Artemisia asiatica extracts protect against ethanol-induced injury in gastric mucosa of rats

Background and Aim:  Based on our previous studies that Artemisia asiatica extracts exert either antioxidative or cytoprotective actions against non-steroidal anti-inflammatory drugs or Helicobacter pylori -induced gastric mucosal injury, or imposes qualified ulcer healing in an acetic acid-induced gastric ulcer model, we investigated the protective effects of Artemisia asiatica extracts against ethanol-induced gastric mucosal injury.
Methods:  Sprague–Dawley rats received 4 g/kg body weight (BW) of absolute ethanol intragastrically, which produced visible hemorrhagic gastric lesions 60 min later.
Results:  In this animal setting, the pretreatment of Artemisia extracts (30 or 100 mg/kg BW), 1 h before ethanol administration, significantly attenuated the source of gastric injury, which was assessed with gross and microscopic analysis ( P  < 0.01). Protection from alcohol-induced damage with Artemisia pretreatment was associated with significantly decreased lipid peroxidation, protecting gastric mucosa from glutathione depletion, as well as the inhibition of the cytochrome 2E1 ethanol-metabolizing enzyme. It attenuated the expressions of ethanol-induced pro-inflammatory cytokines, including interleukin (IL)-1β and interferon-γ, a weak activation of IL-10, the inhibition of the alcohol-induced overexpression of intercellular adhesion molecule-1, and the considerable induction of heat shock protein-72 expression in gastric mucosal homogenates .
Conclusion:  The data suggest that the ethanol extracts of Artemisia asiatica exerted significant protection from alcohol-induced gastric mucosal injury through bioregulation, which is essential for cytoprotection and anti-inflammation.     

Gastroprotection by 4-Methylpyrazole Against Ethanol in Humans

4-Methylpyrazole (4-MP), a specific inhibitor ofalcohol dehydrogenase, exerts gastroprotection ofunusually long duration in rats. We tested thehypothesis that pretreatment with 4-MP might protect the human gastric mucosa against alcohol-inducedacute injury. Fourteen healthy volunteers receivedpretreatment with either 4-MP, 15 mg/kg body weightdissolved in 50 ml of orange juice, or placebo and 2 hr later 100 ml of 40% ethanol. The endoscopicappearance of the gastric mucosa was evaluated andscored (scale 0-5) and mucosal biopsies were obtainedjust before pretreatment and 30 min after ethanol for histologic examination and prostaglandinE₂ measurement. In the 4-MP group the meanendoscopic injury score was significantly lower thanthat in placebo group, in both the body and the antrum.Histologically, 4-MP significantly reduced disruption ofsurface epithelium and completely prevented the deephemorrhagic mucosal lesions. In the 4-MP group nochanges in gastric mucosal PGE₂ levels weredetected. In rats, 4-MP did not inhibit gastric acid output,whereas it markedly increased the adherent gastric mucusevaluated by the alcian blue recovery method. When lipidperoxidation was induced by carbon tetrachloride in hepatic microsomes, 4-MP caused significantinhibition of malondialdehyde generation. We concludethat 4-MP provides significant protection of the humanstomach against alcohol-induced acute mucosal injury. 4-MP, besides inhibiting the conversionof alcohol to acetaldehyde, might protect the gastricmucosa by increasing adherent gastric mucus and byscavenging free radicals.     

Gastric mucosal protection with β-phenylethylamine (PEA) and other sympathomimetic amines against absolute ethanol in the rat

The purpose of this study was to investigate the potential of -phenylethylamine (PEA), an amphetamine-like compound present in the blood during high stress situations, to protect rat gastric mucosa against absolute ethanol. F-344 rats were pretreated with PEA in saline at several dose levels and at various times prior to oral administration of 1 ml absolute ethanol. PEA at dose levels of 50 and 100 mg/kg significantly reduced the severity of alcohol-induced lesions following oral, but not parenteral, treatment. The duration of protection with PEA was approximately 90 min, with maximum protection observed when PEA was administered 15–30 min before alcohol. Pretreatment with indomethacin did not prevent or reduce the protection induced by PEA. Other sympathomimetic amines such as isoproterenol and ephedrin were similarly cytoprotective against absolute ethanol while amphetamine, phenylephrine, and epinephrine proved ineffective. These results add further support to the role of the sympathetic nervous system in regulating gastric mucosal protection in the rat.     

