Echinacea. Extracts Contain Significant and Selective Activities Against Human Pathogenic Bacteria

Figures & data

Table 1 Composition of extracts.

Species and plant part	ETOH content	Code	Total caffeic derivatives (μ g/mL)	PID 8/9 TET (μ g/mL)	Polysaccharides (mg/mL)
E. angustifolia.. root	48%	A1	1036	614.8	5.7
Same	48%	A2	879	623.5	ND
E. purpurea.. Root + aerial	40%	B1	1286	156	ND
Same	40%	B2	1243	155	ND
E. purpurea. root	0	C1	1237	0	48.0
Same	0	C2	1366	0	44.1

ND, not detected.

Figure 1 Dose-response curve for S. pyogenes. incubated with extract B1. Aliquots of S. pyogenes. were treated with different 10-fold dilutions of extract B1, according to the standard protocol described in “Materials and Methods,” with or without exposure to light. The treated samples were then plated out for colony formation.

Table 2 Streptococcus pyogenes. susceptibility.

Extract	CFU + light	Log10 reduction	CFU in dark	Log 10 reduction
None, control	1.1 × 10^4
A1	< 10^1	> 3.0	< 10^1	> 3.0
A2	< 10^1	> 3.0	< 10^1	> 3.0
B1	< 10^1	> 3.0	< 10^1	> 3.0
B2	< 10^1	> 3.0	< 10^1	> 3.0
C1	0.9 × 10^4	NS	1.0 × 10^4	NS
C2	0.9 × 10^4	NS	1.0 × 10^4	NS

CFU, colony-forming units per 2.5 μ L; NS, no significant reduction.

Table 3 Haemophilus influenzae. susceptibility.

Extract	CFU + light	Log10 reduction	CFU in dark	Log 10 reduction
None, control	6.0 × 10^3
A1	1.3 × 10^3	0.66	1.9 × 10^3	0.50
A2	1.3 ×10^3	0.66	2.0 × 10^3	0.48
B1	< 10^1	> 2.7	4.0 ×10^1	> 2.10
B2	< 10^1	> 2.7	3.0 × 10^1	> 2.30
C1	3.0 × 10^3	0.30	6.0 × 10^3	0
C2	5.0 × 10^3	NS	7.0 × 10^3	0

CFU, colony-forming units per 2.5 μ L; NS, no significant reduction.

Table 4 Legionella pneumophila. susceptibility.

Extract	CFU + light	Log10 reduction	Cfu in dark	Log 10 reduction
None, control	4.0 × 10^5
A1	4.7 × 10^2	2.93	4.5 × 10^2	2.95
A2	3.4 × 10^2	3.07	5.0 × 10^2	2.90
B1	3.6 × 10^2	3.05	4.0 × 10^2	3.0
B2	3.1 × 10^2	3.11	4.6 × 10^2	2.94
C1	5.0 × 10^2	2.90	5.3 × 10^2	2.88
C2	5.5 × 10^2	2.86	5.6 × 10^2	2.85

CFU, colony-forming units per 2.5 μ L.

Table 5 Propionibacterium acne. susceptibility.

Extract	CFU + light	Log10 reduction	Cfu in dark	Log 10 reduction
None, control	1.4 × 10^5
A1	1.2 × 10^5	NS	1.5 × 10^5	0
A2	1.7 ×10^5	0	1.4 × 10^5	0
B1	< 10^1	> 4.1	3.5 ×10^4	0.60
B2	< 10^1	> 4.1	6.6 × 10^4	0.33
C1	1.1 × 10^5	NS	1.1 × 10^5	NS
C2	1.5 × 10^5	0	1.0 × 10^5	NS

CFU, colony-forming units per 2.5 μ L; NS, no significant reduction.

Table 6 Clostridium difficile. susceptibility.

Extract	CFU + light	Log10 reduction	Cfu in dark	Log 10 reduction
None, control	1.5 × 10^4
A1	6.4 × 10^2	1.37	8.5 × 10^2	1.25
A2	2.1 ×10^2	1.85	5.6 × 10^2	1.43
B1	< 10^1	> 3.1	6.0 ×10^1	2.40
B2	< 10^1	> 3.1	1.9 × 10^2	1.90
C1	9.0 × 10^3	0.22	1.3 × 10^4	NS
C2	4.0 × 10^3	0.57	2.2 × 10^4	0

CFU, colony-forming units per 2.5 μ L; NS, no significant reduction.

Table 7 Species relatively insensitive to Echinacea. extracts (<1 log₁₀ CFU inactivated).

Acinetobacter baumanii.

Bacillus cereus. (spores and cells)

Bacillus subtilis.

Enterococcus faecalis. (vancomycin resistant)

Escherichia coli.

Klebsiella pneumoniae.

Mycobacterium smegmatis.

Pseudomonas aeruginosa.

Candida albicans.

Trichoderma viride.