AIM: To investigate the protective mechanisms of Weikang (WK) decoction on gastric mucosae. METHODS: Ninety rats were randomly divided into nine groups of 10 each, namely group, model group, group with large WK dosage, group with medium WK dosage, group with small WK dosage, group with herbs of jianpiyiqi (strengthening the spleen and replenishing qi), group with herbs of yangxuehuoxue (invigorating the circulation of and nourishing the blood), group with herbs of qingrejiedu (clearing away the heat-evils and toxic materials), group with colloidal bismuth pectin (CBP) capsules. According to the method adopted by Yang Xuesong, except normal control group, chronic gastric ulcer was induced with 100% acetic acid. On the sixth day after moldmaking, WK decoction was administered, respectively at doses of 20, 10 and 5 g/kg to rats of the WK groups, or the groups with herbs of jianpiyiqi, yangxuehuoxue and qingrejiedu, 10 ml/kg was separately administered to each group every day. For the group with CBP capsules, medicine was dissolved with water and doses 15 times of human therapeutic dose were administered (10 mL/kg solution containing 0.35% CBP). Rats of other groups were fed with physiological saline (10 ml/kg every day). Administration lasted for 16 d. Rats were killed on d 22 after mold making to observe changes of gastric mucosa. The mucus thickness of gastric mucosa surface was measured. Levels of epidermal growth factor (EGF) in gastric juice, nitric oxide (NO) in gastric tissue, endothelin (ET) in plasma, superoxide dismutase (SOD) in plasma, malondialdehyde (MDA) in plasma and prostaglandin I2 (PGI2) were examined. RESULTS: Compared with control group, ulceration was found in gastric mucosa of model group rats. The mucus thickness of gastric mucosa surface, the levels of EGF, NO, 6-K-PGF1α and SOD decreased significantly in the model group (EGF: 0.818±0.18 vs 2.168±0.375, NO: 0.213±0.049 vs 0.601±0.081, 6-K-PGF1α 59.7±6.3 vs 96.6±8.30, SOD: 128.6±15.0 vs 196.6±35.3, P<0.01),the levels of ET (179.96±37.40 vs 46.64±21.20, P<0.01) and MDA (48.2±4.5 vs 15.7±4.8, P<0.01) increased. Compared with model group, the thickness of regenerative mucosa increased, glandular arrangement was in order, and cystic dilative glands decreased, while the mucus thickness of gastric mucosa surface increased (20 g/kg WK: 51.3±2.9 vs 23.2±8.4,10 g/kg WK: 43.3±2.9 vs23.2±8.4,, 5 g/kg WK: 36.1±7.2 vs 23.2±8.4, jianpiyiqi: 35.4±5.6 vs 23.2±8.4, yangxuehuoxue: 33.1±8.9 vs 23.2±8.4, qingrejiedu: 31.0±8.0 vs 23.2±8.4 and CBP: 38.2±3.5 vs23.2±8.4, P<0.05-0.01). The levels of EGF (20 g/kg WK: 1.364±0.12 vs 0.818±0.18, 10 g/kg WK: 1.359±0.24 vs 0.818±0.18, 5 g/kg WK: 1.245±0.31 vs 0.818±0.18, jianpiyiqi: 1.025± 0.45 vs 0.818±0.18, yangxuehuoxue: 1.03±0.29 vs 0.818±0.18, qingrejiedu: 