Thromboxane Health Dictionary

Mill.

Synonym: A. Vera Tourn. Ex Linn. A. indica Royle A. littoralis Koening

Family: Liliaceae; Agavaceae.

Habitat: Cultivated throughout India, wild on coasts of Maharashtra, Gujarat and South India.

English: Curacao Aloe, Barbados Aloe, Indian Aloe, Jaffarabad Aloe.

Ayurvedic: Kanyaasaara, Eleyaka (dried juice of the leaves). Kumaari, Kumaarikaa, Kanyaa, Grihkanyaa, Ghritkumaarika (plant).

Unani: Gheekwaar, Sibr.

Siddha/Tamil: Sotru Kattraazhai, Kumaari. Moosaambaram (dried juice).

Folk: Elwaa, Musabbar (dried juice of leaves).

Action: Purgative (causes griping), emmenagogue. Gel—topically emollient, anti-inflammatory, antimicrobial (used for wound healing, sunburn).

Key application: In occasional constipation; contraindicated in intestinal obstruction and acutely inflamed intestinal diseases, ulcerative colitis, appendicitis. (German Commission E, ESCOP, WHO.)

The Ayurvedic Pharmacopoeia of India recommends the use of dried juice of leaves in dysmenorrhoea and diseases of the liver.

Aloe vera improved the hypoglycaemic effect of glyburide (gliben- clamide) when one tablespoonful aloe juice was given orally in the morning and at bedtime to 36 diabetic patients for 42 days. The juice (same dose) showed antihyperglycaemic activity (independently). (Francis Brinker.)

Anthraquinone glycosides, known as aloin, in small doses act as a tonic to the digestive system, and at higher doses become a strong purgative, as well as increase colonic secretions and peristaltic contractions. Resin fraction is also as important as aloin in cathartic action. In A. barbadensis the highest percentage of aloin is 21.8%.

Aloe produces pelvic congestion and is used for uterine disorders, generally with Fe and carminatives. The pulp is used in menstrual suppressions.

A molecule in the Aloe vera gel, ace- mannan, stimulates macrophages and releases immune system potentiators; enhances function of T cells and interferon production. Animal studies have shown promising results in sarcoma.

The carboxypeptidase and salicylate components of Aloe gel can inhibit bradykinin, a pain-producing agent; C-glycosyl chromone appears to reduce topical inflammation. Aloe gel also slows or inhibits the synthesis of thromboxane, which may accelerate the healing of burns. (Natural Medicines Comprehensive Database, 2007.)

Dosage: Leaf pulp juice—10-20 ml. (CCRAS.) Dried leaf pulp juice— 125-500 mg powder. (API Vol. I.)... aloe barbadensis

Those natural substances, so-called because they were ?rst discovered in the SEMEN and thought to arise in the PROSTATE GLAND, are a group of fatty-acid substances with a wide range of activity. The richest known source is semen, but they are also present in many other parts of the body. Their precise mode of action is not yet clear, but they are potent stimulators of muscle contraction and they are also potent VASODILATORS. They cause contraction of the UTERUS and have been used to induce labour (see PREGNANCY AND LABOUR); they are also being used as a means of inducing therapeutic abortions (see ABORTION).

Prostaglandins play an important part in the production of PAIN, and it is now known that ASPIRIN relieves pain by virtue of the fact that it prevents, or antagonises, the formation of certain prostaglandins. In addition, they play some, although as yet incompletely de?ned, part in producing in?ammatory changes. (See INFLAMMATION; NON-STEROIDAL ANTIINFLAMMATORY DRUGS (NSAIDS).)

Thus prostaglandins have potent biological effects, but their instability and rapid metabolism make them short-acting. They are produced but not stored by most living cells and act locally. The two most important prostaglandins are prostacycline and thromboxane: prostacycline is a vasodilator and an inhibitor of platelet aggregation; thromboxanes have the opposite effects and cause vasoconstriction and platelet aggregation. The NSAIDs act by blocking an ENZYME called cyclo-oxygenase which converts arachidonic acid to the precursors of the various prostaglandins. Despite their potent pharmacological properties, the role of prostaglandins in current therapeutics is limited and controversial. They have been used most successfully as an inhibitor of platelet aggregation in extra-corporeal haemoperfusion systems. The problems with the prostacyclines is that they have to be given intravenously as they are inactive by mouth, and continuous infusion is required because the drug is rapidly eliminated with a half-life of minutes. Side-effects tend to be severe because the drug is usually given at the highest dose the patient can tolerate. The hope for the future lies in the exploitation of the compound to generate, synthetically, stable orally active prostacycline analogues which will inhibit platelet aggregation and hence thrombotic events, and yet have minimal effects on the heart and blood vessels.... prostaglandins

n. a derivative of *prostaglandin H produced by the endothelium lining blood vessel walls. It inhibits blood clotting by preventing platelet aggregation and causes vasodilatation (compare thromboxane A2). *Epoprostenol is a pharmaceutical preparation of prostacyclin.... prostacyclin

the process whereby platelets adhere to collagen released from endothelial cells in damaged blood vessels and aggregate to form a plug. An important metabolic pathway in platelets converts membrane phospholipids to *thromboxane A2 (TXA2), which can activate platelets. ADP, released from platelet granules, and *thrombin are other activators. The adhesive and aggregation reactions of platelets are mediated through surface membrane glycoproteins (Glp), Glp Ib and Glp IIb/IIIa. Aspirin acts as an *antiplatelet drug by irreversibly inhibiting one of the enzymes of this pathway, cyclo-oxygenase. Clopidrogel inhibits the ADP receptor on platelet membranes, and *abciximab blocks platelet aggregation by inhibiting Glp IIb/IIIa (see illustration overleaf).... platelet activation