Zuojin Pill ameliorates inflammation in indomethacin-induced gastric injury via inhibition of MAPK pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Zuojin Pill (ZJP) has been a classic prescription for the treatment of gastrointestinal diseases in China since ancient times. But its effect on non-steroidal anti-inflammatory drugs (NSAIDs) induced gastric injury (GI) is still uncharted. AIM OF THE STUDY: This study aims to investigate the therapeutic effect and molecular mechanism of ZJP on indomethacin (IDO) induced gastric injury. MATERIALS AND METHODS: GI was induced in rat by oral administration of 5 mg/kg IDO. Then the rats were treated with ZJP (1.26, 2.52, 5.04 g/kg, ig). The changes of food intake, body weight, gastric pH and general state observation were carried out to determine the improvement of ZJP in IDO-induced GI: HE staining and AB-PAS staining was analyzed to characterize the thickness of gastric mucosa and micro mucosal injury; in order to elucidate the effect of ZJP on IDO-induced inflammatory injury, the inflammatory infiltration of gastric tissue was observed by MPO immunohistochemical method, and the contents of TNF-α, IL-6 and IL-10 were measured. Furthermore, the regulatory mechanism of ZJP in treating IDO-induced GI was predicted with the help of network pharmacology, and the expression levels of key proteins ERK, p-ERK, P38, p-P38, JNK, p-JNK were determined to elucidate the molecular mechanism of ZJP. RESULTS: Current data strongly demonstrated that ZJP alleviated food intake reduction, weight loss and gastric injury caused by IDO and made gastric pH and mucosal thickness return to normal. In addition, ZJP could reduce the level of MPO to alleviate the inflammatory infiltration of gastric tissue. Simultaneously, ZJP could down regulate the expression of TNF-α and IL-6 and up regulate the expression of IL-10 to reduce the damage caused by inflammatory, and create a healing environment. Furthermore, ZJP could significantly inhibit the phosphorylation of ERK, p38 and JNK, which leaded to the increase of inflammatory factors and the damage of gastric mucosa. CONCLUSION: ZJP improved local inflammation by inhibiting MAPK signaling pathway, and had a good therapeutic effect on IDO-induced GI. This study has reference significance for the study of ZJP in the prevention and treatment of NSAID induced gastric injury. In addition, ZJP may be a new treatment option for the prevention and treatment of NSAID induced gastric disease.

Curcumin: A Potent Protectant against Esophageal and Gastric Disorders.

Turmeric obtained from the rhizomes of Curcuma longa has been used in the prevention and treatment of many diseases since the ancient times. Curcumin is the principal polyphenol isolated from turmeric, which exhibits anti-inflammatory, antioxidant, antiapoptotic, antitumor, and antimetastatic activities. The existing evidence indicates that curcumin can exert a wide range of beneficial pleiotropic properties in the gastrointestinal tract, such as protection against reflux esophagitis, Barrett's esophagus, and gastric mucosal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) and necrotizing agents. The role of curcumin as an adjuvant in the treatment of a Helicobacter pylori infection in experimental animals and humans has recently been proposed. The evidence that this turmeric derivative inhibits the invasion and proliferation of gastric cancer cells is encouraging and warrants further experimental and clinical studies with newer formulations to support the inclusion of curcumin in cancer therapy regimens. This review was designed to analyze the existing data from in vitro and in vivo animal and human studies in order to highlight the mechanisms of therapeutic efficacy of curcumin in the protection and ulcer healing of the upper gastrointestinal tract, with a major focus on addressing the protection of the esophagus and stomach by this emerging compound.

Polyphenols in Kuding tea help prevent HCl/ethanol-induced gastric injury in mice.

