Effect of electroacupuncture combined with Zhuang-medicine-thread moxibustion on oxidative stress in gastric antrum of diabetic gastroparesis rats

Abstract

To observe the effect of electroacupuncture (EA) combined with Zhuang-medicine-thread moxibustion on oxidative stress-related indicators in diabetic gastroparesis (DGP) rats, so as to explore its mechanism underlying improvement of DGP. Male SD rats were randomly divided into normal, model, medication, EA, Zhuang-medicine-thread moxibustion (moxibustion) and EA+Zhuang-medicine-thread moxibustion (combination) groups (15 rats in each group). The DGP model was established by intraperitoneal injection of streptozotocin (STZ). Rats of the medication group were treated by gavage of 0.15 mg/mL mosapride citrate suspension（10 mL/kg）. EA (10 Hz/50 Hz, 2 mA, 20 min) or Zhuang-medicine-thread moxibustion (3 cones) was applied to "Zhongwan" (CV12), bilateral "Neiguan" (PC6) and bilateral "Sanyinjiao" (SP6) of the related groups, once a day for 3 weeks. The body weight, blood glucose, gastric emptying rate and intestinal propulsion rate of rats were measured. The serum malondialdehyde (MDA) content was measured by thiobarbituric acid method, the serum supero-xide dismutase (SOD) activity was measured by xanthine oxidase method, and the serum reactive oxygen species (ROS) activity was detected by ELISA. HE staining was used to observe the pathological changes of gastric antrum. The expression of heme oxygenase-1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), nicotin-amide adenine dinucleotide phosphate oxidases (NOX4), peroxisome proliferators activated receptor-gamma coactivator 1α(PGC-1α) proteins and mRNAs in gastric antrum was detected by Western blot and real-time quantitative PCR, respectively. Compared with the normal group, the body weight, gastric emptying rate, intestinal propulsion rate, serum SOD activity, the expressions of HO-1, PGC-1α, total Nrf2 proteins and mRNAs, and Nrf2 nuclear translocation in gastric antrum were decreased (P<0.01), while the blood glucose, serum MDA content and ROS activity, NOX4 protein and mRNA expressions in gastric antrum were increased (P<0.01) in the model group. Compared with the model group, the blood glucose was decreased in the EA, moxibustion and combination groups (P<0.01); the body weight, gastric emptying rate, intestinal propulsion rate, and the expressions of HO-1 and PGC-1α mRNAs in gastric antrum were all increased in the four treatment groups (P<0.01, P<0.05), while the serum MDA content and ROS activity, NOX4 protein and mRNA expressions in gastric antrum were all decreased (P<0.01); the serum SOD activity and total Nrf2 protein expression in gastric antrum were increased in medication, moxibustion and combination groups (P<0.01, P<0.05); the expressions of HO-1 and PGC-1α proteins, and Nrf2 nuclear translocation in gastric antrum were increased in medication and combination groups (P<0.05, P<0.01); the expression of Nrf2 mRNA was increased in the medication, EA and combination groups (P<0.01, P<0.05). Compared with the combination group, the body weight, gastric emptying rate and intestine propulsion rate were decreased in the medication, EA and moxibustion groups(P<0.01, P<0.05), and the blood glucose increased (P<0.01); the serum MDA content and ROS activity, NOX4 protein and mRNA expressions in gastric antrum were increased (P<0.01, P<0.05), serum SOD activity, and the expressions of total Nrf2 protein, PGC-1α protein and mRNA, HO-1 mRNA in gastric antrum were decreased (P<0.01, P<0.05) in the EA and moxibustion groups; the expression of Nrf2 mRNA was decreased in the moxibustion group (P<0.05). HE staining showed a large number of inflammatory cell infiltration in the lamina propria and submucosa, and the gastric glands in the lamina propria were significantly expanded, the submucosa was severely edematous in the model group, which were relative milder in the four treatment groups. EA combined with Zhuang-medicine-thread moxibustion can effectively improve the activity of antioxidant enzymes, reduce the production of lipid peroxide, and regulate the expression of antioxidant related proteins and genes, which may be one of the mechanisms in treating DGP.