Effects of rutin and harmaline on rat reflux oesophagitis

Columbianadin ameliorates experimental acute reflux esophagitis in rats via suppression of NF-κB pathway

PURPOSE

Reflux esophagitis is a condition characterized by inflammation and irritation of the esophagus, resulting from the backflow of stomach acid and other gastric contents into the esophagus. Columbianadin is a coumarin derivative that exhibits anti-inflammatory and antioxidant effects. In this study, we tried to scrutinize the protective effect of Columbianadin against acute reflux esophagitis in rats.

METHODS

RAW 264.7 cells were utilized to assess cell viability and measure the production of inflammatory parameters. The rats received anesthesia, and reflux esophagitis was induced via ligation of pylorus and fore stomach and corpus junction. Rats received the oral administration of Columbianadin (25, 50 and 100 mg/kg) and omeprazole (20 mg/kg). The gastric secretion volume, acidity, and pH were measured. Additionally, the levels of oxidative stress parameters, cytokines, and inflammatory markers were determined. At the end of the study, mRNA expression was assessed.

RESULTS

Columbianadin remarkably suppressed the cell viability and production of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and prostaglandin (PGE2). Columbianadin treatment remarkably suppressed the secretion of gastric volume, total acidity and enhanced the pH level in the stomach. Columbianadin remarkably altered the level of hydrogen peroxidase, free iron, calcium, and plasma scavenging activity, sulfhydryl group; oxidative stress parameters like malonaldehyde, glutathione, superoxide dismutase, catalase, glutathione peroxidase; inflammatory cytokines viz., TNF-α, IL-6, IL-1β, IL-10, IL-17, and monocyte chemoattractant protein-1; inflammatory parameters including PGE2, iNOS, COX-2, and nuclear kappa B factor (NF-κB). Columbianadin remarkably (P < 0.001) suppressed the mRNA expression TNF-α, IL-6, IL-1β and plasminogen activator inhibitor-1.

CONCLUSIONS

Columbianadin demonstrated a protective effect against acute reflux esophagitis via NF-κB pathway.

Protective Effects of Cudrania tricuspidata Against Helicobacter pylori-Induced Inflammation in C57BL/6 Mice

Helicobacter pylori modulates the host inflammatory response, resulting in chronic gastritis, which contributes to gastric cancer pathogenesis. We verified the effect of Cudrania tricuspidata on H. pylori infection by inhibiting H. pylori-induced inflammatory activity. Five-week-old C57BL/6 mice (n = 8) were administered C. tricuspidata leaf extract (10 or 20 mg/kg per day) for 6 weeks. An invasive test (campylobacter-like organism [CLO]) and noninvasive tests (stool antigen test [SAT] and H. pylori antibody enzyme-linked immunosorbent assay) were performed to confirm the eradication of H. pylori. To evaluate the anti-inflammatory effect of C. tricuspidata, pro-inflammatory cytokines levels and inflammation scores were measured in mouse gastric tissue. C. tricuspidata significantly decreased the CLO score and H. pylori immunoglobulin G antibody optical density levels at both 10 and 20 mg/kg per day doses (P < .05). C. tricuspidata decreased the H. pylori antibody levels in a concentration-dependent manner, increased negative responses to SAT by up to 37.5%, and inhibited the pro-inflammatory cytokines interleukin (IL; IL-1β, IL-6, 1L-8, and tumor necrosis factor alpha). C. tricuspidata also relieved gastric erosions and ulcers and significantly reduced the inflammation score (P < .05). We measured rutin in C. tricuspidata extract as a standard for high-performance liquid chromatography. C. tricuspidata leaf extract showed anti-H. pylori activity through the inhibition of inflammation. Our findings suggest that C. tricuspidata leaf extract is potentially an effective functional food material against H. pylori.

Treatment with Rutin - A Therapeutic Strategy for Neutrophil-Mediated Inflammatory and Autoimmune Diseases: - Anti-inflammatory Effects of Rutin on Neutrophils

Objectives:

Neutrophils represent the front line of human defense against infections. Immediately after stimulation, neutrophilic enzymes are activated and produce toxic mediators such as pro-inflammatory cytokines, nitric oxide (NO) and myeloperoxidase (MPO). These mediators can be toxic not only to infectious agents but also to host tissues. Because flavonoids exhibit antioxidant and anti-inflammatory effects, they are subjects of interest for pharmacological modulation of inflammation. In the present study, the effects of rutin on stimulus-induced NO and tumor necrosis factor (TNF)-α productions and MPO activity in human neutrophils were investigated.