健脾理气颗粒对大鼠胃溃疡作用的研究

目的：研究健脾理气颗粒对大鼠胃溃疡及胃粘膜损伤的作用。方法：采用水浸应激致胃溃疡及口服乙醇致胃粘膜损伤法制模，再用健脾理气颗粒3个剂量组进行药效评价，并设对照组进行比较。结果：健脾理气颗粒3个剂量组对大鼠应激性胃溃疡的形成有明显的抑制作用（P＜0.05-0.01)，对口服乙醇致胃粘膜损伤也有保护作用，尤以10g/kg、20g/kg组为明显（P＜0.05-0.01)。结论：健脾理气颗粒具有明显地抑制大鼠胃溃疡及保护胃粘膜损伤作用。     

Antioxidant Effect of T-Type Calcium Channel Blockers in Gastric Injury

It is known that calcium ion has an important role in the cellular function. For this reason, calcium channel blockers may have a protective action against gastric injury which is induced by various stimuli. In this study, the influence of mibefradil on ethanol-induced gastric injury was investigated in rats. Mibefradil was given at a dose 50 mg/kg intraperitoneally 30 min before administration of 1 ml absolute ethanol given by gavage. We compared this effect of mibefradil with that of omeprazol. Ethanol-induced mucosal damage was evaluated using three different approaches: analysis of biochemical parameters and pathologic and macroscopic investigation. It was found that pretreatment with mibefradil significantly reduced ethanol-induced macroscopic, pathologic, and biochemical changes in the gastric mucosa. In conclusion, it is speculated that this findings may prove important in the development of new and improved therapies for the treatment and prevention of gastric ulcers in humans.     

Gastric mucosal blood flow in rats after administration of 16,16-dimethyl prostaglandin E2 at a cytoprotective dose

The purpose of the present study was to determine whether the gastric cytoprotective effect of a prostaglandin such as 16,16-dimethyl prostaglandin (dmPGE2) is mediated by an increase in mucosal blood flow. Gastric mucosal blood flow was measured in urethane-anesthetized rats by the hydrogen gas clearance technique. In control rats given no ethanol, intragastric administration of dmPGE2 (10 micrograms/kg body wt) produced a significant reduction (15.3%) in gastric mucosal blood flow 30 min after treatment. This dose of dmPGE2 significantly reduced the formation of the gross gastric lesions produced by absolute ethanol in anesthetized rats. In vehicle-pretreated animals, blood flow was invariably absent in the ethanol-induced mucosal lesion areas. In the nonlesion areas, gastric mucosal blood flow was the same in prostaglandin-pretreated and vehicle-pretreated animals as in control (no ethanol) rats. Thus, although dmPGE2 pretreatment protected against ethanol-induced gastric mucosal injury and prevented the accompanying blood flow stasis, it did not do this by an increase in gastric mucosal blood flow. The protection also is not due to a decrease in flow because, in separate groups of anesthetized rats, a 15% reduction in gastric mucosal blood flow induced by either hemorrhage or intravenous vasopressin did not protect the gastric mucosa against absolute ethanol-induced injury. Whether the maintenance of gastric mucosal blood flow is a primary or secondary effect of prostaglandin cytoprotection remains to be determined.     

