Protection of garlic against carcinogen genotoxicity
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

Protection of garlic against carcinogen genotoxicity PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on
  • Presentation posted in: General

Protection of garlic against carcinogen genotoxicity. Anne-Marie Le Bon , Christine Belloir, Varsha Singh. Milestones :.  In vitro evaluation of the antigenotoxic properties of garlic compounds in HepG2 cells

Download Presentation

Protection of garlic against carcinogen genotoxicity

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Protection of garlic against carcinogen genotoxicity

Protection of garlic against carcinogen genotoxicity

Anne-Marie Le Bon , Christine Belloir, Varsha Singh

Milestones :

 In vitro evaluation of the antigenotoxic properties of garlic compounds in HepG2 cells

 Evaluation of the antigenotoxic properties of garlic extracts in tissues of rat


Protection of garlic against carcinogen genotoxicity

The studied molecules were :

DADS (diallyl sulfide)

DADSO (allicin)

SAC (S-allyl cystein)

AM (allyl mercaptan)

Range : 5 to 100 µM

Genotoxic compound

Broken DNA = comet

Undamaged DNA

In vitro evaluation of antigenotoxic properties of garlic compounds

in HepG2 cells

Objectives : to assess if garlic compounds prevent DNA alterations induced by mutagenic compounds in a human cell line, HepG2 cells.

DNA alterations were measured using the comet test.


Protection of garlic against carcinogen genotoxicity

Garlic compound +mutagen

PROTOCOLS

 Pre-treatment studies : cells are treated firstwith the garlic compound and

then with the pro-mutagen

Garlic compound

Pro-mutagen

Hypothesis : inhibition or induction of xenobiotic metabolizing enzymes

Mutagens : benzopyrene (BaP)

aflatoxin B1 (AFB1)

nitrosodimethylamine (NDMA)

P450 1A

P450 1A, 3A

P450 2E1

 Co-treatment studies : cells are treated with both the garlic compound and

the direct-acting mutagen at the same time

Hypothesis : scavenging of mutagenic compounds

Mutagens : hydrogen peroxide (H2O2)

methyl methane sulfonate (MMS)

4-nitrosoquinoline oxide (4-NQO)


Protection of garlic against carcinogen genotoxicity

DADS

DADSO

AM

SAC

BaP

()

AFB1

n.d.

n.d.

n.d.

n.d.

NDMA

RESULTS

Pre-treatment studies

 : inhibition of the genotoxicity

() : slight inhibition

- : no effect

n.d. : not determined


Protection of garlic against carcinogen genotoxicity

SAC

DADS

DADSO

AM

()

H2O2

MMS

()

()

4-NQO

RESULTS

Co-treatment studies

 : inhibition of the genotoxicity

() : slight inhibition

() :slight increase

- : no effect


Protection of garlic against carcinogen genotoxicity

120

100

80

% of DNA alterations

60

40

20

0

H202

5 µM

25 µM

50 µM

100µM

RESULTS

Effects of S-allylcystein on H2O2 genotoxicity in HepG2 cells


Protection of garlic against carcinogen genotoxicity

CONCLUSIONS

 Garlic sulfur compounds prevent genotoxicity induced by direct-

and indirect-acting compounds

 DADS and AM can act throught both mechanisms : modulation of EMX

and scavenging

DADS is more efficient than AM

 DADS and SAC act rather by scavenging genotoxic compounds

 The metabolites of DADS, DADSO and AM, could be the effective

compounds in vivo


Protection of garlic against carcinogen genotoxicity

In vivo evaluation of antigenotoxic properties of garlic extracts in rats

Objectives : to assess if garlic ingestion prevent DNA alterations induced by

genotoxic compounds in rat liver

Studied material :

Garlic powder «  0 kg/ha SO4 »

Garlic powder «  100 kg/ha SO4  »

Garlic powder «  200 kg/ha SO4  »


Protection of garlic against carcinogen genotoxicity

5

6

7

4

5 %garlic powder

PROTOCOL

intraperitoneal injection of

a genotoxic agent : AFB1

NDMA

(4 hours before sacrifice)

60 Wistar male rats

weeks

Sacrifice

Group C : control diet

SA : Garlic 0 kg/ha SO4

SB : Garlic 100 kg/ha

SC : Garlic 200 kg/ha

Liver

DNA damage

evaluation

(comet test)


Protection of garlic against carcinogen genotoxicity

7

6

5

*

4

*

DNA damage (OTM)

*

3

2

1

0

C

SA

SB

SC

C

SA

SB

SC

C

SA

SB

SC

+

NDMA

+

AFB1

(control)

RESULTS

Effects of garlic ingestion on DNA damage in rat liver

(5 rats / group)

*: significantly different from the group C (Dunnett ’s test, p < 0.05)


Protection of garlic against carcinogen genotoxicity

CONCLUSIONS

 Garlic powders are not genotoxic by themselves.

 Garlic powder ingestion reduce liver DNA damage induced by AFB1.

No statistical difference was observed between fertilisation levels.

Mechanims of action : induction of CYP 1A and/or GST ?

 A slight reduction of NDMA genotoxicity was observed but this effect

was not significant.

Mechanims of action : inhibition of CYP 2E1 ?

 To be done shortly : colon study (preliminary studies in progress)


Wp 6 cancer general conclusion

WP 6 Cancer : General conclusion

Metabolism of DADS almost elucidated, proposition of a scheme of the metabolic pathway.

 In vivo after garlic powder administration to rats, we observed a modulation of hepatic enzymes involved in carcinogen activation or detoxication.

Sulfur compounds prevent the genotoxicity of carcinogens in a human cell-line. They act by scavenging ultimate metabolites and/or by modulating the activity of carcinogen metabolizing enzymes


Wp 6 cancer deliverables

WP 6 Cancer : Deliverables

DH. 8:In vitro metabolism of diallyl disulfide, ajoene and allicin (P12) : done, publication in progress

DH. 9: In vitro effects of sulphur compounds on human P450 iso-enzymes (P12) : done

DH. 10: In vitro evaluation of the anti-genotoxic properties of garlic compounds in HepG2 cells (P12) : done

DH.13: In vivo metabolism of diallyl disulfide (P12) : done, publication submitted

DH. 14: Effects of garlic extracts on carcinogen-metabolising enzymes (P12) : done, publication in progress

DH. 15: In vivo evaluation of the antigenotoxic properties of garlic extracts in rats (P12) : in progress


  • Login