The role of mucus in the protection of the gastroduodenal mucosa

A review on the mucus dynamics in the human respiratory airway

Research interest in the dynamics of respiratory flow and mucus has significantly increased in recent years with important contributions from various disciplines such as pulmonary and critical care medicine, surgery, physiology, environmental health sciences, biophysics, and engineering. Different areas of engineering, including mechanical, chemical, civil/environmental, aerospace, and biomedical engineering, have longstanding connections with respiratory research. This review draws on a wide range of scientific literature that reflects the diverse audience and interests in respiratory science. Its focus is on mucus dynamics in the respiratory airways, covering aspects such as mucins in fluidity and network formation, mucus production and function, response to external conditions, clearance methods, relationship with age, rheological properties, mucus surfactant, and mucoviscidosis. Each of these areas contains multiple subtopics that offer extensive depth and breadth for readers. We underscore the crucial importance of regulating and treating mucus for maintaining the health and functionality of the respiratory system, highlighting the ongoing need for further research to address respiratory disorders associated with mucus dynamics.

Holothuria polii Extract as a Potential Anticoccidial Agent: Evidence of Its MUC2 Regulatory Impact in Murine Jejunum

Eimeria is a parasite that causes coccidiosis in a variety of animals, leading to nutritional imbalances, issues with food digestion and absorption, low weight, and intestinal inflammation of varying degrees in its hosts. Anticoccidial medication resistance has become a significant obstacle to disease control efforts, leading to a renewed focus on discovering novel chemicals for alternative therapeutic approaches. The purpose of this study was to determine the efficacy of Holothuria polii extract (HpE) in treating eimeriosis in mice. Five groups of mice were studied, with E. papillata sporulated oocysts (1 × 103) used to infect three groups experimentally. The first group was treated with 200 mg/kg of HpE, the second group with Amprolium (120 mg/kg), and the third group was left untreated as a control. The fourth and fifth groups were uninfected, with one of them treated with 200 mg/kg of HpE and the other used as a negative control. The results revealed that HpE has 10 phytochemical compounds according to GC-MS analysis. Treatment with HpE resulted in a substantial decrease in oocyst output in feces. Also, the parasitic stages showed morphometric alterations, with reductions in the measurements compared with the infected, untreated mice. Moreover, expression of the mucin gene (MUC2) was higher in treated mice compared to infected ones, with significant increases in goblet cell numbers, which provided additional evidence for the activity of HpE as an anticoccidial product. In conclusion, there are a wide variety of natural products and many have been employed in folk medicine for treating a range of parasitic diseases.

Morphological description of the digestive tract of the Amazonian Diving Lizard Uranoscodon superciliosus (Linnaeus, 1758) and its associations to the diet and foraging mode

The study aimed to characterize the digestive tract of Uranoscodon superciliosus and its associations to the diet and foraging behavior already described for the species. Five lizards were captured in forest areas near the city of Manaus, Amazonas, Brazil. Tongue, oesophagus, stomach, small and large intestines fragments were collected, fixed, and processed for light microscopy. Hyaline cartilage was present in the center of the tongue, and the papillae from the apex and glands from the radix showed positive reaction to Alcian blue. The oesophagus presented a folded mucosa, covered by an epithelium with mucous and goblet cells positive to PAS and Alcian blue. There was presence of gastric glands in the cardic and fundic stomach regions, plus all the regions reacted positively to PAS. Fold and villi variations in both small and large intestine were noted, as well as the number and arrangement of goblet cells. Mucous and goblet cells from the small intestine were positively stained in PAS, while only the goblet cells were Alcian blue positive. These findings indicate that the Amazonian Diving Lizard's digestive tract organs, mainly the tongue and stomach, present morphologies associated to ambush-type foraging and a specific diet largely based on small invertebrates.

Extraction and Fractionation of Human Gastric Mucins from Gastric Juice

Mucin, a major component of the mucus, is considered to be one of the principal factors in the physiological defense mechanism of the gastrointestinal mucosa. Measuring the mucin content of human gastric mucus is a useful tool for the assessment of Helicobacter pylori (H. pylori) eradication or the involvement of mucus secretion in various gastroduodenal diseases. Here, we describe a methodology for the isolation of the mucin fraction from human gastric juice and the quantification of mucin.

Pharmacological Effects of Grape Leaf Extract Reduce Eimeriosis-Induced Inflammation, Oxidative Status Change, and Goblet Cell Response in the Jejunum of Mice

Coccidiosis is a parasitic infection threatening poultry products globally. Parasite resistance to drugs is one of the barriers to Eimeria control. Natural products are one of the sources of compounds that prevent parasite infections. The current study was, therefore, conducted to evaluate the effect of Vitis vinifera leaf extract on anti-inflammatory response, oxidative status, and goblet cell response against Eimeria papillate infection in mice. Methanol was used as a solvent for phytochemicals. The mice were divided into six groups: The first group was the control. The second group was uninfected and treated with 200 mg/kg of extract to test toxicity, and the third, fourth, fifth, and sixth groups of mice received 1 × 10³ sporulated E. papillate oocysts. The third group received no treatment. The fourth and fifth groups were treated daily with 100 and 200 mg/kg of V. vinifera leaf extract, respectively, while the sixth group received 25 mg/kg of toltrazuril daily via gavage. On day 5 p.i., the animals were sacrificed, and jejunum samples were prepared for analyses of histological sections and oxidative stress. The phytochemical analysis using GC-MS of the extract showed the presence of 12 biologically active compounds. The most effective dose was 200 mg/kg, which significantly decreased the number of parasitic stages in the jejunal sections of the mice. The findings demonstrate that E. papillate infection in mice results in significant histopathological changes in the jejunum, including inflammation, epithelial vacuolation, villi loss, and a decrease in goblet cell density. When infected mice received treatment, the histological injury score within the infected jejunum tissue decreased by 63%, and the goblet cell quantity dramatically increased, approaching the control values. Finally, the extract ameliorated the changes in glutathione and malondialdehyde due to E. papillate infection. The extract was proven to have anti-inflammatory properties and reduce the number of oocysts. Overall, the findings show that V. vinifera leaf extract has significant anticoccidial effects in vivo.

Anticoccidial and Antioxidant Activities of Moringa oleifera Leaf Extract on Murine Intestinal Eimeriosis

BACKGROUND

Coccidiosis is an intestinal disease caused by protozoan parasites of the genus Eimeria and responsible for considerable economic loss in the livestock and poultry industries. Resistance to the current anticoccidial drugs is now a major challenge to efforts to control the disease, and this has stimulated the search for new compounds as alternative treatments. In this context, plant extracts have emerged as an alternative and complementary approach to control coccidiosis. In the present study, an ethanol extract of Moringa oleifera leaves was screened for its anticoccidial activity against Eimeria papillata infection in mice.

METHODS

To this end, albino mice were allocated into three groups: the first group was the non-infected control; the second and third groups were infected with 10³ E. papillata oocysts. Of these, the second group was kept as an infected control; while the third group was gavaged with 100 μl of moringa leaf extract (MLE) at a dose of 400 mg MLE/kg, once daily, for five days.

RESULTS

MLE significantly suppressed oocyst excretion in faeces, and histological study of the jejunum showed a significant decrease in the number of parasitic stages, with significant improvement in the numbers of goblet cells. Furthermore, the expression of MUC2 gene was upregulated in the treated mice compared with infected, which further supports the anticoccidial potential of MLE. Moreover, our study evidenced that MLE reduced oxidative damage by decreasing TBARS and iNOS expression, and increasing the GSH and GPX levels. Also, treatment with MLE promoted the expression of Bcl-2 and ultimately, inhibited the apoptosis of host cells in the treated mice.