Adaptive cytoprotection through modulation of nitric oxide in ethanol-evoked gastritis

AIM: To assess the mechanisms of protective action by different mild irritants through maintenance of gastric mucosal integrity and modulation of mucosal nitric oxide (NO) in experimental gastritis rats.METHODS: Etcher 200 mL/L ethanol, 50 g/L NaG or 0.3 mol/L HCl was pretreated to normal or 800 mL/L ethanol-induced acute gastritis Sprague-Dawley rats before a subsequent challenge with 500 mL/L ethanol. Both macroscopic lesion areas and histological damage scores were determined in the gastric mucosa of each group of animals. Besides,gastric mucosal activities of NO synthase isoforms and of superoxide dismutase, along with mucosal level of leukotriene (LT)C4 were measured.RESULTS: Macroscopic mucosal damages were protected by 200 mL/L ethanol and 50 g/L NaCI in gastritis rats.However, although 200 mL/L ethanol could protect the surface layers of mucosal cells in normal animals (protection attenuated by NG-nitro-L-arginine methyl ester), no cytoprotection against deeper histological damages was found in gastritis rats. Besides, inducible NO synthase activity was increased in the mucosa of gastritis animals and unaltered by mild irritants. Nevertheless, the elevation in mucosal LTC4 level following 500 mL/L ethanol administration and under gastritis condition was significantly reduced by pretreatment of all three mild irritants in both normal and gastritis animals.CONCLUSION: These findings suggest that the aggravated 500 mL/L ethanol-evoked mucosal damages under gastritis condition could be due to increased inducible NO and LTC4 production in the gastric mucosa. Only 200 mL/L ethanol is truly “cytoprotective“ at the surface glandular level of nongastritis mucosa. Furthermore, the macroscopic protection of the three mild irritants involves reduction of LTC4 level in both normal and gastritis mucosa, implicating preservation of the vasculature.     

Beneficial effects of Foeniculum vulgare on ethanol-induced acute gastric mucosal injury in rats

AIM： To examine the anti-ulcerogenic and antioxidant effects of aqueous extracts of Foeniculum vu/gare （FVE） on ethanol-induced gastric lesions in rats.
METHODS： FVE was administered by gavage at doses of 75, i50 and 300 mg/kg, and famotidine was used at the dose of20mg/kg.Following a 60 min period, all the rats were given 1 mL of ethanol （80%） by gavage. One hour after the administration of ethanol, all groups were sacrificed, and the gastric ulcer index was calculated; whole blood malondialdehyde （MDA） and reduced glutathione （GSH）, serum nitrate, nitrite, ascorbic acid, retinol and β-carotene levels were measured in all the groups.
RESULTS： It was found that pretreatment with FVE significantly reduced ethanol-induced gastric damage. This effect of FVE was highest and statistically significant in 300 mg/kg group compared with the control （4.18 ± 2.81 vs 13.15 ± 4.08, P 〈 0.001）. Also, pretreatment with FVE significantly reduced the MDA levels, while significantly increased GSH, nitrite, nitrate, ascorbic acid, retinol and β-carotene levels.
CONCLUSION： FVE has clearly a protective effect against ethanol-induced gastric mucosal lesion, and this effect, at least in part, depends upon the reduction in lipid peroxidation and augmentation in the antioxidant activity.     

铝碳酸镁对胃粘膜保护的实验研究

研究铝碳酸镁对幽门结扎及乙醇诱发大鼠胃粘膜损伤的保护作用及其机制。方法：通过结扎幽门和灌服乙醇制备大鼠胃牯膜损伤模型，测定胃酸分泌、胃蛋白酶活性、胃粘膜中前列腺素、血流、丙二醛(MDA)、氨基己糖含量和一些酶的活性。结果：口服铝碳酸镁500mg／kg连续3天，能显著防止幽门结扎和乙醇诱发的胃粘膜损伤，并中和胃酸及抑制胃蛋白酶活性。铝碳酸镁有促进前列腺素分泌和粘膜血流的作用。此外，铝碳酸镁能降低乙醇所致MDA含量的增加，并阻止乙醇引起的醌还原酶，谷胱甘肽转移酶、谷胱甘肽还原酶和谷胱甘肽过氧化物酶活性的降低。结论：铝碳酸镁对幽门结扎和乙醇诱发的大鼠胃粘膜损伤具有保护作用，其作用机制与粘膜保护和抗脂质过氧化作用有关。     

