Akinori Yanaka

Dietary Sulforaphane-Rich Broccoli Sprouts Reduce Colonization and Attenuate Gastritis in Helicobacter pylori-Infected Mice and Humans

The isothiocyanate sulforaphane [SF; 1-isothiocyanato-4(R)-methylsulfinylbutane] is abundant in broccoli sprouts in the form of its glucosinolate precursor (glucoraphanin). SF is powerfully bactericidal against Helicobacter pylori infections, which are strongly associated with the worldwide pandemic of gastric cancer. Oral treatment with SF-rich broccoli sprouts of C57BL/6 female mice infected with H. pylori Sydney strain 1 and maintained on a high-salt (7.5% NaCl) diet reduced gastric bacterial colonization, attenuated mucosal expression of tumor necrosis factor-α and interleukin-1β, mitigated corpus inflammation, and prevented expression of high salt-induced gastric corpus atrophy. This therapeutic effect was not observed in mice in which the nrf2 gene was deleted, strongly implicating the important role of Nrf2-dependent antioxidant and anti-inflammatory proteins in SF-dependent protection. Forty-eight H. pylori–infected patients were randomly assigned to feeding of broccoli sprouts (70 g/d; containing 420 μmol of SF precursor) for 8 weeks or to consumption of an equal weight of alfalfa sprouts (not containing SF) as placebo. Intervention with broccoli sprouts, but not with placebo, decreased the levels of urease measured by the urea breath test and H. pylori stool antigen (both biomarkers of H. pylori colonization) and serum pepsinogens I and II (biomarkers of gastric inflammation). Values recovered to their original levels 2 months after treatment was discontinued. Daily intake of sulforaphane-rich broccoli sprouts for 2 months reduces H. pylori colonization in mice and improves the sequelae of infection in infected mice and in humans. This treatment seems to enhance chemoprotection of the gastric mucosa against H. pylori–induced oxidative stress.

Constitutive Expression of Aryl Hydrocarbon Receptor in Keratinocytes Causes Inflammatory Skin Lesions

ABSTRACT Occupational and environmental exposure to polycyclic aromatic hydrocarbons (PAHs) has been suggested to provoke inflammatory and/or allergic disorders, including asthma, rhinitis, and dermatitis. The molecular mechanisms of this PAH-mediated inflammation remain to be clarified. Previous studies implied the involvement of PAHs as irritants and allergens, with the reactive oxygen species generated from the oxygenated PAHs believed to be an exacerbating factor. It is also possible that PAHs contribute to the pathogenesis through activation of aryl-hydrocarbon receptor (AhR)-mediated transcription, since PAHs are potent inducers of the AhR. To address this point, we generated transgenic mouse lines expressing the constitutive active form of the AhR in keratinocytes. In these lines of mice, the AhR activity was constitutively enhanced in the absence of ligands, so that any other direct effects of PAHs and their metabolites could be ignored. At birth, these transgenic mice were normal, but severe skin lesions with itching developed postnatally. The skin lesions were accompanied by inflammation and immunological imbalance and resembled typical atopic dermatitis. We demonstrate that constitutive activation of the AhR pathway causes inflammatory skin lesions and suggests a new mechanism for the exacerbation of inflammatory diseases after exposure to occupational and environmental xenobiotics.

Newly Developed Antibiotic Combination Therapy for Ulcerative Colitis: A Double-Blind Placebo-Controlled Multicenter Trial

OBJECTIVES:Fusobacterium varium may contribute to ulcerative colitis (UC). We conducted a double-blind placebo-controlled multicenter trial to determine whether antibiotic combination therapy induces and/or maintains remission of active UC.METHODS:Patients with chronic mild-to-severe relapsing UC were randomly assigned to oral amoxicillin 1500 mg/day, tetracycline 1500 mg/day, and metronidazole 750 mg/day, vs. placebo, for 2 weeks, and then followed up. The primary study end point was clinical response (Mayo score at 3 months after treatment completion) and secondary end points were clinical and endoscopic score improvements at 12 months. Anti-F. varium antibodies were measured by enzyme-linked immunosorbent assay.RESULTS:Treatment and placebo groups each had 105 subjects. At the primary end point, response rates were significantly greater with antibiotics than with placebo (44.8 vs. 22.8%, P=0.0011). Endoscopic scores significantly improved at 3 months (P=0.002 vs. placebo). Remission rates were 19.0% (antibiotics) vs. 15.8% (placebo) at 3 months (P=0.59). At the secondary end point, response rates were significantly greater with antibiotics than with placebo (49.5 vs. 21.8%, respectively, P<0.0001). Endoscopic scores were significantly improved at 12 months after antibiotic treatment (P=0.002 vs. placebo). Remission rates had improved to 26.7% with antibiotics vs. 14.9% for placebo, at 12 months (P=0.041). F. varium antibody titers decreased in responders but not in nonresponders, and more in the antibiotic than in the placebo group. More pretreatment steroid-dependent UC patients discontinued corticosteroids after treatment completion (6 months: 28.6 vs. 11.8%, respectively, P=0.046; 9 months: 34.7 vs. 13.7%, respectively, P=0.019; and 12 months: 34.7 vs. 13.7%, respectively, P=0.019). These effects were greater in the subanalysis of the active group (Mayo scores of 6–12) than in that of total cases (0–12). No serious drug-related toxicities occurred.CONCLUSIONS:The 2-week triple antibiotic therapy produced improvement, remission, and steroid withdrawal in active UC more effectively than a placebo.

