1. Introduction

Taraxacum has been worldwide tested against several bacterial and fungal strains under various extract conditions and bioassays, and we compiled enough published information with the aim of comparing and/or relationship between the various existing methods and their result in the antimicrobial profile.

#### 1.1. Antimicrobial bioassay methods used in Taraxacum genus

Several different methods have been used for testing antimicrobial activity, the application of which most often depends on the available instrumentation and the training of the investigators [1]. Screening for antibacterial and antifungal activity is often done by agar disc diffusion, agar well test diffusion, and agar dilution or microdilution broth. In agar disc diffusion, a paper disc soaked with the extract is laid on top of an inoculated agar plate and is generally

© The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

distribution, and eproduction in any medium, provided the original work is properly cited.


B. cereus NCTC 7464

B. cinérea B. cinerea SGR-1 B. cinerea SGR-1

B. sorokiniana B. sorokiniana 6/10 B. sorokiniana F-1446

B. subtilis B. subtilis B. subtilis

B. subtilis B. subtilis B. subtilis B. subtilis B. subtilis

B. subtilis ATCC 1149 B. subtilis ATCC 6633

B. subtilis ATCC 6633 B. subtilis ATCC 6633

 Agar diffusion method

 Disc diffusion method

 Broth inhibition method

 Inhibition zone, MIC

 Inhibition zone

 % Inhibition

 Control (8 mm)

 None

Erythromicin

 1.0 μM

 18 mg/mL

1000–2000 μg/mL 1000–2000 μg/mL

 0–12.5 mm

 5.1–97.9%

 [21] [21]

273

No activity

 [8]

 Agar well diffusion

 Inhibition zone,

antimicotic

 index

Broth dilution

Agar well diffusion

Broth dilution assay Disc diffusion method

MIC

 Inhibition zone

 MIC

 Inhibition zone

 Tetracyclin

(22 mm) Chloramphenicol

 (8 mm, 0.3) 30 μg

 100 μg/mL

 None Tetracyclin

 100 μg/mL (84%)

 50 mg/mL 50 mg/mL

Agar inoculation

Disc diffusion method

Disc diffusion method

MIC

 Inhibition zone

 Inhibition zone

 None

 Tetracyclin

(23.6 mm) Tetracyclin

 (MIC 5.0 μg/mL)

 10 μg/mL

120 μg/mL

5.1–97.9% 10.0–14.0 mm

10–54% 11–19 mm 11 mm, 0.1

 [9]

[4]

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

> [20]

[4]

[19]

 10 μg/disc

 Microtiterd Agar diffusion method

 method

 IC52

 Inhibition zone

Gentamicyn

Tetracyclin

None

No information No information

10 mg/mL

 7.0 mg/mL

 12.04 mm 5.1–97.9%

[19]

 [17] [18]

 2 mg/disc

 1 mg/disc,

None

15.6–250 μg/mL

4–12 μg/disc

 No activity weak activity, not

indicated

 [10, 11]

[16]

 Broth dilution assay

Microtiterd

Broth dilution assay

 method

 IC51

 IC50, MIC, Morphological

changes

 IC50 (50% growth

None

6–10 μM

5.2 μM

[5]

inhibition)

None None

15.6–250 μg/mL

15 μM

 No activity >15 μM; >15 μM;

 [11]

 [10]

 Microtiterd Microassay

slides

Broth dilution assay

 IC50 (50% growth

inhibition)

 method on

 method

 MIC ICG, IGTE

Bioassay

Results expresion

 Positive control

None Only in vivo assays (Imazalil,

Fenhexamid)

None

6–10 μM

5.2–5.8 μM

 [5]

Active 2 mg/mL

0.75X

concentration

 Main results

250 μg/mL

9%, 38%

 Reference

 [15]

[7]


Alternaria alternata

A. alternata A. carbonarius (Bainier)

Thom

A. flavus 0064

A. fumigatus 66

A. hidrophila (food poisoning patients)

A. niger A. niger 0198

A. niger UPCC 3701

A. niger van Thiegem

A. niger VKM F-33

A. niger VKM F-33

A. flavus QC 6658

A. fumigatus

A. niger B. cereus B. cereus (spoiled rice)

B. cereus ATCC 1778 B. cereus NCTC 7464

 Microtiterd

 Disk diffusion method Disk diffusion method Disk diffusion method Agar diffusion method

 Agar diffusion method

 Broth dilution assay

 Broth dilution assay

 method

 IC50

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 MIC

 MIC

 Cephalotin

 Cephalotin

 30 μg/mL (20 mm) 10 mg/mL

Cloramphenicol

None

 (0.004 μM)

 No information

2 mg/mL

 2.5 μM 500 μg/mL

 [14]

 30 μg/mL (22 mm) 10 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

None

15.6–250 μg/mL

 No activity

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

18 mm 18 mm

 [12]

[9]

[9]

[13]

 [12]

 [12]

 [11]

 Microassay

slides

 Broth dilution assay

 IC50 (50% growth

inhibition)

 method on

ICG, IGTE

Only in vivo assays (Imazalil,

0.75X

3%, 45%

[7]

Fenhexamid)

