Plant Poisoning Glycosides - Cardiac Publications (121)
Plant Poisoning Glycosides - Cardiac Publications
In order to better understand and exploit them as cardiac ionotropes, studies are being pursued using different cardiac glycosides such as digitoxin, digoxin, ouabain, oleandrin etc. Several cardiac glycosides as peruvoside have shown promise in cancer control, especially ovary cancer and leukemia. Functional variability of these glycosides has revealed that not all cardiac glycosides are alike. Apart from their specific affinity to sodium-potassium ATPase, their therapeutic dosage and behavior in poly-morbidity conditions needs to be considered. This review presents a concise account of the key findings in recent years with adequate elaboration of the mechanisms. This compilation is expected to contribute towards management of cardiac, cancer, even viral ailments.
, which is a potentially lethal plant, since it has cardiac glycosides. However, numerous researches of its extracts have been performed against cancer cell lines in recent literature. This contradiction leads to misinterpretation and induces the prevalence of intoxication or fatal cases.
This case is associated with an oleander-poisoned patient, who was admitted to the Emergency unit 20 hours after the first dose, and 8 hours after the second dose. Although she lives in a metropolis and has a higher level of education and numerous hospital facilities available, she had decided to take self-medication for her Hashimoto's thyroiditis and malignant thyroid disease which was caused by her apprehensive thoughts. Oleandrin was detected in the urine at a concentration of 3.2 ng/mL and in the serum at a concentration of 8.4 ng/mL by chromatographic analysis at the time of admission.
This case represents the misunderstanding of herbal treatments by the community. Promoting awareness of the potential toxicity of this plant among the public may help to reduce the incidence of poisoning due to Nerium species.
"Krimpsiekte" is a plant poisoning only reported from South Africa and is regarded as the most important plant poisoning of small stock in the semi-arid Little Karoo and southern fringes of the Great Karoo. The toxicosis is caused by cumulative bufadienolides which have neurotoxic properties. Four types of cumulative neurotoxic bufadienolides, namely cotyledoside, and the tyledosides, orbicusides and lanceotoxins, have been isolated. Based on the structure activity relationships and certain toxicokinetic parameters possible reasons for their accumulation are presented. Consumption of edible tissues from animals that have ingested these plants poses a potential risk to humans.
obesum (AOAgNPs). The synthesis of AOAgNPs was monitored by color change and ultraviolet-visible spectroscopy (425 nm). It was further characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The FTIR spectra for the AOAgNPs indicated the presence of terpenoids, long chain fatty acids, secondary amide derivatives and proteins that could be responsible for the reduction and capping of the formed AOAgNPs. X-ray diffraction confirmed the crystallinity of the AgNPs. The TEM images revealed mostly spherical particles in the size range of 10-30 nm. The biological properties of novel AOAgNPs were investigated on MCF-7 breast cancer cells. Cell viability was determined by the MTT assay. Generation of reactive oxygen species (ROS), DNA damage, induction of apoptosis and autophagy were assessed. A dose-dependent decrease in the cell viability was observed. The IC50 value was calculated as 217 μg/ml. Both qualitative and quantitative evaluation confirmed about a 2.5 fold increase in the generation of ROS at the highest concentration of 150 μg/ml. A significant (p<0.05) increase in the DNA damage evaluated by comet assay was evident. Flow cytometry revealed an increase in the apoptotic cells (24%) in the AOAgNPs treated group compared to the control. Acridine orange staining of acidic vesicles in exposed cells confirmed the induction of autophagy. These findings suggest that AOAgNPs increased the level of ROS resulting in heightened the DNA damage, apoptosis and autophagy in MCF-7 cells.
Three hours after admission, a 200-mg empiric dose of digoxin-specific Fab antibody fragments was administered intravenously over 30 minutes. A 12-lead electrocardiogram (ECG) revealed sinus rhythm at the end of infusion. After 72 hours, the patient was discharged without any symptoms.
After excluding other likely causes of hypoglycemia, the finding was attributed to oleander toxicosis, which has not been previously reported in dogs. A 7-year-old female spayed Maltese was presented to the emergency service after ingesting oleander leaves. Toxicosis was confirmed by measurement of digoxin using a competitive binding immunoassay, patient level 0.7 ng/mL (0.9 nmol/L) 24-h post-ingestion. Clinical symptoms included vomiting, cardiac arrhythmia, mild hyperkalemia, and hypoglycemia. Treatment was successful with aggressive supportive care, and the dog was discharged from the hospital after 48 h and made a full recovery. This case reviews the presentation and treatment of oleander toxicity but also highlights possible effects of oleander on blood sugar in dogs. Hypoglycemia in this dog, attributed to oleander poisoning, is interesting as it supports experimental research into hypoglycemic properties of oleander extracts.
Cross-reactivities of purified convallatoxin and oleandrin with five common digoxin immunoassays were determined. Serum from mice challenged with convallatoxin was tested for apparent digoxin levels. Binding of convallatoxin to digoxin immune Fab was determined in vitro.
Both convallatoxin and oleandrin were detectable by a panel of commonly used digoxin immunoassays, but cross-reactivity was variable between individual assays. We observed measurable apparent digoxin levels in serum of convallatoxin intoxicated mice at sublethal doses. Convallatoxin demonstrated no binding by digoxin immune Fab.
Multiple digoxin immunoassays detect botanical cardiac glycosides including convallatoxin and thus may be useful for rapid determination of severe exposures, but neutralization of convallatoxin by digoxin immune Fab is unlikely to provide therapeutic benefit.
These include important medicinal uses and pharmacological properties ranging from antimicrobial, antiviral, anticancer, anti-inflammatory as well as those that are used as aphrodisiacs and for maternal health care.