1 / 11

ACROPOLIS. Overview on in vitro tests for craniofacial malformations.

ACROPOLIS. Overview on in vitro tests for craniofacial malformations. Giavini E., Menegola E., Di Renzo F. Studies in vitro: postimplantation rat whole embryo culture. triadimefon 12.5-250 µM triadimenol 6.25-125 µM flusilazole 3.125-25 µM tebuconazole 31.25-500µM

cain-gibson
Download Presentation

ACROPOLIS. Overview on in vitro tests for craniofacial malformations.

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ACROPOLIS. Overview on in vitro tests for craniofacial malformations. Giavini E., Menegola E., Di Renzo F.

  2. Studies in vitro: postimplantation rat whole embryo culture triadimefon12.5-250 µM triadimenol6.25-125 µM flusilazole 3.125-25 µM tebuconazole 31.25-500µM cyproconazole 15.625-250µM fluconazole62.5-500 µM triazole 5000 µM Medium: rat serum imazalil5-100 µM ketoconazole5-100 µM imidazole 1000 µM E9.5 rat 48/60h

  3. In vitro tested azoles: In vitro testedazoles triadimefon 25-250 µM triadimenol 12.5-125 µM flusilazole 6.25-25 µM cyproconazole 15.625-250µM fluconazole 125-500 µM tebuconazole 31.25-500µM imazalil 5-10-50-100 µM ketoconazole 5-10-50-100 µM Fusion and reduction of the 1° and 2° branchial arches In vivo tested azoles: Triadimefon, Ketoconazole, Cyproconazole Fluconazole, Itraconazole Craniofacial malformations Control Azoles Control Azoles

  4. Pathogenic pathway Normal Neural Crest cell migration Abnormal neural crest cell igration

  5. Control Triadimefon

  6. Azole inhibition

  7. Undirectevidencesthat RA isimplied in Azole-inducedCM: • The craniofacialmalformationsinducedbyazoles are similartothoseproducedbyexcessof RA; • The co-exposureofratembryosin vitro tosubteratogenicconcentrationsof RA and fluconazoleresulted in malformations; • The co-exposureto a teratogenicconcentrationoffluconazole and tocitral (inhibitorof RA synthesis) resulted in a reductionofmalformations; • The exposuretoembryostoazolefungicidesproducedanincreasedexpressionof Cyp26. Conclusion: the azoles induce CM with the same pathway and the same mechanism of action.

  8. The testedazolebelongto a chemical family with: • similarchemicalstructure; • samemechanismofpesticideaction; • same target oftoxic (teratogenic) effects; • samepathogenicpathway; • samemechanismoftoxicologicalaction (?) • Cumulative assessmentgroupforteratogenesis

  9. Fig. 1. Percentage of branchial arch abnormalities (partial or total fusion between I and II branchial arches) and plurimalformed embryos in controls and in embryos exposed in vitro to tebuconazole or cyproconazole.

  10. Fig. 2. Percentage of branchial arch abnormalities in controls and in embryos exposed in vitro to MIX2 and MIX3. Mix2: triadimefon + imazlil (NOEL concentrations) Mix3: triadimefon+imazalil+fluconazole (NOEL concentrations)

  11. Future perspectives • Next 6 months: • To test in vitro some otherazoles (e.g. propiconazole and prochloraz) • In vitro studyofteratogeniceffectsofmixtures: • a) evaluationof Mix –dependenceusing a differentnumberofazoles • b) toverify the best dose approach (benchmark dose, fractionsofNOELs etc.) • c) identificationofmolecularbiomarkersofembryotoxicity (Krox20, Tgfβ, Cyp26) • Nextyears: • Effectsofmixturesofazolesadministeredtopregnantmice and rats • a) fetalmorphologicalabnormalities (in particularcraniofacial); • b) confirmationofvalidityofbiomarkers in in vivo exposure.

More Related