None

6–10 μM

1.2–5.6 μM

 [10]

Agar tube dilution

 Agar well diffusion

Broth dilution assay

 IC50, MIC,

None

15 μM

4.2 μM; 2.8 μM; + [5]

Morphological

changes

 Inhibition growth

 Inhibition zone,

antimicotic

 index

 Terbinafine Canesten (23 mm, 1.3)

 12 mg/mL 100%

 17 mg/mL

 30 μg

37.40% No activity

 [9]

[8]

Paper disc diffusion method % Inhibition

Microassay

slides

Agar tube dilution

Agar tube dilution

Agar diffusion method

 Inhibition growth

 Inhibition growth

 Inhibition zone

 Terbinafine

 Terbinafine

 Cephalotin

 30 μg/mL (20 mm) 10 mg/mL

 12 mg/mL 100%

 16 mg/mL

 12 mg/mL 100%

 15 mg/mL

70.80% 84.80% No activity

 [9]

[8]

[8]

 method on

ICG, IGTE

Bioassay Broth dilution assay

 IC50, MIC, Morphological

changes

 None Only in vivo assays (Imazalil,

Fenhexamid)

S, S/2, S/10, S/100

0.75X

 16.7–76.2%

4%, 0%

 [6] [7]

Results expresion

 Positive control

None

Active

15 μM

concentration

 Main results 2.9 μM; 1.0 μM; + [5]

 Reference

272 Herbal Medicine


C. jejuni NCTC 11168

(ATCC 700819)

C. lagenarium C. lagenarium C. neoformans ATCC 32608 Broth dilution assay

C. parapsilepsis ATCC

Agar diffusion method

22019

C. sativus (S. Ito and

Paper disc diffusion method Inhibition zone

Kurib.)

C. tropicalis ATCC 750

C. utilis ATCC 22023

C. violaceum ATCC 12472 C. violaceum ATCC 31532 C. violaceum NTCT 13274

C. albicans C. glabrata ATCC 2001

C. krusei ATCC 6258 C. parapsilosis ATCC 22019 Disk diffusion method

C.

michiganense subesp.

Agar diffusion method

> Michiganense Ac-1144

Cupriavidus sp. E. coccus ATCC 13048

E. coli E. coli E. coli

Disk diffusion method

 Agar diffusion method

Disc diffusion, broth

dilution

Agar inoculation

Agar diffusion method

MIC

 Inhibition zone

 None

None

No information

0.1–1.0 mg/mL

 1.0 mg/mL

 >0.5 mg/mL

(1–4 mm)

 [17] [35]

275

 Inhibition zone

 Inhibition zone, MIC

Inhibition zone, MIC

Ciprofloxacin

Erythromicin

Erythromicin

 (MIC 27 μg/mL) 10–500 μg/mL

 1.0 μM

 19 mg/mL

 5 μg/disc

 130–200 mg/mL

 >200 mg/mL

No activity

 13.3 mm, MIC

50 μg/mL

 [12]

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

> [8]

[34]

 Agar diffusion method

 Agar diffusion method

 Quorum sensing

 Quorum sensing

 Quorum sensing Disk diffusion method

 Disk diffusion method

 Disk diffusion method

 Inhibition zone

 Inhibition zone Inhibition zone Inhibition zone Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Anfotericin

 Anfotericin

 None

 None

 None

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

6–10 μM

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 (5

μg/disc)

 130–200 mg/mL

 (0.4 mm)

 200 μg/mL

No information No information No information

 7 mm

 No activity

 No activity

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

0.8–1.4

 [12]

[5]

 [12]

 [12]

 [12]

 [33]

 [33]

 (0.4 mm)

 200 μg/mL

Direct inoculation Direct inoculation

Bioassay Broth dilution assay

 MIC, IC50, %

Inhibition

Rates of Inhibition Rates of Inhibition

 MIC

 Inhibition zone

 Anfotericin

 Mancozeb, Benomyl (1 mg/disc)

 Thiram, Carboxin,

5 mg/disc

weak activity, not

[31]

indicated

2.0 mm >200 μg/mL

 [26] [32]

[26]

 (0.4 mm)

 200 μg/mL

 Control untreated leaves

 Control untreated leaves

Anfotericin

 B (0.0008 μM)

 No information

 No information

 No information

 1.90

 12.80

 0.039 μM

>200 μg/mL

 [26]

[30}

[30]

[13]

Results expresion

 Positive control Ampicillin (IC50 1.61 μg/mL)

 15 μM

Active

concentration

 Main results

No activity

 Reference

 [29]


B. subtilis ATCC 6633 B. subtilis KCTC 1021 B. subtilis KCTC 1021

B. subtilis VKM 1053 B. cereus NCTC 7464

B. pumilus

isolate)

B. subtilis NCTC 10400

Disk diffusion method

 Inhibition zone

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL No information

 No activity

0–70% 14–20 mm

[4]

 [24]

[4]

 >200 mg/mL

 [12]

> (NCIMB 8054)

C. albicans C. albicans C. albicans C. albicans ATCC 10231 C. albicans ATCC 10231 C. albicans ATCC 18804 C. albicans ATCC 90028

