Glucose analyzer

All animals’ procedures were approved by the Animal Ethics Committee of West China Hospital, Sichuan University. All methods were performed in accordance with the relevant guidelines and regulations. C57BL/6 male mice, about eight weeks old, weighing 18–22 g, were obtained from the Experimental Animal Center of Sichuan University. All mice were tested with a random blood glucose measured by Glucose Analyzer (Roche, Shanghai, China) as baseline blood glucose concentration and then randomly assigned to normal mice group or diabetes mice group. Each group had 10 mice. All mice were fasted overnight, and injected intraperitoneally with 150 mg kg⁻¹ streptozocin (Sigma, St. Louis, MO, USA) dissolved in citrate buffer (pH 4.5, Sigma, St. Louis, MO,USA) or with an equal volume of citrate buffer. 72 h later, mice with a random blood glucose higher than16.7 mM were defined as diabetic mice^{35 (link)–37} . Then mice were feed 8 weeks after injection. Glucose levels were monitored weekly and mice did not meet this criterion were excluded.

The effect of seaweed supplementation on fasting blood glucose, insulin, and HOMA-IR was evaluated at the end of the treatment. Blood samples were collected from the tail vein of rat after an overnight fasting (8 h). Fasting blood glucose levels were determined by glucose analyzer (Roche, Mannheim, Germany). Insulin concentrations were estimated using an enzyme-linked immunosorbent assay (ELISA) analyzer (Tecan Genios, Salzburg, Austria). For insulin assay, 200 μL of blood sample was centrifuged at 3000 rpm of 10 min, and serum was collected into a separate tube. Insulin levels were then determined using ELISA kit provided by Diagnostic Systems Laboratories (Webster, TX, USA). HOMA-IR was calculated based on the fasting blood glucose and insulin values.