Methods:

Human peripheral blood neutrophils were isolated using Ficoll-Hypaque density gradient centrifugation coupled with dextran T500 sedimentation. The cell preparations containing > 98% granulocytes were determined by morphological examination through Giemsa staining. Neutrophils were cultured in complete Roswell Park Memorial Institute (RPMI) medium, pre-incubated with or without rutin (25 μM) for 45 minutes, and stimulated with phorbol 12-myristate 13-acetate (PMA). Then, the TNF-α, NO and MPO productions were analyzed using enzyme-linked immunosorbent assay (ELISA), Griess Reagent, and MPO assay kits, respectively. Also, the viability of human neutrophils was assessed using tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and neutrophils were treated with various concentrations of rutin (1 - 100 μM), after which MTT was appended and incubated at 37ºC for 4 hour.

Results:

Rutin at concentrations up to 100 μM did not affect neutrophil viability during the 4-hour incubation period. Rutin significantly decreased the NO and TNF-α productions in human peripheral blood neutrophils compared to PMA-control cells (P < 0.001). Also, MPO activity was significantly reduced by rutin (P < 0.001).

Conclusion:

In this in vitro study, rutin had an anti-inflammatory effect due to its inhibiting NO and TNF-α productions, as well as MPO activity, in activated human neutrophils. Treatment with rutin may be considered as a therapeutic strategy for neutrophil-mediated inflammatory/ autoimmune diseases.

Effect of rutin against gastric esophageal reflux in experimental animals

CONTEXT

The present study was undertaken to elucidate the effect of rutin against gastric esophageal reflux in experimental animals.

METHODS

Groups of rats, fasted overnight received normal saline (3 ml/kg, sham control) or esophagitis control (3 ml/kg, normal saline) or pantoprazole (30 mg/kg) or rutin (50 and 100 mg/kg) were subjected to pylorus and forestomach ligation. Animals were sacrificed after 12 h and scrutinized physiologically (gastric pH, total acidity, free acidity and esophagitis index), biochemically (TBAR's, SOD, catalase, GSH and protein carbonyl) and morphologically. The esophageal tissues were also inquested for the presence of proinflammatory (IL-2 and IL-1β) and immunoregulatory (IL-4 and IL-6) cytokines.

RESULTS

The results demonstrated momentous physiological, biochemical and morphological protection imparted by rutin. The rutin also restored the altered levels of proinflammatory and immunoregulatory cytokines, which further strengthens the implication of rutin in GERD.

CONCLUSION

The beneficial effects as observed in the current experiment could be accredited to the antioxidant and anti-inflammatory (through inhibition of COX and LOX) property of rutin.

Rutin decreases lipopolysaccharide-induced acute lung injury via inhibition of oxidative stress and the MAPK-NF-κB pathway

Acute lung injury (ALI) is a serious disease with unacceptably high mortality and morbidity rates. Up to now, no effective therapeutic strategy for ALI has been established. Rutin, quercetin-3-rhamnosyl glucoside, expresses a wide range of biological activities and pharmacological effects, such as anti-inflammatory, antihypertensive, anticarcinogenic, vasoprotective, and cardioprotective activities. Pretreatment with rutin inhibited not only histopathological changes in lung tissues but also infiltration of polymorphonuclear granulocytes into bronchoalveolar lavage fluid in lipopolysaccharide (LPS)-induced ALI. In addition, LPS-induced inflammatory responses, including increased secretion of proinflammatory cytokines and lipid peroxidation, were inhibited by rutin in a concentration-dependent manner. Furthermore, rutin suppressed phosphorylation of NF-κB and MAPK and degradation of IκB, an NF-κB inhibitor. Decreased activities of antioxidative enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase-1 caused by LPS were reversed by rutin. At the same time, we found that ALI amelioration by chelation of extracellular metal ions with rutin is more efficacious than with deferoxamine. These results indicate that the protective mechanism of rutin is through inhibition of MAPK-NF-κB activation and upregulation of antioxidative enzymes.

Cross-organ sensitization of thoracic spinal neurons receiving noxious cardiac input in rats with gastroesophageal reflux

