Fig. 2. Polydatin Inhibits G6PD causing redox imbalance, which leads to ER stress and cell death.

a Viability assay (MTT) of UMSCC103 treated with polydatin (20 µM) and 4μ8c (IRE inhibitor), GSK2606414 (PERK inhibitor) or with siRNA for either IRE1 or PERK, 24 or 48 h posttreatment, respectively. b IF with CellROX (for oxidative stress determination), 24 h posttreatment (In fig S5: menadione is used as positive control; N-acetylcysteine (NAC) is used as ROS scavenger; quantitative assay). c IF with ER-Tracker on UMSCC103 treated with polydatin in combination with NAC, 24 h posttreatment. d G6PD enzymatic assay on UMSCC103 cell lysates (the same assay performed with purified enzyme is found in Fig. S2C). e NADP + /NADPH ratio on polydatin-treated cells. f Invasion assay of UMSCC103 after polydatin treatment. *p < 0.05, N = 3, error bar = 95% confidence