We conducted the present study to determine the gastric injury preventive effects of polyphenols in Kuding tea (KTPs) in Kunming (KM) mice through the inhibition of gastric-acid secretion and the protection of the gastric mucosa. Mice treated with a high concentration of Kuding tea polyphenols (HKTP) had lower serum levels of interleukin-6 (IL-6), IL-12, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), motilin (MOT), substance P (SP), and endothelin-1 (ET-1), and higher serum levels of somatostatin (SS) and vasoactive intestinal peptide (VIP) than did the mice in the control group. Serum and gastric tissue levels of nitrous oxide (NO), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and GSH were higher in the HKTP-treated mice than in the control mice, but malondialdehyde (MDA) levels were lower in the HKTP-treated mice than in the control mice. The expression of occludin, epidermal growth factor (EGF), EGF receptor (EGFR), vascular endothelial growth factor (VEGF), nuclear factor of κ-light polypeptide gene enhancer in B-cells inhibitor-α (IκBα), Cu/Zn-SOD (cuprozinc-superoxide dismutase), Mn-SOD (manganese-superoxide dismutase), GSH-Px (glutathione peroxidase), neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS), messenger RNA (mRNA) and protein in gastric tissue was stronger in the HKTP-treated mice than in the control mice, while the expression of p38 mitogen-activated protein kinase (P38MAPK, or p38), nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), inducible NOS (iNOS), and cyclooxygenase-2 (COX-2) was weaker in the HKTP group than in the control group. And HKTP also could reduce the TNF-α, IL-1ß (interleukin-1 beta), and IL-6 mRNA expression in gastric injury mice. A high performance liquid chromatography (HPLC) assay showed that Kuding tea polyphenols (KTPs) contained chlorogenic acid, cryptochlorogenic acid, and isochlorogenic acids A, B, and C. These constituents contributed to the preventive effects of KTPs on gastric injury. According to these results, KTPs are a kind of active component that have a strong preventive effect on gastric injury.

Apple Polyphenol Suppresses Indomethacin-Induced Gastric Damage in Experimental Animals by Lowering Oxidative Stress Status and Modulating the MAPK Signaling Pathway.

Indomethacin is a nonsteroid anti-inflammatory drug (NSAID) that is used to alleviate pain and inflammation in clinical medicine. Previous studies indicated that NSAIDs can cause gastrointestinal mucosal complications, and it is associated with mucosal lipid peroxidation and oxidative damage. Based on the evidences, decreasing oxidative stress may be an ideal therapeutic strategy for preventing gastrointestinal ulcer. Apple (Rosaceae Malus sp.) is one of the most commonly consumed fruits worldwide. The abundant polyphenolic constituents have received increasing attention for decades. In both in vivo and in vitro studies, the reports showed that apple polyphenol (AP) seems to provide an indirect antioxidant protection by activating cellular antioxidant enzymes to defend against oxidative stress. To address this issue and develop AP into a healthy improvement supplement, we studied the effect and potential mechanisms of AP in indomethacin-treated animal. The results showed AP can decelerate the gastric lesion, significantly suppress lipid peroxidation, increase the level of glutathione and the activity of catalase, and regulate the MAPK signaling proteins. These findings imply that AP protects the gastric mucosa from indomethacin-caused lesions and the protection is at least partially attributable to its antioxidative properties. This alternative medical function of AP may be a safe and effective intervention for preventing indomethacin-induced gastric complications.

Cutaneous neurogenic inflammation in the sensitized acupoints induced by gastric mucosal injury in rats.

BACKGROUND: In acupuncture practice, the most important step is to confirm the location of a sensitized acupoint which reflects a diagnosis and can be stimulated with a specialized needle to treat the disease. Abnormal symptoms such as hyperalgesia or allodynia at the sensitized acupoints in patients with visceral disorders are considered to be in relation with referred pain and neurogenic inflammation. Yet, limited study has investigated the cutaneous neurochemical changes of the sensitized acuponits. METHODS: The resent study developed an animal model of gastric mucosal injury (GMI) by HCl administered into the stomach of the rats. Evans Blue (EB) dye was applied by injection of tail vein after mucosal damage to observe the neurogenic plasma extravasation dots in the skin of the rats. The EB dots extravagated in the skin were compared with locations of acupoints. Immnohistochemistry analysis was used to detect the expression of calcitonin gene-related peptide (CGRP)- or substance P (SP)-labeled nerve fibers, histamine (HA)-, serotonin (5-HT)-, and tryptase-labeled cells in EB dots. Images were recorded and analyzed by Confocal imaging system and Olympus Image Processing Software. RESULTS: The results showed that GMI resulted in neurogenic plasma extravasation in the skin of the acupoints over the back and abdomen, which mostly occurred in the T9-11 dermatomere. The EB extravasation dots appeared after GMI and disappeared gradually during the natural self-recovery of the gastric mucosa. More SP and CGRP positive nerve fibers were distributed in EB dots than that in regions beside EB dots and in the control, mostly distributed in the nerve fibers around both the vessels and root of hair follicle. Mast cells also aggregated and degranulated to release algogenic substances of 5-HT and HA around the vessels in areas of the EB dots. CONCLUSIONS: Our results indicates that the mechanism of EB extravasation in the skin of the acupoints induced by GMI are closely related to neurogenic inflammation, and that the high expression of local allergic substances and nociceptive neuropeptides in the local skin including SP, CGRP, HA, 5-HT, and mast cell tryptase may be the underlying mechanism of the acupoint sensitization.

