. 2021 Nov 23;16(11):e0260463. doi: 10.1371/journal.pone.0260463

Table 2. The mean ± SE FRAP antioxidant capacity (A), phenolic content (P) and flavonoid content (F) from 58 bottles of over the counter herbal supplements extracted with hot water and methanol by supplier^*.

		Water Extraction			Methanol Extraction
Supplier	Supplement	A (TE)	P (GAE)	F (CE)	A (TE)	P (GAE)	F (CE)
Nature’s Way	Aloe	76637 ± 4295^{^}	8.94 ± 0.43^{^}	4063 ± 359^{^}	85256 ± 8460^{^}	10.64 ± 0.52^{^}	5646 ± 217^{^}
Nature’s Way	Astragalus	9342 ± 1294^B	1.91 ± 0.08^A	1308 ± 417^A	8794 ± 1827^A	1.09 ± 0.05^B	542 ± 59^B
NOW	Astragalus	22629 ± 1525^A	1.66 ± 0.16^A	675 ± 13^A	10114 ± 520^A	1.89 ± 0.18^A	725 ± 23^A
NOW	Biotin	412 ± 91^{^}	0.23 ± 0.02^{^}	555 ± 241^{^}	4060 ± 915^{^}	0.41 ± 0.04^{^}	1169 ± 348^{^}
Nature’s Way	Cranberry	26359 ± 1781^{^}	3.26 ± 0.26^{^}	2185 ± 240^{^}	25754 ± 1780^{^}	1.55 ± 0.12^{^}	3910 ± 903^{^}
Spring Valley	Echinacea	200190 ± 31988^A	10.59 ± 0.60^A	15962 ± 566^A	11163 ± 170^A	1.04 ± 0.05	1793 ± 101^A
Sundown Naturals	Echinacea	94474 ± 15013^B	6.13 ± 0.61^B	7790 ± 714^B	8311 ± 401^B	1.34 ± 0.51	521 ± 84^B
Nature’s Way	Echinacea Goldenseal	98618 ± 3687^A	3.97 ± 0.41^B	8206 ± 247^b	30641 ± 640^A	4.60 ± 0.72^A	3880 ± 140^A
Spring Valley	Echinacea Goldenseal	57687 ± 9677^B	6.74 ± 0.46^A	9652 ± 664^a	14733 ± 1783^B	1.57 ± 0.19^B	1308 ± 422^B
NOW	Ginger	88335 ± 2353^A	3.43 ± 0.15^A	1243 ± 36^B	373256 ± 46229^A	7.48 ± 0.14^A	6660 ± 1006^A
Spring Valley	Ginger	72285 ± 3836^B	2.98 ± 0.22^A	1444 ± 48^A	140170 ± 46229^B	5.09 ± 0.30^B	3472 ± 117^B
Sundown Naturals	Ginseng Xtra	5950 ± 869^A	0.76 ± 0.10^A	303 ± 68^B	3035 ± 401^B	0.59 ± 0.04^A	455 ± 96^A
Spring Valley	Korean Panax Ginseng	73 ± 23^B	0.18 ± 0.04^B	775 ± 217^A	4770 ± 1102^A	0.32 ± 0.03^B	26 ± 9^B
Nature’s Way	Red Raspberry Leaf	488121 ± 34130^{^}	12.38 ± 0.36^{^}	8272 ± 130^{^}	86122 ± 3019^{^}	4.30 ± 0.18^{^}	4081 ± 89^{^}
Nature’s Way	Reishi	15575 ± 1729^{^}	2.29 ± 0.18^{^}	1469 ± 194^{^}	5536 ± 1153^{^}	0.56 ± 0.04^{^}	1768 ± 505^{^}
Nature’s Way	Rhodiola	853458 ± 28330^A	15.59 ± 0.52^A	15566 ± 315^A	757413 ± 109746^A	17.07 ± 0.88^A	18741 ± 1404^A
NOW	Rhodiola	602570 ± 46729^B	7.59 ± 1.88^B	7764 ± 739^B	222758 ± 42227^B	13.66 ± 0.96^B	10941 ± 852^B
Nature’s Way	Silent Night	70378 ± 4516^{^}	3.38 ± 0.36^{^}	5324 ± 336^{^}	12044± 899^{^}	3.58 ± 0.22^{^}	1515 ± 203^{^}
