Sodium arsenite naaso2

Forty-eight healthy Wistar rats, with initial weights of 80 g–100 g, were randomly divided into six groups, with eight rats in each group, half male and half female. Six groups were treated with sodium arsenite (NaAsO₂) (0.0, 2.5, 5.0, 10.0 mg/kg) (Sigma, St. Louis, MO, USA), 10 mL/kg of R. roxburghii juice (Sinopharm Group Guizhou Healthcare Industry Development Co., Ltd., Guiyang, China; the health food license number of National Health Commission of the People’s Republic of China [2002]0004) and 10.0 NaAsO₂ mg/kg + 10 mL/kg of R. roxburghii juice by gavage, respectively, once a day for 16 weeks. All animals were given a standard diet and housed in separate cages with a temperature of 22–24 °C, humidity of 60–70%, and light/dark for 12 h/12 h. The rats were anesthetized using an intraperitoneal injection of 1% sodium pentobarbital at the end of the treatment and then sacrificed by cervical dislocation. The liver tissues of the rats were collected. A portion of the isolated liver was soaked in 4% paraformaldehyde for 48 h, and then hematoxylin and eosin (HE) staining were performed to assess the pathological changes. The remaining isolated liver was stored at −80 °C for subsequent assays. The study protocol was reviewed and approved by the Ethics Committee of Guizhou Medical University (Approval No. 1403059).

Sodium arsenite (NaAsO₂, ≥99.0%) was obtained from Sigma Chemical Co. (St. Louis, MO, USA). NaAsO₂ was dissolved in distilled water and diluted to the desired concentrations. Glutathione (GSH), maleic dialdehyde (MDA) and total antioxidative capacity (T-AOC) assay kits were purchased from Jiancheng Biological Institute (Nanjing, China). Primary antibodies of NRF2 (H-300: sc-13032), HO-1 (H-105: sc-10789), GSTO1/2 (FL-241: sc-98560), GCLC (H-300: sc-28965), β-actin (I-19: sc-1616) and corresponding secondary antibodies were all purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Real-time polymerase chain reaction (real-time PCR) kits were from Takara Co. (Otsu, Japan). Potassium hydroxide (KOH), hydrochloric acid (HCl) and potassium borohydride (KBH₄) were purchased from Shanghai Chemical Co. (Shanghai, China) with arsenic free (<0.01 mg/L). All other chemicals used were of the highest grade commercially available. Water used in all the preparations was distilled and deionized.

Human bronchial epithelial BEAS-2B (BEAS-2B) and As-T cells were established and cultured in DMEM medium mixed with 10% heat-inactivated fetal bovine serum (FBS), 100 units/mL penicillin G, and 100 μg/mL streptomycin, as previously described (21 (link)). Sodium arsenite (NaAsO₂) and CRM197 were purchased from Sigma Aldrich (St. Louis, MO). EGFR, p-EGFR, PKM2, p-ERK, β-actin antibodies were purchased from Cell Signaling Technology (Danvers, MA, USA). SiHB-EGF, HB-EGF, PKM2 and siPKM2 were purchased from Santa Cruz Biotechnology (Dallas, TX, USA).

PS and LDPE resin pellets (3 mm in particle size) purchased from Sigma-Aldrich Australia were used as the adsorbents. Multi-element standard solution 4 for ICP (40 mg/L of As) was supplied by Sigma-Aldrich Pty Ltd., Australia. The solution was diluted by deionized water with a resistivity of 18 MΩ. Analytical grade sodium arsenate dibasic heptahydrate (Na₂HAsO₄⋅7H₂0) and sodium arsenite (NaAsO₂), purchased from Sigma-Aldrich Pty Ltd, were dissolved with deionized water to obtain As(III) and As(V) stock solutions (100 mg/L). The phosphoric acid (H₃PO₄, 85% w/w) and hydroxylamine hydrochloride (NH₂OH⋅HCl, 99% purity) were also obtained from Sigma-Aldrich Pty Ltd. Then, solutions of 1.0 M phosphoric acid and 0.2 M hydroxylamine hydrochloride were prepared by diluting their original standard solution with deionized water. All plasticware and glassware were soaked in 2% (v/v) HNO₃, followed by repeated rinsing with deionized water, and then dried before use.