Evaluation of cytoprotection against ethanol-induced injury in gastric mucosa pretreated with misoprostol,cimetidine, or placebo

The authors have developed a primate model for evaluating cytoprotection against alcohol-induced injury in gastric mucosa pretreated with antiulcer agents. In the present study, groups of squirrel monkeys received either a single oral dose of misoprostol (500 or 200 μg/kg), cimetidine (3 or 6 mg/kg), placebo, or no treatment. After 30 min, 1 ml of 50% ethanol was administered to all animals, except for one of two untreated controls. At 90 min, stomachs from lethally anesthetized primates were processed for scanning electron and quantitative stereoscopic microscopy. Fifty percent ethanol alone damaged epithelial cells and produced submucosal hemorrhagic lesions. Pretreatment with misoprostol limited alcohol-induced injury to superficial erosion of epithelial cells. Cimetidine did not protect the mucosa against ethanol-induced injury. We conclude that misoprostolconferred cytoprotection in primate gastric mucosa correlates with the endoscopic findings by others that misoprostol, but not cimetidine, protected human stomach against alcohol-induced injury.     

抗氧化剂对胃粘膜的保护作用

目的：研究抗氧化剂对大鼠和胃溃疡患者胃粘膜的保护作用。方法：大鼠用乙醇灌胃造模，给予抗氧化剂银杏制剂预防胃粘膜损伤，测定胃粘膜和血中的脂质过氧化物（LPO）含量。胃溃疡患者在根除幽门螺杆菌的同时服用硒卡拉胶囊治疗，测定治疗前后胃粘膜中的LPO含量，并与对照组进行比较。结果：银杏预防组大鼠胃粘膜和血中的LPO含量均明显低于乙醇模型组（P＜0.05和P＜0.01)。胃溃疡患者服用硒卡拉胶囊治疗后，胃粘膜中LPO含量的降低幅度明显大于对照组（P＜0.001)。结论：抗氧化剂银杏制剂和硒卡拉胶囊对大鼠和胃溃疡患者由氧自由基所致的胃粘膜损伤有保护作用。     

猴头菌对实验大鼠胃粘膜保护作用的研究

探讨猴头菌对实验大鼠胃牯膜损伤的保护作用及可能机制。方法：在无水乙醇形成大鼠胃牯膜损伤模型前后．应用猴头菌给予预防和治疗．观察胃粘膜损伤程度及病理改变：并检测胃粘膜氮基己糖及血浆胃泌素含量。结果：预服猴头菌2周后溃疡抑制率为62％．治疗2周后溃疡抑制率为91％：猴头菌能增进大鼠食欲,并可明显减轻胃牯膜的充血、出血,水肿和坏死：减轻粘膜下炎细胞浸润：促进粘膜氮基己糖的恢复：防止胃泌素的升高。结论：猴头菌对胃粘膜有良好的细胞保护作用。     

Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500mL.L(-1), i.g.) was used to induce gastric mucosa damage. RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L(-1) ethanol challenge, the ulcer area found in the rats with 7d sleep deprivation (19.15 +/- 4.2)mm(2) was significantly lower (P<0.01) than the corresponding control (53.7 +/- 8.1) mm(2). CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.     

Protective effects of the whisky congeners on ethanol-induced gastric mucosal damage

