Re: Detoxifying acetaldahyde

Mucus, the slippery gelatinous secretion covering epithelial cells in the respiratory, gastrointestinal, urogenital, visual, and auditory systems of the body, can be considered to be a part of the innate immune system. One of its primary functions is protection against infectious agents such as fungi, bacteria, and viruses. In areas exposed to the external environment such as the airways it also traps foreign particles and expels them via continuous flow towards the digestive tract where they can be excreted. Sneezing and coughing are secondary more violent forms of expulsive processes that occur when the normal flow of mucus is interrupted or insufficient to deal with a perceived threat. Mucus has lubricating and protective properties as well that are utilized in the digestive tract to assist the passage of food down the esophagus and to shield the lining of the stomach from the highly acidic environment that occurs during digestion.

Ear infections occur when the movement of mucus through the Eustachian tube draining the middle ear is impaired sufficiently to allow trapped fluid to become a breeding ground for infectious agents. The smaller size and horizontal positioning of the Eustachian tube in children is such that they are more prone to infection in this region.

Since continuous movement of mucus is vital to its function there are body organelles that are found in the areas where it abounds to assure that this occurs. Motile cilia are specialized protuberances from cells adjacent to mucus-secreting cells that beat in an asymmetric but coordinated waves to accomplish this movement.




Cilia are about 10 micrometers in length with a beating frequency that provides continuous unidirectional movement of the slime blanket of mucus above them at about 10 mm per minute. Any impairment of this motion can result in increased occurrence of infection in the regions where this mucociliary transport system is an integral part.

A mature ciliated cell may have up to 200 cilia. Each cilium is composed a concentric cylinder of microtubule proteins around a central bridge with fibrous ridges and radial spokes that provide structural stability. Within this sheath are many tiny nanomachine protein motors called dyneins that synchronously slide the microtubule structures against one another until the overall cellular protuberance is stretched and bent first in one direction and then another with the result being a form of repeating whiplash motion.




The dynein motors are protein structures that actually physically walk along tracks in the microtubulues (think of a back-packer hiking along railroad tracks stepping from one railroad tie to the next). The motors are powered by the conversion of chemical energy stored in ATP (Adenosine Triphosphate) to mechanical energy (protein "leg" movement) via the enzyme dynein ATPase which converts ATP to ADP (Adenosine Diphosphate), releasing energy with the dephosphorylation.




Mucociliary transport systems in the respiratory tract (lower and upper, sinuses, Eustachian tube, middle ear) and fallopian tubes are vital to the well being of these regions but also provide suitable habitats for onboard yeast colonization. Budding yeast cells range in size from 5 to 10 micrometers in diameter. A motile cilium is about 10 micrometers in length. This means that budding yeast cells can anchor themselves quite nicely into the inter-cilia gaps underneath the mucus layer. Although the composition of mucus spans a wide variety of substances including enzymes, immunoglobulins, inorganic salts, and proteins, a major constituent is mucin composed of glycoproteins that can provide a food source for yeast metabolism.

The yeast Candida Albicans has a nasty habit of interfering with host mechanisms designed to eradicate it -- evolution has tuned it well in this regard with the mucociliary transport system being no exception to the rule. The mucociliary environment is ideal from a yeast perspective except for one thing...the continuous movement which is trying to clear it from the area, thus disrupting its ability to form stable colonies. However, acetaldehyde emitted from the budding yeast phase [1] can inhibit dynein ATPase [2], form protein adducts with the microtubule tracks that the dynein motors traverse [3] and slow down, perhaps even stop, the beating of the cilia that propel the mucus!

It has been demonstrated that Antibiotic therapy is a major risk factor for increased levels of yeast colonization [4] and also that yeast is present in the region of the middle ear [5]. Since yeast-emitted acetaldehyde can interfere with the mucociliary transport system responsible for draining and clearing the Eustachian tube and since the efficient functioning of this process is essential for keeping this region clear from all types of pathogens, this provides a connection between Antibiotic therapy, yeast-released acetaldehyde, and persistent recurrent ear infections, especially in children where the size and orientation of this channel render it more vulnerable to infection. If the rising yeast levels are not addressed concurrently with the Antibiotic therapy targeting the ear infection, then a vicious cycle of increasing acetaldehyde mucociliary transport interference is in place that will also increase the probability of reinfection.

[1] Truss C.O., "Metabolic abnormalities in patients with chronic candidiasis: the acetaldehyde hypothesis.", Orthomol Psychiatr 1984; 13:66–93.
http://orthomolecular.org/library/jom/1984/pdf/1984-v13n02-p066.pdf

[2] Sisson JH et al.,"Acetaldehyde-mediated cilia dysfunction in bovine bronchial epithelial cells.", Am J Physiol. 1991 Feb;260(2 Pt 1):L29-36.
http://www.ncbi.nlm.nih.gov/pubmed/1825452

[3] Tuma DJ et al., "Acetaldehyde and microtubules.", Ann N Y Acad Sci. 1991;625:786-92.
http://www.ncbi.nlm.nih.gov/pubmed/2058934

[4] Wey SB et al., "Risk factors for hospital-acquired candidemia. A matched case-control study.", Arch Intern Med. 1989 Oct;149(10):2349-53.
http://www.ncbi.nlm.nih.gov/pubmed/2802900

[5] Cohen SR et al., "Otitic candiadiasis in children: an evaluation of the problem and effectiveness of ketoconazole in 10 patients.", Ann Otol Rhinol Laryngol. 1990 Jun;99(6 Pt 1):427-31.
http://www.ncbi.nlm.nih.gov/pubmed/2350126