[Effects of Buzhong Yiqi Formula on structure and function of sublingual glands of rat model of type 2 diabetes mellitus].

The efficacy of Buzhong Yiqi Formula(BZYQF) in alleviating type 2 diabetes mellitus(T2DM) is well-established, while the effect of this formula on T2DM-caused hyposalivation remains unclear. Specifically, the effects of BZYQF on the structure and function of sublingual glands in the rat model of T2DM have not been reported. To investigate the improving effects of BZYQF on the structure and function of sublingual glands in the rat model of T2DM, this study established a rat model of T2DM and treated the modeled rats with BZYQF by gavage at a dose of 8 g·kg~(-1)·d~(-1) for 11 weeks. Serum and total saliva were collected to determine blood biochemical indicators, salivary flow rate, and salivary α-amylase(sAA) activity. After the last administration, rats were sacrificed. The sublingual glands were collected to observe the histopathological structure, measure biochemical parameters, and quantify the expression of signaling molecules in saliva secretion pathways and inflammatory factors. The results showed that BZYQF significantly reduced the levels of fasting blood glucose, total cholesterol, and triglyceride, elevated the insulin level and homeostasis model assessment of insulin resistance, and significantly increased the salivary flow rate and sAA activity in the rat model of T2DM. In addition, BZYQF reduced glucose and lipid accumulation, increased acetylcholine content, ameliorated the structure and arrangement disorder of acinar cells and secretory ducts, reduced inflammatory cell infiltration, and restored the expression of signaling molecules including β-adrenergic receptor, protein kinase A, sAA, cholinergic receptor muscarinic 3, inositol triphosphate receptor, and aquaporin 5 in the saliva secretion pathways and inflammatory factors such as tumor necrosis factor-α and interleukin-6 in the sublingual glands of the rat model of T2DM. These results suggest that BZYQF effectively ameliorates T2DM and T2DM-caused pathological damage and salivary secretion disorder in sublingual glands of rats, which may be one of the mechanisms by which BZYQF ameliorates hyposalivation in the rat model of T2DM. This study provides a novel theoretical foundation and therapeutic strategy for BZYQF in the treatment of diabetic xerostomia.