CONCLUSION

Our data indicate that MLE has anticoccidial, anti-oxidant and anti-apoptotic activities in mice infected with Eimeria papillata.

Mulberry extract as an ecofriendly anticoccidial agent: in vitro and in vivo application

Natural products are ecofriendly agents that can be used against parasitic diseases. Eimeria species cause eimeriosis in many birds and mammals and resistance to available medications used in the treatment of eimeriosis is emerging. We investigated the in vitro and in vivo activity of Morus nigra leaf extracts (MNLE) against sporulation of oocysts and infection of mice with Eimeria papillata. Phytochemical analysis of MNLE showed the presence of seven compounds and the in vitro effects of MNLE, amprolium, DettolTM, formalin, ethanol, and phenol were studied after incubation with oocysts before sporulation. Furthermore, infection of mice with E. papillata induced an oocyst output of approximately 12 × 105 oocysts/g of feces. MNLE significantly decreased oocyst output to approximately 86% and the total number of parasitic stages in the jejunum by approximately 87%. In addition, the reduction in the number of goblet cells in the jejuna of mice was increased after treatment. These findings suggest that mulberry exhibited powerful anticoccidial activity.

The Physiology of the Gastric Parietal Cell

Parietal cells are responsible for gastric acid secretion, which aids in the digestion of food, absorption of minerals, and control of harmful bacteria. However, a fine balance of activators and inhibitors of parietal cell-mediated acid secretion is required to ensure proper digestion of food, while preventing damage to the gastric and duodenal mucosa. As a result, parietal cell secretion is highly regulated through numerous mechanisms including the vagus nerve, gastrin, histamine, ghrelin, somatostatin, glucagon-like peptide 1, and other agonists and antagonists. The tight regulation of parietal cells ensures the proper secretion of HCl. The H+-K+-ATPase enzyme expressed in parietal cells regulates the exchange of cytoplasmic H+ for extracellular K+. The H+ secreted into the gastric lumen by the H+-K+-ATPase combines with luminal Cl- to form gastric acid, HCl. Inhibition of the H+-K+-ATPase is the most efficacious method of preventing harmful gastric acid secretion. Proton pump inhibitors and potassium competitive acid blockers are widely used therapeutically to inhibit acid secretion. Stimulated delivery of the H+-K+-ATPase to the parietal cell apical surface requires the fusion of intracellular tubulovesicles with the overlying secretory canaliculus, a process that represents the most prominent example of apical membrane recycling. In addition to their unique ability to secrete gastric acid, parietal cells also play an important role in gastric mucosal homeostasis through the secretion of multiple growth factor molecules. The gastric parietal cell therefore plays multiple roles in gastric secretion and protection as well as coordination of physiological repair.

X-ray evaluation of intestinal dysmotility induced by Eimeria pragensis infection in C57BL/6 mice

This study was conducted to elucidate the intestinal dysmotility during coccidiosis. C57BL/6 male mice at seven weeks of age were inoculated with Eimeria pragensis sporulated oocysts (100 to 1,000 oocysts). The intestinal motility was evaluated by observing discharging time of barium sulfate (Ba₂SO₄) after oral administration (WITT: the whole intestinal transit time). The exact location of the dysmotility was analyzed by intermittent barium gastrography. Upper intestinal dysmotility was evaluated by charcoal propulsion study. Additionally, the occurrence of dysmotility was observed at different post-infection times (4, 7, and 14 days post-infection (d.p.i.)) and in infection-dose dependent manner (100, 300, and 1,000 oocysts). As the E. pragensis infected mice had significantly lower feed intake compared to the control group, we designed a feed apprehension study to evaluate the effect of low feed intake on the intestinal dysmotility. The WITT of infected mice at 7 d.p.i. was significantly longer (6 hr) than the uninfected mice (2.5 hr). Intestinal dysmotility was observed in the small intestine, caecum, and colorectum in the infected mice. Charcoal propulsion was slower in infected group (reaching to 40.4% of the whole small intestine) compared to control group (68.0%). The dysmotility was observed at the beginning of the patent period (7 d.p.i.) and subsided as the patency ended (14 d.p.i.). Mice with lower feed intake appeared to have similar intestinal motility as control mice. In summary, this study revealed the evidence of intestinal hypomotility during E. pragensis infection.

Carbohydrate-Dependent and Antimicrobial Peptide Defence Mechanisms Against Helicobacter pylori Infections

The human stomach is a harsh and fluctuating environment for bacteria with hazards such as gastric acid and flow through of gastric contents into the intestine. H. pylori gains admission to a stable niche with nutrient access from exudates when attached to the epithelial cells under the mucus layer, whereof adherence to glycolipids and other factors provides stable and intimate attachment. To reach this niche, H. pylori must overcome mucosal defence mechanisms including the continuously secreted mucus layer, which provides several layers of defence: (1) mucins in the mucus layer can bind H. pylori and transport it away from the gastric niche with the gastric emptying, (2) mucins can inhibit H. pylori growth, both via glycans that can have antibiotic like function and via an aggregation-dependent mechanism, (3) antimicrobial peptides (AMPs) have antimicrobial activity and are retained in a strategic position in the mucus layer and (4) underneath the mucus layer, the membrane-bound mucins provide a second barrier, and can function as releasable decoys. Many of these functions are dependent on H. pylori interactions with host glycan structures, and both the host glycosylation and concentration of antimicrobial peptides change with infection and inflammation, making these interactions dynamic. Here, we review our current understanding of mucin glycan and antimicrobial peptide-dependent host defence mechanisms against H. pylori infection.

Dietary tuna hydrolysate modulates growth performance, immune response, intestinal morphology and resistance to Streptococcus iniae in juvenile barramundi, Lates calcarifer

This study investigated the effects of tuna hydrolysate (TH) inclusion in fishmeal (FM) based diets on the growth performance, innate immune response, intestinal health and resistance to Streptococcus iniae infection in juvenile barramundi, Lates calcarifer. Five isonitrogenous and isoenergetic experimental diets were prepared with TH, replacing FM at levels of 0% (control) 5%, 10%, 15% and 20%, and fed fish to apparent satiation three times daily for 8 weeks. The results showed that fish fed diets containing 5% and 10% TH had significantly higher final body weight and specific growth rate than the control. A significant reduction in blood glucose was found in fish fed 10%, 15% and 20% TH compared to those in the control whereas none of the other measured blood and serum indices were influenced by TH inclusion. Histological observation revealed a significant enhancement in goblet cell numbers in distal intestine of fish fed 5 to 10% TH in the diet. Moreover, fish fed 10% TH exhibited the highest resistance against Streptococcus iniae infection during a bacterial challenge trial. These findings therefore demonstrate that the replacement of 5 to 10% FM with TH improves growth, immune response, intestinal health and disease resistance in juvenile barramundi.

Nanoselenium prevents eimeriosis-induced inflammation and regulates mucin gene expression in mice jejunum

Background

Although elemental selenium has been found to be effective against Eimeria, no study has yet investigated the effects of selenium nanoparticles (SeNPs) on the Eimeria parasite. The aim of this study, therefore, was to evaluate the ameliorative effect of SeNPs compared with elemental selenium on mice jejunum infected with sporulated oocysts of Eimeria papillata.

