Anti-arthralgic activity of the n-hexane extract (HTp) of yellow oleander seeds; Thevetia peruviana (Pers.) K. Schum

Thevetia peruviana (Pers.) K.Schum. (Apocynaceae) seeds are known to possess cardioactive glycosides such as thevetin A, thevetin B, nerifolin etc. They are also used locally for general pain relief for which there is no scientific evidence to our knowledge. Arthralgia is regarded generally as pain without inflammation. It is endemic in the society and sufferers continue to imbibe pain relieving drugs in their tons all over the world. Analgesic activity test was carried out using the formalin-induced pain models, at 0.1g, 0.2g and 0.3g/kg doses of n-hexane extracts of Thevetia peruviana seeds (HTp) in Wistar mice. Diclofenac was used as positive control. Acute toxicity test was carried out at doses of 1000, 2500 and 5000 mg/kg weight of test subject. It was observed that HTp at concentrations of 0.1g, 0.2g and 0.3g/kg showed significant analgesic effect at compared to the control. The percentage inhibition observed was 29.60%, 44.80% and 50.72% for the early pain phase and 100% for the late pain phase respectively, indicating HTps NSAID-like property. HTp showed the highest percentage inhibition at 300 mg/kg (50.72 %) and significant; P < 0.005 pain reduction. HTp did not produce any toxicity up to a dose of 5000 mg/kg weight which is very interesting as the seeds are known for their toxicity due to the cardiac glycoside presence. The results of the study suggest that HTp does indeed relieve pain significantly in a dose dependent manner, thus justifying its use in management of arthralgia. Keywords: Arthralgia, Herbal medicine, Pain,Thevetia peruviana, yellow oleander

A Case Report of Accidental Intoxication following Ingestion of Foxglove Confused with Borage: High Digoxinemia without Major Complications

Foxglove (Digitalis purpurea L.) leaves are frequently confused with borage (Borago officinalis L.), which is traditionally used as a food ingredient. Due to the presence of the cardiac glycosides, mostly digitoxin, foxglove leaves are poisonous to human and may be fatal if ingested. A 55-year-old Caucasian woman complaining weakness, fatigue, nausea, and vomiting was admitted to the Emergency Department. Her symptoms started following consumption of a home-made savory pie with 5 leaves from a plant bought in a garden nursery as borage. Digoxinemia was high (10.4 μg/L). The patient was admitted to the cardiac intensive care unit for electrocardiographic monitoring. Two days after admission, a single episode of advanced atrioventricular (AV) block was recorded by telemetry, followed by a second-degree AV block episode. Plasma samples at day 11 were analysed by LC-MS spectrometry, and gitoxin was identified suggesting that this compound may be responsible for the clinical toxicity rather than digoxin. In the case of Digitalis spp. poisoning, laboratory data should be interpreted according to the clinical picture and method of analysis used since a variety of glycosides, which are chemically similar to the cardioactive glycosides but without or with fewer cardiac effects, may be incorrectly recognized as digoxin by the test, giving misleading results.

Improved method for diagnosis of Nerium oleander poisoning in necropsy tissues

ABSTRACT: Nerium oleander is an ornamental cardiotoxic plant found in tropical and subtropical areas of the World. Its toxicity is related to the content of cardioactive glycosides, mainly oleandrin, found throughout the plant. The present study aimed to describe a new and improved method for oleandrin detection in tissue samples. The determination of oleandrin was made after extraction with a modified QuEChERS technique and measurement by UFLC-MS/MS. A total of 36 guinea pigs (Cavia porcellus) were distributed into 3 groups (n=12): control group that received only water orally (CON), and two treated groups that received hydroalcoholic oleander extract at doses of 150mg.kg-1 (OLE 150) and 300mg.kg-1 (OLE 300) in single oral dose. After three hours, fragments of heart, kidneys, liver and brain were collected for determination of oleandrin levels. The extraction and chromatographic procedures were effective for oleandrin detection and quantification in tissues, with retention time of 1.2 min and detection limit of 0.001μg g-1. The chromatographic analysis of treated guinea pigs indicated that oleandrin is distributed equally among the analyzed tissues. The developed methodology is a reliable, effective and rapid form of diagnosis of N. oleander poisoning based on necropsy tissue samples.

Digoxin and ouabain induce the efflux of cholesterol via liver X receptor signalling and the synthesis of ATP in cardiomyocytes

Cardioactive glycosides exert positive inotropic effects on cardiomyocytes through the inhibition of Na+/K+-ATPase. We showed previously that in human hepatoma cells, digoxin and ouabain increase the rate of the mevalonate cascade and therefore have Na+/K+-ATPase-independent effects. In the present study we found that they increase the expression and activity of 3-hydroxy-3 methylglutaryl-CoA reductase and the synthesis of cholesterol in cardiomyocytes, their main target cells. Surprisingly this did not promote intracellular cholesterol accumulation. The glycosides activated the liver X receptor transcription factor and increased the expression of ABCA1 (ATP-binding cassette protein A1) transporter, which mediates the efflux of cholesterol and its delivery to apolipoprotein A-I. By increasing the synthesis of ubiquinone, another derivative of the mevalonate cascade, digoxin and ouabain simultaneously enhanced the rate of electron transport in the mitochondrial respiratory chain and the synthesis of ATP. Mice treated with digoxin showed lower cholesterol and higher ubiquinone content in their hearts, and a small increase in their serum HDL (high-density lipoprotein) cholesterol. The results of the present study suggest that cardioactive glycosides may have a role in the reverse transport of cholesterol and in the energy metabolism of cardiomyocytes.