Recurrent Peptic Ulcers in Patients Following Successful Helicobacter pylori Eradication: A Multicenter Study of 4940 Patients

Objective.  Although curative treatment of Helicobacter pylori infection markedly reduces the relapse of peptic ulcers, the details of the ulcers that do recur is not well characterized. The aim of this study is to describe the recurrence rate and specific features of peptic ulcers after cure of H. pylori infection.

Rebamipide Significantly Inhibits Indomethacin-Induced Mitochondrial Damage, Lipid Peroxidation, and Apoptosis in Gastric Epithelial RGM-1 Cells

Nonsteroidal antiinflammatory drugs (NSAIDs) cause complications such as gastrointestinal injury. NSAIDs were recently reported to cause mitochondrial injury: to dissipate the mitochondrial transmembrane potential (MTP), and to induce mitochondrial permeability transition pore (PTP), which liberates cytochrome c. This enzyme generates reactive oxygen species (ROS) thereby triggers caspase cascade and cellular lipid peroxidation, resulting in cellular apoptosis. However, the mechanism of this NSAID-induced MTPs role in cellular apoptosis remains unknown. Rebamipide, an antiulcer drug, is reported to scavenge ROS and to show the protective effects on indomethacin-induced tissue peroxidations. Since cytochrome c and its generation of ROS are involved in indomethacin-induced cellular apoptosis, rebamipide may attenuate mitochondrial damage. The aim of this study was to elucidate whether indomethacin induces both the MTP decrease and cellular apoptosis, and the effect of rebamipide on these phenomena. We examined the effect of rebamipide on 1) MTP change, 2) lipid peroxidation, 3) apoptosis, and 4) caspase activation using gastric mucosal epithelial cell-line treated with indomethacin. With a specially designed fluorescence analyzing microscope system, MTP change, cellular lipid peroxidation, and cellular apoptosis were investigated with the ⋆ following fluorescent dyes, MitoRed, DPPP, and Hoechst 33258, respectively. Indomethacin treatment decreased MTP but increased both cellular lipid peroxidation and cellular apoptosis via caspase 3 and 9 activation. Rebamipide clearly inhibited these phenomena {in vitro}. We demonstrated that fluorescent dyes such as MitoRed, DPPP, and Hoechst 33258 are useful indicators for detecting oxidative cellular injuries in living cells. Rebamipide exerts a protective effect on mitochondrial membrane stability in gastric epithelial cells.

Geranylgeranylacetone Protects the Human Gastric Mucosa from Diclofenac-Induced Injury via Induction of Heat Shock Protein 70

Background/Aim: Geranylgeranylacetone (GGA) enhances gastric mucosal protection against nonsteroidal anti-inflammatory drugs by upregulating mucosal heat shock proteins (HSP), but the effects of GGA on the human gastric mucosa have not been well examined. This study was conducted to determine whether a clinical dose of GGA protects the human gastric mucosa from diclofenac (DIC)-induced gastric mucosal injury. Methods: The study group comprised 40 healthy volunteers: 20 subjects were randomly assigned to take either placebo (lactose 1.5 g/day) or GGA (150 mg/day) for 2 weeks (study 1), and 20 subjects were assigned to take DIC (75 mg/day) plus placebo (lactose 1.5 g/day) or DIC (75 mg/day) plus GGA (150 mg/day) for 2 weeks (study 2). In both studies, gastroscopic biopsy specimens were obtained before and after treatment. Mucosal HSP70 expression and DNA damage were analyzed by measuring the levels of HSP70 and 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-OHdG), respectively. Results: In study 1, GGA increased the mucosal HSP70 expression without increasing the 8-OHdG production. In study 2, DIC treatment increased the 8-OHdG production, whereas the combination of GGA and DIC enhanced the HSP70 expression and attenuated the increase in 8-OHdG induced by DIC. Conclusion: The clinical dose of GGA enhanced the gastric mucosal HSP70 expression and inhibited the DIC-induced gastric mucosal damage in humans.

