Table 3

Furanocoumarins in grapefruit and other citrus fruit juices and their inhibitory effects on CYP3A activity

Code^3-a	Furanocoumarin in Juice^3-b		Residual Percentage Activity^3-c (Mean ± S.D.)
Code^3-a	μM^3-b		Residual Percentage Activity^3-c (Mean ± S.D.)
	DHB	GF-I-5	GF-I-1	GF-I-6	GF-I-2	GF-I-4
Grapefruit juices
Ki-1	34.7 (1)	0.77 (1)	0.49 (2)	8.70 (1)	20.4 (2)	0.37 (2)	29.3 ± 2.9
Jo	2.3 (4)	0.64 (3)	0.60 (1)	6.15 (2)	29.6 (1)	0.53 (1)	32.7 ± 1.7
Ito	1.1 (6)	0.48 (7)	0.10 (5)	UD	11.5 (6)	0.17 (6)	35.8 ± 3.0
Ber	1.2 (5)	0.60 (4)	0.23 (4)	UD	20.3 (3)	0.31 (4)	37.3 ± 2.1
Ki-2	14.1 (2)	0.65 (2)	0.36 (3)	3.46 (3)	14.5 (4)	0.35 (3)	43.0 ± 2.3
BbW	0.8 (7)	0.52 (6)	0.09 (6)	0.24 (4)	13.9 (5)	0.21 (5)	46.0 ± 0.5
Kag	6.0 (3)	0.56 (5)	UD	UD	10.8 (7)	0.11 (7)	49.1 ± 2.9
BbP	UD	0.48 (7)	0.04 (7)	UD	7.2 (8)	0.10 (8)	57.6 ± 4.3
Sweetie juices
Sw-1	49.5	2.59	0.28	8.05	43.09	0.51	20.2 ± 1.7
Sw-2	9.6	3.48	0.09	1.65	9.40	0.50	64.1 ± 0.3
Pomelo juices
ToB	1.9	0.87	UD	UD	0.70	0.06	45.8 ± 2.0
SoW	1.0	UD	0.16	0.54	1.36	0.61	37.2 ± 1.1
SoP	0.8	UD	UD	UD	0.50	0.35	52.2 ± 3.7
Sour orange juice
Dd	10.3	1.39	0.04	0.23	0.80	0.06	57.9 ± 6.2
Sweet orange juices
BbO	UD	UD	UD	UD	UD	UD	75.5 ± 5.1
CalO	UD	UD	UD	UD	UD	UD	98.2 ± 5.8

↵3-a See Table 2 for sample descriptions.
↵3-b Mean concentration of triple tests for each juice sample. UD, under the limit of detection; figure in parentheses, order of ranking within grapefruit juices.
↵3-c Residual percentage of testosterone 6β-hydroxylation by human liver microsomes when incubated with 2.5% juice sample. Data are shown as mean ± S.D. of at least three determinations.