title: Diallyl sulfide protects against N-nitrosodiethylamine-induced liver tumorigenesis: role of aldose reductase.
abstract: OBJECTIVE
  To evaluate the protective effect of diallyl sulfide (DAS) against N-nitrosodiethylamine (NDEA)-induced liver carcinogenesis.
  
  
  METHODS
  Male Wistar rats received either NDEA or NDEA together with DAS as protection. Liver energy metabolism was assessed in terms of lactate, pyruvate, lactate/pyruvate, ATP levels, lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PD) activities. In addition, membrane disintegration of the liver cells was evaluated by measuring lipid-peroxidation products, measured as malondialdehyde (MDA); nitric oxide (NO) levels; glucose-6-phosphatase (G6Pase), catalase (CAT) and superoxide dismutase (SOD) activities. Liver DNA level, glutathione-S-transferase (GST) and cytochrome c oxidase activities were used as DNA fragmentation indices. Aldose reductase (AR) activity was measured as an index for cancer cells resistant to chemotherapy and histopathological examination was performed on liver sections from different groups.
  
  
  RESULTS
  NDEA significantly disturbed liver functions and most of the aforementioned indices. Treatment with DAS significantly restored liver functions and hepatocellular integrity; improved parameters of energy metabolism and suppressed free-radical generation.
  
  
  CONCLUSIONS
  We provide evidence that DAS exerts a protective role on liver functions and tissue integrity in face of enhanced tumorigenesis caused by NDEA, as well as improving cancer-cell sensitivity to chemotherapy. This is mediated through combating oxidative stress of free radicals, improving the energy metabolic state of the cell, and enhancing the activity of G6Pase, GST and AR enzymes.
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini, Cairo 11562, Egypt.
authors.forename: Safinaz-S
authors.initials: SS
authors.lastname: Ibrahim
authors.forename: Noha-N
authors.initials: NN
authors.lastname: Nassar
mesh_terms: D000449:Aldehyde Reductase / Q000378:metabolism*; D000498:Allyl Compounds / Q000494:pharmacology*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000378:metabolism; D004249:DNA Damage; D004052:Diethylnitrosamine; D004734:Energy Metabolism / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology / Q000517:prevention & control*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D013440:Sulfides / Q000494:pharmacology*
chemical_list: D000498:Allyl Compounds; D016588:Anticarcinogenic Agents; D000975:Antioxidants; D017382:Reactive Oxygen Species; D013440:Sulfides; D004052:Diethylnitrosamine; C038491:allyl sulfide; D000449:Aldehyde Reductase