Nature’s Way	St. John’s Wort	206984 ± 12697^A	8.00 ± 0.47^B	8755 ± 255^B	53124 ± 3352^C	4.14 ± 0.16^C	4278 ± 98^C
Spring Valley	St. John’s Wort	180944 ± 21774^A	17.00 ± 0.68^A	16036 ± 714^A	93851 ± 15547^B	16.64 ± 0.45^A	10028 ± 760^B
Sundown Naturals	St. John’s Wort	196151 ± 23313^A	17.42 ± 0.71^A	16816 ± 1013^A	154977 ± 12703^A	13.77 ± 0.49^B	11177 ± 301^A
Sundown Naturals	Stress formula	93095 ± 15299^{^}	6.53 ± 0.34^{^}	10698 ± 366^{^}	18168 ± 1524^{^}	1.23 ± 0.25^{^}	1176 ± 164^{^}
Nature’s Way	Turmeric	1762 ± 84^C	0.68 ± 0.07^C	0 ± 0^B	183344 ± 10703^C	14.03 ± 0.71^B	339869 ± 21356^A
Spring Valley	Turmeric	5948 ± 693^B	1.03 ± 0.06^B	2984 ± 794^A	125930 ± 17877^B	8.56 ± 1.69^C	49705 ± 7829^C
Sundown Naturals	Turmeric	17353 ± 543^A	1.33 ± 0.16^A	1786 ± 208^A	266502 ± 18262^A	17.90 ± 1.11^A	176657 ± 7828^B
Nature’s Way	Valerian Root	29662 ± 1460^B	2.77 ± 0.08^B	3106 ± 101^B	11684 ± 767^B	1.47 ± 0.06^B	1808 ± 76^A
Spring Valley	Valerian Root	10390 ± 3289^C	1.23 ± 0.20^C	2633 ± 416^C	6401 ± 381^C	0.79 ± 0.18^C	355 ± 59^B
Sundown Naturals	Valerian Root	43176 ± 2577^A	3.88 ± 0.24^A	3424 ± 99^A	15973 ± 772^A	1.81 ± 0.09^A	1854 ± 84^A
Nature’s Way	Yarrow	141389 ± 10630^{^}	7.67 ± 0.66^{^}	11126 ± 665^{^}	37482 ± 913^{^}	2.72 ± 0.13^{^}	3100 ± 300^{^}

* The assays include the Ferrric Reducing Antioxidant Power (FRAP) assay for antioxidant capacity expressed as Trolox equivalents per gram, the Folin-Ciocalteu method for phenolics expressed as gallic acid equivalents per gram (GAE), and the AlCl3 precipitation assay for flavonoids expressed as +-catechin equivalents per gram. The values are expressed as the mean ± SE (n = 20) for each extraction from each supplier of each supplement. Means within the same supplement with different capital letters are significantly different based on the LSD Student’s T-test (± of 0.05). For specific p-values for each supplement supplier see S1 Table.

^—Means followed by this symbol indicate a supplement where there were no duplicate suppliers.

Table 2. The mean ± SE FRAP antioxidant capacity (A), phenolic content (P) and flavonoid content (F) from 58 bottles of over the counter herbal supplements extracted with hot water and methanol by supplier*.

Table 2. The mean ± SE FRAP antioxidant capacity (A), phenolic content (P) and flavonoid content (F) from 58 bottles of over the counter herbal supplements extracted with hot water and methanol by supplier^*.