Toxicity assessment of mouthwashes in the pollen tube growth test

AIM: Mouthwashes are frequently used to treat oral discomfort, halitosis or superficial infections. Adverse effects of mouthwash use are recognized, e.g. mucosal peeling and stomatitis. In addition, mouthwashes have been accused of causing oral cancer. The aim of this study was to analyse the acute toxicity of mouthwashes in an in vitro testing system, the pollen tube growth test (PTG test).

MATERIALS AND METHODS: Twenty mouthwash brands were prepared for study. The mouthwashes were added to suspensions of pollen of tobacco plants (Nicotiana sylvestris) that were collected during the early stages of anthesis. The inhibition of the pollen germination and pollen tube growth T(t) was measured photometrically from centrifuged supernatants of the Alcian blue-stained suspensions at a wavelength of 607 nm after 18 hours of incubation. The results were compared to inhibitions that resulted from other toxic substances.

RESULTS: In the PTG-test, the acute toxicity of several mouthwashes exceeds the toxic effect of alcohol. Calculated IC50 values for the mouthwashes ranged from 49,326 +/- 4881 mg/l to 541 +/- 137 mg/l.

CONCLUSION: Consumers should be informed about the number and concentrations of mouthwash ingredients and their toxic potential. These declarations would provide the basis for further testing the toxic effects of mouthwashes.