Salvianolic acid A improves intestinal motility in diabetic rats through antioxidant capacity and upregulation of nNOS

Objective This study aimed to detect the effect of a new herbal extract salvianolic acid A (SalA) on gastrointestinal complications in diabetic rats. Methods Altogether 80 rats were divided randomly into five groups, including normal control (NC) group, high‐fat (HF) diet group, diabetes mellitus (DM) control group, and DM treated with SalA (0.1 mg/kg and 0.3 mg/kg) groups, respectively. DM was induced by feeding the rats with HF diet and the administration of streptozotocin (30 mg/kg). Four weeks after the establishment of the DM model, the rats received SalA or double distilled water for 8 weeks. After the evaluation of intestinal motility, the animals were sacrificed and their intestines were isolated and collected. The levels of advanced glycation end‐products (AGE) and malondialdehyde (MDA) were detected. Protein gene product 9.5 (PGP9.5) and neuronal nitric oxide synthase (nNOS) expressions in the intestine were also detected. Results Compared with the NC and HF rats, the DM control rats showed significantly increased blood glucose level and decreased weight. Compared with the DM control group, SalA did not influence their weight and blood glucose level, but significantly reduced the levels of AGE and MDA. Intestinal transit was promoted by SalA in diabetic rats, and the expressions of PGP9.5 and nNOS in the intestine were both upregulated. Conclusion The effect of SalA on the intestinal motility of diabetic rats might be due to its antioxidant capacity and restoring nNOS expression.