treated THP-1 macrophages. LPS-treated THP-1 macrophages had a significant increase in both TNF-α and IL-10 levels compared to the untreated group. Data represent means ± SE from 6 trials. *, P < 0.05, indicates significant decrease in TNF-α and IL-10 levels with NAC treatment. **, P < 0.005, indicates significant decrease in TNF-α and IL-10 levels with NAC treatment. #, P < 0.05, indicates significant increase in TNF-α and IL-10 levels with LPS treatment. ##, P < 0.005, indicates significant increase in TNF-α and IL-10 levels with LPS treatment.