Methods

The mice were divided into 4 groups, with the first being the non-infected, control group, and the second, third, and fourth groups being orally inoculated with 1,000 sporulated oocysts of E. papillata. The third and fourth groups also received, respectively, an oral dose of 0.1 mg/kg sodium selenite and 0.5 mg/kg SeNPs daily for 5 consecutive days.

Results

The infection induced severe histopathological jejunal damage, reflected in the form of destroyed jejunal mucosa, increased jejunal oxidative damage, a reduction in the number of jejunal goblet cells, and increased production of pro-inflammatory cytokines, quantified by real-time polymerase chain reaction. Treatment of mice with SeNPs significantly decreased the oocyst output in the feces by ~80%. Furthermore, the number of parasitic stages counted in stained jejunal paraffin sections was significantly decreased after the mice were treated with SeNPs. In addition, the number of goblet cells increased from 42.6±7.3 to 95.3±8.5 cells/10 villus-crypt units after treatment. By day 5 post-infection with E. papillata, SeNPs could be seen to have significantly increased the activity of glutathione peroxidase from 263±10 to 402.4±9 mU/mL. Finally, SeNPs were able to regulate the gene expression of mucin 2, interleukin 1β, interleukin 6, interferon-γ, and tumor necrosis factor α in the jejunum of mice infected with E. papillata.

Conclusion

The results collectively showed that SeNPs are more effective than sodium selenite with regard to their anti-coccidial, anti-oxidant, and anti-inflammatory role against eimeriosis induced in the jejunum of mice.

Modulation of murine intestinal immunity by Moringa oleifera extract in experimental hymenolepiasis nana

The potential therapeutic value of Moringa oleifera extract (MOE), due to its anti-inflammatory and anti-oxidant effects, has been reported previously. In this study, Hymenolepis nana antigen (HNA) in combination with MOE was used in immunization against H. nana infection. Adult worm and egg counts were taken, while histological changes in the intestine were observed. Mucosal mast (MMCs) and goblet cells (GCs) were stained with specific stains, while serum and intestinal IgA were assayed using enzyme-linked immunosorbent assay (ELISA). Reduced glutathione (GSH) and lipid peroxidation (thiobarbituric acid reactive substances, TBARS) were assayed. Real-time polymerase chain reaction (PCR) was used for detection of mRNA expression in ileum tissue. The results demonstrated an improvement in the architecture of intestinal villi, decreased inducible nitric oxide synthase (iNOs) and TBARS, and increased GSH in HNA, MOE and MOE + HNA groups. In the same groups, an increase in GCs, mucin 2 (MUC2), interleukins (IL)-4, -5 and -9, and stem cell factor (SCF) versus a decrease in both interferon-gamma (IFN-γ) and transforming growth factor (TGF-β) expression appeared. HNA and MOE + HNA increased serum and intestinal IgA, respectively. MOE decreased MMCs and achieved the highest reductions in both adult worms and eggs. In conclusion, MOE could achieve protection against H. nana infections through decreased TGF-β, IFN-γ and MMC counts versus increased GC counts, T-helper cell type 2 (Th2) cytokines and IgA level.

Soft coral Cespitularia stolonifera: New cytotoxic ceramides and gastroprotective activity

In the present study, a new ceramide, namely 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diol (1), along with four known steroids, including 24-methylcholesta-5, 24(28)-diene-3β-ol (2), 24-methylcholesta-5, 24(28)-diene-3β-acetate (3), 4-methyl-24-methylcholesta-22-ene-3-ol (4), and cholesterol, was isolated and characterized from CH₂Cl₂/MeOH extract of Cespitularia stolonifera. A new acetate derivative of compound 1, termed 2S, 3R-4E, 8E-2-(heptadecanoylamino)-heptadeca-4, 8-diene-1, 3-diacetate (1a), was also prepared in the present study. All the structures were established on the basis of modern spectroscopic techniques, including FT-IR, 1D, 2D-NMR, HRESI-MS, and GC-MS, in addition of chemical methods. (-)-Alloaromadendren, ledane, (1)-alloaromadendren oxide, isoaromadendrene epoxide and (-)-caryophellen oxide were identified from the n-hexane fraction using GC-MS. The extract and the two ceramides (1) and (1a) exhibited significant cytotoxic activity against lung cancer A549 cells, while the extract and the two steroids (2) and (3) exhibited significant cytotoxic activity against breast cancer MCF-7 cells. The CH₂Cl₂/MeOH extract exhibited significant antiulcer activity in both ethanol and acetic acid induced ulcer models in rats, as evidenced by histopathological, histochemical, and biochemical examinations.

Digestive Physiological Characteristics of the Gobiidae: - Characteristics of CCK-producing Cells and Mucus-secreting Goblet Cells of Stomach Fish and Stomachless Fish

In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portion (P<0.05), while CCK-producing cells are scattered throughout the intestine. Gluttonous goby (Chasmichthys gulosus), which is stomach fish, mucus-secreting goblet cells are most abundant in the mid intestine portion (P<0.05), whereas CCK-producing cells are observed only in the anterior and mid intestine portion. Trident goby (Tridentiger obscurus) which is stomach fish, mucus-secreting goblet cells were most abundant in the mid intestine portion (P<0.05). CCK-producing cells are found in the anterior and mid intestine portion. Giurine goby, Rhinogobius giurinus which is also stomach fish, the largest number of mucus-secreting goblet cells showed in anterior intestine portion except for esophagus (P<0.05). CCK-producing cells are present only in the anterior and mid intestine portion. In S. geneionema, digestive action occurs in the posterior intestine portion to protect and functions to activate digestion. In contrast, in C. gulosus, T. obscurus and R. giurinus, their digestive action occurs in the anterior and mid intestine portion to protect and functions to activate digestion. Further studies of the modes of food ingestion by these fish, the contents of their digestive tracts, and the staining characteristics of the goblet cells need to be carried out.

Anticoccidial and antioxidant activities of zinc oxide nanoparticles on Eimeria papillata-induced infection in the jejunum

Nanomedicine has recently emerged as a better option for the treatment of various diseases. Here, we investigated the in vivo anticoccidial properties of zinc oxide nanoparticles (ZNPs). ZNPs were crystalline in nature, with a smooth and spherical surface and a diameter in the range of ~10–15 nm. The X-ray diffraction pattern was utilized to identify the crystalline property of the grown ZNPs, whereas field emission scanning electron microscopy was employed to check the size and morphology of the ZNPs. The data showed that mice infected with Eimeria papillata produced 29.7×10³±1,500 oocysts/g feces on day 5 postinfection. This output was significantly decreased, to 12.5×10³±1,000 oocysts, in mice treated with ZNPs. Infection also induced inflammation and injury of the jejunum. This was evidenced (1) through an increase in the inflammatory histological score, (2) through increased production of nitric oxide and malondialdehyde, and (3) through a decrease in both the glutathione level and goblet cell number in mice jejuna. All these infection-induced parameters were significantly altered during treatment with ZNPs. Our results indicate, therefore, that ZNPs have protective effects against E. papillata-induced coccidiosis.

