Table 1

Effect of PB, βNF, and PB + βNF treatments on P450, NADPH-cytochrome P450 reductase, CYP2B4, and CYP1A2 protein levels

Treatment GroupNADPH-Cytochrome P450 ReductaseP450 ContentCYP1A2CYP2B4
pmol/mg protein nmol/mg protein
PB58.2  ± 4.61.57  ± 0.111.00  ± 0.142.37  ± 0.041-b
βNF41.5  ± 5.91-a 1.02  ± 0.192.57  ± 0.861.00  ± 0.071-a
PB +βNF38.8  ± 3.81-a 2.08  ± 0.331-b 7.00  ± 0.711-a 1-b 1.69  ± 0.041-a 1-b

P450 content was determined by measuring the formation of the carbon monoxide adduct of ferrous P450. Reductase content was estimated by measuring the rate of reduction of cytochrome c. Cytochromec reductase activities were converted into nanomoles of NADPH-cytochrome P450 reductase using a standard curve of purified NADPH-cytochrome P450 reductase. A turnover number of 3300 was obtained under these assay conditions. Relative contents of CYP2B4 and CYP1A2 were estimated by immunoblotting estimating staining intensity per milligram of protein. The results represent the mean ± S.E. for four determinations.

  • 1-a  Significantly different from the PB-treated group.

  • 1-b  Significantly different from the βNF-treated group.