The non-nutritive sweetener erythritol adversely affects brain microvascular endothelial cell function

Abstract

The experimental aim of this study was to determine, in vitro, the effect of the non-nutritive sweetener erythritol on brain microvascular endothelial cell oxidative stress, nitric oxide (NO) and endothelin (ET)-1 production, as well as tissue-type plasminogen activator (t-PA) release. Human cerebral microvascular endothelial cells (hCMECs) were cultured and treated with 6 mM erythritol, equivalent to a typical amount of erythritol (30 g) in an artificially sweetened beverage, for 3 h. Intracellular reactive oxygen species (ROS) production was significantly higher in hCMECs treated with erythritol (204 ± 32% vs. 105 ± 4%) as well as the expression of antioxidant proteins, superoxide dismutase-1 [332.1 ± 16.2 vs. 214.9 ± 4.7 arbitrary units (AU); P = 0.002] and catalase (30.9 ± 0.3 vs. 24.4 ± 0.9 AU; P = 0.002). Although endothelial nitric oxide synthase (eNOS) expression was not significantly altered (102.8 ± 21.4 vs. 99.0 ± 19.9 AU); the expression of p-eNOS (Ser1177) was lower (52.1 ± 2.1 vs. 77.3 ± 9.1 AU; P < 0.001), and p-eNOS (Thr495) was higher (63.4 ± 8.0 vs. 45.6 ± 6.9 AU; P = 0.006) in hCMECs treated with erythritol. Cell expression of Big ET-1 was also higher in erythritol-treated cells (56.4 ± 9.8 vs. 40.9 ± 6.5 AU; P = 0.02). Consequently, the endothelial NO production was significantly lower (5.8 ± 0.8 vs. 7.3 ± 0.7 µmol/L) and ET-1 production was significantly higher (34.6 ± 2.3 vs. 26.9 ± 1.5 pg/mL) in response to erythritol. t-PA release in response to thrombin was significantly blunted in erythritol-treated (from 87.4 ± 6.3 to 87.6 ± 8.3 pg/mL) versus untreated (90.1 ± 5.5 to 110.2 ± 6.4 pg/mL) hCMECs. In summary, erythritol adversely affects oxidative stress, NO production, ET-1 production, and t-PA release in brain microvascular endothelial cells, potentially contributing to the increased risk of ischemic stroke associated with erythritol.NEW & NOTEWORTHY Erythritol, a common non-nutritive sweetener, is associated with increased risk of cardiovascular and cerebrovascular events. This study provides novel data, demonstrating that erythritol (at a concentration typically contained in a standard-size commercially available artificially sweetened beverage) adversely affects brain microvascular endothelial cell oxidative stress, eNOS activation and NO production, ET-1 expression, and t-PA release in vitro.

Keywords: eNOS; endothelin-1; erythritol; oxidative stress; tissue-type plasminogen activator.