Role of the nrf-2 gene in protection and repair of gastric mucosa against oxidative stress

Helicobacter pylori infection, as well as NSAIDs induce oxidative stress on gastric mucosa, thereby causing mucosal damage and retarding mucosal repair. Cells can survive against chronic oxidative stress by enhancing activities of anti-oxidant enzymes, thereby protecting cells from DNA damage. Recent studies have clearly shown that the gene encoding Nrf-2 (NF-E2 p45-related factor-2) plays an important role in the induction of antioxidant enzymes against oxidative stress. In this paper, we will describe the cellular mechanisms by which the nrf-2 gene stimulates anti-oxidant enzyme activities during exposure to oxidative stress. Secondly, we will also mention the beneficial effects of sulforaphane, an isothiocyanate family which is abundantly included in broccoli sprouts, on gastric mucosa. Sulforaphane stimulates nrf-2 gene-dependent anti-oxidant enzyme activities, thereby protecting cells from oxidative injury. Finally, we will state our perspective on the efficacy of sulforaphane in protection and repair of gastric mucosa against oxidative stress during H. pylori infection.

Sulforaphane Enhances Protection and Repair of Gastric Mucosa Against Oxidative stress In Vitro, and Demonstrates Anti-inflammatory Effects on Helicobacter pyloriInfected Gastric Mucosae in Mice and Human Subjects

Helicobacter pylori infection induces oxidative stress on gastric mucosa, thereby causing mucosal damage, retarding mucosal repair, and eventually inducing gastric cancer. Cells can survive against chronic oxidative stress by enhancing activities of antioxidant enzymes, thereby protecting cells from DNA damage. Recent studies have clearly shown that the genes encoding nrf2 (NF-E2 p45-related factor-2) and keap1 (Kelch-like ECH-associated protein 1) play an important role in the induction of antioxidant enzymes against oxidative stress. In this paper, we will first describe the cellular mechanisms by which the nrf2-keap1 system contributes to induction of a variety of antioxidant enzymes during exposure to oxidative stress. Secondly, we will also mention beneficial effects of a natural compound sulforaphane, an isothiocyanate family, rich in broccoli sprouts, on gastric mucosa. Sulforaphane stimulates nrf2 gene-dependent antioxidant enzyme activities, thereby protecting cells from oxidative injury. Finally, we will show our data on the effect of sulforaphane, a natural chemical compound rich in broccoli sprouts, on protection and repair of gastric mucosa against oxidative stress, and anti-inflammatory effects on gastric mucosa during H. pylori infection, which appears to be closely related to chemoprotection against gastric cancer induced by .H. pylori-infection.

Helicobacter pylori eradication and metachronous gastric cancer after endoscopic mucosal resection of early gastric cancer: H. PYLORI ERADICATION AND GASTRIC CANCER AFTER EMR

To conduct a retrospective multicentre study at 31 medical centres in Japan, to investigate the association between the eradication of Helicobacter pylori and the development of new gastric cancer after endoscopic mucosal resection (EMR) for early gastric cancer.

Therapeutic efficacy of the Qing Dai in patients with intractable ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that may become intractable when treated with conventional medications such as aminosalicylates, corticosteroids, and azathioprine. The herbal medicine Qing Dai has traditionally been used in Chinese medicine to treat UC patients, but there is a lack of published data on the efficacy of Qing Dai in UC treatment. We report several cases of patients with intractable UC who take Qing Dai in a retrospective observational study. Furthermore, we explore the mechanisms of action of Qing Dai. Nine patients with active UC who received conventional medications but wished to receive Qing Dai as an alternative medication were included in our analysis. The UC severity level was determined based on the clinical activity index (CAI). Additionally, 5 of the 9 patients were endoscopically evaluated according to the Matts grading system. Each patient received 2 g/d of Qing Dai orally and continued taking other medications for UC as prescribed. Electron spin resonance was applied to explore the mechanisms of action of Qing Dai. After 4 mo of treatment with Qing Dai, the CAI score decreased from 8.3 ± 2.4 to 2.4 ± 3.4 (mean ± SD; P < 0.001). Similarly, the endoscopic Matts grade decreased from 3.4 ± 0.5 to 2.2 ± 0.8 (P = 0.02). Six of 7 patients who were on prednisolone upon enrollment in the study were able to discontinue this corticosteroid. Electron spin resonance revealed that Qing Dai possesses strong hydroxyl radical scavenging activity. Qing Dai showed significant clinical and endoscopic efficacy in patients who failed to respond to conventional medications. Scavenging of hydroxyl radicals appears to be a potential mechanism through which Qing Dai acts, but the significance of the scavenging ability of Qing Dai with respect to the anti-inflammatory effect in UC patients warrants further investigation.