1.02±0.47 vs 0.818±0.18 and CBP: 1.237±0.20 VS 0.818±0.18, p<0.05-0.01), NO (20 g/kg WK: 0.480±0.026 vs 0.213±0.049, 10 g/kg WK: 0.390±0.055 vs 0.213±0.049, 5 g/kg WK: 0.394±0.026 vs 0.213±0.049, jianpiyiqi: 0.393±0.123 vs 0.213±0.049, yangxuehuoxue: 0.463±0.077 vs 0.213±0.049, qingrejiedu: 0.382±0.082 vs 50.213±0.049 and CBP: 0.395±0.053 vs 0.213±0.049, P<0.05-0.01), 6-K-PGF1α (20 g/kg WK: 86.8±7.6 vs 59.7±6.3,10 g/kg WK: 77.9±7.0 vs 59.7±6.3, 5 g/kg WK: 70.0±5.4 vs 59.7±6.3, jianpiyiqi: 73.5±12.2 vs 59.7±6.3, yangxuehuoxue: 65.1±5,3 vs 59.7±6.3, qingrejiedu: 76.9±14.6 vs 59.7±6.3,and CBP: 93.7±10.7 vs 59.7±6.3, P<0.05-0.01) and SOD (20 g/kg WK: 186.4±19.9 vs 128.6±15.0,10 g/kg WK: 168.2±21.7 vs 128.6±15.0, 5 g/kg WK: 155.6±21.6 vs 128.6±15.0, jianpiyiqi: 168.0±85.3 vs 128.6±15.0, yangxuehuoxue: 165.0±34.0 vs 128.6±15.0, qingrejiedu: 168.2±24.9 vs 128.6±15.0, and CBP: 156.3±18.1 vs 128.6±15.0, P<0.05-0.01) significantly increased. The levels of ET (20 g/kg WK: 81.30± 17.20 vs 179.96±37.40, 10 g/kg WK: 83.40±25.90 vs 179.96±37.40, 5 g/kg WK: 93.87±20.70 vs 179.96±37.40, jianpiyiqi: 130.67±43.66 vs 179.96±37.40, yangxuehuoxue: 115.88±34.09 vs 179.96±37.40, qingrejiedu: 108.22±36.97 vs 179.96±37.40, and CBP: 91.96±19.0 vs 179.96±37.40, P<0.01) and MDA (20 g/kg WK: 21.6±7.4 vs 48.2±4.5, 10 g/kg WK: 32.2±7.3 vs 48.2±4.5, 5 g/kg WK: 34.2±6.2 vs 48.2±4.5, jianpiyiqi: 34.9±13.8 vs 48.2±4.5, yangxuehuoxue: 35.5±16.7 vs 48.2±4.5, qingrejiedu: 42.2±17.6 vs 48.2±4.5, and CBP: 30.1±6.1 vs 48.2±4.5, P<0.05-0.01) obviously decreased. The 20 g/kg WK group was better than 10 g/kg (the mucus thickness: 51.3±2.9 vs 43.3±2.9, NO: 0.480±0.026 vs 0.390±0.055, SOD: 186.4±19.9 vs 168,2±21.7, P<0.01) and 5 g/kg (the mucus thickness: 51.3±2.9 vs36.1±7.2, NO: 0.480±0.026 vs0.394±0.026, SOD: 186.4±19.9 vs155.6±21.6, P<0.01) groups and CBP group (the mucus thickness: 51.3±2.9 vs 38.2±3.5, NO: 0.480±0.026 vs 0.395±0.053, SOD: 186.4±19.9 vs 156.3±18.1, P<0.01) in the mucus thickness, NO and SOD levels and better than 10 g/kg (86.8±7.6 vs 77.9±7.0, P<0.05) and 5 g/kg (86.8±7.6 vs 70.0±5.4,P<0.05) groups in 6-K-PGF1α level, 10 g/kg WK group was better than 5 g/kg WK (the mucus thickness: 43.3±2.9 vs 36.1±7.2, P<0.01, SOD: 168.2±21.7 vs 155.6±21.6, P<0.05) and CBP groups (the mucus thickness: 43.3±2.9 vs 38.2±3.5, P<0.01, SOD: 168.2±21.7 vs 156.3±18.1, P<0.05) in the mucus thickness and SOD level. In compound group, jianpiyiqi group, yangxuehuoxue group, qingrejiedu group, the level of ET was decreased, NO contents were increased in gastric tissue of ulcers in rats. CONCLUSION: WK decoction and separated recipes have significantly protective effect on ethanol-induced gastric mucosal injury. They can increase the content of EGF in gastric juice, PGI2 SOD in plasma