Sex-determined susceptibility and differential MUC2 mRNA expression during the course of murine intestinal eimeriosis

Parasitic diseases differ in prevalence, course, and severity between males and females. The study was designed to compare males with females for the susceptibility to Eimeria papillata infection as well as the expression of the mucin gene, MUC2. Oocysts output was detected to be more in the feces of male mice (3.5 × 10(4) ± 4000 oocysts/g feces) than in females (2 × 10(4) ± 2000 oocysts/g feces). In addition, infected males showed a significant higher number of meronts, gamonts, and developing oocysts compared to infected female mice. Moreover, E. papillata induced a marked goblet cell hypoplasia where the jejuna of infected male mice contained lower numbers of goblet cells per ten villus-crypt units compared to infected females. Also, the expression of MUC2 mRNA is found to be more expressed in infected females than males. In addition, testosterone, nitric oxide, and inducible nitric oxide synthase activities were found to be higher in infected male mice than in infected females. In general, male Swiss albino mice have been shown to be relatively more susceptible to infection with E. papilaata when compared with female mice.

Effects of Dietary Supplementation of Barodon, an Anionic Alkali Mineral Complex, on Growth Performance, Feed Utilization, Innate Immunity, Goblet Cell and Digestibility in Olive Flounder (Paralichthys olivaceus)

A 15-wk feeding trial was conducted to examine the supplemental effects of Barodon on growth performance, gastrointestinal histology, feed digestibility and innate immunity in olive founder. A basal commercial diet was used as a control and two other diets were prepared by spraying 0.1% or 0.2% of Barodon. Triplicate groups of fish (BW, 145 g) were fed one of the test diets to apparent satiation twice daily. At the end of the feeding trial, fish growth performance was not significantly affected by dietary treatments; however, feed utilization was significantly improved (linear and quadratic, p<0.05) by Barodon supplementation. Significantly higher (p<0.05) survival rates were obtained in fish fed Barodon containing diets. Hepatosomatic index increased significantly in Barodon treated groups. Also, the use of Barodon resulted in significant increase (linear and quadratic, p<0.05) of intestine length and number of goblet cells. Significantly higher (Quadratic, p<0.05) apparent digestibility coefficient of DM was obtained by supplementation of Barodon. Lysozyme and myeloperoxidase activities increased quadratically and linearly, respectively, in Barodon treated fish. Also, significantly higher (linear and quadratic, p<0.05) superoxide dismutase activity was found in Barodon fed fish. The findings in this study show that inclusion of Barodon in diets for olive flounder improves feed utilization and digestibility, and positively affects digestive tract histology and innate immunity.

Goblet cells and mucin related gene expression in mice infected with Eimeria papillata

Coccidiosis causes considerable economic loss in the poultry industry. The current study aimed to investigate the response of goblet cells as well as the induced tissue damage during Eimeria papillata infection. Mice were infected with sporulated E. papillata oocytes. On day 5 postinfection, the fecal output was determined. Also, the jejunum was prepared for the histological, histochemical, and molecular studies. Our results revealed that the intestinal coccidian infection with E. papillata induced a marked goblet cell hypoplasia and depleted mucus secretion. Also, the infection was able to alter the jejunal architecture and increased the apoptotic cells inside the villi. In addition, the real-time PCR results indicated that the inflammatory cytokines: TNF-α, iNOS, IFN-γ, and IL-1β, were significantly upregulated. In contrast, the mRNA expression patterns of IL-6 in response to E. papillata infection did not differ significantly between control and infected mice. Moreover, the mRNA expression of TLR4 was significantly upregulated, whereas the expression of MUC2 is significantly downregulated upon infection. Further studies are required to understand the regulatory mechanisms of goblet cells related genes.

Dietary selenium affects intestinal development of Eimeria papillata in mice

Here, we investigated the effect of the trace element selenium (Se) on course and outcome of Eimeria-paplllata-induced coccidiosis in mice. Male mice were fed on Se-adequate (0.15 ppm), Se-deficient, and Se-high diets (1.0 ppm) for 6 weeks. Mice were orally infected with 1,000 oocysts. The prepatent period lasts for 3 days, but the course of infections varied. At Se-adequate diet, the maximum fecal output of oocysts amounted to 68,300 ooccysts/g feces on day 5 p.i.. However, fecal shedding of oocysts was accelerated in mice on Se-deficient diet and occurred already on day 4 p.i.. By contrast, maximal shedding is impaired in mice on high-Se diet, which takes place on day 5 p.i., but with a decreased output of only 7,300 oocysts/g feces. Light microscopy reveals that all developmental stages are affected: meronts, micro- and macrogamonts, and developing oocysts are increased in comparison with mice fed on selenium-adequate diet. At high Se, the number of parasitic stages in the jejunum is substantially higher than at Se-deficient diet. Se does not affect the number of jejunal Alcian blue-stained goblet cells. Se deficiency increased the number of apoptotic cells in the jejunum. Substantially increased histological injury scores reveal more injuries in jejunum tissue infected by E. papillata. Our data indicate that high dietary Se exerts potential anticoccidial activity. This may be taken advantage of in control measures towards Eimeriosis as a feed additive, potentially alleviating the need for concomitantly utilized anti-coccidial drugs in the feed.

Chemical constituents and anti-ulcerogenic potential of the scales of Cynara scolymus (artichoke) heads

BACKGROUND

Cynara scolymus L. (Asteraseae) (artichoke) is commonly eaten as a vegetable; its leaves are frequently used in folk medicine in the treatment of hepatitis, hyperlipidaemia, obesity and dyspeptic disorders. The purpose of this study is to determine the chemical composition of the volatile oil and alcoholic extract of artichoke head scales. In addition, the role of the methanol extract as an anti-ulcer agent against ethanol-induced gastric ulcer in rats was evaluated.

RESULTS

Six flavonoids and one phenolic acid were obtained from the methanol extract. Also, 37 compounds were identified in the volatile oil, the majority including mono- and sesquiterpenes. The artichoke extracts (200 and 400 mg kg(-1)) significantly (P < 0.05) reduced the ulcer index (55.33% and 72.14% inhibition). Histopathological examination of rat stomachs demonstrated that artichoke induced an increase in gastric mucus production, and a reduction of the depth and severity of mucosal lesions. Artichoke dose-dependently reduced the elevated ethanol gastric malonylaldehyde, and reduced glutathione levels and catalase activity. These results suggest that the head scales of artichoke possess potential anti-ulcer activity.

CONCLUSIONS

The present paper describes the identification of volatile oil for the first time along with the isolation and identification of the constituents of the methanol extract. Moreover, the high anti-ulcerogenic potential of scales of C. scolymus heads was established here for the first time.

Characterization of cholecystokinin-producing cells and mucus-secreting goblet cells in the blacktip grouper, Epinephelus fasciatus

The characteristics and distributions of cholecystokinin (CCK)-producing cells and mucus-secreting goblet cells were investigated in the digestive tract of the blacktip grouper (Epinephelus fasciatus). CCK-producing cells were scattered throughout the digestive tract. The highest frequency of CCK-producing cells was observed in the anterior intestine portion and pyloric ceca, with a very small number of cells distributed as far as the rectum. Mucus-secreting goblet cells were found to differ remarkably in their regional distributions and relative frequencies. High frequencies of mucus-secreting goblet cells were found in the digestive tract, mainly in the anterior intestine portion and pyloric ceca, but not the esophagus; the frequency decreased slightly toward the rectum. Our result suggests that food digested by gastric acid in the stomach moves on the anterior (including the pyloric ceca) and mid intestine portion, thereby ensuring effective stimulation of the CCK-producing cells. In addition, the distribution pattern of the CCK-producing cells closely resembled that of mucus-secreting goblet cells. In E. fasciatus, CCK-producing cells and mucus-secreting goblet cells seem to be well adapted to promoting optimal control of the digestive process.