BACKGROUND: The ingestion of both ethanol and whisky can induce acute gastrointestinal bleeding. The effects of the congeners, substances other than ethanol in whisky, on the ethanol-induced gastric mucosal damage were examined in the rat model. METHODS: After the whisky congeners were intragastrically administered previous to or simultaneous with ethanol ingestion, the gastric damage was macroscopically and microscopically measured. RESULTS: The simultaneous administration of the whisky congeners at a dose of 5 mg/kg body weight, which corresponds to the concentration of congeners contained in whisky, with 50% ethanol did not inhibit the hemorrhagic lesions, but inhibited them at a dose of 150 mg/kg. The treatment with the whisky congeners 30 minutes before the ethanol ingestion prevented the ethanol-induced gastric damage in a dose-dependent manner at 0.5 to 150 mg/kg. The butanol extract of the congeners revealed the strongest prevention compared with the ethyl acetate extract or the water fraction. The administration of indomethacin 60 minutes before the congener treatment partly inhibited the protective effects of the congeners, indicating the partial contribution of prostaglandins in this mechanism. The congeners did not prevent the mucosa by action as a "mild irritant" because the immunohistochemical studies using the antimucin monoclonal antibodies showed that no damage was induced by the administration of the congeners. CONCLUSION: The present results showed that the whisky congeners have a protective activity against ethanol-induced gastric mucosal injury.     

Attenuation of gastric mucosal inflammation induced by aspirin through activation of A2A adenosine receptor in rats

AIM:To determine whether a specific adenosine A_(2A) re-ceptor agonist(ATL-146e)can ameliorate aspirin-inducedgastric mucosal lesions in rats,and reduce neutrophil ac-cumulation and production of pro-inflammatory cytokines.METHODS:Gastric lesions were produced by oralgarage of aspirin(200 mg/kg)and HCl(0.15 mol/L,8.0 mL/kg).4-{3-[6-Amino-9-(5-ethylcarbamoyl-3,4-dihydroxy-tetrahydro-furan-2-yl)-9H-purin-2-yl]-prop-2-ynyl}-cyclohexanecarboxylic acid methyl ester(ATL-146e,2.5-5 μg/kg,IP)was injected 30 min before the admin-istration of aspirin.Tissue myeloperoxidase(MPO)con-centration in gastric mucosa was measured as an indexof neutrophil infiltration.Gastric mucosal concentrationsof tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)were determined by ELISA.Also,we examinedthe effect of ATL-146e on tissue prostaglandin E2(PGE2)production and gastric secretion.RESULTS:Intragastric administration of aspirin inducedmultiple hemorrhagic erosions in rat gastric mucosa.Thetotal length of gastric erosions(ulcer index)in controlrats was 29.8±7.75 mm and was reduced to 3.8±1.42mm after pretreatment with 5.0 g/kg ATL-146e(P<0.01).The gastric contents of MPO and pro-inflammatory cy-tokines were all increased after the administration ofaspirin and reduced to nearly normal levels by ATL-146e.Gastric mucosal PGE2 concentration was not affected byintraperitoneal injection of ATL-146e.CONCLUSION:The specific adenosine A_(2A) receptor ago-nist,ATL-146e,has potent anti-ulcer effects presumablymediated by its anti-inflammatory properties.     

环氧合酶-2在低分子肝素干预大鼠酒精性肝病中的作用机制研究

目的研究低分子肝素干预大鼠酒精性肝病模型的作用机制。方法 56%(V/V)的白酒平均以8 g/kg的剂量2次/d灌胃10周,初步制备大鼠酒精性肝病模型,成模后部分大鼠低分子肝素(100 IU/kg)皮下注射进行干预,4周后观察低分子肝素对大鼠的血清生物化学指标、肝组织中丙二醛及环氧化酶-2的影响。结果与模型组比较,低分子肝素治疗组大鼠血清转氨酶、血脂及丙二醛含量明显下降(P<0.05);光学显微镜观察HE染色见脂肪变性、炎症反应程度明显减轻(P<0.01),免疫组织化学染色及逆转录聚合酶链反应显示环氧化酶-2的表达均明显降低(P<0.05)。结论低分子肝素通过改善脂肪代谢、抑制氧化应激及降低环氧化酶-2的表达而对酒精性肝病大鼠起到一定的保护治疗作用。     

Effect of electro-acupuncture at Foot-Yangming Meridian on somatostatin and expression of somatostatin receptor genes in rabbits with gastric ulcer

