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Stimulation of Diethylnitrosamine Metabolism Reduces Its General Toxic and Hepatocarcinogenic Effects

S I Il'nitskaya1, V I Kaledin2, L A Bogdanova3

  • 1Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia. pathol@inbox.ru.

Bulletin of Experimental Biology and Medicine
|November 24, 2016
PubMed

Insights

Metabolism stimulation with TCPOBOP reduced the toxic and carcinogenic effects of diethylnitrosamine in mice. This involved increased liver enzyme activity, leading to less body weight loss and fewer liver tumors.

Area of Science:

  • Toxicology
  • Hepatocarcinogenesis
  • Drug Metabolism

Background:

  • Diethylnitrosamine (DEN) is a known hepatotoxin and carcinogen.
  • 1,4-bis[2-(3,5-dichloropyridyloxy)]-benzene (TCPOBOP) is a compound known to induce cytochrome P450 enzymes.
  • Understanding how metabolic enzyme induction affects DEN toxicity is crucial for risk assessment.

Purpose of the Study:

  • To investigate the impact of TCPOBOP-induced metabolic stimulation on the toxic and hepatocarcinogenic effects of diethylnitrosamine (DEN).
  • To evaluate changes in liver microsomal hydroxylating activity following TCPOBOP administration.
  • To assess the incidence of tumors and pre-neoplastic lesions in the liver after DEN exposure in TCPOBOP-pretreated mice.

Main Methods:

  • Administration of TCPOBOP to C57Bl/6Mv and ICR mice to induce metabolic enzymes.
  • Measurement of liver microsomal hydroxylating activity using p-nitrophenol as a substrate.
  • Injection of diethylnitrosamine (DEN) at varying time points after TCPOBOP administration.
  • Assessment of body weight changes, food consumption, and liver tumor/pre-tumorous node development.

Main Results:

  • TCPOBOP administration significantly increased liver microsomal hydroxylating activity (over 4-fold) in C57Bl/6Mv mice.
  • Pre-treatment with TCPOBOP reduced body weight loss and food consumption following DEN injection.
  • TCPOBOP induction of cytochrome P450 2e1 activity led to a 2-fold decrease in liver tumors and pre-tumorous nodes in suckling ICR mice exposed to DEN.

Conclusions:

  • Metabolism stimulation by TCPOBOP effectively reduces the general toxic effects of diethylnitrosamine.
  • TCPOBOP-induced enzyme activity mitigates the hepatocarcinogenic potential of diethylnitrosamine.
  • These findings suggest a potential strategy for modulating chemical-induced liver injury and cancer.
Keywords:
cytochrome P450 2e1diethylnitrosaminehepatocarcinogenesistoxicity

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