Possible biochemical effects following inhibition of ethanol-induced gastric mucosa damage by Gymnema sylvestre in male Wistar albino rats

CONTEXT

Gymnema sylvestre (GS) R. Br. (Gymnema) (Asclepiadaceae) has been used from ancient times as a folk medicine for the treatment of diabetes, obesity, urinary disorder, and stomach stimulation.

OBJECTIVE

The present study was designed to investigate the effects of G. sylvestre leaves ethanol extract on gastric mucosal injury in rats.

MATERIALS AND METHODS

Gastric mucosal damage was induced by 80% ethanol in 36 h fasted rats. The effect of G. sylvestre on gastric secretions induced in Shay rats was estimated. In stomach, wall mucus, non-protein sulfhydryl groups (NP-SH), malondialdehyde (MDA), total proteins and nucleic acids levels were estimated. Histopathological changes were observed.

RESULTS

G. sylvestre pretreatment at doses of 100, 200 and 400 mg/kg provided 27, 49, and 63% protection against the ulcerogenic effect of ethanol, respectively. Pylorus ligation accumulated 10.24 mL gastric secretions with 66.56 mEq of acidity in control rats. Pretreatment with G. sylvestre significantly inhibited the secretions volume and acidity in dose-dependent manner. Ethanol caused significant depletion in stomach-wall mucus (p < 0.001), total proteins (p < 0.01), nucleic acids (p < 0.001), and NP-SH (p < 0.001) levels. Pretreatment with G. sylvestre showed protection against these depleted levels in dose-dependent manner. The MDA levels increased from 19.02 to 29.22 nmol/g by ethanol ingestion and decreased with G. sylvestre pretreatments in dose-dependent manner.

CONCLUSION

The protective effect of G. sylvestre observed in the present study is attributed to its effect on mucus production, increase in nucleic acid and NP-SH levels, which appears to be mediated through its free radical scavenging ability and/or possible cytoprotective properties.

Protective effect of Azadirachta indica extract against Eimeria papillata-induced coccidiosis

Coccidiosis in poultry is caused by protozoan parasites of the genus Eimeria, which is responsible for worldwide economic losses. The methanolic extract of Azadirachta indica (neem) leaves was used in vivo for its pharmacological, antioxidant, and anticoccidial properties. Four groups of mice were investigated. The first group was inoculated only with sterile saline and served as the control group. The second group was treated by oral gavage with neem extract (500 mg/kg) daily for 4 days. The third and fourth groups were infected with 10(3) sporulated oocysts of Eimeria papillata. The fourth group was also treated once daily with neem extract for 4 days. Paraffin sections from the jejunum as well as jejunal homogenate were prepared for the histopathological and biochemical investigations, respectively. The data showed that mice infected with E. papillata revealed an output of 6.5 × 10(5) ± 29,753 oocysts per gram feces on day 4 postinoculation. This output is significantly decreased to 2.7 × 10(5) ± 37,341 oocysts in neem-treated mice. Infection with E. papillata induced marked histopathological alterations in the jejunum in the form of inflammation, vacuolation of the epithelium, and destruction of some villi. Also, the neem extract greatly diminished body weight loss of infected mice. Moreover, the number of goblet cells stained with Alcian blue within the infected villi was significantly lowered (P ≤ 0.05). In addition, E. papillata enhanced lipid peroxidation and nitric oxide production in both serum and jejunum with concomitant reduction in glutathione. Neem induced marked improvements in all of the studied parameters as well as the histopathological features of the jejunum. Our study revealed that neem as a natural product has protective effects against E. papillata-induced coccidiosis.

[Hemodynamic effects of intravenous omeprazole in critically ill children]

INTRODUCTION

Critical patients usually have hemodynamic disturbances which may become worse by the administration of some drugs. Omeprazole is a drug used in the prophylaxis of the gastrointestinal bleeding in these patients, but its cardiovascular effects are unknown. The objective was to study the hemodynamic changes produced by intravenous omeprazole in critically ill children and to find out if there are differences between two different doses of omeprazole.

MATERIAL AND METHODS

A randomized prospective observational study was performed on 37 critically ill children aged from 1 month to 14 years of age who required prophylaxis for gastrointestinal bleeding. Of these, 19 received intravenous omeprazole 0.5mg/kg every 12 hours, and 18 received intravenous omeprazole 1mg/kg every 12 hours. Intravenous omeprazole was administered in 20 minutes by continuous infusion pump. Heart rate, systolic, diastolic and mean arterial blood pressure, central venous pressure and ECG were recorded at baseline, and at 15, 30, 60 and 120 minutes of the infusion.

RESULTS

There were no significant changes in the electrocardiogram, heart rate, blood pressure and central venous pressure. No patients required inotropic therapy modification. There were no differences between the two doses of omeprazole.

CONCLUSIONS

Intravenous omeprazole administration of 0.5mg/kg and 1mg/kg is a hemodynamically safe drug in critically ill children.

The potential role of Phoenix dactylifera on Eimeria papillata-induced infection in mice

Coccidiosis is a common infectious disease in poultry causing major economic losses. Here, we investigated the effect of Khodary date fruit aqueous extract (4 ml/kg) on the outcome of coccidiosis caused by Eimeria papillata in Swiss Albino mice. Date fruit extract was able to decrease the intracellular development by lowering the faecal output of E. papillata oocysts from 8.7 ± 0.5 × 10(3) to 6.6 ± 0.4 × 10(3) oocysts per gram faeces. Also, date extract caused a great diminish in body weight of infected mice from 19.3 to 3.2 %. The number of parasitic stages in the intestinal villi of the infected mice was reduced to about 52 % after treatment with date extract. The infection was associated with marked histopathological lesions of the murine jejunum in the form of inflammation, vacuolation of the epithelium, and destruction of some villi. Also, the number of goblet cells within the infected villi was significantly lowered (P ≤ 0.05). These changes lead to an oxidative damage of the infected tissue. Moreover, infection induced a disturbance in both protein and carbohydrate content in the infected mice. Treatment of mice with date extract could improve the above-studied parameters. On the basis of the above results it can be hypothesized that date fruit can protect against coccidiosis-induced infection, this hypothesis can be revealed by the anti-inflammatory activity of date protecting host tissue from injuries induced by the parasite, and hence it is recommended to be used as an excellent food additive.

Protective effect of a cysteine prodrug and antioxidant, L-2-oxothiazolidine-4-carboxylate, against ethanol-induced gastric lesions in rats

Earlier studies have suggested an important role of glutathione (GSH) in cytoprotection against free radicals induced oxidative damage. This study reports gastroprotective effects of a cysteine precursor, L-2-oxothiazolidine-4-carboxylate (OTC), in experimental models of gastric secretion and ulceration. Acid secretion studies (volume and acidity) were undertaken in pylorus-ligated rats whereas the gastric lesions were induced by ethanol. Different groups of animals were treated with OTC (0, 100, 200 and 400 mg/kg). The levels of gastric wall mucus, nonprotein sulfhydryls (NP-SH) and myeloperoxidase (MPO) were measured in the glandular stomach of rats following ethanol-induced gastric lesions. Both medium and high doses of OTC significantly reduced the volume and acidity of gastric secretion in pylorus-ligated rats. Pretreatment with OTC significantly and dose-dependently attenuated the formation of ethanol-induced gastric lesion. OTC significantly protected the gastric mucosa against ethanol-induced depletion of gastric wall mucus, NP-SH and MPO. The gastroprotective effects of OTC may be attributed to its ability to inhibit neutrophils activity and replenish GSH demand.

