Sodium iodate

C57BL/6J male mice weighing 20–25 g (Damul Science, Deajeon, Korea) were housed in cages with free access to food and water and maintained in temperature and light controlled rooms (23 ± 2 °C, 55 ± 10%, 12/12 h light/dark cycle with lights on at 8:00) at least one week before the experiments. The in vivo experiment was performed in accordance with the Jeonju AgroBio-Materials Institute (JAMI) guidelines under a protocol approved by the Institutional Animal Care and Use Committee (IACUC) of institute and all experiments strictly followed committee guidelines (JAMI IACUC 2019001). Mice were randomly divided into the following six groups (n = 6 per group), which were N (normal control), C (control), P-Y (195 mg/kg), FP-Y (1 × 10⁸ CFU for L. plantarum and 195 mg/kg for P-Y), P-O (195 mg/kg), or FP-O (1 × 10⁸ CFU for L. plantarum and 195 mg/kg for P-O) treatment group. The raw or fermented paprika powder was suspended in saline. Each of the samples were administered orally once a day for 1 week following SI (sodium iodate, Sigma-Aldrich) treatment. SI was dissolved in sterile normal saline and treated for 5 days by intraperitoneal injection. C group were administered with the normal saline instead of samples. At the end of the study, blood and tissues were harvested from the sacrificed mice after being anesthetized with tribromoethanol (Avertin, Sigma-Aldrich).

Sodium tungstate
dihydrate (Na₂WO₄·2H₂O), sodium
borohydride (NaBH₄), sodium iodide (NaI), and sodium iodate
(NaIO₃) were purchased from Sigma Aldrich and used as received.
All solutions were prepared using deionized (DI) water. Other chemicals
used for experiments were purchased from commercial sources and used
without further purification.

After the Sodium iodate (SI, Sigma-aldrich, San Francisco, CA, United States) treatment, the cell viability was measured with CCK-8 kit (Yeasen, Shanghai, China) according to the manufacturer’s protocol then was detected with a microplate reader (BioTek, VT, United States). Propidium Iodide (PI) staining assay was also used to evaluate the cell viability. Briefly, after treatment, cells were incubated with PI (10 μg/ml) and Hoechst for 10 min before imaging at 550 nm.

C57BL/6 mice (male, 6–7-week-old, weight range: 18–23 g) were purchased from Guangdong Laboratory Animal Center (Guangzhou, China) and maintained in the animal facility of the Zhongshan Ophthalmic Center at Sun Yat-sen University (Guangzhou, China). Sodium iodate (Sigma, #71702) and D609 (R&D Systems, #1437) were diluted in sterile phosphate-buffered saline (PBS) to concentrations of 2 mg/mL and 20 mg/mL and stored at 4 °C. SI was injected via the tail vein. D609 was injected via the orbital venous plexus. The control mice were injected with the same volumes of PBS.