Prophylactic and therapeutic effects of garlic extract on Nerium oleander-induced arrhythmia: a new approach to antiarrhythmic therapy in an ovine model.
BACKGROUND
Oleander is a potent cardiotoxic plant and is a common cause of poisoning in human and animals. There is no affordable and cost-effective treatment for oleander poisoning. Objective. To evaluate the prophylactic and therapeutic effects of garlic extract (Allium sativum) on Nerium oleander (a potent cardiotoxic plant) intoxication in sheep.


METHODS
Eight sheep were intravenously infused with an unsterilized hydro-ethanol extract of garlic (50 mg/kg) before or after receiving a lethal dose of dried leaves (as a powder) of oleander (100 mg/kg, orally). The cardiac rhythm was continuously monitored using biopotential wireless transmitters and telemetry system. For evaluation of therapeutic effects, six sheep received the lethal dose of oleander and were administered with garlic extract after development of cardiac arrhythmias. Subsequently, the survived animals from the therapeutic study (four sheep) were administered with oleander without receiving any medication. Some blood constituents, including total antioxidant capacity, malondialdehyde, and troponin I, were compared between treated and untreated animals.


RESULTS
Pretreatment with garlic extract reversed the arrhythmia caused by oleander to its previous normal rhythm in seven sheep, but, one sheep died of ventricular fibrillation. On therapeutic treatment, four sheep survived while two died of ventricular fibrillation. Dosing with oleander without receiving garlic extract resulted in death of all sheep due to ventricular fibrillation. Blood constituents did not show any significant changes between treated and untreated sheep, and before and after intoxication.


CONCLUSIONS
Garlic extract reduced the case fatality from 100% to 12.5% and 33.3% as a prophylactic or therapeutic agent, respectively. Additionally, garlic extract delayed the time of onset of arrhythmias and prolonged the interval between intoxication and death of the animals. Garlic extract could be considered to be a potential and affordable antidote in oleander poisoning. However additional studies with a larger sample size and in other species need to be performed to confirm the results in this study.
Department of Clinical Sciences, Faculty of Veterinary Medicine, Urmia University , Urmia , Iran.
M
M
Fattahi
B
B
Dalir-Naghadeh
M
M
Maham
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000931:Antidotes / Q000302:isolation & purification / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000188:drug therapy* / Q000517:prevention & control; D005260:Female; D005737:Garlic / Q000737:chemistry*; D008315:Malondialdehyde / Q000378:metabolism; D030007:Nerium / Q000506:poisoning*; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D010939:Plant Poisoning / Q000188:drug therapy / Q000517:prevention & control; D012756:Sheep; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D019210:Troponin I / Q000378:metabolism
D000889:Anti-Arrhythmia Agents; D000931:Antidotes; D000975:Antioxidants; D010936:Plant Extracts; D019210:Troponin I; D008315:Malondialdehyde