The effect of simvastatin and different pharmacological inhibitors on LPS-stimulated IL-6 secretion by coculture of gingival fibroblasts and U937 cells. Gingival fibroblasts and U937 cells were co-cultured in the Transwell system and treated with or without 100 ng/ml of LPS in the absence or presence of 10 µM of simvastatin, 10 µM of PD98059, 10 µM of SP600125, 10 µM of SB203580, 5 µM of Bay117085 or 5 µM of parthenolide for 24 h. After the treatment, IL-6 (A) and MMP-1 (B) in culture medium were quantified using ELISA.