Hurdzan Christopher M, Basta Nicholas T, Hatcher Patrick G, Tuovinen Olli H
Soil Science Program, Ohio State University, Columbus, OH 43210, USA.
Ecotoxicol Environ Saf. 2008 Mar;69(3):525-30. doi: 10.1016/j.ecoenv.2007.02.006. Epub 2007 Apr 11.
The aliphatic region of natural organic matter (NOM) can retain polycyclic aromatic hydrocarbons (PAH) due to the presence of non-polar binding sites. Thus NOM may act as a vehicle for entry of PAH into the gastrointestinal system in man and animals. In this study, the release of phenanthrene from the aliphatic NOM surrogates cutin and cutan was measured under simulated human gastrointestinal formulations using three treatments designed to simulate the biological and chemical conditions of the gastrointestinal environment. The three experimental treatments were composed of fecal microorganisms, chyme, and chyme+fecal microorganisms. Water was used as a control treatment. Phenanthrene laden biopolymer and a C18 membrane were immersed in each treatment. Phenanthrene was extracted from each membrane and measured with HPLC. Membrane-associated phenanthrene was taken to represent the fraction that had desorbed from the biopolymer. Cutin was found to yield an average phenanthrene release 55% higher than cutan (94% vs. 39%). A significant decrease (p<0.05) in phenanthrene release was observed in both the chyme and chyme+fecal microorganism treatments as compared to the water treatment (control). The presence of enteric microorganisms did not significantly influence phenanthrene release and did not reduce phenanthrene bioaccessibility in gastrointestinal chyme. Over 80% of the phenanthrene in cutin was recovered in the C18 matrix and its relative amount was uninfluenced by the treatments. For cutan, only 25-50% of the phenanthrene was recovered, suggesting that cutin-associated phenanthrene was more loosely bound. These data demonstrate that the fractions of NOM retained phenanthrene to a varying extent and thus the predictions of phenanthrene bioavailability should also be assessed on the basis of the constituents of the NOM matrix.
由于存在非极性结合位点，天然有机物（NOM）的脂肪族区域能够保留多环芳烃（PAH）。因此，NOM可能作为PAH进入人和动物胃肠道系统的载体。在本研究中，在模拟人体胃肠道制剂的条件下，使用三种旨在模拟胃肠道环境生物和化学条件的处理方法，测定了菲从脂肪族NOM替代物角质和角质体中的释放情况。这三种实验处理分别由粪便微生物、食糜以及食糜+粪便微生物组成。用水作为对照处理。将负载菲的生物聚合物和C18膜浸入每种处理中。从每个膜中提取菲并用高效液相色谱法进行测定。膜结合的菲被视为从生物聚合物中解吸出来的部分。结果发现，角质产生的菲平均释放量比角质体高55%（分别为94%和39%）。与水处理（对照）相比，在食糜和食糜+粪便微生物处理中均观察到菲释放量显著降低（p<0.05）。肠道微生物的存在并未显著影响菲的释放，也未降低胃肠道食糜中菲的生物可及性。角质中超过80%的菲在C18基质中被回收，其相对含量不受处理的影响。对于角质体，仅回收了25%-50%的菲，这表明与角质体结合的菲结合得更松散。这些数据表明，NOM的不同组分对菲的保留程度不同，因此菲生物有效性的预测也应基于NOM基质的成分进行评估。