and NO in gastric tissues, thicken the mucus on the gastric mucosa, and decrease the impairing factor MDA, ET in plasma. AIM: To investigate the protective mechanisms of Weikang (WK) decoction on gastric mucosae. METHODS: Ninety rats were randomly divided into nine groups of 10 each, namely group, model group, group with large WK dosage, group with medium WK dosage, group group with herbs of qingrejiedu (clearing the heat-evils and toxic materials According to the method adopted by Yang Xuesong, except normal control group, chronic gastric ulcer was induced with 100% acetic acid. On the sixth day after moldmaking, WK decoction was administered, respectively at doses of 20, 10 and 5 g / kg to rats of the WK groups, or the groups with herbs of jianpiyiqi, yangxuehuoxue and qingrejiedu, 10 ml / kg was separately administered to each group every day. p with CBP capsules, medicine was dissolved with water and doses 15 times of human therapeutic dose were administered (10 mL / kg solution containing 0.35% CBP). Rats of other groups were fed with physiological saline (10 ml / kg every day). The rats were killed on d 22 after mold making to observe changes of gastric mucosa surface. The mucus thickness of gastric mucosa surface was measured. Levels of epidermal growth factor (EGF) in gastric juice, nitric oxide (NO) in RESULTS: Compared with plasma and prostaglandin I2 (PGI2), plasma and prostaglandin I2 (PGI2) were detected in gastric mucosa of model group rats . The mucus thickness of gastric mucosa surface, the levels of EGF, NO, 6-K-PGF1α and SOD decreased significantly in the model group (EGF: 0.818 ± 0.18 vs 2.168 ± 0.375, NO: 0.213 ± 0.049 vs 0.601 ± 0.081, 6-K-PGF1α 59.7 ± 6.3 vs 96.6 ± 8.30, SOD: 128.6 ± 15.0 vs 196.6 ± 35.3, P <0.01), the levels of ET (179.96 ± 37.40 vs 46.64 ± 21.20, P <0.01) and MDA (48.2 ± 4.5 vs 15.7 ± 4.8, P <0.01) regenerative mucosa increased, glandular was was order, and cystic dilative glands decreased, while the mucus thickness of gastric mucosa surface increased (20 g / kg WK: 51.3 ± 2.9 vs 23.2 ± 8.4, 10 g / kg WK: 43.3 ± 2.9 vs 23 .2 ± 8.4 ,, 5 g / kg WK: 36.1 ± 7.2 vs 23.2 ± 8.4, jianpiyiqi: 35.4 ± 5.6 vs 23.2 ± 8.4, yangxuehuoxue: 33.1 ± 8.9 vs 23.2 ± 8.4, qingrejiedu: 31.0 ± 8.0 vs 23.2 ± 8.4 and CBP: 38.2 ± 3.5 vs 23.2 ± 8.4, P <0.05-0.01) The levels of EGF (20 g / kg WK: 1.364 ± 0.12 vs 0.818 ± 0.18, 10 g / kg WK: 1.359 ± 0.24 vs 0.818 ± 0.18 , 5 g / kg WK: 1.245 ± 0.31 vs 0.818 ± 0.18, jianpiyiqi: 1.025 ± 0.45 vs 0.818 ± 0.18, yangxuehuoxue: 1.03 ± 0.29 vs 0.818 ± 0.18, qingrejiedu: 1.02 ± 0.47 vs 0.818 ± 0.18 and CBP: 1.237 ± 0.20 VS 0.818 ± 0.18, p <0.05-0.01), NO (20 g / kg WK: 0.480 ± 0.026 vs 0.213 ± 0.049, 10 g / kg WK: 0.390 ± 0.055 vs 0.213 ± 0.049, 5 g / k g WK: 0.394 ± 0.026 vs 0.213 ± 