Systemic effects of H₂S inhalation at human equivalent dose of pathologic halitosis on rats

Abstract

Objectives: Halitosis is composed by hundreds of toxic gases. It is still not clear whether halitosis gases self-inhaled by halitosis patients cause side effects. The aim of the study was to investigate the effect of H₂S inhalation at a low concentration (human equivalent dose of pathologic halitosis) on rats.

Materials and methods: The threshold level of pathologic halitosis perceived by humans at 250 ppb of H₂S was converted to rat equivalent concentration (4.15 ppm). In the experimental group, 8 rats were exposed to H₂S via continuous inhalation but not the control rats. After 50 days, blood parameters were measured and tissue samples were obtained from the brain, kidney and liver and examined histopathologically to determine any systemic effect.

Results: While aspartate transaminase, creatine kinase-MB and lactate dehydrogenase levels were found to be significantly elevated, carbondioxide and alkaline phosphatase were decreased in experimental rats. Other blood parameters were not changed significantly. Experimental rats lost weight and became anxious.

Histopathological examination showed mononuclear inflammatory cell invasion in the portal areas, nuclear glycogen vacuoles in the parenchymal area, single-cell necrosis in a few foci, clear expansion in the central hepatic vein and sinusoids, hyperplasia in Kupffer cells and potential fibrous tissue expansion in the portal areas in the experimental rats. However, no considerable histologic damage was observed in the brain and kidney specimens.

Conclusions: It can be concluded that H₂S inhalation equivalent to pathologic halitosis producing level in humans may lead to systemic effects, particularly heart or liver damage in rats.

Keywords:

• Halitosis
• intoxication
• H2S
• inhalation

Acknowledgements

The authors thank Ismail Günay from Biophysics department for his valuable comments and assistance in calculating experimental parameters, Figen Doran, MD from Pathology department for her critical input on histologic sections, Hüseyin Aydın, MD from Biochemistry department for his generous help, Hatice Dobur for valuable support, Dr. Yener Ünal for his statistical assistance and Medical Biologist Deniz Yılmaz for English corrections. This research study was supported by the Scientific Research Project Fund of Cumhuriyet University (Project ID: Diş-106).

Disclosure statement

The authors declare that no financial or personal conflicts of interest exist with regard to the submission of this manuscript.

Additional information

Funding

This research study was supported by the Scientific Research Project Fund of Cumhuriyet University (Project ID: Diş-106).