[Effects of acupuncture stimulation of different acupoint groups on sleeping latency, serum and hippocampal TNF-α and IL-25 contents in rats with gastric mucosal injury].

OBJECTIVE: To observe the effect of acupuncture intervention on gastric ulcer (GU) and sleeping quality from the viewpoint of brain-gut axis which plays an important role in the regulation of many vital functions in the body. METHODS: Forty male Wistar rats were randomized into normal control, GU model, acupuncture of "Zhongwan"(CV 12)-"Zusanli"(ST 36, gastric function regulating acupoints), acupuncture of "Shenmai" (BL 62)-"Zhaohai" (KI 6, sleep-promotion acupoints), and acupuncture of CV 12-ST 36+ BL 62-KI 6 (combined treatment) groups, with 8 rats in each group. GU model was established by intragastric perfusion of dehydrated alcohol (1 mL/rat), and sleep model established by intraperitoneal injection of pentobarbital sodium (40 mg/kg) after the last treatment. The abovementioned acupoints were punctured with filiform needles and stimulated by manipulating the needle for about 30 s, once every 5 min during 20 min of needle retention. The treatment was conducted once daily for five days. The contents of tumor necrosis factor-alpha (TNF-α) and interleukin-25(IL-25) in the serum and hippocampal tissues were detected by ELISA. RESULTS: Compared with the normal control group, the gastric ulcer index score, barbiturate-induced sleeping time, and TNF-α and IL-25 contents in both serum and hippocampus were significantly increased in the model group (P < 0.01). Following acupuncture treatment, in comparison with the model group, the gastric ulcer index score, barbiturate-induced sleeping time, and TNF-α and IL-25 contents in both serum and hippocampus were significantly down-regulated in the CV 12-ST 36, BL 62-KI 6 and combined treatment groups (P < 0.01, P < 0.05). The effects of the CV 12-ST 36 and combined treatment groups were remarkably superior to those of the BL 62-KI 6 group in down-regulating ulcer index score, serum IL-25, and hippocampal TNF-α and IL-25 contents (P < 0.01, P < 0.05). In addition, the effects of the BL 62-KI 6 and combined treatment groups was considerably better than that of the CV 12-ST 36 group in shortening barbiturate-induced sleeping time (P < 0.01, P < 0.05). The effect of the combined treatment group was markedly better than that of the CV 12-ST 36 and BL 62-KI 6 groups in lowering serum TNF-α content (P < 0.05). CONCLUSION: Acupuncture stimulation of CV 12, ST 36, KI 6 and BL 62 can relieve the gastric mucosal lesion, and shorten barbiturate-induced sleeping time in gastric ulcer rats, which may be related to its effects in reducing TNF-α and IL-25 contents in the serum and hippocampus tissues, suggesting a correlation between the gastrointestinal disorder and sleeping.

[Establishment of animal model with gastric cold syndrome].

This study is to establish the gastric cold model of rats. After gastric feeding with cold water for 5 weeks and extra iced water bath in the last 2 weeks, model group show distinct physical sign of gastric cold syndrome. The pathology of gastrics reveals gastricism of model group, while treatment group(treated with Fanzuojin Wan) show mild lesion. Elisa detection of model group show that the solution of interleukin-2 (IL-2) is higher than blank group. The difference with significance among model group, treatment group and blank group reveals the success of the establishment of gastric cold syndrome.

[Study on efficacy and accompanying toxic and side effects of volatile oil of Evodia Fructus based on stomach cold syndrome model].