AIM: To discuss the protective effect of electroacupunc-ture at the Foot-Yangming Meridian on gastric muco-sal lesion, somatostatin (SS) and the expression of SS receptor genes (SSRimRNA ) in rabbits with gastric ulcer and to further explore the relative specificity of meridians and viscera at gene expression level. METHODS: Forty rabbits were randomly divided into control group (A), gastric ulcer model group (B), Foot-Yangming Meridian group (C), Foot-Shaoyang Meridian group (D) and Foot-Taiyang Meridian group (E). The gastric ulcer model was prepared by infusing alcohol into stomach. Groups C-E were treated with electro-acupuncture at points along the above meridians using meridian stimulating instruments for 7 days respectively. By the end of treatment, the index of gastric ulcer was determined, the amount of epidermal growth factor(EGF) and somatostatin was measured by radioimmunoassay (RIA). SS-RimRNA expression in gastric mucosa was determined by RT-PCR. RESULTS: The value of EGF in model group was obviously lower(73.6±14.8 vs 91.3±14.9 pg/mL, P<0.01) than that in control group. The index of gastric ulcer, content of SS and expression of SSRimRNA in gastric mucosa were significantly higher than those in control group (24.88±6.29 vs 8.50±2.98 scores, P<0.01; 2978.6±587.6 vs 1852.4±361.7 mIU/mL, P<0.01; 2.56±0.25 vs 1.04±0.36, P<0.01) . The value of EGF in Foot-Yangming Meridian group was higher than that in model group(92.2±6.7 vs 73.6±14.8 pg/mL, P<0.01). The index of gastric ulcer, content of SS and expression of SS-R1mRNA in gastric mucosa were significantly lower than those in control group(10.88±3.23 vs 24.88±6.29 scores, P< 0.01; 1800.2±488 vs 2978.6±587.6 mIU/mL, P<0.01; 1.07±0.08 vs 2.56±0.25mIU/mL, P<0.01). Compared to the model group, the content of SS and expression of SSRimRNA in gastric mucosa in Foot-Shaoyang Meridian group decreased (2441.0±488. vs 2978.6±587.6 mIU/mL, P<0.05;1.73±0.16 vs 2.56±0.25 mIU/mL, P<0.01). But the above parameters in Foot-Taiyang Meridian group did not improve and were significantly different from those in Foot-Yangming Meridian group (P<0.05) CONCLUSION: Electro-acupuncture at Foot-Yangming Meridian can protect gastric mocusa against injury. The mechanism may be releted to the regulation of brain-gut peptides and the expression of SSRimRNA.     

硝苯啶治疗消化性溃疡的疗效及其机理探讨

用硝苯碇预防无水乙醇和幽门结扎所致大鼠胃溃疡，结果显示用药组胃溃疡指明显低于对照组，对溃疡的抑制率与ＮＦＤ剂量呈正相关。临床观察４２例十二指肠球部溃疡患者，服用ＮＦＤ １０ｍｇ，每日４次，６周后溃疡愈合２７例，总有效３９例，与对照比较有显著差异。     

Protective action of omeprazole, a benzimidazole derivative, on gastric mucosal damage by aspirin and ethanol in rats

This study was designed to compare the influence of omeprazole, a potent inhibitor of H+/K+-ATP-ase involved in the final step of H+ secretion and prostaglandin (PG) I2 on the formation of gastric mucosal lesions induced by absolute ethanol or acidified aspirin (ASA). Omeprazole given intragastrically in both inhibitory (20 or 200 mumol/kg) and noninhibitory doses (2 mumol/kg) prevented dose dependently ASA- and ethanol-induced gastric lesions. The protective effect of omeprazole against ASA-induced lesions occurred when mucosal generation of PGs was completely suppressed and that against ethanol lesions when PG generation was increased above normal values. Pretreatment with PGI2 given intragastrically or subcutaneously both in inhibitory and noninhibitory doses prevented almost completely the formation of gastric mucosal lesions caused by both absolute ethanol and acidified ASA. This study indicates that omeprazole is capable of protecting gastric mucosa against ASA- and ethanol-induced injury and that this protection is unrelated to gastric inhibition or the biosynthesis of mucosal PGs.