title: Tetramethylpyrazine protects rat renal tubular cell apoptosis induced by gentamicin.
abstract: BACKGROUND
  Gentamicin, a widely used antibiotic for the treatment of bacterial infection, can cause nephrotoxicity. Tetramethylpyrazine (TMP) is a compound purified from the rhizome of Ligusticum wallichi (Chuanxiong) and has been found to protect against ischaemia-reperfusion injury, nephritis and alcohol-induced toxicity in rat kidneys.
  
  
  METHODS
  We used rat renal tubular cells (RTCs), NRK-52E, in this study. The cytotoxicity of gentamicin was checked with transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) staining, and the generation of reactive oxygen species was measured using the fluorescent probe 2,7-dichlorofluorescein. We evaluated several apoptotic parameters: cleaved caspase levels, tumour necrosis factor (TNF-alpha) excretion and nuclear factor Kappa B (NF-kappaB) activity. We also examined the TMP protective effect on gentamicin-induced apoptosis in rat kidneys.
  
  
  RESULTS
  The results of this study showed that gentamicin was found to markedly induce apoptosis in NRK-52E cells in a dose-dependent manner; that TMP expressed a dose-dependent protective effect against gentamicin-induced apoptosis; that pre-treatment of the cells with 50 or 100 microM of TMP effectively decreased the reactive oxygen species formation induced by gentamicin; that TMP was found to inactivate the gentamicin-stimulated activities of caspase-3, caspase-8 and caspase-9, to inhibit gentamicin-induced release of cytochrome c, as well as to raise the expression of Bcl-x(L); that TMP inhibited the gentamicin-induced TNF-alpha excretion, and inactivated the transcription factor NF-kappaB; and that the TMP treatment significantly reduced apoptotic injury in rat RTCs.
  
  
  CONCLUSIONS
  Based on the results of this study, we suggest that TMP can attenuate gentamicin-induced oxidative stress and apoptotic injury in rat RTCs, and that its character may have therapeutic potential for patients with renal diseases.
authors.affiliation: Department of Physiology, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shu-Hui
authors.initials: SH
authors.lastname: Juan
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Chen
authors.forename: Yung-Ho
authors.initials: YH
authors.lastname: Hsu
authors.forename: Chun-Cheng
authors.initials: CC
authors.lastname: Hou
authors.forename: Tso-Hsiao
authors.initials: TH
authors.lastname: Chen
authors.forename: Heng
authors.initials: H
authors.lastname: Lin
authors.forename: Yen-Ling
authors.initials: YL
authors.lastname: Chu
authors.forename: Yuh-Mou
authors.initials: YM
authors.lastname: Sue
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D061945:Caspase Inhibitors; D045304:Cytochromes c / Q000187:drug effects; D004247:DNA / Q000235:genetics; D004195:Disease Models, Animal; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D015870:Gene Expression / Q000187:drug effects; D005839:Gentamicins / Q000493:pharmacokinetics / Q000633:toxicity*; D020287:In Situ Nick-End Labeling; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D030004:Ligusticum; D008297:Male; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D011719:Pyrazines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000378:metabolism; D014665:Vasodilator Agents / Q000494:pharmacology*; D051020:bcl-X Protein / Q000187:drug effects / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; C494813:Bcl2l1 protein, rat; D061945:Caspase Inhibitors; D005839:Gentamicins; D016328:NF-kappa B; D011719:Pyrazines; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D014665:Vasodilator Agents; D051020:bcl-X Protein; D045304:Cytochromes c; D004247:DNA; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; C017953:tetramethylpyrazine