State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing, Jiangsu 210046, China.
Environ Sci Technol. 2015 Jan 6;49(1):150-8. doi: 10.1021/es505075z. Epub 2014 Dec 17.
Food is a major source of human exposure to perfluorooctanoic acid (PFOA), however, PFOA bioavailability in food has not been studied. An in vivo mouse model and three in vitro methods (unified BARGE method, UBM; physiologically based extraction test, PBET; and in vitro digestion method, IVD) were used to determine the relative bioavailability and bioaccessibility of PFOA in the presence of 17 foods. PFOA was mixed with foods of different nutritional compositions and fed to mice over a 7-d period. PFOA relative bioavailability was determined by comparing PFOA accumulation in the liver following PFOA exposure via food to that in water. PFOA bioavailability relative to water ranged from 4.30 ± 0.80 to 69.0 ± 11.9% and was negatively correlated with lipid content (r = 0.76). This was possibly due to competitive sorption of free fatty acids with PFOA onto transporters on intestine epithelial cells. Besides, cations in the gastrointestinal tract, such as Ca(2+) and Mg(2+), are capable of complexing PFOA and partitioning to the lipid phase. On the other hand, when assessed using in vitro assays, PFOA bioaccessibility varied with methods, being 8.7-73% (UBM), 9.8-99% (PBET), and 21-114% (IVD). PFOA bioaccessibility was negatively correlated with lipid content when assessed using UBM (r = 0.82); however, a poor correlation with food composition was observed for PBET and IVD (r = 0.01-0.50). When in vivo and in vitro data were compared, a strong correlation was observed for UBM (r = 0.79), but poor relationships were observed for PBET and IVD (r = 0.11-0.22). This was probably because the higher lipolysis ability and presence of Ca(2+) and Mg(2+) in the gastrointestinal fluid of UBM resulted in a lower potential to form stable micelles compared to PBET and IVD. These results indicated that PFOA relative bioavailability was mainly affected by lipid content in foods, and UBM has the potential to determine PFOA bioaccessibility in food samples.
食物是人类接触全氟辛酸 (PFOA) 的主要来源，但食物中 PFOA 的生物利用度尚未得到研究。本研究使用体内小鼠模型和三种体外方法（统一 BARGE 方法、UBM；生理基础提取试验、PBET；和体外消化方法、IVD）来确定 17 种食物中 PFOA 的相对生物利用度和生物可及性。将 PFOA 与不同营养成分的食物混合，在 7 天内喂给小鼠。通过比较通过食物暴露于 PFOA 后肝脏中 PFOA 的积累与水中的积累，来确定 PFOA 的相对生物利用度。PFOA 相对于水的生物利用度范围为 4.30 ± 0.80 至 69.0 ± 11.9%，与脂质含量呈负相关（r = 0.76）。这可能是由于游离脂肪酸与 PFOA 在肠上皮细胞转运体上的竞争吸附所致。此外，胃肠道中的阳离子，如 Ca(2+) 和 Mg(2+)，能够与 PFOA 形成配合物并分配到脂质相。另一方面，当使用体外测定法评估时，PFOA 的生物可及性因方法而异，范围为 8.7-73%（UBM）、9.8-99%（PBET）和 21-114%（IVD）。当使用 UBM 评估时，PFOA 的生物可及性与脂质含量呈负相关（r = 0.82）；然而，对于 PBET 和 IVD，观察到与食物成分的相关性较差（r = 0.01-0.50）。当比较体内和体外数据时，UBM 之间存在很强的相关性（r = 0.79），但对于 PBET 和 IVD 则相关性较差（r = 0.11-0.22）。这可能是因为 UBM 中的胃肠道液具有较高的脂肪分解能力和 Ca(2+) 和 Mg(2+) 的存在，与 PBET 和 IVD 相比，形成稳定胶束的潜力较低。这些结果表明，PFOA 的相对生物利用度主要受食物中脂质含量的影响，UBM 有可能确定食物样品中 PFOA 的生物可及性。
