Inhibitory Effect of Cetylpyridinium Chloride on the Activities of Gingipains and the Influence of Salivary Components on its Efficacy

Abstract

Porphyromonas gingivalis produces gingipains, which are virulence factors that can destroy periodontal tissues. While cetylpyridinium chloride (CPC) has been reported to have an inhibitory effect on gingipains, the bactericidal activity of CPC is known to decrease in the presence of saliva, making it unclear if CPC can exert its gingipain-inhibitory effect in saliva. This study was aimed at verifying the inhibitory effect of CPC against gingipains in the presence of saliva and at investigating the factors influencing this effect.

While CPC dissolved in PBS was confirmed to exert its inhibitory effect against gingipains, the compound failed to exert this effect in the presence of saliva. Therefore, focusing on the components of saliva, we examined the inhibitory effect of CPC against gingipains by adding metal salts and proteins to the CPC solution. The results revealed that only the addition of divalent metal salts attenuated the inhibitory effect of CPC against gingipains. Furthermore, addition of chelating agents did not diminish the inhibitory effect of CPC in the presence of saliva. Thus, we concluded that it is the divalent metal salts in saliva that diminish the inhibitory effect of CPC against gingipains.

Since chelating agents are only added at low concentrations to CPC and are therefore unlikely to cause demineralization, their addition to CPC is expected to contribute to the development of oral care products that can inhibit gingipain activity.