OBJECTIVE: To preliminarily study the effective dosage range and mechanism of the abirritation of volatile oil of Evodia Fructus on the stomach cold syndrome model in mice, and discuss the correlation between its accompanying toxicity and oxidative damage mechanism, in order to provide the experimental basis for explaining the efficacy-syndrome-toxicity correlation. METHOD: The stomach cold-syndrome model in mice was induced by the classic hot plate test by orally administrating with different doses of volatile oil of Evodia Fructus, in order to observe its abirritation and companying toxic and side effects and detect serum ALT, AST, PGE2, NO, NOS, MDA, SOD, GSH, GSH-Px, BUN, CR and hepatic ALT, AST. The companying toxic symptoms in mice were recorded in toxic reaction integral table. RESULT: Volatile oil of Evodia Fructus had an obvious analgesic effect at 30 min after the oral administration and reached the peak effect at 60 min, with certain "dose-effect" and "time-effect" relations, rises in serum and hepatic ALT and AST levels, serum PGE2, MDA, NO and NOS and hepatic indexes, decreases in SOD, GSH and GSH-Px and no notable change in BUN, CR levels and kidney weight/body ratio. Conclusion: The abirritation mechanism of volatile oil of Evodia Fructus was related to the inhibition of pain transmitter release, peroxidative damage and NO damage, which is accompanied by certain hepatotoxicity, mainly mainly oxidative damage, with a concurrent "dose-time-toxicity" relationship.

Dose-dependent inhibition of gastric injury by hydrogen in alkaline electrolyzed drinking water.

BACKGROUND: Hydrogen has been reported to relieve damage in many disease models, and is a potential additive in drinking water to provide protective effects for patients as several clinical studies revealed. However, the absence of a dose-response relationship in the application of hydrogen is puzzling. We attempted to identify the dose-response relationship of hydrogen in alkaline electrolyzed drinking water through the aspirin induced gastric injury model. METHODS: In this study, hydrogen-rich alkaline water was obtained by adding H2 to electrolyzed water at one atmosphere pressure. After 2 weeks of drinking, we detected the gastric mucosal damage together with MPO, MDA and 8-OHdG in rat aspirin induced gastric injury model. RESULTS: Hydrogen-dose dependent inhibition was observed in stomach mucosal. Under pH 8.5, 0.07, 0.22 and 0.84 ppm hydrogen exhibited a high correlation with inhibitory effects showed by erosion area, MPO activity and MDA content in the stomach. Gastric histology also demonstrated the inhibition of damage by hydrogen-rich alkaline water. However, 8-OHdG level in serum did not have significant hydrogen-dose dependent effect. pH 9.5 showed higher but not significant inhibitory response compared with pH 8.5. CONCLUSIONS: Hydrogen is effective in relieving the gastric injury induced by aspirin-HCl, and the inhibitory effect is dose-dependent. The reason behind this may be that hydrogen-rich water directly interacted with the target tissue, while the hydrogen concentration in blood was buffered by liver glycogen, evoking a suppressed dose-response effect. Drinking hydrogen-rich water may protect healthy individuals from gastric damage caused by oxidative stress.

Gastroprotective effects of Leejung-tang, an oriental traditional herbal formula, on ethanol-induced acute gastric injury in rats.

Leejung-tang (LJT, Rechu-to in Japanese and Lizhong-tang in Chinese) is an oriental traditional traditional herbal formula. LJT has been used for treatment of gastrointestinal disorders in Korea, Japan, and China for a long time. In present study, we investigated the protective effects of LJT against absolute ethanol induced gastric injuries. Rats in the control group were given PBS orally (5 mL/kg body weight) as the vehicle, and the absolute-ethanol group (EtOH group) received absolute ethanol (5 mL/kg body weight) by oral gavage. Rats in the positive control group were given omeprazole orally (50 mg/kg body weight) 2 h prior to the administration of absolute ethanol. The treatment groups received LJT (400 mg/kg body weight) 2 h prior to absolute ethanol administration. All rats were sacrificed 1 h after receiving the ethanol treatment. The stomach was excised for macroscopic examination and biochemical analysis. The administration of LJT protected gastric mucosa against ethanol-induced acute gastric injury, including hemorrhage and hyperemia. LJT reduced the increase in lipid peroxidation in ethanol-induced acute gastric lesions. LJT increased GSH content and activities of the antioxidant enzymes, catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and superoxide dismutase. These results indicate that LJT protects gastric mucosa against ethanol-induced acute gastric injury by increasing their antioxidant content. We suggest that LJT can be developed as an effective drug for the treatment of acute gastric injury.

Effects of ghrelin on gastric distention sensitive neurons in the arcuate nucleus of hypothalamus and gastric motility in diabetic rats.

This study was performed to observe the effects of ghrelin on the activity of gastric distention (GD) sensitive neurons in the arcuate nucleus of hypothalamus (Arc) and on gastric motility in vivo in streptozocin (STZ) induced diabetes mellitus (DM) rats. Electrophysiological results showed that ghrelin could excite GD-excitatory (GD-E) neurons and inhibit GD-inhibitory (GD-I) neurons in the Arc. However, fewer GD-E neurons were excited by ghrelin and the excitatory effect of ghrelin on GD-E neurons was much weaker in DM rats. Gastric motility research in vivo showed that microinjection of ghrelin into the Arc could significantly promote gastric motility and it showed a dose-dependent manner. The effect of ghrelin promoting gastric motility in DM rats was weaker than that in normal rats. The effects induced by ghrelin could be blocked by growth hormone secretagogue receptor (GHSR) antagonist [d-Lys-3]-GHRP-6 or BIM28163. RIA and real-time PCR data showed that the levels of ghrelin in the plasma, stomach and ghrelin mRNA in the Arc increased at first but decreased later and the expression of GHSR-1a mRNA in the Arc maintained a low level in DM rats. The present findings indicate that ghrelin could regulate the activity of GD sensitive neurons and gastric motility via ghrelin receptors in the Arc. The reduced effects of promoting gastric motility induced by ghrelin could be connected with the decreased expression of ghrelin receptors in the Arc in diabetes. Our data provide new experimental evidence for the role of ghrelin in gastric motility disorder in diabetes.

Banhabaekchulchunma-tang, a traditional herbal formula attenuates absolute ethanol-induced gastric injury by enhancing the antioxidant status.

BACKGROUND: Banhabaekchulchunma-tang (hange-byakujutsu-tenma-to in Japanese and banxia-baizhu-tianma-tang in Chinese) is a mixture of fourteen herbs. It is used traditionally for the treatment of anemia, anorexia, general weakness, and female infertility in China, Japan, and Korea. In this study, we investigated the protective effects of a Banhabaekchulchunma-tang water extract (BCT) against ethanol-induced acute gastric injury in rats. METHODS: Gastric injury was induced by intragastric administration of 5 mL/kg body weight of absolute ethanol to each rat. The positive control group and the BCT group were given oral doses of omeprazole (50 mg/kg) or BCT (400 mg/kg), respectively, 2 h prior to the administration of absolute ethanol. The stomach of each animal was excised and examined for gastric mucosal lesions. To confirm the protective effects of BCT, we evaluated the degree of lipid peroxidation, the level of reduced glutathione (GSH), and the activities of the antioxidant enzymes catalase, glutathione-S-transferase, glutathione peroxidase, and glutathione reductase in the stomach. In addition, we conducted an acute toxicity study to evaluate the safety of BCT according to OECD guideline. RESULTS: BCT reduced ethanol-induced hemorrhage, hyperemia, and loss of epithelial cell in the gastric mucosa. BCT reduced the increased lipid peroxidation associated with ethanol-induced acute gastric lesions, and increased the mucosal GSH content and the activities of antioxidant enzymes. In addition, BCT did not cause any adverse effects at up to 5000 mg/kg. CONCLUSIONS: These results indicate that BCT protects the gastric mucosa against ethanol-induced gastric injury by increasing the antioxidant status. We suggest that BCT could be developed as an effective drug for the treatment of gastric injury caused by alcohol intake.

Protective effect of Bojungikki-tang, a traditional herbal formula, against alcohol-induced gastric injury in rats.

ETHNOPHARMACOLOGICAL EVIDENCE: Oxidative stress plays an important role in the pathogenesis of ethanol-induced acute gastric mucosal injury. Bojungikki-tang (Hochuekkito in Japanese, Bu-zhong-yi-qi-tang in Chinese) is a traditional herbal formula used in Korea, Japan, and China to treat allergic diseases and gastrointestinal disorders. However, the mechanism responsible for its actions has not been investigated experimentally. AIM OF THE STUDY: The aims of this study were to investigate whether Bojungikki-tang water extract (BJITE) has protective effects against ethanol-induced acute gastric injury in rats and to perform an acute toxicity study to evaluate its safety. MATERIALS AND METHODS: In this rat model, gastric mucosal injury was imposed by oral administration of 5 mL/kg body weight of absolute ethanol. BJITE at one of two doses (200 or 400 mg/kg body weight) was administered by gavage 2 h before ethanol administration. Gastric tissues were collected and analyzed to assess the gastric injury index, and content or activity of catalase, superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), glutathione-S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx). RESULTS: Acute administration of ethanol significantly increased the gastric injury index concomitantly with an increase in MDA and GSH content, and a decrease in the activities of catalase, GST, GR, GPx, and SOD. Pretreatment with 200 or 400 mg/kg BJITE attenuated ethanol-induced gastric mucosal injury; this was accompanied by an increase in the content or activity of PGE(2), catalase, GSH, GST, GR, GPx, and SOD, and a decrease in MDA content. In the acute toxicity study, no adverse effects of BJITE were observed at doses up to 2000 mg/kg body weight. CONCLUSION: These results indicate that BJITE can partly protect the gastric mucosa from ethanol-induced acute gastric injury and suggest that these protective effects might be induced by increasing the antioxidant status. We suggest that BJITE can be developed as an effective drug for the treatment of acute gastric injury.

