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

Table 3. 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 bottle and supplier^*.

			Water Extraction			Methanol Extraction
Supplier	Supplement	Bottle	A (TE)	P (GAE)	F (CE)	A (TE)	P (GAE)	F (CE)
Nature’s Way	Aloe	1	66460 ± 7203^a	8.54 ± 0.86^a	4193 ± 735^a	496322 ± 1549^a	11.20 ± 0.80^a	5276 ± 315^a
Nature’s Way	Aloe	2	86814 ± 1728^b	9.34 ± 0.13^a	3933 ± 33^a	120880 ±4217^b	10.08 ± 0.67^a	6016 ± 264^a
Nature’s Way	Astragalus	1	13014 ± 2001^a	1.81 ± 0.14^a	2030 ± 786^a	16712 ± 364^a	1.21± 0.08^a	308 ± 43^b
Nature’s Way	Astragalus	2	5670 ± 269^b	2.02 ± 0.09^a	587 ± 22^b	875 ± 185^b	0.97 ± 0.02^b	776 ± 28^a
NOW	Astragalus	1	28942 ± 857^a	2.05 ± 0.25^a	667 ± 15^a	11878 ± 477^a	1.16 ± 0.06^b	757 ± 22^a
NOW	Astragalus	2	16316 ± 482^b	1.26 ± 0.11^b	685 ± 21^a	8351 ± 475^b	2.62 ± 0.12^a	692 ± 40^a
NOW	Biotin	1	32 ± 9^b	0.22 ± 0.03^a	1111 ± 421^a	8044 ± 105^a	0.29 ± 0.03^b	2338 ± 456^a
NOW	Biotin	2	792 ± 56^a	0.24 ± 0.01^a	0 ± 0^b	76 ± 39^b	0.52 ± 0.04^a	0 ± 0^b
Nature’s Way	Cranberry	1	24622 ± 3459^a	4.21 ± 0.29^a	2255 ± 487^a	19145 ± 1250^b	1.34 ± 0.17^b	589 ± 64^b
Nature’s Way	Cranberry	2	28095 ± 869^a	2.31 ± 0.06^b	2114 ± 71^a	32362 ± 1455^a	1.77 ± 0.15^a	7230 ± 994^a
Spring Valley	Echinacea	1	330437 ± 19358^a	9.49 ± 1.00^a	14186 ± 663^b	11249 ± 231	1.01 ± 0.05^a	1421 ± 95^b
Spring Valley	Echinacea	2	69943 ± 13259^b	11.70 ± 0.52^a	17738 ± 460^a	11077 ± 258	1.07 ± 0.09^a	2164 ± 61^a
Sundown Naturals	Echinacea	1	29672 ± 1656^b	4.16 ± 0.33^b	5358 ± 405^b	9212 ± 565^a	0.94 ± 0.09^a	700 ± 136^a
Sundown Naturals	Echinacea	2	159277 ± 3976^a	8.10 ± 0.77^a	10222 ± 821^a	7409 ± 423^b	1.73 ± 1.03^a	341 ± 62^b
Nature’s Way	Echinacea Goldenseal	1	98028 ± 7015^a	5.53 ± 0.39^a	7797 ± 395^a	32553 ± 929^a	2.36 ± 0.10^b	3956 ± 70^a
Nature’s Way	Echinacea Goldenseal	2	99208 ± 2847^a	2.42 ± 0.07^b	8615 ± 252^a	28728 ± 230^b	6.84 ± 1.04^a	3804 ± 277^a
Spring Valley	Echinacea Goldenseal	1	85953 ± 14036^a	6.55 ± 0.73^a	10709 ± 797^a	21867 ± 1432^a	2.33 ± 0.13^a	2093 ± 722^a
Spring Valley	Echinacea Goldenseal	2	29421 ± 1134^b	6.94 ± 0.59^a	8477 ± 986^a	7599 ± 265^b	0.80 ± 0.05^b	436 ± 114^b
NOW	Ginger	1	81890 ± 2301^b	3.25 ± 0.13^a	1181 ± 35^a	559238 ± 35560^a	7.38 ± 0.17^a	3803 ± 207^b
NOW	Ginger	2	94782 ± 2976^a	3.60 ± 0.26^a	1306 ± 59^a	187273 ±8513^b	7.58 ± 0.22^a	9516 ± 1554^a
