Antioxidant and pro-oxidant properties of chlorhexidine and its interaction with calcium hydroxide solutions
Journal
International Endodontic Journal
Journal Volume
40
Journal Issue
11
Pages
837-844
Date Issued
2007
Author(s)
Yeung S.Y.
Huang C.S.
Chan C.P.
Lin H.N.
Lee P.H.
Jia H.W.
Huang S.K.
Chang M.C.
Abstract
Aim To evaluate the antioxidant and pro-oxidant properties of chlorhexidine (CHX). Methodology The scavenging and generation of reactive oxygen species (ROS) by CHX in the presence or absence of saturated Ca(OH) 2 solutions was evaluated. The reaction emitted chemiluminescence in the presence of lucigenin thus was determined by a luminometer to evaluate the levels of ROS production. Changes in DNA conformation were analysed by agarose gel electrophoresis. Paired Student's t-test was used to compare the difference between groups. Results Chlorhexidine (0.00002-0.02%) effectively scavenged 56-88% of the superoxide radicals generated by the xanthine/xanthine oxidase reaction. Through analysis of PUC18 DNA conformation changes, CHX was shown to be a mild scavenger of hydroxyl radicals generated by H 2O 2 plus FeCl 2. However, CHX (>0.083%) decreased the mobility of PUC18 plasmid DNA with potential production of DNA-DNA cross-link and severe DNA breaks (presence of DNA smear) at further higher concentrations. Furthermore, CHX induced ROS production including H 2O 2 and superoxide radicals in 0.1N NaOH (pH = 12.76) or Ca(OH) 2 (pH = 12.5) solutions. Conclusion Chlorhexidine exhibited both antioxidant and pro-oxidant properties under different conditions. These events are possibly involved in the killing of root canal and periodontal microorganisms when CHX and Ca(OH) 2 were used in combination or separately. Potential genotoxicity and tissue damage when extruded into the periradicular tissue and at higher concentrations should be considered during periodontal and endodontic practice. © 2007 International Endodontic Journal.
Type
journal article