Seleno l methionine

Seleno-L-methionine (≥98% (TLC)) and D-pantethine were purchased from Sigma (St. Louis, MO), and doxorubicin hydrochloride was obtained from Pfizer (New York, NY). Antioxidants were dissolved in sterile 0.9% sodium chloride solution prior to per os treatment of animals or addition to cell culture.

After expansion in their optimum media, the different cell types were trypsinized and transferred to organoid media as described by Unno et al.¹⁶ . Briefly; 5000 cells were resuspended in organoid media containing low percentage matrigel (5%) then plated in to 96-well ultralow attachment plates (Corning no. 3474). A hunderd microliters of fresh media was added to the cultures every four days or every two days once the treatments commenced. Treatments were added to the following final concentrations; 40 μM DL-αTocopherol-Acetate (Sigma no. T3376), 40 μM RRR-γ-Tocopherol (Sigma no. T1782) and/or 1.3 μM Seleno-L-methionine (Sigma no. S3132) representing the mean concetrations attained in the blood plasma of the SELECT subjects^{21 (link)}. N-acetyl cysteine (NAC; Sigma no. A9165) and Etomoxir sodium salt hydrate (Eto; Sigma no. E1905) were used at various concentrations as indicated in the figures. Organoid growth was captured by brightfield microscopy using Zeiss Axioskop/Nuance microscope (Carl Zeiss Inc. Oberkochen, Germany).

Folin–Ciocalteu reagent
and nitric acid were purchased from VWR International (Barcelona,
Spain); methanol, acetone, sodium carbonate, and Trolox standard were
purchased from Fisher Scientific (Madrid, Spain); hydrogen peroxide
was purchased from Panreac Applichem (Barcelona, Spain); gallic acid,
diphenyl-2,4,6-trinitrophenyl iminoazanium (DPPH), sodium selenite,
sodium selenate, seleno-l-methionine (≥98%), seleno-l-cystine (95%), and Se-(Methyl) selenocysteine hydrochloride
(≥95%) were purchased from Sigma-Aldrich (St. Louis); and Milli-Q
water was purified through a purification system from Millipore (Billerica,
MA).