C. albicans UPCC 2168 C. glabrata ATCC 2001

C. gloesporoides

C. jejuni

Broth dilution assay

 Agar diffusion method

Broth dilution assay

 Inhibition zone

 IC50, MIC, Morphological

changes

 Adhesion,

3-sialyllactose

mL)

 (IC50 1.4 mg/

500 mg/mL

IC50 < 3 mg/mL,

[28]

<10%, no activity

cytotoxicity,

Antibacterial

 Anfotericin

 (0.4 mm)

 200 μg/mL

15 μM

>200 μg/mL >15 μM; >15 μM;-

 [26]

 [10]

 Agar diffusion method

 Broth dilution assay

 Agar well diffusion

 Agar well diffusion

 Inhibition zone,

antimicotic

 index

 Inhibition zone

 MIC

 Anfotericin Anfotericin

Anfotericin

Canesten (18 mm, 0.3)

 B (100

μg/disc)

 40 μg

 30 μg

 B (0.0004 μM)

 No information

 0.039 μM

3.0 mm 12 mm, 0.2

 [9]

 (0.2 mm)

 200 μg/mL

>200 μg/mL

 [26] [13]

[27]

 Paper disc diffusion method Inhibition zone

Disc diffusion method

Broth dilution assay Disc diffusion method

 Inhibition zone

 MIC

 Inhibition zone

 Tetracyclin

(20 mm)

(27 mm)

Chloramphenicol

 30 mcg

50 μL/disc

No activity

 [25]

 100 μg/mL

 No information

Tetracyclin

 100 μg/mL (68%)

 50 mg/mL

50 mg/mL

(wildtype hand

Disk diffusion method

 Broth dilution assay

 Disc diffusion method

 Broth dilution

 Agar diffusion method

 Disk diffusion method

 MIC

 Inhibition zone

% Inhibition

 Inhibition zone

 Inhibition zone

 Inhibition zone

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

 >200 mg/mL

 >200 mg/mL

 [12]

 [12]

 Control (8 mm)

 None

Bioassay

Results expresion

 Positive control

None

Active

No information 500–2000 μg/mL 1000–2000 μg/mL

6–10 μM

concentration

 Main results

 No activity

 8.5–12.5 mm

 5.1–97.9% 0.8–1.2 μM

 [5]

 [23] [23]

 [22]

 Reference

274 Herbal Medicine


E. coli KCTC 2441 E. coli KCTC 2441

E. coli NCTC 25922

E. coli NCTC 9001 E. coli UPCC 1195

E. faecalis

E. faecalis ATCC 19433

E. coli 0157 NCTC 12900

E. coli DH5 Enterobacter/Klebsiella

E. faecalis NCTC 775

Exophiala dermatitidis QC 7895

F. avenaceum

F. 1668 F. oxysporium

F. oxysporium F. oxysporium

H. pylori H. pylori NCTC 11639

(ATCC 43629)

TSKHA-4

 Microtiterd

Paper disc diffusion method Inhibition zone

Broth dilution assay

 MIC, IC50, %

Inhibition

 method

 IC53

None

 Control (8 mm)

Gentamicin

(IC50 0.081 μg/mL)

15.6–250 μg/mL

No information

500 mg/mL

 No activity

 10 mm

25%

 [11] [42]

[29]

277

TSKHA-4

 Broth dilution assay

 IC50 (50% growth

inhibiton)

Schlecht

 Paper disc diffusion method Inhibition zone

graminearum VKM F-

Broth dilution assay

Broth dilution assay

 IC50, MIC, Morphological

changes

 IC50 (50% growth

inhibition)

 Mancozeb,

Benomyl (1 mg/disc)

Kanamycin

6 μM

5.7 μM

[5]

 Thiram, Carboxin,

6 μM

5.7 μM

[31]

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

(Wangiella)

Disk diffusion method

 sp. Disk diffusion method

 Disk diffusion method

 Disk diffusion method Disk diffusion method

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

15 μM 6–10 μM

>10 μM

[5]

13.1 μM; 6.7 μM; + [10]

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

 [12]

 [12]

 [12]

 [12]

 [12]

 Agar diffusion method

 Inhibition zone, MIC

Erythromicin

Cefixime 1.0 μM

 1.0 μM.

21 mg/mL

No activity

 [8]

Irrigation in situ

 Disc diffusion method

 Broth dilution

 Disk diffusion method

 Disk diffusion method

 Agar well diffusion

 Inhibition zone

% Inhibition

 Inhibition zone

 Inhibition zone

 Inhibition zone,

antimicotic

 index

3.2)

None

7 mg/mL

weak activity, not

[41]

indicated

 Control (8 mm)

 None

Ciprofloxacin

Chloramphenicol

 (25 mm,

 5 μg/disc

 130–200 mg/mL

30 μg

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Bioassay

Results expresion

 Positive control

Active 500–2000 μg/mL 1500–2000 μg/mL

 9.0–12 mm

 13–98.4%

 >200 mg/mL

 >200 mg/mL

11 mm, 0.1

 [12]

 [9]

 [12]

 [23] [23]

concentration

 Main results

 Reference


E. coli E. coli

E. coli E. coli E. coli E. coli

E. coli E. coli E. coli E. coli E. coli 7075 E. coli 8739 E. coli ATCC 11229 E. coli ATCC 11229

E. coli ATCC 1229

E. coli ATCC 15224 E. coli ATCC 25322

E. coli ATCC 8677 E. coli ATCC 8739

E. coli DSM 1103 E. coli DSM 1103

Agar diffusion method

 Disc diffusion method

 Broth inhibition method

 Broth dilution assay

 Agar diffusion method

 Agar well diffusion

 Paper disc diffusion method Inhibition zone

 Broth dilution assay Broth dilution assay

Microtiterd

 method

 MIC

 MIC

 MIC

 Inhibition zone

 Inhibition zone

 % Inhibition

 MIC

 Inhibition zone, MIC

 Inhibition zone

 Ticarcillin 75 mcg (27 mm)

None None None

Gentamycin

 None

 Control (8 mm)

 None None Erythromicin

 1.0 μM

 20 mg/mL 240 mg/mL

 50 μL/disc

S, S/2

2 mg/mL 2 mg/mL

No activity No activity

 [14]

 [15]

1 mg/mL 500–2000 μg/mL 500–2000 μg/mL

No information

 11–13.5 mm

 98.1–100%

 No activity No activity

6.5 mm

No activity

Inhibition

[40]

 [26]

 [22]

 [8] [39]

 [21] [21]

>1 mg/mL

[38]

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

 2 mg/disc

 1 mg/disc,

4–12 μg/disc

No activity

 [16]

Disc diffusion method

Agar well diffusion

Broth dilution assay Disc diffusion method

 Inhibition zone

 Inhibition zone

 MIC

 Inhibition zone

 Tetracyclin

(18 mm)

 100 μg/mL

 No information

 None Tetracyclin

 100 μg/mL (78%)

 50 mg/mL 50 mg/mL

Broth dilution

MIC

Diet

Disc diffusion method Disc diffusion method Disc diffusion method

CFU count

 Inhibition zone

 Inhibition zone

 Inhibition zone

 None

 None

(18.9 mm) Gentamycin

mL)

 (MIC 1.25 μg/

10 μg/mL

No information

120 μg/mL

 11–13 mm 2.0–3.0 mm

14–62% 12–15 mm

[4]

 [20]

[4]

[24]

250–500 μg/mL

 [19]

Gentamycin

 10 μg/disc

Bioassay

Agar diffusion method

 Inhibition zone

(30.5 mm)

Control

No information

1 g/mL No information

10 mg/mL

 13.21 mm 12.05–14.21

 mm

 [19]

 Inhibition 10.2–18.5 mm

 [37] [18]

[8]

Cloramphenicol

 10 mg/mL

50–200 mg/mL

Results expresion

 Positive control

Active

concentration

 Main results

 5.25–23.5 mm

 [36]

 Reference

276 Herbal Medicine

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849 277


M. luteus ATCC 10240

M. piriformis

M. smegmatis MC2 155

M. tuberulosis H37RA MRSA (clinical isolated)

MRSA AARM 3696

P. acnes P. aeruginosa P. aeruginosa P. aeruginosa P. aeruginosa P. aeruginosa P. aeruginosa P. aeruginosa

P. aeruginosa ATCC 15442 Broth dilution assay

P. aeruginosa ATCC 7221

P. aeruginosa ATCC 9027

P. aeruginosa ATCC 9721

P. aeruginosa UPCC 1244

 Broth dilution assay

 Paper disc diffusion method Inhibition zone

 Agar well diffusion

 Inhibition zone,

antimicotic

 index

2.8)

 MIC

 Agar diffusion method

Broth dilution Agar well diffusion

MIC

 Inhibition zone

 MIC

 Inhibition zone, MIC

 None Cloramphenicol

Erythromicin

Cefixime 1.0 μM

None

 Ticarcillin 75 mcg (20 mm)

Chloramphenicol

 (23 mm,

No information

 50 μL/disc

30 μg

 No activity No activity

11 mm, 0.1

 [22]

 [25]

 [9] 279

 1.0 μM.

 (0.015 μM)

 No information

24 mg/mL

 2.5 μM No activity

 [8]

Disc diffusion method

 Inhibition zone

(20.0 mm) Gentamycin

 (MIC 2.5 μg/mL)

 10 μg/mL 120 μg/mL

125–250 μg/mL

8.0–13.0 mm

 [19]

 [20] [13]

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

Gentamycin

 10 μg/disc

10 mg/mL

16.52–19.19

 mm

 [19]

Agar diffusion method

 Inhibition zone

(26.0 mm)

Cloramphenicol

 10 mg/mL

50–200 mg/mL

—

[36]

Broth dilution assay Broth dilution assay Disc diffusion, broth

dilution

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

 2 mg/disc

 1 mg/disc,

4–12 μg/disc

No activity

 [16]

 No information

 No information Inhibition zone, MIC

 No information

 No information

Erythromicin

No information No information

10–500 μg/mL

 No information

 No information

 No activity

 [34]

 [46]

 [46]

 Disc diffusion method

 Inhibition zone

 Gentamicin

(20.1 mm)

 0.2 mg/disc

0.5–3.0 mg/disc

 6.8–16.5 mm

 [45]

 Broth dilution assay.

Microtiterd

 method

 Broth dilution method

 MIC MIC

 Agar diffusion method

Paper disc diffusion method % Inhibition

 Broth dilution

MIC

 MIC

Bioassay

Results expresion

 Positive control

Erythromicin

 None Streptomycin

mL)

Rifampim.

Kanamycin

None

2 mg/mL

375 μg/mL. 500 μg/

[14]

mL

 Isoniazid.

No information

 > 200 μg/mL

 [44]

 (IC50 1.14 μg/

 1.0 μM

 23 mg/mL S, S/2, S/10, S/100

120 μg/mL

 5.3–66.7% 5.3–66.7%

[43]

Active

concentration

 Main results

1.0 μM

 Reference

[8]

[6]


K. pneumoniae K. pneumoniae K. pneumoniae K. pneumoniae K. pneumoniae ATCC

13866

K. pneumoniae UC 5

K. aerogenes NCTC 9528

K. pneumoniae 700,603

L. 40307

L. 40307

L. 11994

M. aureum 4721 E

M. bovis BCG

M. canis M. kristinae

M. laxa M. luteus

Agar well diffusion, agar

No information

 No information

> tube dilution

Agar inoculation

Microassay

slides

Agar well diffusion

 Inhibition zone

 None

 method on

MIC ICG, IGTE

None Only in vivo assays (Imazalil,

Fenhexamid)

No information

0.75X

120 μg/mL

5.0–9.0 mm

 [20]

 5.0–7.0 mg/mL

11%, 5%

 [17]

[7]

Broth dilution

MIC

 Broth dilution

monocytogenes NCTC

monocytogenes KCCM

Disc diffusion method. Broth Inhibition method

Disk diffusion method

monocytogenes KCCM

 Disk diffusion method

 Disk diffusion method Disc diffusion method. Broth Inhibition method

 Inhibition zone

 Inhibition zone Inhibition zone. %

Inhibition

Inhibition zone. %

Control (8 mm). None

 500–2000 μg/mL

 10.5–12 mm.

[23]

27.2–94%

Inhibition

 Inhibition zone

MIC

Streptomycin

mL)

Streptomycin

mL)

 (IC50 1.14 μg/

500 μg/mL No information

 Inhibition

[44]

>500 μg/mL

 [43]

 (IC50 1.14 μg/

500 μg/mL

>500 μg/mL

 [41]

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

 >200 mg/mL

 [12]

Control (8 mm). None

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

 500–2000 μg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

 >200 mg/mL

 >200 mg/mL

 0–12 mm. 5.1–97.9%

 [21]

 [12]

 [12]

 Agar diffusion method

 Inhibition zone, MIC

Erythromicin

Cefixime 1.0 μM

 1.0 μM.

22 mg/mL

No activity

 [8]

Broth dilution Broth dilution assay

MIC

 MIC

Disc diffusion method

 Inhibition zone

(18.9 mm) Gentamycin

 (MIC 5.0 μg/mL)

Cloramphenicol

 (0.001 μM)

 No information

 0.625 μM

 10 μg/mL

125–250 μg/mL

 [19] [13]

Gentamycin

 10 μg/disc

10 mg/mL

13.24–17.72

 mm

 [19]

Agar diffusion method

 Inhibition zone

(26.5 mm)

Cloramphenicol

 10 mg/mL

50–200 mg/mL

—

[36]

Bioassay

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

 2 mg/disc

 1 mg/disc,

Results expresion

 Positive control

Active

4–12 μg/disc

concentration

 Main results

No activity

 Reference

278 Herbal Medicine

 [16] *Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849 279


Strains P. vulgaris Penicillium sp. QC 743275

Pseudomona

P. aeruginosa NCTC 1662

P. aeruginosa NCTC 27853 Disk diffusion method

Pseudomonas sp.

R. solani 18,619

R. solani Kühn S. aureus NCTC 8178 S. abony enterica NCTC

6017

S. agalactiae

S. aureus S. aureus S. aureus S. aureus S. aureus S. aureus S. aureus S. aureus S. aureus S. aureus

Broth dilution

MIC

Disc diffusion method Disc diffusion method

Disc diffusion method

 Inhibition zone

 Inhibition zone

 Inhibition zone

 None

 None

 Tetracyclin

(38.8 mm) Tetracyclin

 (MIC 2.5 μg/mL)

 10 μg/mL

250 μg/mL

 [19] 281

 10 μg/disc

1 g/mL No information

10 mg/mL

 16.15 mm 11.22–15.07

 mm

 [19]

9.7–19.9 mm

 [37] [18]

Agar diffusion method

 Inhibition zone

(35.0 mm)

Cloramphenicol

 10 mg/mL

100–200 mg/mL

 9.0–10.75 mm

 [36]

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

> Agar inoculation

Agar diffusion method

MIC

 Inhibition zone

 None

Disc diffusion method

Broth dilution assay Disc diffusion, broth

dilution

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

None

No information

0.1–1.0 mg/mL

 5.0 mg/mL

 >0.5 mg/mL

(1–4 mm)

 [17] [35]

 2 mg/disc

 1 mg/disc,

4–12 μg/disc

 Inhibition zone

 No information Inhibition zone, MIC

 None

 No information

Erythromicin

 (MIC 33 μg/mL) 10–500 μg/mL

 Microtiterd Broth dilution assay

 method

 MIC

 MIC

Disk diffusion method

Agar tube dilution

Paper disc diffusion method Inhibition zone

 sp.

