Table 1.

The half-maximum inhibitory concentration (IC₅₀) of the samples on CYP3A4 and the ratios of the titer to grapefruit juice.

Name of crude drug or formula	Lot number	Extracting ratio (%)	Extract (g) in one time dosage of crude drugs or Kampo formula(a)	Estimated concentration when taken(a) (mg/ml)	IC50 (mg/ml)	Ratio of inhibitory titer to grapefruit juice (%)
Grapefruit juice	18.5.20 CK/3B	–	–	100	0.96	100
Moutan Bark	5I11M	43	0.43	2.2	0.10	21
Glycyrrhiza	6B22	27	0.27	1.3	0.11	12
Mentha Herb	2F18M	43	0.43	2.1	0.66	3.1
Peony Root	5D08M	41	0.41	2.1	0.81	2.4
Ginger	5J16M	22	0.22	1.1	0.62	1.7
Cinnamon Bark	5B23M	9.3	0.09	0.47	0.42	1.1
Bupleurum Root	3I05M	15	0.15	0.76	0.67	1.1
Gardenia Fruit	9I11M	25	0.25	1.3	1.1	1.1
Japanese Angelica Root	7B06M	41	0.41	2.1	1.9	1.0
Atractylodes Lancea Rhizome	5G13M	26	0.47	2.3	2.4	0.94
Alisma Tuber	6C07M	6.9	0.07	0.35	0.39	0.85
Cindium Rhizome	1F08M	47	0.26	1.3	2.0	0.63
Peach Kernel	3I18M	9.8	0.10	0.49	7.0	0.067
Poria Sclerotium	5H18M	3.1	0.03	0.16	3.0	0.050
Tokishakuyakusan	–	39	2.8	14	3.1	4.4
Kamishoyosan	–	32	2.4	12	0.38	30
Keishibukuryogan	–	17	0.82	4.1	0.25	16
Tokishakuyakusan (Tsumura)	2150023010	18	1.3	6.7	1.1	5.8
Kamishoyosan (Tsumura)	2160024010	18	1.3	6.7	0.40	16
Keishibukuryogan (Tsumura)	2150025010	12	0.58	2.9	0.72	3.9

(a) One-time dosages for crude drugs were set as 1 g. One time dosages for Kampo formula were set as one-third of daily dosage.

(b) Estimated concentration when one-time dosage extract was taken with 200 ml H₂O.