Risikoanalyse des zytotoxischen Potentials von Methoxypyrazinen aus der Hämolymphe des Asiatischen Marienkäfers Harmonia axyridis auf humane Zellen

The multicolored Asian ladybird or harlequin beetle Harmonia axyridis has established in Europe within the last 16 years. In the year 2007 we observed the first mass developments of this species in vineyards in Germany. At the end of summer the adult beetles like to feed on ripening grapes resulting in high numbers of beetles contaminating the harvested grapes. Due to the fact that the beetles react to increasing pressure during processing with reflex bleeding or getting crushed together with grape berries, their defensive compounds (methoxypyrazines) are released in the must. These compounds cause an off-flavor in the wine, the so-called “ladybird taint” and may release allergic reactions in humans. In the presented study we analyzed to which extent contaminations of wine by methoxypyrazines may have toxic effects on the consumer. We used a non-invasive monitoring system for cell viability (XCELLigence) and analyzed the metabolic activity (WST) of a human liver carcinoma cell line (HEP-G2). Irreversible cytotoxic effects to HEP-G2 were observed at a concentration of 0.8 mg IBMP or SBMP or higher per liter vine. Due to the fact that a single beetle actually contain less than one ng methoxypyrazines, the processing of 5 million beetles per L vine would be necessary to cause toxicity in cells of the consumer. This is not a realistic scenario. Thus we can conclude that the consumption of spoiled wine with ladybird taint does not bear any risks for intoxication of consumers.