title: Comparison of S-adenosyl-L-methionine (SAMe) and N-acetylcysteine (NAC) protective effects on hepatic damage when administered after acetaminophen overdose.
abstract: In the clinical setting, antidotes are generally administered after the occurrence of a drug overdose. Therefore, the most pertinent evaluation of any new agent should model human exposure. This study tested whether acetaminophen (APAP) hepatotoxicity was reversed when S-adenosyl-L-methionine (SAMe) was administered after APAP exposure, similar to what occurs in clinical situations. Comparisons were made for potency between SAMe and N-acetylcysteine (NAC), the current treatment for APAP toxicity. Male C57BL/6 mice were fasted overnight and divided into groups: control (VEH), SAMe treated (SAMe), APAP treated (APAP), N-acetylcysteine treated (NAC), SAMe or NAC administered 1h after APAP (SAMe+APAP) and (NAC+APAP), respectively. Mice were injected intraperitoneal (i.p.) with water (VEH) or 250 mg/kg APAP (15 ml/kg). One hour later, mice were injected (i.p.) with 1.25 mmol/kg SAMe (SAMe+APAP) or NAC (NAC+APAP). Hepatotoxicity was evaluated 4h after APAP or VEH treatment. APAP induced centrilobular necrosis, increased liver weight and alanine transaminase (ALT) levels, depressed total hepatic glutathione (GSH), increased protein carbonyls and 4-hydroxynonenal (4-HNE) adducted proteins. Treatment with SAMe 1h after APAP overdose (SAMe+APAP) was hepatoprotective and was comparable to NAC+APAP. Treatment with SAMe or NAC 1h after APAP was sufficient to return total hepatic glutathione (GSH) to levels comparable to the VEH group. Western blot showed reversal of APAP mediated effects in the SAMe+APAP and NAC+APAP groups. In summary, SAMe was protective when given 1h after APAP and was comparable to NAC.
authors: Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, One John Marshall Drive, Huntington, WV 25755-9388, USA.
authors: Marcus V
authors: MV
authors: Terneus
authors: J Michael
authors: JM
authors: Brown
authors: A Betts
authors: AB
authors: Carpenter
authors: Monica A
authors: MA
authors: Valentovic
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000633:toxicity*; D000111:Acetylcysteine / Q000627:therapeutic use*; D000410:Alanine Transaminase / Q000097:blood / Q000378:metabolism; D000447:Aldehydes / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D062787:Drug Overdose; D005978:Glutathione / Q000378:metabolism; D007274:Injections, Intraperitoneal; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D017114:Liver Failure, Acute / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008859:Microscopy, Polarization / Q000379:methods; D009929:Organ Size / Q000187:drug effects; D050050:Protein Carbonylation / Q000187:drug effects; D012436:S-Adenosylmethionine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D000447:Aldehydes; C468227:adenosyl-methionine 1,4-butanedisulfonate; D000082:Acetaminophen; D012436:S-Adenosylmethionine; D000410:Alanine Transaminase; D005978:Glutathione; C027576:4-hydroxy-2-nonenal; D000111:Acetylcysteine