Diabetes mellitus (DM) is one of the major metabolic diseases. Xerostomia and salivary gland dysfunction are of its common oral complications. Exosomes, as a new therapeutic potential containing nucleic acids, proteins and lipids, act as effective vehicles for target molecules delivery. Accordingly, their therapeutic use is gaining much interest. Therefore, this work aimed to assess the therapeutic efficacy of salivary exosomes in ameliorating DM and combating xerostomia as a complication of salivary gland dysfunction in diabetic rats. In the current study, salivary exosomes were injected intravenously to rats of group II (Salivary Exo-treated group) one week after diabetes induction. Group I (Diabetic group) was left untreated. Blood sugar level was checked weekly. Water intake, salivary flow rate, salivary amylase and serum nitric oxide were assessed before and after diabetes induction and at the end of the study. After 5 weeks from the beginning of the study, salivary gland tissues were dissected and examined histologically and ultrastructurally. Gene expression of the inflammatory markers NFκB/p65 and TNFα was assessed by polymerase chain reaction. The results showed that salivary exosomes reduced blood glucose levels and enhanced salivary glands’ function. This was indicated by a decrease in water intake, salivary amylase and serum nitric oxide in addition to an increase in salivary flow rate. This was confirmed histologically, ultrastructurally and via downregulation of NFκB/p65 and TNFα gene expression. Our results concluded that salivary exosomes could be considered as a novel cell free based therapy in treatment of xerostomia and salivary gland dysfunction in DM.

糖尿病（DM）是主要的代谢性疾病之一。口腔干燥症和唾液腺功能障碍是其常见的口腔并发症。外泌体作为一种含有核酸、蛋白质和脂质的新治疗潜力，可作为靶分子递送的有效载体。因此，它们的治疗用途越来越受到关注。因此，这项工作旨在评估唾液外泌体在改善糖尿病和对抗作为糖尿病大鼠唾液腺功能障碍并发症的口腔干燥症方面的治疗效果。在目前的研究中，在糖尿病诱导一周后，将唾液外泌体静脉注射给第 II 组（唾液外泌体治疗组）的大鼠。第 I 组（糖尿病组）未经治疗。每周检查血糖水平。饮水量、唾液流量、在糖尿病诱导前后和研究结束时评估唾液淀粉酶和血清一氧化氮。从研究开始 5 周后，解剖唾液腺组织并进行组织学和超微结构检查。通过聚合酶链反应评估炎症标志物 NFκB/p65 和 TNFα 的基因表达。结果表明，唾液外泌体降低了血糖水平并增强了唾液腺的功能。除了唾液流速增加外，水摄入量、唾液淀粉酶和血清一氧化氮的减少也表明了这一点。这在组织学、超微结构和通过下调 NFκB/p65 和 TNFα 基因表达得到证实。