Naturally occurring cardiac glycosides

Area of Science:

• Toxicology
• Pharmacology
• Analytical Chemistry

Background:

• Cardiac glycoside poisoning, particularly from oleander ingestion, is a significant concern in tropical and subtropical regions.
• Ornamental plants and certain animals are known sources of cardiac glycosides, posing a risk of accidental poisoning.

Purpose of the Study:

• To quantify cardiac glycoside content in various plant and animal specimens.
• To assess the utility of radioimmunoassays for detecting cardiac glycosides in different matrices.
• To raise awareness about potential sources of cardiac glycoside toxicity.

Main Methods:

• Radioimmunoassays utilizing antibodies with varying specificities for cardiac glycosides were employed.
• Specimens analyzed included ornamental shrubs (e.g., Thevetia peruviana, Nerium oleander) and milkweeds (e.g., Asclepias curassavica, Calotropis procera).
• The venom gland of the cane toad (Bufo marinus) was also examined for cardiac glycoside presence.

Main Results:

• Significant levels of immunoreactive cardiac glycosides were detected in multiple plant species, including yellow oleander, oleander, wintersweet, bushman's poison, sea-mango, frangipani, redheaded cotton-bush, balloon cotton, king's crown, and rubber vine.
• The cane toad's venom gland was found to contain substantial quantities of cardiac glycosides.
• The competitive immunoassay method proved effective for rapid screening of suspected cardiac glycoside-containing specimens.

Conclusions:

• Several common ornamental plants and the cane toad are significant sources of cardiac glycosides.
• Radioimmunoassay provides a rapid and effective method for screening and confirming cardiac glycoside presence in poisoning cases.
• Increased awareness of these toxic sources can aid in preventing poisoning incidents.