title: In vivo modulation of iNOS pathway in hepatocellular carcinoma by Nigella sativa.
abstract: OBJECTIVE
  Nitric oxide (NO) and inducible nitric oxide synthase enzyme (iNOS) have been implicated in various tumors. Hepatocellular carcinoma is a highly aggressive form of solid tumor. The lack of effective therapy necessitates the introduction of novel therapeutic strategies to counter this disease. Nigella sativa (NS) has been shown to have specific health benefits. The aim of this study was to investigate the in vivo modulation of the iNOS pathway by NS ethanolic extract (NSEE) and the implications of this effect as an antitumor therapeutic approach against diethylnitrosamine (DENA)-induced hepatocarcinogenesis.
  
  
  METHODS
  Rats were divided into four groups, normal control, NSEE control, cancer control, and NSEE-DENA groups. The diagnosis of cancer was based on alpha-fetoprotein (AFP) levels and histological variations. Serum NO, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels and serum iNOS activity were measured. Liver iNOS expression was investigated by reverse transcriptase (RT)-PCR and western blot assays.
  
  
  RESULTS
  Serum AFP, NO, TNF-α, and IL-6 levels and iNOS enzyme activity were significantly increased in rats treated with DENA. Significant up-regulation of liver iNOS mRNA and protein expression was also observed. Subsequent treatment with NSEE significantly reversed these effects and improved the histopathological changes in malignant liver tissue which appeared after treatment with DENA, without any toxic effect when given alone.
  
  
  CONCLUSIONS
  These results provide evidence that attenuation of the iNOS pathway and suppression of the inflammatory response mediated by TNF-α, and IL-6 could be implicated in the antitumor effect of NSEE. As such, our findings hold great promise for the utilization of NS as an effective natural therapeutic agent in the treatment of hepatocarcinogenesis.
authors.affiliation: Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan.
authors.forename: Moustafa
authors.initials: M
authors.lastname: Fathy
authors.forename: Toshio
authors.initials: T
authors.lastname: Nikaido
mesh_terms: D000477:Alkylating Agents / Q000633:toxicity; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D015153:Blotting, Western; D016207:Cytokines / Q000097:blood*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004052:Diethylnitrosamine / Q000633:toxicity; D004797:Enzyme-Linked Immunosorbent Assay; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000188:drug therapy / Q000201:enzymology*; D008297:Male; D031881:Nigella sativa / Q000737:chemistry*; D009569:Nitric Oxide / Q000097:blood*; D052247:Nitric Oxide Synthase Type II / Q000097:blood / Q000235:genetics*; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000378:metabolism*
chemical_list: C483800:Afp protein, rat; D000477:Alkylating Agents; D000970:Antineoplastic Agents; D016207:Cytokines; D018076:DNA, Complementary; D010936:Plant Extracts; D012333:RNA, Messenger; D000509:alpha-Fetoproteins; D009569:Nitric Oxide; D004052:Diethylnitrosamine; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat