A TRADITIONAL Chinese tea used to relieve headaches and period pain could trigger a fatal heart attack, warn scientists.
Traditional Chinese medicinal plants and products reach the European market relatively uncontrolled
Extracts from the berries that grow on the Evodia rutaecarpa plant also combat nausea, vomiting and mouth ulcers.
The dried and nearly ripe fruit is known as Wu Zhu Yu and is among the most popular and widely used herbal drugs.
But it also contains potentially deadly chemicals that raise the risk of severe heart rhythm disturbances – or arrythmias – that cause sudden cardiac death, according to new research.
Professor Matthias Hamburger and colleagues called for increased vigilance regarding possible toxic effects of Evodia preparations. The findings could also apply to other herbal remedies, they said.
Traditional Chinese medicinal plants and products reach the European market relatively uncontrolled, and they can also be bought on the internet.
The researchers isolated the natural substances DHE (dehydroevodiamine) and hortiamine from the plant and found they were very potent inhibitors of potassium channels in the heart muscle.
If these channels are blocked, the excitation processes in the heart muscle change, This can lead to the organ beating too fast known as Torsade de pointes (TdP). This is a potentially fatal disruption of the organ’s normal beat.
Professor Hamburger, of the Department of Pharmaceutical Sciences at the University of Basel, said: “The popularisation of medicinal plants from other cultures entails risks.
“These plants can contain highly active substances with side effects, as in the case of Evodia.
“A closer examination of such risks is therefore indispensable to protect the population.”
Medicinal plants are an essential part of Traditional Chinese Medicine
A closer examination of such risks is therefore indispensable to protect the population
Professor Hamburger
When Dutch colleagues at the University of Utrecht administered DHE to dogs ECG (electrocardiogram) tests showed they developed severe TdP arrhythmias.
This is a reliable animal model used to test safety in the drugs industry.
The experiments followed tests on heart cells cultured in the lab and live rabbits that came up with the same results.
Further investigations found DHE and hortiamine cause oscillations in the heart muscle cells even in very low concentrations, which can cause cardiac arrhythmia.
For instance, these substances can get into a tea made from Evodia fruits.
‘These plants can contain highly active substances with side effects, as in the case of Evodia’
For drugs that may potentially trigger arrhythmias, it is typically required that a cardiac examination using ECG is carried out before medication.
This is especially true for heart disease patients for their risk to be assessed.
To date, no clinical studies have been conducted to investigate the incidence of cardiac arrhythmias after taking Evodia preparations.
Professor Hamburger’s team has also shownn the DHE content of Evodia fruits is considerable.
He currently investigates the extent to which these substances find their way into tea preparations.
Professor Hamburger said: “If DHE and hortiamine are detected, the safety of Evodia products has to be re-evaluated.”
Varieties of tea:Bancha, Japan; Tian Mu Qing, Li Zi Xiang, Dragon Pearls, and Mudan, from China.
He said herbal drugs are one of the cornerstones of traditional Chinese medicine.
Professor Hamburger said: “However, in contrast to the elaborate preclinical safety evaluations to which new drug molecules are subjected, herbal drugs are considered as safe on the basis of empirical knowledge from use over centuries.
“This may be an issue, in particular, with herbal drugs containing pharmacologically potent molecules, such as is the case for some traditional Chinese medicine herbs.
“Use of some traditional Chinese medicine herbal preparations have been associated with severe side effects, and even deaths due to organ failure, as was the case with a slimming product containing Aristolochia fanchi.”
That product has since been banned after being linked to deaths from kidney failure.
Professor Hamburger added: “From a consumer safety perspective, the case of Evodia products and DHE shows that investigations into cardiac safety of other herbal products are needed.”
The study was published in Pharmacological Research.
Source: Daily Express