Gastroesophageal reflux (GER) frequently triggers or worsens cardiac pain or symptoms in patients with coronary heart disease. This study aimed to determine whether GER enhances the activity of upper thoracic spinal neurons receiving noxious cardiac input. Gastric fundus and pyloric ligations as well as a longitudinal myelotomy at the gastroesophageal junction induced acute GER in pentobarbital-anesthetized, paralyzed, and ventilated male Sprague-Dawley rats. Manual manipulations of the stomach and lower esophagus were used as surgical controls in another group. At 4-9 h after GER surgery, extracellular potentials of single neurons were recorded from the T3 spinal segment. Intrapericardial bradykinin (IB) (10 microg/ml, 0.2 ml, 1 min) injections were used to activate cardiac nociceptors, and esophageal distensions were used to activate esophageal afferent fibers. Significantly more spinal neurons in the GER group responded to IB compared with the control group (69.1 vs. 38%, P < 0.01). The proportion of IB-responsive neurons in the superficial laminae of GER animals was significantly different from those in deeper layers (1/8 vs. 46/60, P < 0.01); no difference was found in control animals (7/25 vs. 20/46, P > 0.05). Excitatory responses of spinal neurons to IB in the GER group were greater than in the control group [32.4 +/- 3.5 impulses (imp)/s vs. 13.3 +/- 2.3 imp/s, P < 0.01]. Forty-five of 47 (95.7%) neurons responded to cardiac input and ED, which was higher than the control group (61.5%, P < 0.01). These results indicate that acute GER enhanced the excitatory responses of thoracic spinal neurons in deeper laminae of the dorsal horn to noxious cardiac stimulus.

Effect of an herbal preparation, STW 5, in an acute model of reflux oesophagitis in rats

A multitarget herbal preparation, STW 5, has been used clinically in different gastro-intestinal disorders including functional dyspepsia and irritable bowel syndrome. Previous studies have shown that it possesses properties that may render it useful in gastro-oesophageal reflux disease (GERD). We performed this study to test this compound in an acute model of reflux oesophagitis in rats. Oesophagitis was induced surgically by ligating the pyloric end and fore-stomach. Lower oesophageal pH was measured 3 h later in conscious animals. Five hours after surgery, animals were sacrificed and the oesophagi were examined macroscopically and histologically. Selected markers of inflammation were measured in oesophageal homogenates. STW 5 was given orally for 5 days before induction of oesophagitis. Pantoprazole was used as a reference standard. Ligated animals showed a high incidence of ulcerative lesions associated with a marked increase in myeloperoxidase, thiobarbituric acid-reactive substances, tumor necrosis factor-alpha, and interleukin-1beta. STW 5 did not affect oesophageal pH, but dose-dependently reduced the severity of the oesophageal lesions and normalized the deranged level of the inflammation markers. The beneficial effects were confirmed histopathologically. STW 5 proved to be effective in protecting against inflammatory lesions in this model of oesophagitis, thus warranting further investigation of its potential therapeutic usefulness in GERD.

Nitric oxide as a target of complementary and alternative medicines to prevent and treat inflammation and cancer

Nitric oxide (NO) and associated reactive nitrogen species (RNS) are involved in many physiological functions. There has been an ongoing debate to whether RNS can inhibit or perpetuate chronic inflammation and associated carcinogenesis. Although the final outcome depends on the genetic make-up of its target, the surrounding microenvironment, the activity and localization of nitric oxide synthase (NOS) isoforms, and overall levels of NO/RNS, evidence is accumulating that in general, RNS drive inflammation and cancers associated with inflammation. To this end, many complementary and alternative medicines (CAMs) that work in chemoprevention associated with chronic inflammation, are inhibitors of excessive NO observed in inflammatory conditions. Here, we review recent literature outlining a role of NO/RNS in chronic inflammation and cancer, and point toward NO as one of several targets for the success of CAMs in treating chronic inflammation and cancer associated with this inflammation.

Efficacy of the natural antioxidant astaxanthin in the treatment of functional dyspepsia in patients with or without Helicobacter pylori infection: A prospective, randomized, double blind, and placebo-controlled study

OBJECTIVES

The aim of this study was to evaluate the efficacy of the natural antioxidant astaxanthin in functional dyspepsia in different doses and compared with placebo.

DESIGN

The study was a controlled, prospective, randomized, and double blind trial.

PARTICIPANTS

Patients with functional dyspepsia, divided into three groups with 44 individuals in each group (placebo, 16mg, or 40mg astaxanthin, respectively).

INTERVENTIONS

Participants were asked to accept gastroscopy before treatment, together with questionnaires: GSRS and SF-36. Urea breath test (UBT) was done before the treatment.

MAIN OUTCOME

The primary objective was to test the hypothesis that the antioxidant astaxanthin at two doses regimens compared to placebo should ameliorate gastrointestinal discomfort measured as GSRS in patients with functional dyspepsia, who were either positive or negative for Helicobacter pylori, after 4 weeks of treatment.

RESULTS

At the end of therapy (week 4) no difference between the three treatment groups was observed regarding mean Gastrointestinal Symptom Rating Scale (GSRS) scores of abdominal pain, indigestion and reflux syndromes. The same results were observed at the end of follow-up. However reduction of reflux syndrome before treatment to week 4 was significantly pronounced in the higher (40mg) dose compared to the other treatment groups (16mg and placebo, p=0.04).

