title: Study on inter-ethnic human differences in bioactivation and detoxification of estragole using physiologically based kinetic modeling.
abstract: Considering the rapid developments in food safety in the past decade in China, it is of importance to obtain insight into what extent safety and risk assessments of chemicals performed for the Caucasian population apply to the Chinese population. The aim of the present study was to determine physiologically based kinetic (PBK) modeling-based predictions for differences between Chinese and Caucasians in terms of metabolic bioactivation and detoxification of the food-borne genotoxic carcinogen estragole. The PBK models were defined based on kinetic constants for hepatic metabolism derived from in vitro incubations using liver fractions of the two ethnic groups, and used to evaluate the inter-ethnic differences in metabolic activation and detoxification of estragole. The models predicted that at realistic dietary intake levels, only 0.02% of the dose was converted to the ultimate carcinogenic metabolite 1'-sulfooxyestragole in Chinese subjects, whereas this amounted to 0.09% of the dose in Caucasian subjects. Detoxification of 1'-hydroxyestragole, mainly via conversion to 1'-oxoestragole, was similar within the two ethnic groups. The 4.5-fold variation in formation of the ultimate carcinogenic metabolite of estragole accompanied by similar rates of detoxification may indicate a lower risk of estragole for the Chinese population at similar levels of exposure. The study provides a proof of principle for how PBK modeling can identify differences in ethnic sensitivity and provide a more refined risk assessment for a specific ethnic group for a compound of concern.
authors.affiliation: Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands. jia.ning@wur.nl.
authors.forename: Jia
authors.initials: J
authors.lastname: Ning
authors.affiliation: Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
authors.forename: Jochem
authors.initials: J
authors.lastname: Louisse
authors.affiliation: Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
authors.forename: Bert
authors.initials: B
authors.lastname: Spenkelink
authors.affiliation: Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Wesseling
authors.affiliation: Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
authors.forename: Ivonne M C M
authors.initials: IMCM
authors.lastname: Rietjens
mesh_terms: D000284:Administration, Oral; D000081248:Allylbenzene Derivatives; D000840:Anisoles / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015239:Arylsulfotransferase / Q000378:metabolism; D044466:Asian People; D002273:Carcinogens / Q000008:administration & dosage / Q000493:pharmacokinetics; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D006801:Humans; D008658:Inactivation, Metabolic; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D044465:White People
chemical_list: D000081248:Allylbenzene Derivatives; D000840:Anisoles; D002273:Carcinogens; C014037:1'-hydroxyestragole; D003577:Cytochrome P-450 Enzyme System; C007633:estragole; D015239:Arylsulfotransferase
keywords: Caucasian; Chinese; Estragole; Inter-ethnic difference; Physiologically based kinetic modeling