Eosinophilic venulitis in the small intestines in a mouse model of late asthma

The allergen-unchallenged enteric lesions in late allergic asthma are largely unknown. To clarify this point, BALB/c mice were sensitized by ovalbumin (OVA)/aluminum adjuvant intraperitoneally two times (on days 0 and 10) and then challenged with OVA intranasally on day 14 (asthma group). Four days after the challenge, small intestinal lesions were examined. By this treatment, diarrhea was not observed in the asthma group. Compared to the controls with or without OVA sensitization and/or OVA challenge, the asthma group developed eosinophilic venulitis without an increase in mucosal mast cells in small intestines, whereas intestinal epithelial cells were relatively intact. A few numbers of interleukin (IL)-4(+) and IL-5(+) lymphoid cells were recognized in intestines in the asthma group, but not in the controls. Expression of vascular cell adhesion molecule-1 on venular endothelium and eotaxin-2(+) eosinophils, but not epithelial cells, in intestines were detected in the asthma group, but not in the controls. Total IgE, OVA-specific IgE and eotaxin, and IL-5, but not interferon-γ, were produced systemically in the asthma group compared to the controls. The present study suggests that eosinophilic venulitis without mast cells in the intestine may be induced by the systemic, but not by local, helper T 2-type responses. In addition, eosinophilic venulitis in small intestines may be subclinical enteric lesions.

Protective effect of polysaccharide from Hizikia fusiformis against ethanol-induced toxicity

Polysaccharide extracted from Hizikia fusiformis (Hf-PS-1) exhibited protective effects against ethanol-induced peptic injury. In in vivo assay, the ethanol group exhibited decrease of total glutathione (GSH) and increase of jun N-terminal kinase (JNK) phosphorylation relative to the control group, whereas levels were significantly increased and decreased, respectively, in the Hf-PS-1 group. Hf-PS-1 reduced ethanol-induced gastric injury. In in vitro assay, ethanol induced IEC-6 cells' death in a dose-dependent manner. Ethanol decreased the phosphorylation of Shc and the binding of Grb2 to Shc, and Hf-PS-1 pretreatment increased them. Ethanol also induced the phosphorylation of JNK and extracellular signal-regulated kinase (ERK), whereas Hf-PS-1 pretreatment decreased JNK activation but not ERK. Co-treatment with JNK inhibitor and ethanol decreased GSH levels, indicating that JNK phosphorylation is a critical factor during ethanol-induced injury. Therefore, Hf-PS-1 may be useful to protect against ethanol-induced gastrointestinal injury.

Disruption of the mucus barrier by topically applied exogenous particles

The mucus barrier is well established as a formidable barrier to exogenous substances and forms the first line of defense for mucosal surfaces. Drugs and particle systems are known to be significantly hindered via a variety of interactions with mucus, and some efforts have been reported that can mitigate these interactions. We investigated topically applied particulate systems (nano and micro) for their potential to interact with mucus and influence on the diffusion of model drugs across the mucus barrier. Functionalized polystyrene nanoparticles and microparticles and diesel particulate matter were topically applied to established in vitro mucus models. Particle treated mucus was then assessed, compared to controls, for drug permeation rates. The average permeation rate of drugs increased 2-fold following the application of particles to mucus compared to permeation of the same drug through mucus alone. In some cases permeation enhancement of small model drugs was over 5 times that of controls. Assessment of particle physicochemical properties also indicated that significant interactions occurred between mucus and the particles as determined by zeta potential changes and size changes. Collectively this work supports the hypothesis that topically applied particles interact with the mucus barrier causing disruption of this barrier allowing for increased drug permeation. These findings have implications for improved drug delivery and enhanced environmental exposure to exogenous substances.

Perforation of peptic ulcer following abrupt cessation of long-term opiate use

PURPOSE

Unaided and abrupt cessation of opiate use without drug substitution and step-down, referred to as "cold turkey," is a common and difficult process for substance users, and is associated with several withdrawal symptoms and complications. This report presents a preliminary series of patients treated at an urban public hospital with acute perforation of peptic ulcers following abrupt cessation of long-term opiate use, a phenomenon that has not been previously described in the literature.

METHODS

Thirty-five patients with acute gastroduodenal perforation and a history of opiate addiction with a recent and abrupt cessation of opiate use were admitted between February 2004 and October 2008. This study evaluated the demographics, antecedent drug use, substance use characteristics, previous medical or surgical treatment of peptic ulcer disease, and surgical findings.

RESULTS

The mean age was 32.3 years (range, 21-41 years) and the patients were overwhelmingly male (94%). The most frequent agent in single opiate users was opium (62.9%) followed by heroin (22.9%). The time interval between opiate cessation and perforation onset was 2-65 days (mean, 6.1 days). All patients underwent an immediate exploratory laparotomy, and the majority of perforations were found to be in the postpyloric area (94%) with mean size of 4.3 x 5.1 mm. Two patients (6%) had perforations in the lesser curvature of the stomach.

CONCLUSION

All of the perforations occurred following sudden self-cessation without step-down or classic maintenance therapy, and this may prove the importance of supervised medical detoxification with special attention to gastroprotective agents such as antacid drugs.

Mechanisms involved in the gastroprotective activity of esculin on acute gastric lesions in mice

This work describes the gastroprotective actions of esculin (6,7-dihydroxycoumarin-6-o-glucoside) against indomethacin- or ethanol-induced lesions and verifies the role of nitric oxide, ATP-dependent K(+) channels, prostaglandins, transient receptor potential vanilloid 1 and antioxidant effects in the gastroprotective mechanism of esculin in the ethanol-induced gastric lesion model. The intragastric administration of esculin at doses of 12.5, 25 and 50 mg/kg was able to protect the gastric mucosa against ethanol (0.2 mL/animal p.o.), and esculin at doses of 25 and 50 mg/kg protected against indomethacin-induced lesions (20mg/kg p.o.). Administration of l-NAME (10mg/kg i.p.), glibenclamide (10mg/kg i.p.) or indomethacin (10mg/kg p.o.), but not capsazepine (5mg/kg p.o.), was able to reduce the gastroprotection promoted by esculin (25mg/kg) on the ethanol-induced lesions. Measurements of nitrite, a NO metabolite, were increased in the group that was pretreated with esculin. In terms of antioxidant activity as a gastroprotective mechanism of esculin, the results show that pre-treatment with esculin decreased the amount of GSH, increased SOD activity, did not interfere with the CAT activity and decreased both the MPO activity and the MDA amount. In conclusion, pre-treatment with esculin confers significant gastroprotective and antioxidant activity and leads to a reduction in gastric injury; the mechanisms underlying these effects include stimulation of endogenous prostaglandins, nitric oxide synthesis, opening of K(ATP) channels and reduction of free radicals or modulation of antioxidant enzyme systems.