Spring Valley	Ginger	1	70175 ± 2565^a	3.24 ± 0.41^a	1367 ± 67^a	144331 ± 4122	5.87 ± 0.21^a	3203 ± 192^b
Spring Valley	Ginger	2	74395 ± 7388^a	2.72 ± 0.13^a	1521 ± 62^a	136009 ± 1325	4.31 ± 0.46^b	3741 ± 72^a
Sundown Naturals	Ginseng Xtra	1	9324 ± 423^a	1.09 ± 0.09^a	577 ± 16^a	4547 ± 399^a	0.73 ± 0.04^a	739 ± 31^a
Sundown Naturals	Ginseng Xtra	2	2202 ± 156^b	0.39 ± 0.05^b	0 ± 0^b	1524 ± 109^b	0.46 ± 0.04^b	138 ± 138^b
Spring Valley	Korean Panax Ginseng	1	146 ± 32^a	0.32 ± 0.04^a	1550 ± 255^a	9540 ± 261^a	0.40 ± 0.02^a	52 ± 14^a
Spring Valley	Korean Panax Ginseng	2	0 ± 0^b	0.05 ± 0.03^b	0 ± 0^b	0 ± 0^b	0.23 ± 0.03^b	0 ± 0^b
Nature’s Way	Red Raspberry Leaf	1	614243 ± 29370^a	13.76 ± 0.30^a	8506 ± 112^a	73693 ± 1121^b	4.46 ± 0.33^a	3752 ± 53^b
Nature’s Way	Red Raspberry Leaf	2	362000 ± 22822^b	11.00 ± 0.18^b	8038 ± 216^a	98551 ± 1702^a	4.14 ± 0.15^a	4410 ± 83^a
Nature’s Way	Reishi	1	16681 ± 3489^a	2.87 ± 0.24^a	1784 ± 370?	10549 ± 137^a	0.59 ± 0.04^a	3088 ± 830^a
Nature’s Way	Reishi	2	14469 ± 415^a	1.72 ± 0.09^b	1154 ± 12	521 ± 82^b	0.53 ± 0.06^a	447 ± 23^b
Nature’s Way	Rhodiola	1	859558 ± 40568^a	14.32 ± 0.67^a	16018 ± 439^a	451224 ± 109504^b	14.73± 0.67^b	15684 ± 1917^a
Nature’s Way	Rhodiola	2	847358 ± 41650^a	16.86 ± 0.59^a	15114 ± 424^a	1063602 ± 134270^a	19.41 ± 1.27^a	21798 ± 1602^b
NOW	Rhodiola	1	739303 ± 57664^a	0.22 ± 0.04^b	5292 ± 512^b	45552 ± 4538^b	11.72 ± 1.43^b	8223 ± 386^b
NOW	Rhodiola	2	465838 ± 41714^b	14.97 ± 1.70^a	10235 ± 827^a	399962 ±23023^a	15.60 ± 1.01^a	13659 ± 1129^a
Nature’s Way	Silent Night	1	87025 ± 2987^a	1.47 ± 0.03^b	6372 ± 256^a	10799 ± 1694	4.91 ± 0.11^a	2354 ± 70^a
Nature’s Way	Silent Night	2	53731 ± 3951^b	5.70 ± 0.42^a	4277 ± 407^b	13289 ± 443	1.86 ± 0.10^b	675 ± 114^b
Nature’s Way	St. John’s Wort	1	166933 ± 3218^b	8.22 ± 0.37^a	9002 ± 360^a	66065 ± 1080^a	4.04 ± 0.11^a	4368 ± 161^a
Nature’s Way	St. John’s Wort	2	247036 ± 17717^a	7.79 ± 0.89^a	8509 ± 364^a	40182 ± 3011^b	4.24 ± 0.30^a	4188 ± 113^a
Spring Valley	St. John’s Wort	1	90260 ± 8356^b	17.62 ± 1.25^a	16212 ± 1355^a	29367 ± 3146^b	17.58 ± 0.57^a	6862 ± 318^b
Spring Valley	St. John’s Wort	2	271628 ± 10226^a	16.38 ± 0.56^a	15860 ± 559^a	158334 ± 9309^a	15.70 ± 0.59^b	13195 ± 335^a
Sundown Naturals	St. John’s Wort	1	104370 ± 8184^b	15.56 ± 1.01^b	13471 ± 857^b	103772 ± 4655^b	12.37 ± 0.61^b	1115 ± 437^b
