TABLE 4

Influence of 18β-glycyrrhetinic acid (GA) on the quantity and enantiomer composition of NNAL obtained on microsomal NNK reduction

NNK (250 μM) was incubated with a NADPH-generating system in an atmosphere of CO at 37°C for 15 min with rat liver microsomes and for 60 min with other microsomal preparations.

Microsomes from	GA Concentration	n	Percentage Change in NNAL Quantity	Percentage of (R)-NNAL
Microsomes from	GA Concentration	n	Percentage Change in NNAL Quantity			without GA	with GA
	μM
Human liver	0.1	4	−10 ± 8	80 ± 3	83 ± 3^a
	10	8	−39 ± 14^a	70 ± 11	84 ± 14^a
Human placenta	10	6	−6 ± 12	87 ± 4	91 ± 3^b
Human lung	0.1	3	−1 ± 5	86 ± 6	86 ± 6
	1	3	+12 ± 8	85 ± 6	87 ± 6
Rat liver^c	0.1	4	−12 ± 8^b	26 ± 1	27 ± 2
	10	3	−43 ± 9^b	28 ± 2	40 ± 7^b
Rat lung^c	0.1	4	−32 ± 10^b	53 ± 8	85 ± 4^a
	10	4	−50 ± 5^a	49 ± 5	86 ± 4^a

↵ a P < 0.001 vs. samples without GA (paired t test, two-tailed).
↵ b P < 0.05 vs. samples without GA (paired t test, two-tailed).
↵ c Male Sprague-Dawley rats.