Effects of aspirin on gastroduodenal permeability in alcoholics and controls

Alcohol and nonsteroidal anti-inflammatory drugs are noxious agents that can disrupt the integrity of the gastroduodenal mucosal and damage the epithelial barrier and lead to increased gastroduodenal permeability. Moreover, it is not uncommon that patients are exposed to these two barrier stressors at the same time. It is thus important to know how simultaneous exposure affects the gastroduodenal barrier, and acquiring that knowledge was the goal of this study. We used a method that has been widely used for the assessment of injury to the gastroduodenal barrier induced by these noxious agents-measurement of gastroduodenal permeability as indicated by urinary excretion of ingested sucrose. We used gas chromatography to measure the amount of sucrose excreted in the urine over the 5-12h after ingestion of a bolus of sucrose. The 148 participants in the study included 92 alcoholics and 56 healthy controls. All study subjects had a baseline permeability test. To determine whether addition of a second noxious agent, in addition to chronic alcohol, further decreases gastroduodenal barrier integrity, a subset of 118 study subjects participated in another permeability test in which they were exposed to aspirin. For this test, participants ingested 1,300 mg aspirin twice, 12 and 1h before the final permeability test. The baseline permeability test showed that alcoholics have significantly higher gastroduodenal permeability than controls. Aspirin caused a significant within-group absolute increase in gastroduodenal permeability in both alcoholics and controls (+7.72%, P=.003 and +2.25%, P=.011, respectively), but the magnitude of these increases was not significantly different from each other. Baseline permeability did vary by gender, self-reported illegal drug use, and employment type. The extent of the permeability increase after aspirin ingestion varied with illegal drug use and recruitment site (a surrogate marker of socioeconomic status). Our data show that alcoholics have greater gastroduodenal permeability than healthy controls. This difference was independent of the duration of any preceding period of sobriety, gender, smoking history, or illicit drug abuse. The injurious effects of alcohol on the gastroduodenal epithelial barrier are long lasting, persisting even after 7 days of sobriety. Although, acute aspirin and chronic alcohol each increase intestinal permeability in alcoholics, their effects appear to be additive rather than synergistic.

Intestinal permeability in irritable bowel syndrome patients: effects of NSAIDs

Intestinal permeability and the effect of NSAIDs on permeability were investigated in 14 irritable bowel syndrome (IBS) patients and 15 healthy subjects. In the study, 24-h urinary recoveries of orally administered polyethylene glycols (PEGs 400, 1500, and 4000) were not significantly different in healthy subjects and IBS patients before or after NSAID ingestion. Lactulose mannitol ratios in healthy subjects and IBS patients were not significantly different. Only time-dependent monitoring of PEG excretion showed that NSAIDs enhanced intestinal permeability for PEG 4000 in healthy subjects (P = 0.050) and for PEGs 400, 1500, and 4000 in IBS patients (P = 0.012, P = 0.041, and P = 0.012, respectively). These results show that intestinal permeability in IBS patients is not different from that in healthy subjects; NSAIDs compromise intestinal permeability in IBS patients to a greater extent than in healthy subjects, which suggests that IBS is associated with an altered response of the intestinal barrier to noxious agents.

Prevention of chronic gastritis by fermented milks made with exopolysaccharide-producing Streptococcus thermophilus strains

Acetyl-salicylic acid (ASA) is a nonsteroidal antiinflammatory/analgesic drug, which may cause gastritis or stomach ulcers if intensively employed. Exopolysaccharide (EPS)-producing lactic acid bacteria have been claimed to induce immunostimulatory/antiulcer effects in the host. This study investigated the potential preventive effect of fermented milks (FM) with EPS-producing Streptococcus thermophilus strains (CRL 1190 and CRL 804) on an in vivo model of chronic gastritis. Fermented milks (2 EPS(+) and 1 EPS(-), separately) were fed to BALB/c mice for 7 d before inducing gastritis with ASA (400 mg/kg of body weight per day for 10 d; gastritis group, n = 5). Appropriate control groups (ASA administered but not given FM, n = 5; and ASA not administered but given FM) were included in this study. Gastric inflammatory activity was evaluated through the stomach's histology and the number of IFNgamma(+) and IL-10(+) cytokine-producing cells in the gastric mucosa. Only mice preventively treated with the EPS-producing Strep. thermophilus CRL 1190 FM and later administered ASA did not develop gastritis, showing a conserved gastric mucosa structure similar to those of healthy mice. A marked decrease of IFNgamma(+)- and increase of IL-10(+)-producing cells compared with the gastritis group mice were observed. Purified EPS from Strep. thermophilus CRL 1190 resuspended in autoclaved milk was also effective for gastritis prevention. The EPS-protein interaction might be responsible for the observed gastroprotective effect; such interactions may be affected by industrial manufacturing conditions. The results indicate that the FM with Strep. thermophilus CRL 1190 or its EPS could be used in novel functional foods for preventing chronic gastritis.

Rocket “Eruca sativa”: A salad herb with potential gastric anti-ulcer activity

AIM: To validate gastric anti-ulcer properties of Rocket “Eruca sativa” on experimentally-induced gastric secretion and ulceration in albino rats.

METHODS: Gastric acid secretion studies were undertaken using pylorus-ligated rats. Gastric lesions in the rats were induced by noxious chemicals including ethanol, strong alkalis, indomethacin and hypothermic restraint stress. The levels of gastric wall mucus (GWM), nonprotein sulfhydryls (NP-SH) and malondialdehyde (MDA) were also measured in the glandular stomach of rats following ethanol administration. The gastric tissue was also examined histologically. The extract was used in two doses (250 and 500 mg/kg body weight) in all experiments.

RESULTS: In pylorus-ligated Shay rats, the ethanolic extract of Rocket “Eruca sativa L.” (EER) significantly and dose-dependently reduced the basal gastric acid secretion, titratable acidity and ruminal ulceration. Rocket extract significantly attenuated gastric ulceration induced by necrotizing agents (80% ethanol, 0.2 mol/L NaOH, 25% NaCl), indomethacin and hypothermic restraint stress. The anti-ulcer effect was further confirmed histologically. On the other hand, the extract significantly replenished GWM and NP-SH levels, as well as the MDA level significantly reduced by extract pretreatment.

CONCLUSION: Rocket extract possesses anti-secretory, cytoprotective, and anti-ulcer activities against experimentally-induced gastric lesions. The anti-ulcer effect is possibly through prostaglandin-mediated activity and/or through its anti-secretory and antioxidant properties.

Protective effects of a polysaccharide from Hizikia fusiformis against ethanol toxicity in rats

Hizikia fusiformis is an edible brown alga that is widely consumed in Korea, Japan, and China and possesses a number of potentially beneficial compounds, including antioxidants and anticoagulants. No reports have investigated potential H. fusiformis protectants against ethanol-induced peptic injury. We extracted a polysaccharide from H. fusiformis (Hf-PS-1) that exhibited protective effects against ethanol-induced peptic injury and related mechanisms in rats. Experimental animals were divided into three groups: control, ethanol-only, and ethanol+Hf-PS-1. The ethanol-only group exhibited decreased levels of total glutathione (GSH) and increased levels of jun N-terminal kinase (JNK) phosphorylation relative to the control group, whereas levels were significantly increased and decreased, respectively, in the ethanol+Hf-PS-1 group. The ethanol-only group also exhibited increased levels of extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation relative to the control group; these levels were not significantly different in the ethanol+Hf-PS-1 group. Hf-PS-1 appeared to reduce ethanol-induced gastric injury. Therefore, we suggest that Hf-PS-1 could protect against ethanol-induced peptic ulcers primarily through a mechanism associated with the inhibition of JNK activation.

