Hesperidin - How does Hesperidin Works?
- By:Robert Baird Baird
Taxonomic class
Apocynaceae
Common Trade Names
Anvirzel (hot water extract)
Common Forms
Available as leaf extract and tincture.
Source
Although active components are found in all parts of Nerium oleander, they are extracted primarily from the leaves. Oleander is cultivated mainly as an ornamental shrub. It is native to the Mediterranean and widely grown in the southern United States and California. The bush grows about 20' high; has long, narrow, pointed leaves; and produces small clusters of red, pink, or white blossoms.
Chemical Components
Oleander contains several cardiac glycosides, including oleandrin, neriin, oleandroside, nerioside, neridiginoside, nerizoside, neritaloside, odoroside-H, neridienone, proceragenin, digitoxigenin, betaanhydroepidigitoxigenin, neriumogenin-A-3 beta-D-digitaloside, gentiobiosyloleandrin, and odoroside A. Other pharmacologically active compounds include folinerin, rutin, rosagenin, cornerine, and oleandomycin. The plant also contains hydrocyanic and ursolic acids and traces of vitamins A, K, and C.
Actions
The cardioactive glycosides in oleander act similarly to the cardiac glycosides used in treating heart failure. Their pharmacologic similarities suggest that these compounds enhance the force and velocity of myocardial contractions through inhibition of the sodium-potassiumadenosine triphosphate pump in the sarcolemmal membrane . The flavonal glycosides influence vascular permeability and have diuretic actions. Cornerine improved myocardial function in clinical trials and is effective in cardiac conditions.
Oleandrin, the principal cardiac glycoside, acts as a diuretic and stimulates the heart. In vivo analysis suggests that it lacks anticancer activity but retains weak macrophage-mediated cell toxicity and weak mitoenic activity. An in vitro study determined that oleandrin inhibits
activation of nuclear transcription factor-kappa B and activator protein1 .and their associated kinases, suggesting the potential of oleandrin to act as an antitumorigenic agent .
Reported Uses
Despite oleander's well-recognized toxicity, claims of its use center around asthma, cancer, cardiac illnesses, corns, dysmenorrhea, epilepsy and rashes. Folk remedies claim actions as an abortifacient, a cardiotonic , a cathartic, a diuretic, an emetic, an insecticide, a menstrual stimulantt, and a parasiticide. In Curacao, the sap is applied to warts, added to beverages, and used as an anthelmintic. In Venezuela, the leaves are IH.iled and the steam inhaled to alleviate sinus problems. The leaves are .also used as poultices for skin diseases and to kill skin parasites and maggots in wounds.
Dosage
No consensus exists. The ingestion of oleander is not recommended. A single ingested leaf may produce fatal poisoning in an adult (Howard
Adverse Reactions
CNS: depression, vertigo.
EENT: severe nasopharyngeal irritation.
GI: abdominal cramps and pain, anorexia, nausea, vomiting.
Metabolic: hyperkalemia.
Respiratory: severe irritation (smoke inhalation), tachypnea.
Skin: contact dermatitis.
Other: death.
Interactions
Digoxin, digitoxin: Increased risk of toxicity and fatal outcomes. Avoid administration with oleander.
contraindications and Precautions
Because of its extreme toxicity, warn patients to avoid using any form of oleander.
Special Considerations
Alert All parts of the oleander plant are toxic. Death has occurred in adults and children after ingestion of the flowers, leaves, and nectar and from using oleander twigs as skewers to roast foods. Fatalities have also occurred after oral and rectal administration of the extract . Smoke from the burning wood and the water in which the plant has been immersed can also be toxic.
The crossreactivity between digoxin and oleander glycosides enables radioimmunoassays to measure serum digoxin levels in oleander poisoning. Assays for serum digoxin levels may not reflect the severity of the toxicity.
Alert Symptoms of oleander toxicity may mimic those of digitalis toxicity and include anorexia, colic, bloody diarrhea, dizziness, drowsiness, heart block, hyperkalemia, mydriasis, nausea, slow and irregular pulse rate, seizures, syncope, ventricular tachycardia or fibrillation, and vomiting. Death usually results from heart failure or respiratory paralysis . A canine model suggests that digoxin antibody fragments (such as Digibind) may be valuable in treating oleander toxicity . Additional studies in dogs also suggest a role for fructose-l ,6-diphosphate in treating oleander toxicity .