Fig. 4

The therapeutic effect of OI on glucose homeostasis and inflammation in STZ-induced diabetes. A Schematic representation of the experimental protocol. C57BL/6 mice with STZ-induced diabetes received OI (25 mg/kg) daily after hyperglycemia onset and for 12 weeks. B Mouse body weight change (n = 6–9 mice per group). C Random blood glucose measurements were performed before the study and at the end of OI treatment. D Week 11 OGTT results. E Representative images of pancreatic histology evaluated by H&E staining (n = 5–7 mice per group). F Representative images of pancreatic immunofluorescence staining for insulin (red), glucagon (green), and DAPI (blue). Insulin expression per islet was determined by analyzing fluorescence intensity with ImageJ. The percentage of glucagon-positive cells per islet was calculated in a bar graph (n = 3 mice per group). G Immunohistochemistry analysis of Nrf2, HMGB1, F4/80, and iNOS expression in mouse pancreas. Nrf2 expression was analyzed by ImageJ and presented as the AOD. The percentage of HMGB1-positive nuclei per islet was quantified in a bar graph. The F4/80- and iNOS-positive cells per islet area were calculated in a bar graph (n = 3–5 mice per group). All values are shown as the mean ± SEM. **p < 0.01, ***p < 0.001, and ****p < 0.0001