04 June 2010

Briefly on Detoxification Systems

Every day we are exposed to toxins, or xenobiotics, that are found in our food, water and environment. The body also makes toxins within itself. These all must be either stored such as in muscle or fat or they are  detoxified and eliminated via the feces or urine.

The body's main detoxification organ is the liver, but can also happen in the intestine and other organs. The detoxification systems handle a wide range of compounds mainly by two steps: phase I and phase II detoxification. 

Phase I detoxification is a reaction that entails functionalization of the compound, breaking it down. The major P450 enzymes are generally involved in phase I detoxification. Most major drugs and exogenous toxins are metabolized this way. At times the product of phase I detoxification can be more harmful than the original product.  

Phase II detoxification is a second reaction that generally follows phase I detoxification. It entails transforming a phase I reactant through conjugation (typically to an amino acid, such as in glucuronidation or sulfation) to become water soluble. When it's water-soluble, the toxin can be excreted in the urine. 

Although the phases of detoxification are not yet well understood, it is clear through observational studies that there are a variety of factors that can inhibit or induce detoxification. An inducer of detoxification can be a a toxin itself or a compound in the diet. 

In a typical detoxification support plan, a nutritionist may suggest various nutrients to support or upregulate phase I cytochrome P450 enzymes and phase II conjugation pathways. 

The plan would generally seek to increase glutathione levels in the body such as with n-acetyl cysteine or cysteine or spare glutathione such as with silymarin. 

The plan may also support detoxification in other ways by increasing antioxidant status with coenzyme Q10, vitamin A, vitamin C, or selenium. Or, it may provide B vitamins to act as co-factors for enzymes.  



No comments: