What detoxification processes occur in the liver?

The liver detoxifies the body by metabolising drugs, neutralising harmful chemicals, and eliminating waste products.

The liver is the primary organ responsible for detoxification in the body. It performs this function through a two-phase process: Phase I (functionalisation) and Phase II (conjugation). In Phase I, the liver uses enzymes, primarily from the cytochrome P450 family, to metabolise drugs and other foreign substances. This process often involves oxidation, reduction, or hydrolysis reactions, which make these substances more polar and therefore more soluble in water. However, this phase can sometimes produce intermediates that are more toxic than the original substance.

In Phase II, these intermediates are further processed through conjugation reactions. These reactions attach small molecules to the intermediates, making them even more water-soluble. The most common conjugation reactions involve glucuronidation, sulfation, and glutathione conjugation. These reactions make the substances more easily excretable by the kidneys.

The liver also plays a crucial role in neutralising harmful chemicals. It does this by converting ammonia, a toxic byproduct of protein metabolism, into urea, which is less harmful and can be excreted in urine. Additionally, the liver breaks down and recycles haemoglobin, creating bilirubin as a byproduct. Bilirubin is then conjugated with glucuronic acid and excreted in bile.

Furthermore, the liver eliminates waste products from the body. It does this by producing bile, a fluid that aids in the digestion and absorption of fats. Bile also serves as a vehicle for the excretion of waste products such as bilirubin, excess cholesterol, and drugs.

In summary, the liver's detoxification processes involve the metabolism of drugs and other foreign substances, the neutralisation of harmful chemicals, and the elimination of waste products. These processes are essential for maintaining the body's overall health and homeostasis.