Protective effect of Chresta martii extract on ethanol-induced gastropathy depends on alpha-2 adrenoceptors pathways but not on nitric oxide, prostaglandins or opioids.

ETHNOPHARMACOLOGICAL RELEVANCE: Species of Chresta genus- are recognized by the population of northeastern Brazil as traditional herbs used to treat gastric diseases and other disorders. AIM OF THE STUDY: This work aimed to find out the action mechanism of Chresta martii hydro alcoholic extract gastro protective effect in the model of ethanol-induced gastropathy. MATERIAL AND METHODS: Gastropathy was assessed by percentual damaged area determination in photographs of mice opened stomachs. Fasted mice treated with ethanol 99.9% (0.2 ml/animal, p.o.) were pre-treated with Chresta martii hydro alcoholic extract (HAE) (50, 100 or 200 mg/kg, p.o.), ranitidine (80 mg/kg, p.o.) or saline (5 ml/kg; p.o.) in different experimental sets, in which pharmacological tools (naloxone, indomethacin, N(ω)-Nitro-L-arginine methyl ester hydrochloride (L-NAME) or yohimbine) were added in order to clarify a possible action mechanism. Animals were sacrificed 30 min after ethanol challenge to stomach analysis. Determination of non-protein sulfhydryl groups and tissue hemoglobin, besides histological assessment (H&E) were taken to fully characterize the HAE gastro protective effect. RESULTS: HAE (100 and 200 mg/kg) was able to protect mucosa against ethanol gastropathy in presence of three (naloxone, indomethacin and L-NAME) of four antagonist/inhibitor tools. The HAE effect was reversed only by yohimbine, showing the alpha-2 adrenoceptors participation on gastro protective effect of this extract. HAE histological characteristics, NP-SH and Hb were compatible with the protective effects. CONCLUSIONS: HAE possesses gastroprotective effects in an ethanol-induced gastropathy model in mice, corroborating the traditional use of this family of plants to treat gastric disorders. This activity is mediated by alpha-2 adrenoceptors activation, but not by nitric oxide release, opioid receptor activation or prostaglandin synthesis. HAE also has antioxidant activity that is thought to either play a role in this biological activity or to be a byproduct of alpha-2 adrenergic complex activation.

Gastric electrical stimulation decreases gastric distension-induced central nociception response through direct action on primary afferents.

BACKGROUND & AIMS: Gastric electrical stimulation (GES) is an effective therapy to treat patients with chronic dyspepsia refractory to medical management. However, its mechanisms of action remain poorly understood. METHODS: Gastric pain was induced by performing gastric distension (GD) in anesthetized rats. Pain response was monitored by measuring the pseudo-affective reflex (e.g., blood pressure variation), while neuronal activation was determined using c-fos immunochemistry in the central nervous system. Involvement of primary afferents was assessed by measuring phosphorylation of ERK1/2 in dorsal root ganglia. RESULTS: GES decreased blood pressure variation induced by GD, and prevented GD-induced neuronal activation in the dorsal horn of the spinal cord (T9-T10), the nucleus of the solitary tract and in CRF neurons of the hypothalamic paraventricular nucleus. This effect remained unaltered within the spinal cord when sectioning the medulla at the T5 level. Furthermore, GES prevented GD-induced phosphorylation of ERK1/2 in dorsal root ganglia. CONCLUSIONS: GES decreases GD-induced pain and/or discomfort likely through a direct modulation of gastric spinal afferents reducing central processing of visceral nociception.

[Effect of acupuncture on contents of beta-endorphin in the plasma and hypothalamus in rats with stress-induced gastric mucosal injury].

