Re: Bile acids in esophageal cancer?

[Guest guest]

Hi All,

In the below,

http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0210 & L=crsociety & P=R56313 & X\

=3C3DD37AEF7B57A97A & Y=old542000

represented a post describing the below.

Hi All,

I found a Lancet Oncology review on bile acids and risk of colon

cancer. I attached it and a paper it referred to. Data on grain fibers and

colon cancer remains uncertain, but suggestive of preventing the

carcinogenesis. The referred to attached paper suggested wheat bran works

via lowering bile acids.

In the second attachment, for which the PDF is available, it referred to a

third attachment on phytates, caloric restriction and colon carcinogenesis.

It seems like most of the messages on phytates are negative.

The role of the role of green leafy vegetables versus grain for goodies

essential

for CRers to consume RDAs comes into context.

THE LANCET Oncology 3, No. 10, 01 October 2002

Bile acids, oxidative stress, and colon cancer

Orellana

New research by German scientists suggests that bile acids contribute

to colon carcinogenesis by inducing oxidative stress and up-regulating

an enzyme called thioredoxin reductase; a key component in

antioxidant defence (Carcinogenesis 2002; 23: 1281-88).

Bile acids are always present in the gastrointestinal tract, but their

concentration varies according to diet and genetic factors. Various

trials have shown that eating food rich in fibre helps prevent colon

cancer. In part, this effect is due to a decrease in the concentration of

toxic bile acid in faecal matter (Am J Med 1999; 106: 32S-37S). The

consumption of diary products also has a protective effect against

colon cancer and has been shown to modulate bile acid production (Am

J Clin Nutr 1997; 66: 1277-82).

The researchers, led by Kullmann (University of Regensburg,

Germany), analysed the effect of different bile acids on human colon

carcinoma cell-lines. Using RNA-primed PCR, they found a threefold

increase in thioredoxin reductase mRNA after incubation with the

hydrophobic bile acid, deoxycolic acid (DCA). This correlates with a

previous study showing that the cytotoxicity of bile is linked to acid

hydrophobicity (J Lab Clin Med 1996; 127: 57-66).

They also analysed the increased oxidative stress caused by DCA by

labelling the cells with an oxidation indicator, dihydrorhodamine (DHR)

that fluoreses when in contact with reactive oxygen species such as

oxygen free radicals, hydrogen peroxide, or hydroxide ions.

Says Kullmann: " Thioredoxin reductase plays a decisive role in cellular

metabolism. Many cell functions are regulated through it, such as

apoptosis and the activity of a variety of intracellular redox-sensitive

proteins...it is very probable that it also plays a role in tumorigenesis.

We are now planning to block thioredoxin reductase to see what

happens with the [cell] membranes, [and discover] whether the

oxidative stress disappears. "

J Gores, from the Mayo Clinic, MN, USA, comments: " This study

significantly extends our knowledge on bile acid-induced gene

regulation, a key feature of these co-carcinogens. Previous studies

have shown that bile acids may signal through nuclear receptors,

activation of MAPK pathways via EGFR activation, and cytotoxicity

through death receptors. This study shows oxidative stress with its

carcinogenic implications is an additional signalling pathway for bile

acids. "

Carol Bernstein (University of Arizona, USA) adds: " These findings and

other reports may indicate that experiments should be undertaken

with animals, comparing cancer incidence when animals are fed a diet

with added bile acids plus antioxidants versus when animals are fed a diet with

added bile acids alone. "

Am J Med 1999 Jan 25;106(1A):32S-37S

Protective role of wheat bran fiber: data from marker trials.

Earnest DL, Einspahr JG, Alberts DS.

PMID: 10089113 [PubMed - indexed for MEDLINE]

9.Corpet,D.E., Tache,S. and Peiffer,G. (1997) Colon tumor promotion: =

is it a selective process? Effects of cholate, phytate and food =

restriction in rats on proliferation and apoptosis in normal and =

aberrant crypts. Cancer Lett., 114, 135-138.

Cancer Lett 1997 Mar 19;114(1-2):135-8

Colon tumor promotion: is it a selective process? Effects of cholate, =

phytate,

and food restriction in rats on proliferation and apoptosis in normal =

and

aberrant crypts.

Corpet DE, Tache S, Peiffer G.=20

PMID: 9103272

--- Al Pater <old542000@...> wrote:

> Hi All,

>

> CRers seem to generally have fewer difficulties with stomach acid reflux and

bile

> acid abnormalities.

>

> Previously, it had been suggested that bile acids may be implicated in colon

> cancer

> generation via a mechanism involving oxidative stress, in the post:

>

>

http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0210 & L=crsociety & P=R56313 & X\

=3C3DD37AEF7B57A97A & Y=old542000

Al Pater, PhD; email: old542000@...

