2001 Volume 43 Issue 4 Pages 255-260
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-1β) 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-1β production of human gingival fibroblasts induced by tumor necrosis factor alfa (TNFα) in cell culture. PHT (20 μg/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-1β levels in cell lysate were measured using enzyme-linked immunosorbent assay. The cellular IL-1β 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-1β level was 4 pg/ml in the cultures that PHT and TNFα were applied simultaneously (P < 0.05). When PHT and either 20 or 40 ng/ml FA were simultaneously added into TNFα-induced cultures, the IL-1β levels were 1.8 and 1.3 pg/ml, respectively. IL-1β level in gingival tissues might play a role in PHT-induced overgrowth by increasing in the gingival tissues, and FA applicationmight 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. (J. Oral Sci. 43, 255-260, 2001)
