Cytoprotection is a process by which chemical compounds provide protection to cells against harmful agents. [1]
A gastric cytoprotectant is any medication that combats ulcers not by reducing gastric acid but by increasing mucosal protection. [2] Examples of gastric cytoprotective agents include prostaglandins which protect the stomach mucosa against injury by increasing gastric mucus secretion. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the synthesis of prostaglandins and thereby make the stomach more susceptible to injury. [3] Gastric cytoprotective drugs include carbenoxolone, deglycyrrhizinised liquorice, sucralfate (aluminium hydroxide and sulphated sucrose), misoprostol (a prostaglandin analogue), bismuth chelate (tri-potassium di-citrato bismuthate) and zinc L-carnosine.
Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of use, but largely include an increased risk of gastrointestinal ulcers and bleeds, heart attack, and kidney disease.
Peptic ulcer disease is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines is a duodenal ulcer. The most common symptoms of a duodenal ulcer are waking at night with upper abdominal pain, and upper abdominal pain that improves with eating. With a gastric ulcer, the pain may worsen with eating. The pain is often described as a burning or dull ache. Other symptoms include belching, vomiting, weight loss, or poor appetite. About a third of older people with peptic ulcers have no symptoms. Complications may include bleeding, perforation, and blockage of the stomach. Bleeding occurs in as many as 15% of cases.
Prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids that have diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring. They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives.
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that is used to relieve pain, fever, and inflammation. This includes painful menstrual periods, migraines, and rheumatoid arthritis. It may also be used to close a patent ductus arteriosus in a premature baby. It can be used orally or intravenously. It typically begins working within an hour.
Prostaglandin analogues are a class of drugs that bind to a prostaglandin receptor.
Cyclooxygenase (COX), officially known as prostaglandin-endoperoxide synthase (PTGS), is an enzyme that is responsible for biosynthesis of prostanoids, including thromboxane and prostaglandins such as prostacyclin, from arachidonic acid. A member of the animal-type heme peroxidase family, it is also known as prostaglandin G/H synthase. The specific reaction catalyzed is the conversion from arachidonic acid to prostaglandin H2 via a short-living prostaglandin G2 intermediate.
Diclofenac, sold under the brand name Voltaren, among others, is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammatory diseases such as gout. It is taken by mouth or rectally in a suppository, used by injection, or applied to the skin. Improvements in pain last for as much as eight hours. It is also available in combination with misoprostol in an effort to decrease stomach problems.
Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. It is taken by mouth when used to prevent gastric ulcers in people taking nonsteroidal anti-inflammatory drugs (NSAID). For abortions it is used by itself or in conjunction with mifepristone or methotrexate. By itself, effectiveness for abortion is between 66% and 90%. For labor induction or abortion, it is taken by mouth, dissolved in the mouth, or placed in the vagina. For postpartum bleeding it may also be used rectally.
Anti-inflammatory or antiphlogistic is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs remedy pain by reducing inflammation as opposed to opioids, which affect the central nervous system to block pain signaling to the brain.
Esomeprazole, sold under the brand name Nexium [or Neksium] among others, is a medication which reduces stomach acid. It is used to treat gastroesophageal reflux disease, peptic ulcer disease, and Zollinger–Ellison syndrome. Its effectiveness is similar to that of other proton pump inhibitors (PPIs). It is taken by mouth or injection into a vein.
Gastritis is the inflammation of the lining of the stomach. It may occur as a short episode or may be of a long duration. There may be no symptoms but, when symptoms are present, the most common is upper abdominal pain. Other possible symptoms include nausea and vomiting, bloating, loss of appetite and heartburn. Complications may include stomach bleeding, stomach ulcers, and stomach tumors. When due to autoimmune problems, low red blood cells due to not enough vitamin B12 may occur, a condition known as pernicious anemia.
Indometacin, also known as indomethacin, is a nonsteroidal anti-inflammatory drug (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation. It works by inhibiting the production of prostaglandins, endogenous signaling molecules known to cause these symptoms. It does this by inhibiting cyclooxygenase, an enzyme that catalyzes the production of prostaglandins.
Sucralfate, sold under various brand names, is a medication used to treat stomach ulcers, gastroesophageal reflux disease (GERD), radiation proctitis, and stomach inflammation and to prevent stress ulcers. Its usefulness in people infected by H. pylori is limited. It is used by mouth and rectally.
Diflunisal is a salicylic acid derivative with analgesic and anti-inflammatory activity. It was developed by Merck Sharp & Dohme in 1971, as MK647, after showing promise in a research project studying more potent chemical analogs of aspirin. It was first sold under the brand name Dolobid, marketed by Merck & Co., but generic versions are now widely available. It is classed as a nonsteroidal anti-inflammatory drug (NSAID) and is available in 250 mg and 500 mg tablets.
Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. It works by enhancing mucosal defense, scavenging free radicals, and temporarily activating genes encoding cyclooxygenase-2.
Cyclooxygenase-2 (COX-2), also known as Prostaglandin-endoperoxide synthase 2 (HUGO PTGS2), is an enzyme that in humans is encoded by the PTGS2 gene. In humans it is one of three cyclooxygenases. It is involved in the conversion of arachidonic acid to prostaglandin H2, an important precursor of prostacyclin, which is expressed in inflammation.
Cyclooxygenase 1 (COX-1), also known as prostaglandin-endoperoxide synthase 1, is an enzyme that in humans is encoded by the PTGS1 gene. In humans it is one of two cyclooxygenases.
Troxipide is a drug used in the treatment of gastroesophageal reflux disease. Troxipide is a systemic non-antisecretory gastric cytoprotective agent with anti-ulcer, anti-inflammatory and mucus secreting properties irrespective of pH of stomach or duodenum. Troxipide is currently marketed in Japan (Aplace), China (Shuqi), South Korea (Defensa), and India (Troxip). It is used for the management of gastric ulcers, and amelioration of gastric mucosal lesions in acute gastritis and acute exacerbation of chronic gastritis.
Zinc L-carnosine, often simply called zinc carnosine, and also known as polaprezinc, is a mucosal protective chelate compound of zinc and L-carnosine invented by Hamari Chemicals, Ltd. It is a quadridentate 1:1 complex of a polymeric nature. Although it contains 23% zinc and 77% L-carnosine by mass, zinc carnosine is a molecule and not a mixture of zinc and L-carnosine.
Prostaglandin inhibitors are drugs that inhibit the synthesis of prostaglandin in human body. There are various types of prostaglandins responsible for different physiological reactions such as maintaining the blood flow in stomach and kidney, regulating the contraction of involuntary muscles and blood vessels, and act as a mediator of inflammation and pain. Cyclooxygenase (COX) and Phospholipase A2 are the major enzymes involved in prostaglandin production, and they are the drug targets for prostaglandin inhibitors. There are mainly 2 classes of prostaglandin inhibitors, namely non- steroidal anti- inflammatory drugs (NSAIDs) and glucocorticoids. In the following sections, the medical uses, side effects, contraindications, toxicity and the pharmacology of these prostaglandin inhibitors will be discussed.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.