0.049, jianpiyiqi: 0.393 ± 0.123 vs 0.213 ± 0.049, yangxuehuoxue: 0.463 ± 0.077 vs 0.213 ± 0.049, qingrejiedu: 0.382 ± 0.082 vs 50.213 ± 0.049 and CBP: 0.395 ± 0.053 vs 0.213 ± 0.049 , P <0.05-0.01), 6-K-PGF1α (20 g / kg WK: 86.8 ± 7.6 vs. 59.7 ± 6.3, 10 g / kg WK: 77.9 ± 7.0 vs 59.7 ± 6.3, 5 g / kg WK: 70.0 ± 5.4 vs 59.7 ± 6.3, jianpiyiqi: 73.5 ± 12.2 vs 59.7 ± 6.3, yangxuehuoxue: 65.1 ± 5,3 vs 59.7 ± 6.3, qingrejiedu: 76.9 ± 14.6 vs 59.7 ± 6.3, and CBP: 93.7 ± 10.7 vs 59.7 ± 6.3, P <0.05-0.01) and SOD (20 g / kg WK: 186.4 ± 19.9 vs 128.6 ± 15.0, 10 g / kg WK: 168.2 ± 21.7 vs 128.6 ± 15.0, 5 g / kg WK: 155.6 ± 21.6 vs 128.6 ± 15.0, 168.0 ± 85.3 vs 128.6 ± 15.0, yangxuehuoxue: 165.0 ± 34.0 vs 128.6 ± 15.0, qingrejiedu: 168.2 ± 24.9 vs 128.6 ± 15.0, and CBP: 156.3 ± 18.1 vs 128.6 ± 15.0, P <0.05-0.01). The levels of ET (20 g / kg WK: 81.30 ± 17.20 vs 179.96 ± 37.40, 10 g / kg WK: 83.40 ± 25.90 vs 179.96 ± 37.40, 5 g / kg WK: 93.87 ± 20.70 vs 179.96 ± 37.40, jianpiyiqi: 130.67 ± 43.66 vs 1 79.96 ± 37.40, yangxuehuoxue: 115.88 ± 34.09 vs 179.96 ± 37.40, qingrejiedu: 108.22 ± 36.97 vs 179.96 ± 37.40, and CBP: 91.96 ± 19.0 vs 179.96 ± 37.40, P <0.01) and MDA (20 g / kg WK: 21.6 ± 7.4 vs 48.2 ± 4.5, 10 g / kg WK: 32.2 ± 7.3 vs 48.2 ± 4.5, 5 g / kg WK: 34.2 ± 6.2 vs 48.2 ± 4.5, jianpiyiqi: 34.9 ± 13.8 vs 48.2 ± 4.5, yangxuehuoxue: 35.5 ± 16.7 vs 48.2 ± 4.5, qingrejiedu: 42.2 ± 17.6 vs 48.2 ± 4.5, and CBP: 30.1 The 20 g / kg WK group was better than 10 g / kg (the mucus thickness: 51.3 ± 2.9 vs 43.3 ± 2.9, NO: 0.480 ± 0.026 vs 0.390 ± 0.055, SOD: 186.4 ± 19.9 vs 168,2 ± 21.7, P <0.01) and 5 μg / kg (the mucus thickness: 51.3 ± 2.9 vs 36.1 ± 7.2, NO: 0.480 ± 0.026 vs 0.344 ± 0.026, : 186.4 ± 19.9 vs.155.6 ± 21.6, P <0.01) groups and CBP group (the mucus thickness: 51.3 ± 2.9 vs. 38.2 ± 3.5, NO: 0.480 ± 0.026 vs 0.395 ± 0.053, SOD: 186.4 ± 19.9 vs 156.3 ± 18.1 , P <0.01) in the mucus thickness, NO and SOD levels and better than 10 g / kg (86.8 ± 7.6 vs. 77.9 ± 7.0, P <0.05) and 5 g / kg (86.8 ± 7.6 vs 70.0 ± 5.4, P < 0.05) groups in 6-K-PGF1α level, 10 g / kg WK group was better (the mucus thickness: 43.3 ± 2.9 vs 36.1 ± 7.2, P <0.01, SOD: 168.2 ± 21.7 vs 155.6 ± 21.6, P <0.05) ± 3.5, P <0.01, SOD: 168.2 ± 21.7 vs 156.3 ± 18.1, P <0.05) in the mucus thickness and SOD level. In compound group, jianpiyiqi group, yangxuehuoxue group, qingrejiedu group, the level of ET was decreased, NO contents were increased in gastric tissue of ulcers in rats. CONCLUSION: WK decoction and separated recipes have significant protective effect on ethanol-induced gastric mucosal injury. They can increase the content of EGF in gastric juice, PGI2 SOD in plasma and NO in gastric tissues , thicken the mucus on the gastric mucosa, and decrease the impairing factor MDA, ET in plasma.