In vivo relative bioavailability of perfluorooctanoic acid (PFOA) and its alternative hexafluoropropylene oxide trimer acid (HFPO-TA): Influence of food and mechanisms exploration
Xinyi Cui, Qian Gu, Albert L. Juhasz, Yi Chen
Abstract
The extensive use of perfluorooctanoic acid (PFOA), and its substitute hexafluoropropylene oxide trimer acid (HFPO-TA) has resulted in their frequent detection in environmental samples. However, little is known of their bioavailability via oral ingestion and the influence of food co-ingestion on absorption. Here, the relative bioavailability (RBA) of PFOA and HFPO-TA in soil was measured using an in vivo mouse model in the presence of food with different nutritional statuses (n = 11). PFOA and HFPO-TA RBA in soil was variable depending on nutrient co-administration, ranging from 29.8-95.5 % and 43.9-68.0 %, respectively. For both PFOA and HFPO-TA, a significantly negative correlation was observed between RBA and protein content in food (r = 0.57-0.72), while a positive correlation was observed with carbohydrate content (r = 0.51-0.57). Mechanistic studies showed that protein in food decreased PFOA and HFPO-TA RBA by down-regulating the expression of fatty acid binding protein 1 (FABP1) and up-regulating the expression of multidrug resistance associated protein 4 (Mrp4) in the liver, which are responsible for the absorption and efflux of PFOA and HFPO-TA. Dietary carbohydrates promoted albumin synthesis and up-regulated FABP1 expression thereby enhancing absorption and increasing PFOA and HFPO-TA RBA. This study provides an insight into potential dietary strategies for reducing exposure to per- and polyfluoroalkyl substances.