OBJECTIVE: To explore the mechanism of acupuncture in preventing and treating stress-induced gastric mucosal injury from the view of brain-gut axis. METHODS: Forty male Wister rats were randomly divided into normal control, model 1, treatment, model 2 and prevention groups (n=8). Gastric mucosa injury model was established by intragastric perfusion of dehydrated alcohol (1.0 mL/rat). Rats of the treatment group were treated with acupuncture after modeling, while those of the prevention group treated first, followed by modeling. The time of modeling in model 1 group and model 2 group was simultaneous with that of the treatment group and prevention group respectively. Acupuncture was applied to "Zusanli"(ST 36), "Zhongwan" (CV 12) and "Neiguan" (PC 6) for 20 min, once daily for 5 days. Before sampling the tissues, 10% charcoal suspension was intragastric perfused 1 h for analyzing the rate of gastrointestinal propulsion(distance from the upper end of the charcoal powder to the cardia/total length of the cardia to the anus x 100%). Gastric mucosal ulcer index was measured by using Guth's method. The contents of beta-endorphin(beta-EP)in plasma and hypothalamus were determined by enzyme-linked immunosorbent assay. RESULTS: Compared with the normal control group, the gastrointestinal propulsion rates were decreased considerably in the two model groups (P < 0.05), while the gastric mucosal ulcer indexes and the contents of beta-EP in both plasma and hypothalamus were increased significantly in the model groups (P < 0.05, P < 0.01). Compared with the corresponding model groups, the gastrointestinal propulsion rate was increased remarkably in the prevention group (P < 0.05), and the gastric mucosal ulcer indexes and the contents of plasma beta-EP level were decreased obviously in both treatment and prevention groups (P < 0.05, P < 0.01). The contents of hypothalamic beta-EP were increased further in the later two groups (P < 0.01). CONCLUSION: Acupuncture of ST 36, CV 12 and PC 6 can promote the repair of gastric mucosal injury and improve gastrointestinal function, which may be related to its effects in reducing plasma beta-EP and upregulating hypothalamic beta-EP level. Acupuncture also has a better effect in preventing gastric mucosal injury.

Antinociceptive and gastroprotective actions of ethanolic extract from Pluchea sagittalis (Lam.) Cabrera.

ETHNOPHARMACOLOGICAL RELEVANCE: Pluchea sagittalis, an herbaceous plant widely distributed in South America, is used in folk medicine for the treatment of digestive diseases and inflammation. AIM OF THE STUDY: This study was designed to investigate the antinociceptive and gastroprotective effects of the ethanolic extract (EE) of aerial parts from Pluchea sagittalis in rodents. MATERIALS AND METHODS: The antinociceptive effects of EE was evaluated in mice after oral administration in chemical tests (acetic-acid, glutamate and formalin) or by biting behavior following intrathecal administration of cytokines such as interleukin-1beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) in mice. Furthermore, rats were treated with EE and subsequently exposed to acute gastric lesions induced by 80% ethanol. Afterwards the gastric lesion extension and the mucus levels of gastric mucosa were measured. RESULTS: The oral administration of EE showed a dose-dependent inhibition of acetic acid-induced abdominal constrictions and glutamate-induced pain in mice, with ID(50) values of 624.0 (523.0-746.0) mg/kg and 368.0 (216.0-628.0) mg/kg, respectively. In the formalin test, the EE also produced significant inhibition of the inflammatory phase, with an ID(50) value of 411.0 (183.0-721.0) mg/kg; however, it was ineffective in the neurogenic phase caused by formalin. In addition, oral treatment with EE caused a significant inhibition of biting behavior induced by i.t. injection of interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α). The antinociception caused by the EE (300 mg/kg, p.o.) was not reversed by naloxone (1 mg/kg, i.p.) when assessed in the acetic acid writhing test. The EE (300-1000 mg/kg, p.o.) did not affect the motor coordination of animals in an open-field model. Oral treatment with the EE protected rats against gastric lesions induced by ethanol, with an ID(50) value of 55.0 (46.6-64.9) mg/kg, and increased the mucus levels of gastric mucosa to levels found in the non-lesioned group. CONCLUSIONS: The mechanism by which the extract produced antinociception still remains unclear, but this effect seems to be primarily related to the modulation or inhibition of the action of pro-inflammatory mediators. Furthermore, these data support, at least in part, the ethnomedical use of Pluchea sagittalis.

Effect of Vernonia cognata on oxidative damage induced by ethanol in rats.

