Evaluation of genotoxicity related to oral methylene blue chromoendoscopy

Alessandro Repici; Camilla Ciscato; Michael Wallace; Prateek Sharma; Andrea Anderloni; Silvia Carrara; Milena Di Leo; Cesare Hassan

doi:10.1055/a-0630-1004

Evaluation of genotoxicity related to oral methylene blue chromoendoscopy

Alessandro Repici, Camilla Ciscato, Michael Wallace, Prateek Sharma, Andrea Anderloni, Silvia Carrara, Milena Di Leo, Cesare Hassan

Gastroenterology and Hepatology

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

Background -An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy. Methods -This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200mg MB-MMX added to their bowel prep.Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens. Results -Ten patients were included in the study. The mean expression of γH2AX ± 95% confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively (P =0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred. Conclusions -An oral dose of 200mg of MB-MMX did not result in any detectable DNA damage.

Original language	English (US)
Pages (from-to)	1027-1032
Number of pages	6
Journal	Endoscopy
Volume	50
Issue number	10
DOIs	https://doi.org/10.1055/a-0630-1004
State	Published - Jun 15 2018

ASJC Scopus subject areas

Gastroenterology

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10.1055/a-0630-1004

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title = "Evaluation of genotoxicity related to oral methylene blue chromoendoscopy",

abstract = "Background -An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy. Methods -This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200mg MB-MMX added to their bowel prep.Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens. Results -Ten patients were included in the study. The mean expression of γH2AX ± 95% confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively (P =0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred. Conclusions -An oral dose of 200mg of MB-MMX did not result in any detectable DNA damage.",

author = "Alessandro Repici and Camilla Ciscato and Michael Wallace and Prateek Sharma and Andrea Anderloni and Silvia Carrara and {Di Leo}, Milena and Cesare Hassan",

note = "Funding Information: The authors feel indebted to and want to express their gratitude to Mara Gerloni, Cari Rosette, and Frances Agan from Bellatrix Company in San Diego for their support in providing extensive DNA test and result interpretation and validation. Publisher Copyright: {\textcopyright} Georg Thieme Verlag KG Stuttgart · New York. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",

year = "2018",

month = jun,

day = "15",

doi = "10.1055/a-0630-1004",

language = "English (US)",

volume = "50",

pages = "1027--1032",

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T1 - Evaluation of genotoxicity related to oral methylene blue chromoendoscopy

AU - Repici, Alessandro

AU - Ciscato, Camilla

AU - Wallace, Michael

AU - Sharma, Prateek

AU - Anderloni, Andrea

AU - Carrara, Silvia

AU - Di Leo, Milena

AU - Hassan, Cesare

N1 - Funding Information: The authors feel indebted to and want to express their gratitude to Mara Gerloni, Cari Rosette, and Frances Agan from Bellatrix Company in San Diego for their support in providing extensive DNA test and result interpretation and validation. Publisher Copyright: © Georg Thieme Verlag KG Stuttgart · New York. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.

PY - 2018/6/15

Y1 - 2018/6/15

N2 - Background -An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy. Methods -This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200mg MB-MMX added to their bowel prep.Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens. Results -Ten patients were included in the study. The mean expression of γH2AX ± 95% confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively (P =0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred. Conclusions -An oral dose of 200mg of MB-MMX did not result in any detectable DNA damage.

AB - Background -An oral formulation of methylene blue with colonic delivery (MB-MMX) has been developed to increase detection of colorectal polys during colonoscopy. Traditionally, there have been safety concerns regarding DNA damage when methylene blue is exposed to white light. The aim of this study was to evaluate DNA damage in colonic mucosa after MB-MMX chromoendoscopy. Methods -This was an open-label phase II safety study to assess for genotoxicity on colorectal biopsies of patients undergoing two sequential colonoscopies before and after an oral dose of 200mg MB-MMX added to their bowel prep.Analysis of a biomarker of double-stranded DNA breaks, γH2AX, was performed on biopsy specimens. Results -Ten patients were included in the study. The mean expression of γH2AX ± 95% confidence intervals of the 50 biopsies before and after MB-MMX administration were 0.58 ± 0.08 and 0.62 ± 0.09, respectively (P =0.24). None of the analyzed samples showed excess positive γH2AX expression, confirming the absence of DNA damage on biopsies after methylene blue exposure. No deaths or serious adverse events occurred. Conclusions -An oral dose of 200mg of MB-MMX did not result in any detectable DNA damage.

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JO - Endoscopy

JF - Endoscopy

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ER -

Evaluation of genotoxicity related to oral methylene blue chromoendoscopy

Abstract

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