OBJECTIVETo investigate the effect of cyclosporin A (CsA) and tumor necrosis factor-α (TNF-α) on cell proliferation of cultured human gingival fibroblasts (GF), and the relationship between gingival inflammation and drug-induced gingival overgrowth.

METHODSHuman GF were cultured in vitro using tissue culture method. then cells from the 4 - 8 th passage were used in the experiment. The cells were cultured and incubated with various concentrations of CsA and TNF-α (A: blank group, B1: 10 µg/L CsA, B2: 50 µg/L CsA, B3: 250 µg/L CsA, B4: 1250 µg/L CsA, C: 5 µg/L TNF-α, D1: 10 µg/L CsA + 5 µg/L TNF-α, D2: 50 µg/L CsA + 5 µg/L TNF-α, D3: 250 µg/L CsA + 5 µg/L TNF-α, D4: 1250 µg/L CsA + 5 µg/L TNF-α) solution for 3, 5 and 7 days. Methyl thiazolyl tetrazolium assay was used to evaluate the cell proliferation in the culture meidiun.

RESULTSThe proliferation of fibroblasts was inhibited when exposed to different concentration of CsA and A value decreased. There was no significant difference between group B1, B2, B3 and the control group, while the A value of group B4 was significantly higher than that of control group (P < 0.01). Fibroblast proliferation was significantly increased while cultured with 5 µg/L TNF-α. A value increased (P < 0.01). When exposed to CsA + TNF-α, A value of group D1, D2, D3 was much higher than that of group A, but was lower than that of group C (P < 0.05). Cell proliferation in group D4 was significantly increased, and significantly different with that in group C (P < 0.01).

CONCLUSIONSCsA did not stimulate the cell proliferation, and high concentration of CsA inhibited cell proliferation. TNF-α can stimulate the cell proliferation. High-concentration CsA + TNF-α can enhance the fibroblast proliferation, which suggests that CsA in certain concentration have amplification effect on TNF-α to stimulate fibroblast proliferation.