Epigallocatechin gallate (egcg)

Dextran sulfate sodium (DSS) salt, MP Grade (36,000–50,000 Da), was purchased from MP Biomedicals (Santa Ana, CA). DSS solution was prepared by dissolving DSS salt in drinking water at a final concentration of 2.5% (w/v). (−)-Epigallocatechin gallate (EGCG) (≥ 95%) and fluorescein isothiocyanate conjugated dextran (FITC-dextran, 4KDa) was purchased from Sigma-Aldrich (Cat# FD4, St. Louis, MO, USA). EGCG solution was prepared by dissolving EGCG powder in phosphate buffered saline (PBS) at a final concentration of 10 mg/mL PBS and ammonium-chloride-potassium (ACK) lysing buffer was purchased from Thermo Fisher Scientific (Waltham, MA, USA).

Small molecules were purchased from Sigma (St. Louis, MS, USA) or Thermo Fisher (USA), and 5 mM stocks in water (doxycycline hyclate, EGCG, methylene blue) or ethanol (coumarin 1, diflunisal, rifamycin SV, rifampicin) were prepared and stored at −20 °C until needed. “Oxidized” EGCG was prepared by incubating aliquots of EGCG overnight at 37 °C in water, which were then stored at −20 °C. All experiments were carried out in phosphate-buffered saline (PBS; 1.5 mM KH₂PO₄, 8.1 mM Na₂HPO₄, 2.7 mM KCl, 138 mM NaCl, pH 7.4) at 37 °C.
Data were analyzed and figures prepared using the “Tidyverse” [59 (link)] suite of tools for R [60 ], within the RStudio environment [61 ]. Final figures were prepared using Adobe Acrobat.