title: Involvement of multiple molecular events in pyrogallol-induced hepatotoxicity and silymarin-mediated protection: evidence from gene expression profiles.
abstract: In this study, the involvement of various molecular events in pyrogallol-mediated hepatotoxicity was deciphered by differential mRNA transcription profiles of control and pyrogallol treated mice liver. The modulatory effects of silymarin on pyrogallol-induced differentially expressed transcripts were also looked into. Swiss albino mice were treated with or without pyrogallol. In some set of experiments, mice were also treated with silymarin 2 h prior to pyrogallol. Total RNA was isolated from liver and polyadenylated RNA was reverse-transcribed into Cye 3 or Cye 5 labelled cDNA. Equal amounts of labelled cDNA from two different groups were mixed and hybridized with mouse 15 k array. The hybridized arrays were scanned, analyzed and the expression level of each transcript was calculated. The differential expression was validated by quantitative real time polymerase chain reaction. Comparative transcription pattern showed an alteration in the expression of 183 transcripts (150 up-regulated and 33 down-regulated) associated with oxidative stress, cell cycle, cytoskeletal network, cell-cell adhesion, extra-cellular matrix, inflammation, apoptosis, cell-signaling and intermediary metabolism in pyrogallol-exposed liver and silymarin pre-treatment modulated the expression of many of these transcripts. Results obtained thus suggest that pyrogallol induces multiple molecular events leading to hepatotoxicity and silymarin effectively counteracts pyrogallol-mediated alterations.
authors.affiliation: Indian Institute of Toxicology Research (Council of Scientific and Industrial Research), Lucknow, UP, India.
authors.forename: Ghanshyam
authors.initials: G
authors.lastname: Upadhyay
authors.forename: Manindra Nath
authors.initials: MN
authors.lastname: Tiwari
authors.forename: Om
authors.initials: O
authors.lastname: Prakash
authors.forename: Anurag
authors.initials: A
authors.lastname: Jyoti
authors.forename: Rishi
authors.initials: R
authors.lastname: Shanker
authors.forename: Mahendra Pratap
authors.initials: MP
authors.lastname: Singh
mesh_terms: D000818:Animals; D001483:Base Sequence; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology / Q000517:prevention & control*; D017931:DNA Primers; D018076:DNA, Complementary; D020869:Gene Expression Profiling; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D011748:Pyrogallol / Q000633:toxicity*; D012838:Silymarin / Q000494:pharmacology*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D012838:Silymarin; D011748:Pyrogallol