DAO enzyme and histamine

[Guest guest]

I think someone should look into using a supplement of Diamine oxidase (DAO) in

some cases of autism. The DAO enzyme is available commercially for the purpose

of reducing histamine in the intestines. And there are several things that

suggest the DAO enzyme might be off in autism. Here are the things that make me

think that measuring and using the DAO enzyme may be worth considering..

The DAO enzyme breaks down extracellular histamine in the body. In the

intestines, this reduces the reaction you will get from high histamine foods.

There is a genetic variation of the DAO gene associated with autism. [1]

Mercury may lower DAO activity. [2]

Diamine oxidase (DAO) breaks down histamine found outside of cells in the

intestines, nasal passages, and other parts of the body. Presently, Dirk Budka

is conducting clinical trials of DAO's effectiveness in treating

gastrointestinal problems. The medication he uses is called Histrelief DAO. It

contains the enzyme DAO along with a little B6 and quercetin. There is another

DAO product available over-the-counter called Histame, but it is not as strong

as Histrelief. Dirk Budka measures levels of DAO before and after starting

treatment.

The DAO enzyme also appears in the brain, where it is extremely important, but

DAO doesn't cross the blood brain barrier. So, ingesting DAO wouldn't directly

affect the brain function. However, since DAO would affect histamine, and other

amines / aminos, I assume that using DAO would have an affect on the brain.

Therefore, one should proceed with caution. However, since histamine increases

the blood brain permeability, maybe something good can come of reducing

histamine levels in the body --- at least for those whose levels are too high.

References:

Association of the DAO and DAOA gene polymorphisms with autism spectrum

disorders in boys in Korea: A preliminary study

Seockhoon Chung, Jin Pyo Hong, Hanik K. Yoo

Received 23 May 2006; received in revised form 16 August 2006; accepted 3

February 2007.

Abstract

We examined the association of autism spectrum disorders (ASD) with

polymorphisms in the DAO and DAOA genes. The sample comprised 57 children with

ASD, 47 complete trios, and 83 healthy controls in Korea. Although the

transmission disequilibrium test showed no association, a population-based

case-control study showed significant associations between the rs3918346 and

rs3825251 SNPs of the DAO gene and boys with ASD.

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The role of L-arginine in toxic liver failure: interrelation of arginase,

polyamine catabolic enzymes and nitric oxide synthase

Journal

Amino Acids

Issue

Volume 32, Number 1 / January, 2007

Pages

127-131

SpringerLink Date

Sunday, May 14, 2006

J. Nikolic1, I. Stojanovic1, R. Pavlovic2, D. Sokolovic1, G. Bjelakovic1 and S.

Beninati3

Received: 17 November 2005 Accepted: 2 March 2006 Published online: 15 May

2006

Summary. The existing interrelation in metabolic pathways of L-arginine to

polyamines, nitric oxide (NO) and urea synthesis could be affected in sepsis,

inflammation, intoxication and other conditions. The role of polyamines and NO

in the toxic effect of mercury chloride on rat liver function was studied.

Administration of mercury chloride for 24?h led to significantly elevated plasma

activities of Alanine transaminase (ALT) and Aspartate transaminase (AST).

Malondyaldehyde (MDA) levels were unaffected (p > 0.05) and arginase activity

was significantly decreased (p < 0.05) while nitrate/nitrite production was

significantly elevated (p < 0.001) in liver tissue. Polyamine oxidase (PAO) and

diamine oxidase (DAO) activities, enzymes involved in catabolism of polyamines,

were decreased. L-arginine supplementation to intoxicated rats potentiated the

effect of mercury chloride on NO production and it was ineffective on arginase

activity.

Results obtained in this study show that mercury chloride-induced toxicity leads

to abnormally high levels of ALT and AST that may indicate liver damage with the

involvement of polyamine catabolic enzymes and NO.

Keywords: Arginase - Nitric oxide synthase - Polyamine oxidase - Diamine oxidase

- Mercury chloride - Liver