Free radicals production and oxidative stress play a central role in injuries caused by ethanol (EtOH) on gastric mucosal. Thus, strategies to counteract EtOH toxicity are highly desirable. This study was aimed at evaluating whether Vernonia cognata extract would reduce EtOH effects in rats. Rats received Vernonia cognata extract (0, 1 and 2 g/kg bw, by gavage) 1 hour after EtOH had been administered (0 or 70%, 0.5 mL/100 g bw, by gavage) and were killed 1 hour after Vernonia cognata extract administration. The stomach was removed for macroscopic and histopathological evaluation, as well as, oxidative stress markers such as lipoperoxidation (LPO) and non-protein thiol groups (NPSH) levels and catalase (CAT) activity. EtOH acute exposure increased LPO and decreased NPSH levels and CAT activity along with macroscopic and microscopic lesions in gastric tissue, confirming the involvement of oxidative stress in EtOH toxicity. Vernonia cognata extract attenuated oxidative and histopathological features induced by EtOH at all evaluated doses. Moreover, both studied doses of Vernonia cognata extract caused an increase in NPSH levels per se. However, only the dose of 2 g/kg reverted all macroscopic changes caused by EtOH toxicity. The protective effect of the extract could be attributed to antioxidant molecules present in the extract, such as flavonoids and phenolic acids, which were quantified by high performance liquid chromatography (HPLC). Thus, an antioxidant effect of the extract leads to a protection on gastric tissue. Our results indicate that Vernonia cognata hydroethanolic extract could have a beneficial role against EtOH toxicity by preventing oxidative stress and gastric tissue injury.

[Effects of moxibustion on gastric mucosal EGF and TGF-alpha contents and epidermal growth factor receptor expression in rats with gastric mucosal lesion].

OBJECTIVE: To observe the effects of moxibustion on contents of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) expression in the gastric mucosa tissue in rats with gastric mucosal lesion. METHODS: Thirty-six SD rats were randomly and equally divided into control, model and moxibustion groups. Gastric mucosal lesion model was duplicated by restraint and cool water immersion stress. Pre-moxibustion was applied to "Zusanli" (ST 36) and "Zhongwan" (CV 12), "Pishu" (BL 20) and "Weishu" (BL 21) alternately, once everyday for 8 days before modeling. The contents of EGF and TGF-alpha in gastric mucosa were detected by enzyme-linked immunosorbent assay (ELISA) and the expression of EGFR determined by immunohistochemistry. RESULTS: Compared with the control group, only TGF-alpha content in the gastric mucosa in the model group was increased significantly (P < 0.05). Compared with the model group, the EGF and TGF-alpha contents and EGFR immunoactivity in the gastric mucosa were increased significantly in the moxibustion group (P < 0.05, P < 0.01). CONCLUSION: Pre-moxibustion at ST 36, CV 12, BL 20 and BL 21 can up-regulate gastric mucosal EGF and TGF-alpha contents and EGFR protein expression in gastric mucosa lesion rats, which may contribute to its effect in relieving stress-induced gastric mucosal injury.

A bicarbonate-alkaline mineral water protects from ethanol-induced hemorrhagic gastric lesions in mice.

Ingestion of elevated amounts of ethanol in humans and rodents induces hemorrhagic gastric lesions, at least in part by increasing oxidative stress. The present study was undertaken in order to evaluate the influence of a bicarbonate-alkaline mineral water (Uliveto on ethanol-induced hemorrhagic gastric lesions in mice. Lesions were evaluated by both macroscopic and microscopic analysis. In a first set of experiments, mice were allowed to drink Uliveto or reference water ad libitum until 3 h prior to intragastric (i.g.) ethanol (23 ml/kg) administration. Neither Uliveto nor reference water did afford any protection. In a second set of experiments, acute exposure to reference water (35 ml/kg, i.g.), given 30 min before ethanol, did not inhibit gastric lesions. However, administration of the same amount of Uliveto caused a remarkable reduction in ethanol-evoked gastric lesions. Ethanol administration increased 4-hydroxy-2-nonenal levels, a byproduct of oxidative stress, in the luminal part of the gastric mucosa. This response was substantially reduced by about 70% by Uliveto, but not by reference water. Reference water, added with the bicarbonate content, present in the Uliveto water, protected against ethanol-induced lesions. Thus, acute pre-exposure to bicarbonate-alkaline mineral water (Uliveto) protects from both oxidative stress and hemorrhagic gastric lesions caused by ethanol. The elevated bicarbonate content of Uliveto likely accounts for the protection against ethanol-induced gastric injury.