Opposite effect of supernatants from selected periopathogens and oral lactobacilli cultures on ATP levels in human gingival fibroblasts.

Studies were performed on the effects of supernatants obtained from bacterial cultures, including cultures of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Lactobacillus acidophilus strains on ATP levels in human gingival fibroblasts (HGF-1) and on their viability. ATP levels were evaluated using luminescence test and cell viability was estimated using a fluorescence test. In control cultures mean levels of ATP in HGF-1 amounted to 4.90±0.32 mln RLU. Supernatants of P. gingivalis and A. actinomycetemcomitans cultures were found to significantly reduce ATP production in HGF-1 (mean levels of ATP amounted to 3.41±0.33 and 3.55±0.3 mln RLU respectively), which was not accompanied by an increased proportion of dead fibroblasts. Supernatants of P. intermedia induced no significant alterations in ATP level in HGF-1. In turn, supernatants of L. acidophilus H2O2 (+) and H2O2 (-) cultures significantly increased ATP levels in HGF-1 (the mean levels amounted to 5.94±0.31 mln RLU and 5.88±0.28 mln RLU respectively). The results indicate that extracellular products of P. gingivalis and A. actinomycetemcomitans most probably represent mitochondria-targeted peptides, which reduce synthesis of ATP in HGF-1. In turn, extracellular products of L. acidophilus seem to represent exopolysaccharides (EPS) with pro-oxidant activity, which stimulate synthesis of ATP in HGF-1.