The effects of folic acid application on IL-1.BETA. levels of human gingival fibroblasts stimulated by phenytoin and TNF.ALPHA. in vitro: A preliminary study.

Abstract

Folic acid (FA), that is required for the integrity of gingival tissues, was found to decrease in patients using phenytoin (PHT). Interleukin-1 beta (IL-1beta) was reported to enhance the extracellular matrix synthesis in fibroblasts. The purpose of this study was to assess the role of FA supplementation on PHT-induced overgrowth by investigating its effect on IL-1beta production of human gingival fibroblasts induced by tumor necrosis factor alfa (TNFalpha) in cell culture. PHT (20 microg/ml), FA (20 or 40 ng/ml) + PHT, PHT + TNF (10 ng/ml), FA (20 or 40 ng/ml) + PHT + TNF, or only culture medium (control) was added to 24-well plates containing fibroblasts. After an incubation period of 72 h, culture medium and cells were harvested separately. Then, IL-1beta levels in cell lysate were measured using enzyme-linked immunosorbent assay. The cellular IL-1beta level in the PHT group was 1 pg/ml. In PHT + 20 or 40 ng/ml FA-added cultures, the results obtained respectively were 0.8 and 0.7 pg/ml, whereas the control group value was 0.7 pg/ml. IL-1beta level was 4 pg/ml in the cultures that PHT and TNFalpha were applied simultaneously (P < 0.05). When PHT and either 20 or 40 ng/ml FA were simultaneously added into TNFalpha-induced cultures, the IL-1beta levels were 1.8 and 1.3 pg/ml, respectively. IL-1beta level in gingival tissues might play a role in PHT-induced overgrowth by increasing in the gingival tissues, and FA application might play a role in decreasing gingival tissues. However, further studies are needed for a more complete understanding of PHT-induced gingival overgrowth at the cellular level.