Sundown Naturals	St. John’s Wort	2	287932 ± 18868^a	19.29 ± 0.56^a	20160 ± 1057^a	206181 ± 8777^a	15.18 ± 0.45^a	10539 ± 320^a
Sundown Naturals	Stress formula	1	39304 ± 1662^b	7.63 ± 0.34^a	10223 ± 335^a	24750 ± 220^a	0.76 ± 0.05^b	472 ± 30^b
Sundown Naturals	Stress formula	2	160332 ± 10585^a	5.43 ± 0.31^b	11174 ± 634^a	11586 ± 363^b	1.70 ± 0.45^a	1880 ± 52^a
Nature’s Way	Turmeric	1	1555 ± 76^b	0.69 ± 0.04^a	0 ± 0^a	205518 ± 18668^a	14.51 ± 1.33^a	389853 ± 36119^a
Nature’s Way	Turmeric	2	1969 ± 119^a	0.67 ± 0.07^a	0 ± 0^a	161170 ± 5090^b	13.55 ± 0.59^a	289884 ± 8117^a
Spring Valley	Turmeric	1	4816 ± 1234^a	0.98 ± 0.10^a	5384 ± 1275^a	51320 ± 3681^b	1.69 ± 0.14^b	9548 ± 1036^b
Spring Valley	Turmeric	2	7081 ± 466^a	1.08 ± 0.07^a	824 ± 26^b	200538 ± 9945^a	15.44 ±1.25^a	89862 ± 7177^a
Sundown Naturals	Turmeric	1	16762 ± 520^a	0.86 ± 0.08^b	1236 ± 73^b	337434 ± 15251^a	18.26 ± 2.16^a	168328 ± 13461^a
Sundown Naturals	Turmeric	2	17944 ± 946^a	1.81 ± 0.23^a	2336 ± 333^a	195569 ± 7574^b	17.55 ± 0.73^a	184986 ± 7883^a
Nature’s Way	Valerian Root	1	35271 ± 384^a	3.06 ± 0.07^a	3319 ± 154^a	13286 ± 770^a	1.41 ± 0.09^a	1929 ± 79^a
Nature’s Way	Valerian Root	2	24052 ± 1366^b	2.48 ± 0.08^b	2893 ± 95^b	10081 ± 1148^b	1.53 ± 0.08^a	1687 ± 121^a
Spring Valley	Valerian Root	1	8208 ± 6651^a	0.52 ± 0.03^b	4091 ± 505^a	7993 ± 132^a	0.33 ± 0.01^b	105 ± 18^b
Spring Valley	Valerian Root	2	12573 ± 625^a	1.94 ± 0.25^a	1176 ± 65^b	4808 ± 180^b	1.25 ± 0.30^a	606 ± 24^a
Sundown Naturals	Valerian Root	1	53318 ± 1286^a	3.46 ± 0.11^a	3625 ± 147^a	17338 ± 997	1.59 ± 0.12^b	1796 ± 139^a
Sundown Naturals	Valerian Root	2	33033 ± 1876^b	4.30 ± 0.43^a	3224 ± 104^b	14606 ± 1054	2.04 ± 0.11^a	1913 ± 32^a
Nature’s Way	Yarrow	1	114887 ± 12562^b	7.45 ± 0.91^a	11819 ± 1050^a	35094 ± 1356^b	2.69 ± 0.20^a	1840 ± 39^b
Nature’s Way	Yarrow	2	167892 ± 12775^a	7.89 ± 0.98^a	10433 ± 809^a	39870 ± 641^a	2.74 ± 0.19^a	4360 ± 108^a

* 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 = 10) for each extraction from each bottle. Means within the same supplier for a supplement with different lowercase letters are significantly different based on LSD Student’s T-Test (α of 0.05). For specific p-values for each supplement see S2 Table.

Table 3. 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 bottle and supplier*.

Table 3. 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 bottle and supplier^*.