TABLE 1

Estimation of the silymarin flavonolignans in various commercial sources of milk thistle extracts

Milk Thistle Extract	SC	SD	SB_A	SB_B	ISB_A	ISB_B	Total	% Labeled Silymarin (Milk Thistle Extracts)
Sigma-Aldrich
mg/g^a	122 ± 2.1	48.9 ± 1.0	115 ± 2.0	188 ± 3.2	44.6 ± 0.8	21.1 ± 0.5	540 ± 9.3
% (w/w)^b	22.6	9.06	21.3	34.9	8.26	3.91	100
USP
mg/g^a	161 ± 2.0	102 ± 3.3	127 ± 1.5	205 ± 2.8	63.7 ± 1.2	27.5 ± 0.6	686 ± 11
% (w/w)^b	23.5	14.9	18.4	29.9	9.28	4.01	100
Tablet^c
mg/tablet^a	32.9 ± 1.4	13.6 ± 0.6	33.1 ± 1.5	52.8 ± 2.4	12.6 ± 0.6	5.50 ± 0.3	150 ± 6.7	79 (63)
% (w/w)^b	21.9	9.02	22.0	35.1	8.37	3.66	100
Capsule 1^c
mg/capsule^a	39.2 ± 1.7	15.3 ± 0.6	37.7 ± 1.6	58.5 ± 2.5	14.8 ± 0.6	6.31 ± 0.23	172 ± 7.2	72 (57)
% (w/w)^b	22.8	8.93	22.0	34.0	8.59	3.67	100
Capsule 2^c
mg/capsule^a	29.7 ± 1.1	10.9 ± 0.4	26.0 ± 0.9	41.6 ± 1.4	11.4 ± 0.4	5.11 ± 0.2	125 ± 3.9	89 (71)
% (w/w)^b	23.8	8.75	20.8	33.3	9.17	4.10	100

↵ a Mean ± S.D. (n = 6)
↵ b Percentage of individual component relative to the total content of six silymarin flavonolignans
↵ c Labeled total silymarin contents (80% of milk thistle extracts): tablet, 190 mg; capsule 1, 240 mg; capsule 2, 140 mg