Celecoxib enhances the detoxification of diethylnitrosamine in rat liver cancer

Table 1 Effect of celecoxib on hepatic microsomal enzyme activities in a hepatocarcinogenesis assay

Treatment	Alkoxyresorufin O-dealkylation activity (pmol resorufin/min per mg protein)		Testosterone hydroxylase activity (pmol of product/min per mg protein)	p-Nitrophenol hydroxylase activity (nmol 4-nitrocatechol/min per mg protein)
	EROD (CYP1A1)	PROD (CYP2B1/2)	7α-OHT (CYP2A1/2)	PNPH (CYP2E1)
NT	13.1 ± 0.5	2.0 ± 0.5	129.2 ± 18.9	0.38 ± 0.07
CXB 8 d	13.3 ± 4.3	4.2 ± 2.2	ND	0.53 ± 0.16
DEN	4.5 ± 1.3a	7.3 ± 3.2a	54.2 ± 19.2a	0.97 ± 0.14a
DEN+CXB	15.9 ± 4.8b	65.9 ± 35.4ab	66.0 ± 5.9a	0.80 ± 0.25a
CXB 32 d	54.5 ± 11.3a	114.2 ± 23.2a	151.5 ± 29.5	1.40 ± 0.44a

Male rats were treated with a single dose of DEN (200 mg/kg) ip and sacrificed 24 h after administration (DEN and DEN+CXB groups). The CXB diet was provided 7 d before DEN treatment and until sacrifice (8 d). The CXB 8 d and CXB 32 d groups received only a CXB-containing diet.

^aSignificantly different from the NT group;

^bFrom the DEN group, according to the Bonferroni test (P < 0.05). Values shown are the mean ± SD from n = 4. ND: Not determined.