Antimutagenic and anti-oxidant activities of the non-steroidal anti-inflammatory drug celecoxib.

1. Tumors arise and progress through the accumulation of serial genetic changes, including successive mutations, which involve activation of proto-oncogenes and inactivation of tumour suppressor genes, leading to the uncontrolled proliferation of progeny cells. The human body is continuously and unavoidably exposed to structurally diverse chemicals with established carcinogenic activity in animal models and/or mutagenic activity in short-term tests. 2. Celecoxib, a non-steroidal anti-inflammatory drug that specifically inhibits the enzyme cyclo-oxygenase-2, has been reported to be effective against certain types of cancers. The in vitro anti-oxidant and antimutagenic activities of the celecoxib were investigated in the present study using standard procedures. 3. The antimutagenic activity of celecoxib was determined using histidine mutant Salmonella typhimurium strains TA98, TA100, TA102 and TA1535 against directly acting mutagens (sodium azide (NaN3), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitro-o-phenylenediamine (NPDA) and doxorubicin) and mutagens needing activation (2-acetamidofluorene (2-AF) and 7,12-dimethylbenz [a] anthracene (DMBA)). 4. Celecoxib inhibited NaN3-, MNNG- and NPDA-induced mutations of TA100. The antimutagenicity of celecoxib (0.2 mg/plate) against the NaN3-induced mutation of TA1535 was 39.8% (P < 0.001). The MNNG-induced mutation of TA1535 was also inhibited by 0.3 mg/plate celecoxib (46.0%; P < 0.05). At concentrations of 0.2 mg/plate, celecoxib significantly inhibited NPDA- and doxorubicin-induced mutations of TA98 by 52.5 and 58.0%, respectively (P < 0.001 and P < 0.05, respectively). 5. The antimutagenic activity of 0.3 mg/plate celecoxib against 2-AF- and DMBA-induced mutations of TA98 was 81.76 and 98.1%, respectively (P < 0.001). 6. The anti-oxidant activity of celecoxib was determined by the inhibition of lipid peroxidation and superoxide and hydroxyl radical-scavenging activities. 7. The IC50 values of celecoxib for hydroxyl radical-scavenging and the inhibition of lipid peroxidation were 1.97 +/- 0.06 and 1.99 +/- 0.05 micromol/mL, respectively. Celecoxib had no superoxide radical scavenging-activity up to a concentration of 2.6 micromol/mL. 8. The in vitro antimutagenic and anti-oxidant activities of celecoxib indicate its possible therapeutic use as a cancer chemopreventive agent.