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Modulation of rat hepatic cytochrome P-450 activity by garlic organosulfur compounds

M M Reicks1, D L Crankshaw

  • 1Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108, USA.

Nutrition and Cancer
|January 1, 1996
PubMed

Insights

Garlic sulfur compounds like diallyl sulfide and diallyl disulfide inhibit cytochrome P-450 enzymes, specifically CYP2E1, in rats. This suggests a mechanism for their potential cancer-preventive properties.

Area of Science:

  • Biochemistry
  • Pharmacology
  • Toxicology

Background:

  • Garlic organosulfur compounds show chemopreventive effects in rodents.
  • Inhibition of carcinogen activation by cytochrome P-450 enzymes is a proposed mechanism.
  • Variability in tumor inhibition potency may relate to structural differences in garlic compounds.

Purpose of the Study:

  • To investigate the effect of specific garlic sulfur compounds on hepatic cytochrome P-450 activity.
  • To determine if diallyl sulfide (DAS), diallyl disulfide (DADS), and allyl methyl sulfide (AMS) inhibit CYP2E1.
  • To explore the relationship between garlic compound structure and CYP2E1 inhibition.

Main Methods:

  • Administration of DAS, DADS, and AMS to male Sprague-Dawley rats via gastric gavage.
  • Measurement of hepatic microsomal enzyme activities, including p-nitrophenol hydroxylase (a CYP2E1 marker).
  • Assessment of CYP2E1 protein levels using immunodetection.
  • Use of 4-methyl pyrazole, a specific CYP2E1 ligand, to confirm enzyme involvement.

Main Results:

  • All tested garlic compounds significantly decreased p-nitrophenol hydroxylase activity.
  • DAS, DADS, and AMS reduced CYP2E1 protein levels in a dose-dependent manner.
  • Inhibition of p-nitrophenol hydroxylase activity was confirmed by 4-methyl pyrazole administration.

Conclusions:

  • Garlic sulfur compounds, including DAS, DADS, and AMS, inhibit hepatic CYP2E1 activity and protein levels.
  • The variable potency of CYP2E1 inhibition by these compounds warrants further investigation regarding their chemopreventive efficacy.
  • These findings provide insight into the metabolic mechanisms underlying the potential cancer-preventive effects of garlic.

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