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Systemic toxic effects during early phases of topical 4-NQO-induced oral carcinogenesis in rats

Ana Rita Ribeiro Barcessat1, Isaac Huang, Gustavo Davi Rabelo

  • 1General Pathology Department, School of Dentistry, University of SãoPaulo, São Paulo, Brazil.

Journal of Oral Pathology & Medicine : Official Publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology
|June 17, 2014
PubMed
Abstract

Insights

Topical 4-NQO application in rats caused systemic toxicity, affecting the liver, kidneys, and spleen. This highlights the need to consider systemic effects in oral cancer research.

Area of Science:

  • Toxicology
  • Oral carcinogenesis
  • Animal models

Background:

  • 4-Nitroquinoline 1-oxide (4-NQO) is known for oral epithelium toxicity during cancer induction.
  • Systemic toxicity of 4-NQO has been under-researched.
  • Understanding systemic effects is crucial for accurate oral cancer research.

Purpose of the Study:

  • To investigate the systemic toxicity of 4-NQO.
  • To evaluate the effects of topical 4-NQO application on rat organs.
  • To assess systemic impact during early oral cancer induction phases.

Main Methods:

  • Topical application of 4-NQO ointment on rat tongues for 16 weeks.
  • Evaluation of body weight, hematology, and serum chemistry.
  • Histopathological and PCNA immunohistochemistry analyses for toxicity assessment.

Main Results:

  • Significant reduction in body weight gain and white blood cell count.
  • Increased serum ALT and AST levels, indicating liver damage.
  • Histopathology revealed hepatic necrosis, renal degeneration, and splenic white pulp changes.

Conclusions:

  • 16-week topical 4-NQO application induced hepatic, renal, and splenic toxicity in rats.
  • Systemic toxicity must be considered in oral carcinogenesis experiments.
  • Monitoring systemic variables is essential for reliable research outcomes.
Keywords:
4-NQO toxicitycarcinogenesis modelpotentially malignant oral lesions

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