 Disk diffusion method

Disc diffusion method

 Disk diffusion method

Bioassay Broth dilution

Results expresion

MIC

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition zone

 Inhibition growth

 No information

 Terbinafine

 Mancozeb, Benomyl (1 mg/disc)

None None

2 mg/mL

S, S/2

1 g/mL No information

 No information

 12.7 mm, MIC

50 μg/mL No activity

 [16}

 [46] [34]

11.1–19.7 mm

 [37]

500 μg/mL

Inhibition

[40]

 [15]

 Thiram, Carboxin,

 12 mg/mL 100%

 25 mg/mL

5 mg/disc

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

No information

 >200 mg/mL

 11–21 mm

 >200 mg/mL

 >200 mg/mL

 >200 mg/mL

77.47% 4.75–17.63 mm

 [31]

 [12]

[8]

 [12]

 [12]

 [12] [24]

 Positive control

Gentamycin

 (MIC 2.5 μg/mL)

 10 μg/mL

Active

concentration

 Main results 250–500 μg/mL

 [19]

 Reference


P. betae P. betae F-2532 P. debaryanum VKM F-

1505 P. digitatum (Perss) Sacc

P. expansum P. expansum Link.

P. expansum Link. ATCC

42710

P. infestans

P. infestans OSV 12

P. italicum P. mirabilis P. mirabilis

P. ovale P. syringeae VKM B-1546

P. vulgaris P. vulgaris P. vulgaris

Broth dilution assay

 Agar diffusion method

Disc diffusion, broth

dilution

Agar inoculation

Disc diffusion method

MIC

 Inhibition zone

(19.5 mm)

Gentamycin

 10 μg/disc

None

No information

10 mg/mL

 5.0 mg/mL 13.38–18.33

 mm

 [19]

 [17]

 No information

 Inhibition zone Inhibition zone, MIC

Erythromicin

 (MIC 26 μg/mL) 10–500 μg/mL

 No information

No information

6–10 μM

 No information

1.2–1.3 μM

 10.1 mm, MIC

100 μg/mL

 [46]

 [5] [34]

Agar diffusion method

 Inhibition zone

 None

Wehmer

 Microassay

slides

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

 2 mg/disc

 1 mg/disc,

4–12 μg/disc 0.1–1.0 mg/mL

 >0.5 mg/mL

[35]

(4–10 mm)

No activity

 [16]

 method on

ICG, IGTE

Only in vivo assays (Imazalil,

0.75X

2%, 56%

[7]

Fenhexamid)

 Direct inoculation

disc)

 (potato

Disease

development

 None

Microtiterd

 method

 IC55

None

15.6–250 μg/mL

1.3–5.3 μM

 No activity 1.3–5.2 μM

 [11]

 [5]

 Microassay

slides

Paper disc diffusion method % Inhibition

 Microassay

slides

Paper disc diffusion method Inhibition zone

 method on

ICG, IGTE

 method on

ICG, IGTE

Only in vivo assays (Imazalil,

0.75X

12%, 42%

[7]

Fenhexamid)

 None Only in vivo assays (Imazalil,

Fenhexamid)

 Control (8 mm)

0.1 g/mL

12 mm

[47]

S, S/2, S/10, S/100

0.75X

 15.7–69.7% No activity

 [6]

 [7]

Microtiterd

Broth dilution assay

 method

 IC54

 IC50 (50% growth

inhibition)

None None

15.6–250 μg/mL

6–10 μM

 No activity

2.6 μM

 [11]

[5]

Bioassay Broth dilution assay

 IC50, MIC, Morphological

changes

Results expresion

 Positive control

Active

15 μM

concentration

 Main results 10.7 μM; 8.0 μM; + [10]

 Reference

280 Herbal Medicine

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

281


S. aureus UPCC 1143

S. australis S. cerviseae S. cerviseae S. dysgalactiae S. enterica sorovar typhimurium ATCC 13311

S. enteriditis S. epidermis KCTC 1917

S. fiexneri S. haemolyticus

S. marscens S. sonnei ATCC 11060 S. tiphimurium SARB 69

S. typhi S. typhi (food poisoning

patients)

S. typhi H.

S.

typhimurium collection B-69 Salmonella poona NCTC

Disk diffusion method

 Inhibition zone

Ciprofloxacin

 5 μg/disc

 130–200 mg/mL

 >200 mg/mL

 [12] 283

4840

Reference

Microtiterd

 method

 MIC

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

None

2 mg/mL

No activity

 [15]

 2 mg/disc

 1 mg/disc,

4–12 μg/disc

No activity

 [16]

