Effect of melatonin on the production of microsomal hydrogen peroxide and cytochrome P-450 content in rat treated with aflatoxin B1

Hala A. Awney, Ahmed M. Attih, Sami L. Habib, Mostafa H. Mostafa

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Aflatoxin B1 (AFB1) is a food contaminant fungal toxin that has been implicated as a causative agent in human hepatic and extrahepatic carcinogenesis. In this study we went on to show the effect of melatonin as a free radical scavenger on the production of microsomal hydrogen peroxide (H2O2) during the metabolic activation AFB1. The production of microsomal H2O2 in vitro during the metabolic activation of different chemical carcinogens has been reported previously. We also studied the effect of melatonin on the cytochrome P-450 content as a major microsomal monooxygenase isoenzymes system in rat liver responsible for the metabolic activation of AFB1. The amounts of H2O2 and cytochrome P-450 contents in rat treated with melatonin (0.2 mg/kg BW) and/or AFB1 (0.2 mg/kg BW) at various time intervals has been measured. Animals treated with melatonin exhibited markedly inhibition in the amounts of H2O2 after 1, 3, and 6 h. The highest level of inhibition (3.0 nmol H2O2/mg protein) was detected after 6 h. However, cytochrome P-450 contents were also decreased after the same period of time. The highest level of inhibition (2.1 nmol/mg protein) was detected after 3 h of injection. A pronounced augmentation of H2O2 production was observed in rat treated with AFB1 only. The highest level of H2O2 (100 nmol/mg protein) was measured after 1 h. Cytochrome P-450 contents were also decreased in response to AFB1 injection over the same time intervals. Contrary data was detected in animals received both AFB1 and melatonin. The generation of H2O2 was inhibited by melatonin after 1, 3 and 6 h. The highest level of inhibition (44.2 nmol/mg protein) was observed after 6 h. Finally, these data suggested that melatonin as a free radical scavenger inhibited the microsomal production of H2O2 in rat treated with AFB1.

Original languageEnglish (US)
Pages (from-to)143-148
Number of pages6
JournalToxicology
Volume172
Issue number2
DOIs
StatePublished - Mar 20 2002
Externally publishedYes

Keywords

  • Free radical scavenger
  • Melatonin
  • Microsomal HO

ASJC Scopus subject areas

  • Toxicology

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