- Ursodeoxycholic acid - formation
- Ursodeoxycholic acid - mechanism of action
- Ursodeoxycholic acid - routes of elimination and toxicity
- Ursodeoxycholic acid - medical indications
- Ursodeoxycholic acid - contraindications
- Ursodeoxycholic acid - side effects
Help the development of the site, sharing the article with friends!
Ursodeoxycholic acid is a secondary bile acid produced by the intestinal microbiota. It helps metabolize dietary fats by slowing the rate of cholesterol absorption in the intestine and accelerating the breakdown of cholesterol-containing micelles. Due to the hydrophilic properties and negligible toxicity of ursodeoxycholic acid compared to other bile acids, it has found application in medicine as a drug in the prevention and treatment of gallstone disease.
Ursodeoxycholic acid , also known asursodiol , is an organic chemical compound belonging to the group of secondary bile acids.
Contents:
- Ursodeoxycholic acid - formation
- Ursodeoxycholic acid - mechanism of action
- Ursodeoxycholic acid - routes of elimination and toxicity
- Ursodeoxycholic acid - medical indications
- Ursodeoxycholic acid - contraindications
- Ursodeoxycholic acid - side effects
The name ursodeoxycholic acid comes from the Latin word "ursus", which means "bear". In bears, ursodeoxycholic acid is produced in the liver as the main bile acid, unlike in humans, where it is produced by the transformation of other bile acids and accounts for only 1-3% of the total bile acid pool.
Interestingly, the bile of the Chinese black bear is listed in numerous pharmacopoeias in Asian countries as a component of drugs used in various diseases, and in traditional Chinese medicine it is regarded as a means, e.g. for treating liver diseases. The practice of collecting bile from bears is now condemned worldwide. There are over 50 bile substitutes on the market, mostly of artificial origin. Asian activists are fighting to ban farms where permanently mutilated bears are kept in inhumane conditions, and bile is collected from them.
Ursodeoxycholic acid - formation
Human bile contains mainly primary bile acids (eg cholic acid, chenodeoxycholic acid), which are produced by the liver and then accumulated in the gallbladder. The primary bile acids are then secreted into the intestinal lumen where they are converted by the intestinal microbiota tosecondary bile acids, e.g. ursodeoxycholic acid.
Ursodeoxycholic acid - mechanism of action
Lipophilic bile acids, including deoxycholic acid and chenodeoxycholic acid, have been shown to have a toxic effect on hepatocytes by increasing cell membrane permeability and inducing apoptosis.
In contrast, ursodeoxycholic acid is hydrophilic and non-toxic compared to other bile acids and, when administered orally, displaces the toxic bile acids.
Due to this property, ursodeoxycholic acid has been used in medicine as a drug in the inoperable treatment of gallstone disease. The drug inhibits the absorption of cholesterol in the intestine and reduces the secretion of cholesterol into the bile, thereby preventing the formation of new gallstones and dissolving existing ones. On the Polish market, drugs containing ursodeoxycholic acid are: Proursan, Ursocam, Ursofalk, Ursopol, Ursoxyn.
It has also been shown that ursodeoxycholic acid can prevent the production of reactive oxygen species by liver macrophages (Kupffer cells), thus reducing the level of oxidative stress in liver cells and bile ducts. In addition, ursodeoxycholic acid reduces elevated levels of liver enzymes.
We recommend: Liver tests: norms. Blood test to monitor liver function
Ursodeoxycholic acid - routes of elimination and toxicity
Ursodeoxycholic acid is rapidly absorbed from the jejunum and upper ileum, reaching its maximum concentration in the blood after about 30-60 minutes.
In the gastrointestinal tract, ursodeoxycholic acid is converted into lithocholic acid, which is then transformed in the liver, among others. into chenodeoxycholic acid and excreted again in the bile into the gastrointestinal tract and finally excreted in the faeces.
About 60% of ursodeoxycholic acid is metabolised during the first pass through the liver. The biological half-life of ursodeoxycholic acid is 3 to 6 days.
Ursodeoxycholic acid - medical indications
- dissolving cholesterol gallstones with a diameter not exceeding 15 mm, permeable to X-rays, in patients whose gallbladder function is maintained despite the presence of stones
- primary biliary cirrhosis in the initial stage of the disease
- primary sclerosing cholangitis
- inflammation of the stomach lining caused by regurgitation of bile (also known as alkaline reflux)
- hepatobiliary disorders associated with cystic fibrosis in children and adolescentsaged 6 to 18
Ursodeoxycholic acid - contraindications
- acute cholecystitis and biliary tract inflammation
- obstruction of the bile duct (common bile duct or cystic duct)
- frequent episodes of biliary colic
- calcified gallstones visible on X-rays
- decreased contractility of the gallbladder
- bile acid hypersensitivity
- failed portoenterostomy or no improvement in bile flow in children with biliary obstruction
Ursodeoxycholic acid should not be used concomitantly with cholestyramine, colestipol, or antacids containing aluminum hydroxide or other aluminum compounds as these bind ursodeoxycholic acid in the gut and prevent its absorption, rendering treatment ineffective.
Ursodeoxycholic acid may increase the absorption of cyclosporine from the intestine, therefore its concentration in the blood should be monitored in patients treated with cyclosporine.
Ursodeoxycholic acid - side effects
Ursodeoxycholic acid is generally a very well tolerated drug at a dose of 10-20 mg / kg body weight. per day. In most clinical trials, the most common side effects were diarrhea and abdominal pain. Other side effects after using the drug are:
- bladder pain
- cloudy urine
- hematuria
- frequent and painful urination
- dizziness
- accelerated heartbeat
- indigestion
- lower back pain
- nausea and vomiting
- skin rash or itching all over the body
- hives
- weakness
Karolina Karabin, MD, PhD, molecular biologist, laboratory diagnostician, Cambridge Diagnostics Polska A biologist by profession, specializing in microbiology, and a laboratory diagnostician with over 10 years of experience in laboratory work. A graduate of the College of Molecular Medicine and a member of the Polish Society of Human Genetics. Head of research grants at the Laboratory of Molecular Diagnostics at the Department of Hematology, Oncology and Internal Diseases of the Medical University of Warsaw. She defended the title of doctor of medical sciences in the field of medical biology at the 1st Faculty of Medicine of the Medical University of Warsaw. Author of many scientific and popular science works in the field of laboratory diagnostics, molecular biology and nutrition. On a daily basis, as a specialist in the field of laboratory diagnostics, he runs the content department at Cambridge Diagnostics Polska and cooperates with a team of nutritionists at the CD Dietary Clinic.He shares his practical knowledge on diagnostics and diet therapy of diseases with specialists at conferences, training sessions, and in magazines and websites. She is particularly interested in the influence of modern lifestyle on molecular processes in the body.
Read more articles by this author