Li Jie, Chen Shuo, Li Hongbo, Liu Xue, Cheng Jiemin, Ma Lena Q
College of Geography and Environment, Shandong Normal University, Jinan, 250358, People's Republic of China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
Environ Res. 2021 Jul;198:111198. doi: 10.1016/j.envres.2021.111198. Epub 2021 Apr 30.
Rice consumption is a major dietary source of human exposure to arsenic (As), with As bioavailability being an important factor influencing its health risk. In this study, the As bioaccessibility was measured in 11 rice grains (140-335 μg As kg), which were compared to As relative bioavailability previously measured based on a mouse bioassay (Li et al., 2017). Using modified physiologically-based extraction test for rice (MPBET), As bioaccessibility in raw rice samples (44-88% in the gastric phase and 47-102% in the intestinal phase) was similar to those in cooked rice (42-73% and 43-99%). Arsenic bioaccessibility in rice was generally higher in the intestinal phase than in the gastric phase, with Fe and Ca concentrations in rice being negatively correlated with As bioaccessibility in the gastric phase (R = 0.47-0.49). In addition, for cooked rice, strong positive correlation was observed between bioaccessible As and inorganic As (R = 0.63-0.72), suggesting inorganic As in rice was easier to dissolve than organic As in gastrointestinal digestive fluids. Due to limited variation in As bioaccessibility and As bioavailability among the 11 samples, a weak correlation was observed between them (R = 0.01-0.03); however, As bioaccessibility values measured by the gastric phase (GP) of the MPBET agreed with As bioavailability values based on a mouse bioassay, suggesting the potential of the MPBET to predict As bioavailability in rice. Future work is needed to ascertain the robustness of the MPBET in predicting As bioavailability in rice using additional samples.
食用大米是人类接触砷（As）的主要饮食来源，砷的生物可利用性是影响其健康风险的一个重要因素。在本研究中，对11种大米颗粒（含砷量为140 - 335μg/kg）中的砷生物可给性进行了测定，并将其与之前基于小鼠生物测定法测得的砷相对生物利用度进行了比较（Li等人，2017年）。使用改良的基于生理学的大米提取试验（MPBET），生大米样品中的砷生物可给性（胃相阶段为44 - 88%，肠相阶段为47 - 102%）与熟大米中的相似（分别为42 - 73%和43 - 99%）。大米中砷的生物可给性在肠相阶段通常高于胃相阶段，大米中的铁和钙浓度与胃相阶段的砷生物可给性呈负相关（R = 0.47 - 0.49）。此外，对于熟大米，可生物利用的砷与无机砷之间存在强正相关（R = 0.63 - 0.72），这表明大米中的无机砷比有机砷在胃肠消化液中更易溶解。由于11个样品之间砷生物可给性和砷生物利用度的变化有限，二者之间的相关性较弱（R = 0.01 - 0.03）；然而，MPBET胃相（GP）测得的砷生物可给性值与基于小鼠生物测定法的砷生物利用度值相符，这表明MPBET有预测大米中砷生物利用度的潜力。未来需要开展更多工作，通过增加样品来确定MPBET在预测大米中砷生物利用度方面的稳健性。
