Sodium selenite na2seo3

GLSO was purchased from certain commercial company. Sodium selenite (Na₂SeO₃) and ascorbic acid (VC) were purchased from Sigma Aldrich (USA). PI, JC-1, and glutathione peroxidase (GSH-Px), SOD, malondialdehyde (MDA), CCK8, and BCA assay kits were obtained from Beyotime Biotechnology (China). Dulbecco’s modified eagle medium (DMEM), 1640 medium, penicillin–streptomycin, and fetal bovine serum (FBS) were purchased from Gibco (USA). Antibodies for flow cytometry were obtained from Biolegend (USA), and antibodies for Western blot (WB) and ELISA were obtained from Cell Signaling Technology (USA).

The Se concentration in L. paracasei CCFM 1089 strain was determined by hydride atomic fluorescence spectrometry (AFS-8520, Beijing Haiguang Instrument Co., Ltd., Beijing, China), as reported by Li. et al. [21 (link)].
The Se forms in the strains were detected using high-performance liquid chromatography (HPLC, Ultimate3000, Thermo Fisher Scientific, Waltham, MA, USA) and inductively coupled plasma mass spectrometry (ICP-MS, NexION 350D, Perkin-Elmer, Waltham, MA, USA) according to Micaela Pescuma et al. [22 (link)]. Standard samples of SeCys (98%), methylselenocysteine (MeSeCys; 95%), SeMet (99%), sodium selenate (Na₂SeO₄; 98%), and sodium selenite (Na₂SeO₃; 98%) were purchased from Sigma-Aldrich LLC., Saint Louis, MO, USA.

Sodium selenite (Na₂SeO₃, Cat no: 214,485, ≥99% pure) and N-(1-pyrenyl) maleimide (NPM, Cat no: P7908, ≥98.5% pure) were purchased from Sigma-Aldrich (St. Louis, MO, USA). N-acetylcysteine amide (NACA, ≥99.9% pure) was provided by Dr. Glenn Goldstein (David Pharmaceuticals, New York, NY, USA). Casein zymogram gels (12% Ready Gel, Cat no: 161–1168) were purchased from Bio-Rad (Hercules, CA, USA). Rabbit m-calpain Antibody (Cat no: 2539S), GAPDH Rabbit mAb (Cat no: 2118S), and Anti-rabbit IgG, HRP-linked Antibody (Cat no: 7074S) were purchased from Cell Signaling Technology (Beverly, MA, USA). All other chemicals were purchased from Sigma-Aldrich, unless stated otherwise.

Citrus fruits i.e. Citrus limon (lemons) and Citrus paradise (grapefruits) were purchased from Local fruit market of Pakistan while metal salt; Sodium selenite (Na₂SeO₃) was purchased from Sigma Aldrich distributions.

YEP broth was purchased from Shanghai Rui Chu Bio-Tech Co., Ltd. (Shanghai, China). Sodium selenite (Na₂SeO₃, ≥99%) was purchased from Sigma-Aldrich (St. Louis, MO, USA). For the preparation of Na₂SeO₃ stock solution (2 mol/L), Na₂SeO₃ was diluted into distilled deionized water (ddH₂O) and filter-sterilized. All other analytical grade reagents were purchased from Sangon Biotech Co., Ltd. (Shanghai, China) and Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China).

Propanolan titanium (Ti(OCH₂CH₂CH₃)₄) 98%, sodium selenite (Na₂SeO₃) 99%, and sodium selenate (Na₂SeO₄) 98% were purchased from Sigma-Aldrich (Germany); propan-2-ol (C₃H₇OH) was purchased from Chempur (Poland); nitric acid (HNO₃) 65% and ammonia solution (NH₃·H₂O) 30% p.a. were purchased from POCH (Poland); standard solutions (1 mg mL⁻¹): Se(IV), As(III), and As(V) were purchased from Sigma-Aldrich (Germany), and Cr(III), Cr(VI), Cu(II), Pb(II), Zn(II), and Fe(III) were purchased from Merck (Germany); re-destilated water was from Milli-Q System of Millipore (France); filters Whatman 3MM were purchased from GE Healthcare Life Sciences (United Kingdom); Certified Reference Material (CRM) of natural water, NIST 1640a, was purchased from Sigma-Aldrich (Germany).
The following equipment were used for the research: FEI Nova NanoSEM 230 microscope (FEI Company, Hillsboro, Oregon, USA), x-ray powder diffractometer (XRD) (PANalytical, The Netherlands), energy-dispersive x-ray fluorescence spectrometer (EDXRF) XDV-SD model (Helmut Fischer GmbH, Sindelfingen, Germany), energy-dispersive x-ray fluorescence spectrometer (EDXRF) Epsilon 3 model (PANalytical, Almelo, The Netherlands), and inductively coupled plasma optical emission spectrometer (ICP-OES) SpectroBlue FMS16a model (Spectro Analytical Instruments GmbH, Germany). The apparatus is described in detail in ESM.