Cardiac Glycosides PDF

Pharmacognosy and Phytochemistry Cardiac glycosides By Dr. Farah Al-Mamoori Are an important class of naturally occurring drugs whose actions include both beneficial and toxic effects on the heart. Plant glycosides with specific action on heart. Historical use...

Pharmacognosy and Phytochemistry Cardiac glycosides By Dr. Farah Al-Mamoori Are an important class of naturally occurring drugs whose actions include both beneficial and toxic effects on the heart. Plant glycosides with specific action on heart. Historical use: To assassinate people, arrow poisons. Ouabain is a plant derived toxic substance that was traditionally used as an arrow poison in eastern Africa for both hunting and warfare. Modern use: To treat congestive heart failure (dropsy). For treatment of atrial fibrillation  ‫القمعية‬ ‫او فقاز‬ ‫الثعلب‬ Digitalis lanata, Digitalis purpurea Family: Scrophulariaceae Used part: The leaves  ‫وليام وذرنگ طبيب إنجليزي‪ ،‬قام بدراسة كالسيكية لالستخدام الطبي‬ ‫لنبات الديجيتاليس‪.‬ومن اهتمامه بعلم النبات‪ ،‬أولى اهتماما ً بالعالجات‬ ‫الشعبية التي يستعملها جامعو األعشاب‪ ،‬بما فيها ‪foxglove.‬وقد كان‬ ‫مستخلص أوراق النبات فعاالً في حاالت معينة من " "‪dropsy‬‬ ‫‪(oedema,‬الناتجة عن فشل القلب)‪.‬وقد حدد الجرعات اآلمنة‬ ‫لالستخدام‪ ،‬ونشر تقريرا ً عن اكتشافاته المتعلقة بالنبات ‪Foxglove‬‬ ‫‪(1785).‬وقد أعطى تقريره تواريخ جيدة لحاالت مرضية‪ ،‬بما فيها حاالت‬ ‫فشل فيها العالج‪ ،‬وأخر نجح فيها‪.‬وبذلك فقد أضاف الديجيتاليس‪ ،‬كدواء‬ ‫فعال جداً‪ ،‬لجعبة األطباء ليستخدموه العادة انتظام وتقوية عمل القلب‬ Cardiac glycosides inhibit Na/K adenosine triphosphatase, the “sodium pump” which causes more Na to remain inside myocardial cells Increased intracellular Na stimulates Na+/Ca+2 exchange that brings more Ca+2 inside heart cells to increase the force of contraction Cardiac glycosides also stimulate the vagus nerve which decreases heart rate  Rings A/B and C/D are cis fused while rings B/C are trans fused. Such ring fusion give the aglycone nucleus of cardiac glycosides the characteristic 'U' Digoxin immune fab binds molecules of digoxin, making them unavailable for binding at their site of action on cells in the body. The Fab fragment-digoxin complex accumulates in the blood, from which it is excreted by the kidney  Xanthopsia(yellow vision) Due to Digoxin Toxicity Vincent van Gogh, the Dutch postimpressionist painter, died in 1890. He was an uncommon man. Automutilation, depression, insanity, and suicide are part of his medical history. During the last few years of his life, his paintings were characterized by halos and the color yellow. Critics have ascribed these aberrations to innumerable causes, including chronic solar injury, glaucoma, and cataracts. Van Gogh may have been under the influence of digitalis intoxication and its side effects: xanthopsia and coronas. This hypothesis is based on his twice having painted his physician holding a foxglove plant; that this medicine was used in the latter part of the 19th century in the treatment of epilepsy; and that the toxic effects of digitalis may have, in part, dictated the artist's technique. Nerium oleander‫الدفلى‬ Active part: leaves Apocynaceae family  Oleanders are highly toxic, which means ingesting even a small amount of any part of this plant can result in symptoms of poisoning Ingesting oleander plant parts can result in a variety of symptoms ranging from moderate to severe or fatal. These include skin rash, blurred vision, visual disturbances such as halos, diarrhea, nausea, stomach pain, vomiting, loss of appetite, irregular or slowed heartbeat, weakness, low blood pressure, confusion, dizziness, headache, fainting, depression, drowsiness, or lethargy Yellow oleander (Thevetia peruviana) ‫الدفلى الصفراء‬ Rich source of the glycoside thevetin A  Less widely distributed in the nature than cardinolides. Thy are found in some Liliaceae and Ranunculaceae Therapeutically they find little use as cardioactive drugs.  Squill ‫العنصل‬ Squill consists of dried sliced bulbus (used part) of Urginea maritima Family Liliaceae  Scillarins 33 Prof. Talal Aburjai 11/26/2024 Toad venom poisoning is similar to digitalis toxicity and carries a high mortality. Cardiac glycoside poisoning can occur from ingestion of various plants and animal toxins, and the venom gland of cane toad (Bufo marinus) contains large quantities of cardiac glycosides.