Studies on phytochemical, antioxidant, anti-inflammatory, hypoglycaemic and antiproliferative activities of Echinacea purpurea and Echinacea angustifolia extracts

Figures & data

Table 1. Study design.

1 Physical
a) Dry matter
b) Density
2 Chemical
a) Qualitative analyses	Saponins
	Coumarines
	Anthraquinones
	Tannins
	Alkaloids
b) Quantitative analyses	Total phenols
	Total flavonoids
	Caffeic acid
	Chlorogenic acid
	Alkylamides
3 Biological
a) In vitro anti-oxidant capability	DPPH
	ABTS^+
b) Cytotoxicity	MCF-7, HeLa, HCT-15
c) In vivo hypoglycemiant effect	Male Wistar rats
d) In vivo anti-inflammatory effect	Male Wistar rats

Table 2. Evaluation of physical and chemical parameters and biological activity of Echinacea extracts.

	Biological materiala
	A	B	C
Physical
Dry matter (g/mL)	0.024	0.027	0.239
Density (g/mL)	0.933	0.930	0.978
Ethyl alcohol^b	40%	40%	30%
Chemical
Qualitative^c
Saponins	+	++	+
Coumarins	+	–	+
Anthraquinones	–	+	+
Tannins	+	–	+
Quantitative
Total phenols^d	23.3 ± 0.1	17.7 ± 0.1	137.5 ± 2.3
Total flavonoids^e	0.16 ± 0.01	0.16 ± 0.003	0.62 ± 0.02
Caffeic acid^f	–	–	–
Chlorogenic acid^f	–	<1.0	<1.0
Alkylamides^g	11	11	14
Sugars^f
Sucrose	267	77.95	68061.22
Glucose	1660	2475.07	2521.65
Fructose	6788.36	3554.74	29938.56
Biological
Antioxidant capacity^h
DPPH	0.24 ± 0.01	0.45 ± 0.02	4.8 ± 0.4
ABTS^+	1.66 ± 0.06	1.26 ± 0.04	10.5 ± 0.2
Cytotoxicity^i
HeLa	>30,000	>30,000	270.8
MCF-7	>30,000	>30,000	8,171
HCT-15	>30,000	>30,000	9,338

^aExtract produced in a certified ranch using: A, roots of Echinacea purpurea; B, roots, leaves, flowers and seeds of Echinacea purpurea; C, aerial part and roots of Echinacea purpurea and roots of Echinacea angustifolia. ^bThe alcohol type was determined by ¹H-RMN and the percentage was determined by HPLC. ^cQualitative analysis: +++ very abundant; ++ abundant; + scarce; - not oserved. Quantitative analysis: ^dmEAG/mL, equivalent mg of gallic acid per milliliter of extract. ^emEQ/mL, equivalent mg of quercetin per milliliter of extract. ^fPPM determined by HPLC as indicated in the experimental section. ^gNumber of alkylamides found by GC-MS. ^hTrolox Equivalent Antioxidant Capacity, equivalent millimolar per milliliter of extract. ⁱHalf inhibitory concentration (IC₅₀) in μg/mL.

Figure 1. Total ion chromatogram (TIC) of the non-polar fractions of the analyzed hydroethanolic extracts: roots of E. purpurea (A), roots and aerial parts of E. purpurea (B) and roots, aerial parts of E. purpurea and roots of E. angustifolia (C). The identity of the detected peaks is shown in Table 3.

Table 3. Identity, retention times and presence of alkylamides on the non-polar fractions of three Echinacea extracts analyzed GC-MS.

Peak	Rt (min)	Compound	A	B	C
1	13.69	undeca-2E,4Z-diene-8,10-diynoic acid isobutylamide	X	X	X
2	14.12	undeca-2E-ene-8,10-diynoic acid isobutylamide	X	X	X
3	16.25	dodeca-2Z,4E-diene-8,10-diynoic acid isobutylamide	X	X	X
4	16.87	undeca-2Z-ene-8,10-diynoic acid isobutylamide			X
5	18.09	undeca-2E,4Z-diene-8,10-diynoic acid 2-methylbutylamide	X	X	X
6	18.89	dodeca-2E,4E-dienoic acid isobutylamide			X
7	19.46	dodeca-2E-ene-8,10-diynoic acid isobutylamide	X	X	X
8	20.65	dodeca-2E,4E,8Z,10Z-tetraenoic acid isobutylamide	X	X	X
9	21.25	dodeca-2E,4Z,8Z,10E-tetraenoic acid isobutylamide			X
10	21.60	dodeca-2E,4Z,8Z,10Z-tetraenoic acid isobutylamide^a	X	X	X
11	24.66	undeca-2Z,4E-diene-8,10-diynoic acid 2-methylbutylamide^a	X	X	X
12	25.46	dodeca-2E-ene-8,10-diynoic acid 2- methylbutylamide	X	X	X
13	27.467	dodeca-2E,4Z-diene-8,10-diynoic acid isobutylamide	X	X	X
14	34.44	dodeca-2E,4Z-diene-8,10-diynioc acid 2-methylbutylamide	X	X	X

^a The identity of this compounds cannot be determined with a good grade of accuracy, there is a fair probability these compounds are isomers of other compounds of the same molecular weight and similar fragmentation pattern.

Table 4. Hypoglycaemic effect of the three extracts evaluated.

	Measurement day
	2	6	12
A	116.5 ± 6.9^a,b	124.8 ± 9.5^a,b	133.25 ± 10.04^a,b
B	112.8 ± 19.3^a,b	295.0 ± 43.2	317.5 ± 21.5
C	125.0 ± 54.4^a,b	232.5 ± 131.6^a,b	232 ± 135.4^a,b
Control	412.3 ± 11.1	387.0 ± 72.4	436.25 ± 58.78
Glibenclamide	140.0 ± 34. 6^a	104.0 ± 15.2^a	147.75 ± 31. 91^a

Glycaemia average (mg/dL) ± SD, ANOVA, Tukey as post hoc test, n = 8, ^aSignificant difference compared to control (=0.005, p = 1.000, see Supporting information); ^bNo difference compared to glibenclamide (=0.05, p = 1.000).

Figure 2. Anti-inflammatory effect of Echinacea extracts (A–C) in the paw oedema model. *indicates significant differences at α = 0.05, n = 8.