The effect of N-acetylcysteine and calcium hydroxide on TNF-α and TGF-ß1 in lipopolysaccharide-activated macrophages.

OBJECTIVE: The present study was designed to evaluate the pro- and anti-inflammatory effects of NAC and calcium hydroxide (Ca(OH)2) on lipopolysaccharide-stimulated human macrophage cell lines. DESIGN: THP-1 human monocyte precursor cells were differentiated into macrophage adherent cells. Cell cytotoxicity was measured by flow cytometry analysis. NAC and Ca(OH)2 were applied in the presence or absence of lipopolysaccharides (LPS) for time periods of 4, 8, and 24h. Protein and mRNA levels of tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta1 (TGF-ß1) were determined using ELISA and qRT-PCR. The data were statistically analyzed by three-way ANOVA followed by Bonferroni test at α=0.05. RESULTS: In LPS-stimulated cell lines, while the TNF-α protein and mRNA levels were reduced in the first 4h, only the TGF-ß1 mRNA levels increased in the 24th hour following treatment with Ca(OH)2 and NAC when compared with the control group (p<0.001). In LPS-unstimulated cells, the TNF-α protein level was significantly decreased by NAC and Ca(OH)2 at the 4th hour. Additionally, while the TGF-ß1 mRNA levels were significantly reduced, the protein level of TGF-ß1 was increased at the 24th hour. CONCLUSIONS: It was concluded that NAC, similar to Ca(OH)2, has anti-inflammatory properties and might be considered an alternate candidate therapeutical agent to Ca(OH)2.