CONCLUSION

In general, no curative effect of astaxanthin was found in functional dyspepsia patients. Significantly greater reduction of reflux symptoms were detected in patients treated with the highest dose of the natural antioxidant astaxanthin. The response was more pronounced in H. pylori-infected patients.

IL-1β activates p44/42 and p38 mitogen-activated protein kinases via different pathways in cat esophageal smooth muscle cells

AIM: To examine the pathway related to the IL-1β-induced activation of mitogen-activated protein (MAP) kinases in cat esophageal smooth muscle cells.

METHODS: Culture of the esophageal smooth muscle cells from cat was prepared. Specific inhibitors were treated before applying the IL-1β. Western blot analysis was performed to detect the expressions of COX, iNOS and MAP kinases.

RESULTS: In the primary cultured cells, although IL-1β failed to upregulate the COX and iNOS levels, the levels of the phosphorylated forms of p44/42 MAP kinase and p38 MAP kinase increased in both concentration- and time-dependent manner, of which the level of activation reached a maximum within 3 and 18 h, respectively. The pertussis toxin reduced the level of p44/42 MAP kinase phosphorylation. Tyrphostin 51 and genistein also inhibited this activation. Neomycin decreased the density of the p44/42 MAP kinase band to the basal level. Phosphokinase C (PKC) was found to play a mediating role in the IL-1β-induced p44/42 MAP kinase activity. In contrast, the activation of p38 MAP kinase was inhibited only by a pretreatment with forskolin, and was unaffected by the other compounds.

CONCLUSION: Based on these results, IL-1β-induced p44/42 MAP kinase activation is mediated by the Gi protein, tyrosine kinase, phospholipase C (PLC) and PKC. The pathway for p38 MAP kinase phosphorylation is different from that of p44/42 MAP kinase, suggesting that it plays a different role in the cellular response to IL-1β.

The impact of antireflux surgery on oxidative stress of esophageal mucosa caused by gastroesophageal reflux disease: 4-yr follow-up study

BACKGROUND AND AIM

Oxidative stress to esophageal mucosa plays a key role in the pathogenesis of gastroesophageal reflux disease (GERD), Barrett's esophagus, and adenocarcinoma. We investigated whether successful antireflux surgery eliminates oxidative stress.

METHODS

Oxidative stress of esophageal mucosa was measured in 20 GERD patients, before antireflux surgery and 6 and 48 months after it, and compared with normal controls' mucosa (N = 9). Preoperatively, 12 of the 20 had erosive esophagitis or Barrett's metaplasia. Postoperatively, healing of GERD was verified with endoscopy and 24-h pH monitoring. We measured oxidative stress by myeloperoxidase activity (MPA), superoxide dismutase activity, and glutathione content (GSH) in distal esophagus samples from endoscopy.

RESULTS

No patient had reflux symptoms after surgery, and pH measurements had normalized. MPA in the distal esophagus decreased (p < 0.05) after successful antireflux surgery, but remained higher than that of controls both 6 months and 4 yr postoperatively (p < 0.05). At all time-points, MPA was higher in patients with preoperatively detected erosive reflux disease (ERD) as compared to non-erosive reflux disease (NERD) (p < 0.01, p < 0.05, and p < 0.05, respectively). GSH values decreased with time only in NERD. At all time-points, GSH levels in distal esophagus were lower than control levels.

CONCLUSIONS

Antireflux surgery can heal macroscopic esophagitis but cannot fully reverse the oxidative stress (as reflected by MPA and GSH) upon the distal esophageal mucosa.

Gastroprotective activity of sesquiterpene derivatives fromFabiana imbricata

An infusion or decoction of the aerial parts of Fabiana imbricata (Solanaceae) is used in traditional medicine in Chile and Argentina as a digestive and diuretic agent. The main sesquiterpene of the plant was identified as 11-hydroxy-4-amorphen-15-oic acid. At doses of 25, 50 and 100 mg/kg, the compound showed a dose-dependent gastroprotective effect in HCl/EtOH-induced gastric lesions in mice reducing the lesions by 68% at 100 mg/kg. Seven derivatives of the terpene were prepared and their gastroprotective effect was assessed in HCl/EtOH-induced gastric lesions in mice. The cytotoxicity of the products was evaluated in fibroblasts and AGS cells. At 100 mg/kg, 11-hydroxy-4-amorphen-15-p-toluidinamide presented the best gastroprotective effect reducing the gastric lesions by 80%, showing a similar effect to lansoprazole at 20 mg/kg. The compound, however, presented higher cytotoxicity than other derivatives with the IC50 ranging between 110 and 145 microm in AGS cells and fibroblasts, respectively. Most compounds proved to be non-toxic showing cytotoxicity values higher than 1000 microm. The spectroscopic data of six 11-hydroxy-4-amorphen-15-oic acid derivatives are presented here for the first time.