Medicine Newbie: Liver Function

Thursday, 17 October 2013

Liver Function

1. Liver Functions

The liver is the biggest organ in the body. It serves many functions including:

Detoxifying drugs and toxins
Albumin synthesis
Burn fats via beta-oxidation
Synthesis of lipoproteins (VLDL and HDL)
Conjugation of bilirubin
Source of antioxidant enzymes (SOD, GSH)
Source of lipooxygenases

The liver is the primary organ for detoxification of drugs and toxins. Many toxins are either free radicals, or encourage free radical production and may subsequently interfere with the liver's defenses against free radicals

The extract also increases the liver's content of the antioxidant enzyme glutathione (GSH) by ~35%, and increases the levels of the body's major antioxidant enzyme, superoxide dismutase (SOD).

Lipoxygenase acts upon polyunsaturated fatty acids (PUFA) to produce pro-inflammatory compounds called leukotrienes, which cause damage to liver cell membranes (hepatocyte plasma membrane).

2. Liver Dysfunction

What happens when the liver can't function properly? A lot of things go wrong and can be detected or noted when the liver can't function properly.

The liver enzymes (ALT and AST) become elevated (high values are noted in blood tests).
When the liver can't burn its own fat contents, fat accumulates in the liver cells (hepatocytes). So the hepatocytes become laden with fat - these show up as a shiny organ in abdominal ultrasound.
The liver can't manufacture sufficient albumin (low albumin levels appear in blood). When the albumin levels are very low, plasma (water) moves out of blood vessels and enters interstitial space, filling up the space between cells, giving rise to edema. We see swollen feet when the patient sits for too long or stands for long hours.
If the liver cannot conjugate bilirubin, then the liver gets filled with bilirubin which may then regurgitate into the sinuses and back into the blood circulation. Bilirubin is yellow. So excess bilirubin in blood will make the white part of the eye (sclarae) become yellow (jaundice) and the skin changes to yellow colour tones. Of course we can't see this colour change in Malays or Indians with dark skin tones.
Of course when the liver can't function properly, the patient appears tired or fatigued; can't move much or do much work; rests, sits or sleeps most of the time.
If the liver is enlarged, then the belly becomes round and looks distended (pot belly), which can be a discomfort.
When the liver is not functioning properly, fat accumulates in the body, and the patient gets heavier and heavier within a short time, eg, gains 10 kg within a year.

3. Remedies for the Liver

Herbal preps are aimed at liver regeneration and bile solubility. Two known herbal preps are Jetepar (for hepatitis) and Milk Thistle (for fatty liver).

1. Jetepar

This is an Indian herbal preparation. I was prescribed this for hepatitis A/C infection following consumption of ais batu cendol by the roadside in Kota Bharu. It can only be prescribed by medical specialists (doktor pakar) but not medical doctors (MOs). In my case, the Campus Director (a medical specialist) prescribed it for me. I recovered.

Update (22 October 2013):
From Klinik Staf HUSM. I enquired about Jetepar. Jetepar has been discontinued to be prescribed by HUSM doctors since it does not do much to treat liver problems. Jetepar is a liver tonic. I don't have the details of the manufacturer at this point.

2. Milk Thistle

a) Extracts of milk thistle

Milk thistle (Silibanum marianum) extracts have been used since the ancient Greek doctors, some 2000 years ago. Research is focused on liver function, bile production, improved bile solubility, decreased gallstone formation, and improved digestion. Research has shown that milk thistle extracts also significantly enhance cellular immune biomarkers.

b) Silymarin

An extract of the sap is silymarin. Silymarin improves liver regeneration even though the liver (by itself) is capable of extensive self-regeneration.

What is silymarin?

Silymarin refers to three active flavonoid components of milk thistle: silybin, silydianin and silychristin.
Silymarin neutralizes toxins, prevents hepatotoxicity, and improves liver function.
As a potent antioxidant, silymarin intervenes in free radical generation and protects against many reactive oxygen species.
In some measurement systems, silymarin is ten times more effective than vitamin E in preventing unwanted oxidation.
Silymarin also modulates the actions of lipoxygenase in the liver.
Silymarin is active against all of these assaults upon liver cell integrity and function.
Silymarin therefore has direct and indirect antioxidant benefits by elevating the body's own defenses.
Silymarin can markedly increase the liver's ability to replace damaged cells.
Silymarin stimulates protein synthesis in the liver.
Silymarin does not encourage malignant liver cell growth.
Silymarin has protective properties to the kidneys as it has in the liver.
Silymarin is not soluble in water; alcohol was used to dissolve it for research studies (alcoholic tinctures). Today's preps use water, but are made highly concentrated.