Effects of iguratimod on inflammatory factors and apoptosis of submandibular gland epithelial cells in NOD mice

Non-obese diabetic (NOD) mice were taken as primary Sjögren’s syndrome (pSS) model mice to examine the therapeutic impact of iguratimod (IGU) on inflammatory factors levels and apoptosis of submandibular epithelial cells, and provide experimental basis for the treatment of pSS by iguratimod. Twenty-four NOD murine models were divided into the model, high-dose (IGU 30 mg/kg) and low-dose (IGU 10 mg/kg) groups, eight mice per group. The normal control group comprised eight C57B/L mice. From 8 weeks of age, the NOD mice were administered IGU by intragastric gavage administration every day for 8 weeks; their water consumption, saliva secretion, submandibular gland, and spleen indices were measured. The levels of serum inflammatory factor (IL-1β, TNF-α, IL-6, and IL-17) were evaluated, and Bax, caspase-3, and Bcl-2 levels were detected. The histological alterations in the submandibular glands were discovered. IGU can reduce the water intake of NOD mice (p < 0.01), increase the saliva secretion and the submandibular gland index (p < 0.01); reduce the spleen index and the serum inflammatory factors (p < 0.01); improve the pathological tissue damage and cell apoptosis of the submandibular gland (p < 0.05). IGU can reduce the expression levels of inflammatory mediators in the serum and the extent of lymphocyte infiltration and apoptosis in submandibular gland epithelial cells. It can also regulate apoptosis-related protein expression, thereby improving the secretory function of exocrine glands.