Effect of lead on IL–8 production and cell proliferation in human oral keratinocytes

ObjectiveTo investigate the effect of lead on the production of IL-8 and cell proliferation in normal human oral keratinocytes (NHKs).MethodsNHKs were prepared as outgrowths from normal human buccal mucosa. The cells were treated with three concentrations of lead glutamate (4.5×10−5M, 4.5×10−6M and 4.5×10−7M). NHKs grown in glutamic acid were used as control. The amounts of IL-8 secreted in the culture supernatants were evaluated at 12 and 24 h using enzyme-linked immunospecific assay (ELISA). Cell proliferation was determined by the MTT colorimetric assay. Three cultures were used for each experiment, and three independent experiments were performed. Analysis of variance and Duncan's multiple range tests were used for statistical analysis.ResultsAn elevation of IL-8 in culture supernatants of NHKs treated with lead at all concentrations at 12 and 24 h after exposure in a dose-dependent manner was revealed. A significant increase in cell numbers was observed only at 24 h exposed to 4.5×10−5M lead glutamate.ConclusionsThe capacity of NHKs, to secrete IL-8, enhanced by lead glutamate, is demonstrated here. Induction of cell proliferation is revealed only after exposure to high lead concentration. The elevation of secreted IL-8 is a probable initial sign for the acute inflammatory response and may be involved in the pathogenesis of lead stomatitis.