Agar inoculation

 Broth dilution assay

 Broth dilution assay Agar well diffussion, agar

tube dilution Agar diffusion method

 Inhibition zone

 Cephalotin

 30 μg/mL (18 mm) 10 mg/mL

MIC

 MIC

 MIC No information

 No information

Disc diffusion, broth

Inhibition zone, MIC

Erythromicin

10–500 μg/mL

 No activity

 [34]

dilution

Agar diffusion method

 Inhibition zone

Gentamicyn

Tetracyclin

None Cloramphenicol

None

 (0.001 μM)

 No information

2 mg/mL No information

 Inhibition

14 mm

[9]

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849

No information

 1.0–5.0 mg/mL

 2.5 μM No activity

 [14] [44]

 [17] [13]

 2 mg/disc

 1 mg/disc,

4–12 μg/disc

Weak activity, not

[16]

indicated

Disc diffussion method

 Disc diffussion method

 Inhibition zone

 Inhibition zone

 No information

 Gentamicin

(24.4 mm)

 0.2 mg/disc

Disc diffusion method

Broth dilution assay

 Inhibition zone

 MIC

 None Cloramphenicol

 (0.001 μM)

 No information No information 130–200 mg/mL

 No activity

 7.3–16.7 mm

 [45]

 [24]

 5.0 μM

1 g/mL

13.8–9.6 mm

 [37] [13]

Broth dilution assay Broth dilution assay Disc diffussion method

 Growth

 MIC

 Inhibition zone

 Tetracyclin

18 mm)

 100 μg/mL

 Agar well diffussion

 Inhibition zone,

antimicotic

 index

2.3)

None Tetracyclin

 100 μg/mL (50%)

 50 mg/mL 50 mg/mL

10–10,000 ppm

 No activity

0–64% 12–15 mm

[4]

 [46]

[4]

Bioassay

Results expresion

 Positive control Chloramphenicol

 (20 mm,

30 μg

Active

concentration

 Main results

No activity

 Reference

 [9]


S. aureus S. aureus S. aureus S. aureus S. aureus S. aureus (salted white

Agar diffusion method

 Inhibition zone

 Cephalotin

(27 mm)

Chloramphenicol

 30 mcg

50 μl/disc 320 mg/mL

10.4 mm

7.5 mm

[39]

[27]

No activity

 [25]

 30 μg/mL (24 mm) 10 mg/mL

cheese)

S. aureus ATCC 12600 S. aureus ATCC 25922 S. aureus ATCC 43300

S. aureus ATCC 6530 S. aureus ATCC 6538 S. aureus ATCC 6538 S. aureus ATCC 6538 S. aureus ATCC 6538 S. aureus ATCC 6538 S. aureus ATCC 6538 S. aureus KCTC 1916 S. aureus KCTC 1916 S. aureus KCTC 3881 S. aureus NCTC 8178

 Broth dilution assay

 MIC

 Disc diffusion method

 Broth inhibition method

 Agar diffusion method

 Disc diffussion method

 Broth dilution

 Disc diffussion method

 Inhibition zone

 % Inhibition

 Inhibition zone

 Inhibition zone

% Inhibition

 Inhibition zone

 Control (8 mm)

 None

 None

 Control (8 mm)

 None

 Gentamicin

(20.1 mm)

None

2 mg/mL

375 μg/mL

 [14]

 0.2 mg/disc

 Agar well diffusion

 Disc diffusion method

 Broth dilution assay

 Broth dilution assay

 Broth dilution assay

 Agar diffusion method

 Inhibition zone

 Inhibition zone

 MIC

 MIC

 MIC

 Inhibition zone, MIC

 Penicillin

None Cloramphenicol

None Erythromicin

Cefixime 1.0 μM

 1.0 μM.

 (0.063 μM)

 No information

S, S/2

26 mg/mL 1500–2000 μg/mL

1500–2000 μg/mL

1 mg/mL 500–2000 μg/mL 500–2000 μg/mL

0.5–3.0 mg/disc

 8.5–13.5 mm

 98.1–100%

 6.8–16.5 mm

 [45]

 [24] [24]

 0–12 mm

 5.1–97.9%

>1 mg/mL

[22]

[22]

[38]

Erythromycin

 50 μg/well

 40 μg No information

 No activity

 5.0 μM No activity No activity

 [40]

 [8]

 [22] [13]

 Paper disc diffusion method Inhibition zone

Bioassay

Disc diffusion method Agar well diffusion, agar

tube dilution

Agar well diffusion

Broth dilution assay Disc diffusion method

 Inhibition zone

 MIC

 Inhibition zone

 Tetracyclin

(17 mm)

 100 μg/mL

 None Tetracyclin

 100 μg/mL (75%)

 50 mg/mL 50 mg/mL

 Inhibition zone No information

 No information

 No information

Results expresion

 Positive control

Active

No information No information

120 μg/mL

4.0–11.0 mm

0–76% 9–18 mm

16 mm

[9]

[4]

 [20]

[4]

concentration

 Main results

 11–21 mm

 Inhibition

 Reference

282 Herbal Medicine

[24]

[44]


Table 1. Principal types of bioassays carried out to determine the antimicrobial activity of the genus Taraxacum and their respective results.