____________________________________________________

Start your day with - make it your home page

http://www./r/hs

[Guest guest]

Hi All,

In the below,

http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0210 & L=crsociety & P=R56313 & X\

=3C3DD37AEF7B57A97A & Y=old542000

represented a post describing the below.

Hi All,

I found a Lancet Oncology review on bile acids and risk of colon

cancer. I attached it and a paper it referred to. Data on grain fibers and

colon cancer remains uncertain, but suggestive of preventing the

carcinogenesis. The referred to attached paper suggested wheat bran works

via lowering bile acids.

In the second attachment, for which the PDF is available, it referred to a

third attachment on phytates, caloric restriction and colon carcinogenesis.

It seems like most of the messages on phytates are negative.

The role of the role of green leafy vegetables versus grain for goodies

essential

for CRers to consume RDAs comes into context.

THE LANCET Oncology 3, No. 10, 01 October 2002

Bile acids, oxidative stress, and colon cancer

Orellana

New research by German scientists suggests that bile acids contribute

to colon carcinogenesis by inducing oxidative stress and up-regulating

an enzyme called thioredoxin reductase; a key component in

antioxidant defence (Carcinogenesis 2002; 23: 1281-88).

Bile acids are always present in the gastrointestinal tract, but their

concentration varies according to diet and genetic factors. Various

trials have shown that eating food rich in fibre helps prevent colon

cancer. In part, this effect is due to a decrease in the concentration of

toxic bile acid in faecal matter (Am J Med 1999; 106: 32S-37S). The

consumption of diary products also has a protective effect against

colon cancer and has been shown to modulate bile acid production (Am

J Clin Nutr 1997; 66: 1277-82).

The researchers, led by Kullmann (University of Regensburg,

Germany), analysed the effect of different bile acids on human colon

carcinoma cell-lines. Using RNA-primed PCR, they found a threefold

increase in thioredoxin reductase mRNA after incubation with the

hydrophobic bile acid, deoxycolic acid (DCA). This correlates with a

previous study showing that the cytotoxicity of bile is linked to acid

hydrophobicity (J Lab Clin Med 1996; 127: 57-66).

They also analysed the increased oxidative stress caused by DCA by

labelling the cells with an oxidation indicator, dihydrorhodamine (DHR)

that fluoreses when in contact with reactive oxygen species such as

oxygen free radicals, hydrogen peroxide, or hydroxide ions.

Says Kullmann: " Thioredoxin reductase plays a decisive role in cellular

metabolism. Many cell functions are regulated through it, such as

apoptosis and the activity of a variety of intracellular redox-sensitive

proteins...it is very probable that it also plays a role in tumorigenesis.

We are now planning to block thioredoxin reductase to see what

happens with the [cell] membranes, [and discover] whether the

oxidative stress disappears. "

J Gores, from the Mayo Clinic, MN, USA, comments: " This study

significantly extends our knowledge on bile acid-induced gene

regulation, a key feature of these co-carcinogens. Previous studies

have shown that bile acids may signal through nuclear receptors,

activation of MAPK pathways via EGFR activation, and cytotoxicity

through death receptors. This study shows oxidative stress with its

carcinogenic implications is an additional signalling pathway for bile

acids. "

Carol Bernstein (University of Arizona, USA) adds: " These findings and

other reports may indicate that experiments should be undertaken

with animals, comparing cancer incidence when animals are fed a diet

with added bile acids plus antioxidants versus when animals are fed a diet with

added bile acids alone. "

Am J Med 1999 Jan 25;106(1A):32S-37S

Protective role of wheat bran fiber: data from marker trials.

Earnest DL, Einspahr JG, Alberts DS.

PMID: 10089113 [PubMed - indexed for MEDLINE]

9.Corpet,D.E., Tache,S. and Peiffer,G. (1997) Colon tumor promotion: =

is it a selective process? Effects of cholate, phytate and food =

restriction in rats on proliferation and apoptosis in normal and =

aberrant crypts. Cancer Lett., 114, 135-138.

Cancer Lett 1997 Mar 19;114(1-2):135-8

Colon tumor promotion: is it a selective process? Effects of cholate, =

phytate,

and food restriction in rats on proliferation and apoptosis in normal =

and

aberrant crypts.

Corpet DE, Tache S, Peiffer G.=20

PMID: 9103272

--- Al Pater <old542000@...> wrote:

> Hi All,

>

> CRers seem to generally have fewer difficulties with stomach acid reflux and

bile

> acid abnormalities.

>

> Previously, it had been suggested that bile acids may be implicated in colon

> cancer

> generation via a mechanism involving oxidative stress, in the post:

>

>

http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0210 & L=crsociety & P=R56313 & X\

=3C3DD37AEF7B57A97A & Y=old542000

Al Pater, PhD; email: old542000@...

____________________________________________________

Start your day with - make it your home page

http://www./r/hs