Understanding toxic pyrrolizidine alkaloids is of ‘crucial relevance for daily life’: Expert

24-Aug-2020 - Last updated on 28-Sep-2021 at 14:15 GMT

An upcoming symposium will explore the toxicology, pharmacokinetics, analysis, and regulatory perspectives of pyrrolizidine alkaloids, toxic compounds that may be found in food and herbal products.

The upcoming symposium, “Novel insights into Pyrrolizidine Alkaloid Toxicity and Implications for Risk Assessment”, is being hosted by the Society for Medicinal Plant and Natural Product Research (Gesellschaft für Arzneipflanzen- und Naturstoff-Forschung or GA). It features a range of experts from industry and academia, including Dr Olaf Kelber, who serves as GA's secretary. Dr Kelber is also Principal Scientist Phytomedicines, Bayer Phytomedicines Supply and Development Center.

Speaking with NutraIngredients-USA via video, Dr Kelber explained that understanding PAs has “crucial relevance for daily life, for the safety of the consumer, and also it can a tremendous important factor from an economic perspective for the industry because measures to limit these compounds can be quite expensive.”

PAs

According to the European Food Safety Authority (EFSA), an estimated 6,000 plant species worldwide may contain pyrrolizidine alkaloids (PAs), including Boraginaceae (‘Forget-me-nots’), Asteraceae (the Senecioneae and Eupatorieae tribes of the daisy family) and Fabaceae (the Crotalaria genus commonly known as rattlepods).

EFSA issued advice on the risks for human and animal health from pyrrolizidine alkaloids in 2011, and updated that in 2017.

“If you take them just as they are, they are not really so toxic,” explained Dr Kelber, “but what happens is that in the liver, they are metabolized by the P450 enzymes, which are usually for detoxification, but in this case they activate these compounds so that become really reactive and could – that’s the assumption – really react with the DNA of our liver cells and cause, with chronic exposure, liver cancer.

Dr Kelber noted that analytical techniques have improved over the years, allowing scientists to detect PAs in food, herbal teas, and even in honey.

For food and teas, the PAs were coming from weeds that were accidentally contaminating the product.

“This caused big concerns, and industry completely refurbished the whole supply chain of many nutritional plants and herbs starting from the field. Everything was reorganized to avoid these weeds,” Dr Kelber.