TIME COURSE STUDY OF COMBINED N-ACETYL-P-AMINOPHENOL AND DICLOPHENAC INDUCED-HEPATOTOXICITY AND OXIDATIVE STRESS IN WISTAR RATS

The abuse of combined acetaminophen or N-acetyl-p-aminophenol (APAP) and diclofenac (DIC) due to their analgesics, anti-inflammatory and antipyretic properties is a predominant cause of hepatotoxicity and oxidative stress. This study investigated the time-course effects of APAP, DIC and their combination on biomarkers of hepatic function and oxidative stress in rats. Forty male Wistar rats were randomly divided into four groups of 10 animals each as follows; control (distilled water), APAP only, DIC only and APAP + DIC for 4 weeks. Indices of liver damage (serum ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GGT, gamma-glutamyl transferase and bilirubin) were measured. Oxidative stress biomarkers (MDA, malondialdehyde; NO, nitric oxide; CAT, Catalase activity; SOD, superoxide dismutase activity; GSH content, reduced glutathione), GR, glutathione reductase, and GST, glutathione-S-transferase) were also determined using spectrophotometric methods. Statistical analysis was done using one-way ANOVA with p < 0.05 considered significant. Acetaminophen and diclofenac caused marked liver damage as noted by time-dependent significant (p < 0.05) increased activities of serum ALT, AST, ALP, GGT, and bilirubin levels as well as significant (p < 0.05) increase in hepatic MDA and NO levels as compared to the control group. Hepatic GSH content, SOD, CAT, GPx, GST and GR activities were decreased significantly (p < 0.05) in all acetaminophen and diclofenac-treated groups compared to normal control in a time-dependent manner. These findings suggest that prolonged administration of diclofenac, acetaminophen or their combination may induce hepatotoxicity, oxidative stress and alteration of hepatic antioxidant status in a time-dependent manner.