Ozonated water improves lipopolysaccharide-induced responses of an odontoblast-like cell line

It is important to develop an antimicrobial agent without any damage on dental pulp. In the present study, we examined whether pretreatment of bacterial lipopolysaccharides (LPS) with ozonated water (O(3)aq) improves LPS-induced responses of rat odontoblastic cell line, KN-3.

After the pretreatment of LPS with O(3)aq, effects of LPS and O(3)aq-treated LPS on cell viability; calcification ability; expression of cyclooxygenase 2 (COX-2), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha); and activation of p38 of KN-3 cells were examined.

The formation of mineralized nodules by KN-3 cells was suppressed by LPS, whereas that suppression was inhibited by the pretreatment of LPS with ozonated water. We also found that LPS-induced expression of COX-2, IL-6, and TNF-alpha and p38 activation were markedly suppressed when LPS was pretreated with ozonated water. Furthermore, expression of COX-2, IL-6, and TNF-alpha by LPS were mainly induced through p38 activation.

These results suggest that odontoblastic cells exhibit inflammatory responses against LPS and that ozonated water has the ability to improve LPS-induced inflammatory responses and suppression of odontoblastic properties of KN-3 cells through direct inhibition of LPS.