used as a preliminary check for antibacterial activity prior to more detailed studies. In the agar well test diffusion method, the extract is deposited into wells cut into the agar and can be used as a screening method when large numbers of extracts or large numbers of bacterial isolates are to be screened. In the agar dilution method, a known concentration of the extract is mixed with the agar prior to strain inoculation. In some cases, the inoculated plates or tubes are exposed to UV light to screen the presence of light-sensitizing photochemicals. In the broth dilution method, different techniques exist for determining the end-point, such as an optical density measurement or the enumeration of colonies by viable count. Antimicrobial activity can also be analyzed by a spore germination assay in broth or on glass slides. In situ antifungal activity can be achieved by electron microscopy techniques such as scanning and transmission,

Direct tissue inoculation is the least used testing method, probably due to the inherent characteristics of the substrate (fruits, vegetables, etc.) that can affect the final results and the standardized laboratory conditions needed for proper result comparisons. Authors also indicate certain restrictions regarding the use of a specific technique. For instance, diffusion techniques seem to be inadequate for non-polar extracts, although many reports with these techniques have been published. Furthermore, when only a small amount of sample is available, diffusion techniques can be considered more appropriate [3]. The disc diffusion method is quick and easy but has several serious shortcomings, such as false positives and negative results due to poor test substance solubility and diffusion through the semi-solid nutritive medium [1].

The agar diffusion and microdilution broth methods are the two most common techniques for determining the antimicrobial activities of Taraxacum extracts, but the results are not always reproducible; factors, such as the volume and concentration of the extract placed on the paper disc and the solvent used, vary considerably between studies. When results are compared, the different sensitivities of the assays make antimicrobial activity highly dependent on the selection of the proper test. For example, aqueous fractions of T. officinale showed no activity in the disc diffusion test but moderate toxicity against E. coli and B. subtilis in the broth dilution test [4]. Considering this issue, a list of the bioassays used for testing Taraxacum extracts against

When comparing Taraxacum extracts to commercial antibiotics, C. jejuni adhesion was controlled by a Taraxacum extract with an IC50 value of 2.7 mg/mL, slightly less compared to the

Gram positive and Gram negative bacteria, respectively [13]. The MIC value of 1.0 mg/mL for M. luteus was similar for a methanolic extract and for erythromycin and cefixime, but considerably lower than the MIC value of 12.5 mg/mL obtained for V. cholera [8]. In the same work,

MIC values of 0.004 mg/mL, similar to chloramphenicol with MIC values of 0.001


.

*Taraxacum* Genus: Extract Experimental Approaches http://dx.doi.org/10.5772/intechopen.72849 285

–0.8

–0.06 mg/mL

μg/mL for different

–84%, relatively lower

every strain identified, including the main results, is presented in Table 1

2. Taraxacum extracts versus commercial antibiotics

but considerably lower than amphotericin B with MIC values of 0.4

the inhibition percentage for Aspergillus spp. and Rhizoctonia spp. was 37

0

than terbinafine at 12 mg/mL and 100% inhibition.

3.4 mg/mL obtained with 3

as well as by confocal laser scanning microscopy [2].

used as a preliminary check for antibacterial activity prior to more detailed studies. In the agar well test diffusion method, the extract is deposited into wells cut into the agar and can be used as a screening method when large numbers of extracts or large numbers of bacterial isolates are to be screened. In the agar dilution method, a known concentration of the extract is mixed with the agar prior to strain inoculation. In some cases, the inoculated plates or tubes are exposed to UV light to screen the presence of light-sensitizing photochemicals. In the broth dilution method, different techniques exist for determining the end-point, such as an optical density measurement or the enumeration of colonies by viable count. Antimicrobial activity can also be analyzed by a spore germination assay in broth or on glass slides. In situ antifungal activity can be achieved by electron microscopy techniques such as scanning and transmission, as well as by confocal laser scanning microscopy [2].

Direct tissue inoculation is the least used testing method, probably due to the inherent characteristics of the substrate (fruits, vegetables, etc.) that can affect the final results and the standardized laboratory conditions needed for proper result comparisons. Authors also indicate certain restrictions regarding the use of a specific technique. For instance, diffusion techniques seem to be inadequate for non-polar extracts, although many reports with these techniques have been published. Furthermore, when only a small amount of sample is available, diffusion techniques can be considered more appropriate [3]. The disc diffusion method is quick and easy but has several serious shortcomings, such as false positives and negative results due to poor test substance solubility and diffusion through the semi-solid nutritive medium [1].

The agar diffusion and microdilution broth methods are the two most common techniques for determining the antimicrobial activities of Taraxacum extracts, but the results are not always reproducible; factors, such as the volume and concentration of the extract placed on the paper disc and the solvent used, vary considerably between studies. When results are compared, the different sensitivities of the assays make antimicrobial activity highly dependent on the selection of the proper test. For example, aqueous fractions of T. officinale showed no activity in the disc diffusion test but moderate toxicity against E. coli and B. subtilis in the broth dilution test [4]. Considering this issue, a list of the bioassays used for testing Taraxacum extracts against every strain identified, including the main results, is presented in Table 1.
