<em>In vitro</em> metabolism of rebaudioside E under anaerobic conditions: Comparison with rebaudioside A

The hydrolysis of the steviol glycosides rebaudioside (Reb) A and E, as well as steviolbioside (a metabolic intermediate) to steviol was evaluated in vitro using human fecal homogenates from healthy Caucasian and Asian donors. Incubation of each of the Rebs in both groups resulted in a rapid hydrolysis to steviol. Metabolism of 0.2mg/mL sample was complete within 24h, with the majority occurring within the first 16h. There were no clear differences in the rate or extent of metabolism of Reb E relative to the comparative control Reb A. The hydrolysis of samples containing 2.0mg/mL of steviol glycosides Reb A and Reb E tended to take slightly longer than 0.2mg/mL samples. Herein, we report for the first time that there were no apparent gender or ethnicity differences in the rate of metabolism of any of the Rebs, regardless of the concentrations tested. Steviolbioside, an intermediate in the hydrolysis of Reb E to steviol was also found to be rapidly degraded to steviol. These results demonstrate Reb E is metabolized to steviol in the same manner as Reb A. These data support the use of toxicology data available on steviol, and on steviol glycosides metabolized to steviol (i.e., Reb A) to underpin the safety of Reb E.

使用来自健康的高加索人和亚洲人捐赠者的人类粪便匀浆在体外评估了甜菊糖苷莱鲍迪苷（Reb）A和E以及甜菊双糖苷（一种代谢中间产物）水解为甜菊醇的情况。两组中每种莱鲍迪苷的孵育都导致迅速水解为甜菊醇。0.2mg/mL样品的代谢在24小时内完成，大部分在最初的16小时内发生。与对照莱鲍迪苷A相比，莱鲍迪苷E的代谢速率或程度没有明显差异。含有2.0mg/mL甜菊糖苷莱鲍迪苷A和莱鲍迪苷E的样品的水解往往比0.2mg/mL样品所需时间略长。在此，我们首次报告，无论所测试的浓度如何，任何一种莱鲍迪苷的代谢速率都没有明显的性别或种族差异。甜菊双糖苷作为莱鲍迪苷E水解为甜菊醇的中间产物，也被发现迅速降解为甜菊醇。这些结果表明莱鲍迪苷E以与莱鲍迪苷A相同的方式代谢为甜菊醇。这些数据支持利用甜菊醇以及代谢为甜菊醇的甜菊糖苷（即莱鲍迪苷A）的现有毒理学数据来支撑莱鲍迪苷E的安全性。