Prof.dr.ir. Ivonne Rietjens
Chair of Toxicology
Food safety and risk assessment
Food safety and risk assessment
Risk assessment of herbal foods supplements and teas
Herbal food supplements and teas are widely used and marketed. However, the safety of these herbal preparations have not being assessed. Different botanical species in the herbal preparations may contain a variety of toxic and often genotoxic and carcinogenic natural toxins such as the alkenylbenzenes (estragole, methyleugenol, safrole and others), aristolochic acids or pyrrolizidine alkaloids. Our different thesis projects in this topic are oriented to quantify the levels of selected genotoxic carcinogenic ingredients of concern in selected herbal preparations by advanced chemical analytical methods followed by a risk assessment for the human population. The projects also include risk assessment for different populations (Chinese versus Caucasian), or the effect of differences in lifestyle or genetic background for the resulting risks.
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Mode of action and risk assessment of food-borne toxins
Food may contain a wide variety of natural toxins or compounds that may be of concern when exposure exceeds safe limits. These include natural food additives, mycotoxins like aflatoxin B1, phytoestrogens like (iso)flavones, glucosinolates /isothiocyanates, furocoumarins, tropane alkaloids and compounds from food packaging materials like bisphenol A and phthalates. In the thesis projects of this topic focus is on the mode of action of these toxins, and their risk or risk-benefit assessment.
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Techniques involved
Advanced chemical analysis (HPLC, UPLC, LC-MS); exposure assessment; risk assessment; physiologically based kinetic (PBK) modelling; tissue culture; in vitro models for biotransformation; toxicity endpoints such as DNA adduct formation, DNA methylation, genotoxicity, cardiotoxicity, endocrine disruption, receptor mediated gene inductions.
PhD's
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Mebrahtom Hiben: Risks and benefits of ‘Ashkulebya’ as health food or therapeutic alternative.
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Lu Chen: Risks associated with pyrrolidizine alkaloids (PAs) in botanicals and botanical preparations including especially herbal teas and plant food supplements (PFS).
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Jia Ning: Safety and risk assessment of botanicals and botanical preparations.
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Suparmi Suparmi: Risk-benefit analysis of bixin and norbixin from the pericarp of Bixa orellana seeds.
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Shuo Yang: DNA adducts of liver carcinogens.
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Ixchel Gilbert Sandoval: Mode-of-action based risk assessment of combined exposure to mycotoxins in maize and maize products.