Eimeria vermiformis infection reduces goblet cells by multiplication in the crypt cells of the small intestine of C57BL/6 mice

In the gastrointestinal mucosa, mucus produced by goblet cells plays an important role in the defense against various pathogens. It is well known that some helminth parasites are able to up-regulate goblet cell numbers and alter the mucus components. However, the nature of the interactions between the protozoan parasites and goblet cells is still unclear. To clarify this point, we examined the goblet cell response in the small intestinal epithelium in C57BL/6 mice with Eimeria vermiformis infection. On day 6 post-infection (p.i.), we observed E. vermiformis multiplication followed by their destruction within the epithelium of the crypt. However, this was not observed in the villi. There was no evidence that the parasite destroyed the goblet cells; moreover, the number of goblet cells decreased in association with the development of the endogenous stages of E. vermiformis in the jejunum and ileum, but not in the duodenum. During this time, we observed infiltration into the lamina propria by lymphoid cells, such as plasma cells and lymphocytes with some eosinophils, in addition to villous atrophy. A significant reduction of goblet cell numbers occurred on days 8 and 10 p.i. Starting from day 12 p.i., elimination/termination of E. vermiformis was noted, and there was recovery of the villous epithelium along with regeneration of the crypt and goblet cells. The current study examined the reduction of goblet cells and their possible importance in eimerian infections.

Duodenal chemosensitivity and mechanosensitivity in humans during acid and ethanol perfusion

INTRODUCTION

Chemical stimulation with capsaicin in the intestinal lumen induces abdominal pain, presumably through a mechanism involving the polymodal vanilloid receptor TRPV1 (transient receptor potential vanilloid receptor subtype 1). Other stimulators of TRPV1 include heat, acid or ethanol. We evaluated the effects of duodenal acid and ethanol exposure on chemosensitivity and mechanosensitivity in healthy volunteers.

METHODS

In two placebo-controlled arms of the study, healthy volunteers received duodenal infusions of either hydrochloric acid (0.1 mol/l) (n=8) or ethanol (5% vol/vol) through an oroduodenal tube. Mechanosensitivity was tested applying pressure-controlled duodenal distensions and chemosensitivity was tested by duodenal perfusion with capsaicin (40 microg/ml; 2.5 ml/min). Quality and intensity of upper abdominal symptoms were evaluated with a graded questionnaire during mechanical and chemical stimulation of the duodenum.

RESULTS

During hydrochloric acid infusion, capsaicin-induced perception was reduced (P<0.01) and latency to discomfort was increased from 24.5 min (25th/75th%:16.5/36 min) during placebo to 50 min (25.5/60 min) (P<0.01). Ethanol had no significant effect on chemosensitivity [latency to discomfort for placebo vs. ethanol: 26 min (18/40 min) vs. 20 min (9/60 min)] (P>0.05). Neither duodenal acidification nor ethanol altered mechanosensitivity significantly (P>0.05).

CONCLUSION

Duodenal acid activated mechanisms that lead to a decreased sensitivity for intraluminal capsaicin; these mechanisms might protect duodenal chemonociceptors from being sensitized by acid. Whether this mechanism is impaired in patients with upper gastrointestinal functional disease remains to be determined.

Gastroduodenal defense

PURPOSE OF REVIEW

The gastroduodenum resists mucosal injury despite continuous exposure to concentrated gastric acid. The mucosal barrier consists of a preepithelial mucus HCO3- layer, intercellular tight junctions connecting the epithelial cells, and submucosal acid sensors, prostaglandins, cytokines, enteric nerves and blood flow. In the past year, study of these defensive mechanisms has revealed new insight into the observed sex differences in ulcer prevalence, the protective role of transforming growth factor, the role of serotonin in regulating HCO3- secretion, the role of mechanisms in ulcer healing, the interaction of trefoil factors with the mucus gel, the interaction of glucocorticoids with cyclooxygenase and the characterization of novel, mucosal sparing antiinflammatory agents.

RECENT FINDINGS

Transforming growth factor, melatonin, serotonin, trefoil factors and H2S all enhance mucosal barrier function or accelerate ulcer healing. Newer coxibs may have safety and advantages over existing compounds. Existing nonsteroidal antiinflammatory drugs may be safer than originally thought.

SUMMARY

The continued elucidation of basic defense mechanisms has led to the development of several new compounds designed to enhance barrier function and repair mechanisms.

Trefoil factor 2 in gland mucous cell mucin in the mucous gel covering normal or damaged gastric mucosa using the Mongolian gerbil model

OBJECTIVE

Trefoil factor 2 (TFF2) is localized in gastric gland mucous cells. The purpose of the study was to determine whether TFF2 and gastric mucin are localized in mucous cells and in the surface mucous gel layer (SMGL) of the normal gastric mucosa or in the mucoid cap adherent to gastric mucosal lesions in Mongolian gerbils.

MATERIAL AND METHODS

Gastric mucosal lesions were induced in Mongolian gerbils using oral administration of Helicobacter pylori (H. pylori), subcutaneous administration of indomethacin, or oral administration of 30% ethanol. Tissue samples were fixed in Carnoy's solution for preservation of the SMGL, dehydrated, and embedded in paraffin. Histochemical staining for gastric mucins and immunostaining for TFF2 were performed.

RESULTS

It was found that surface mucous cell mucin and gland mucous cell mucin were segregated in the SMGL covering the normal gastric mucosa, and the mucin of the mucoid cap covering the mucosal lesions was primarily gland mucous cell mucin. There was a co-localization of TFF2 in gland mucous cell mucin in gland mucous cells, the SMGL, and the mucoid cap.

CONCLUSIONS

The co-localization of TFF2 in gland mucous cells and in the adherent mucus suggests a physical interaction between TFF2 and gland mucous cell mucin, and the participation of TFF2 trapped in the adherent mucus functions in mucosal defense, healing, and repair.

Quantitative determination of gland mucous cells-type mucin using a monoclonal antibody, HIK1083: its pathophysiological changes in human gastric juice

BACKGROUND

Pathological alteration in gastric mucosa is caused by Helicobacter pylori infection and is detectable by histological analysis. In particular, the alteration of gland mucous cells (GMCs)-type mucin, which plays a protective role against H. pylori infection, is critical in the pathogenesis of H. pylori-related gastritis. We established an assay for GMCs-type mucin and quantitatively assessed the pathophysiological changes in its content in human gastric juice samples.

METHODS

The assay method for GMCs-type mucin was based on ELISA using a monoclonal antibody (HIK1083), and was used it to measure GMCs-type mucin in gastric juice obtained from patients with or without H. pylori infection.

RESULTS

All the basic characteristics of the current method were satisfactory to quantify the GMCs-type mucin content in gastric juice. The GMCs-type mucin content, but not total mucin content, was significantly higher in patients with H. pylori infection (n=17; 437+/-476 U, mean+/-SD) than in those without H. pylori infection (n=55; 168+/-322 U, p<0.05).

CONCLUSIONS

The current method is suitable for the quantitative analysis of GMCs-type mucin in gastric juice. The change in GMCs-type mucin content in gastric juice may be possibly implicated in the pathophysiology of the gastric mucosa and in the patient's gastric mucosal lesions.

Bromophenacyl bromide, a phospholipase A2 inhibitor attenuates chemically induced gastroduodenal ulcers in rats

AIM

To study the effect of bromophenacyl bromide (BPB), a phospholipase A2 inhibitor on gastric secretion and to protect chemically induced gastric and duodenal ulcers in rats.

METHODS

Acid secretion studies were undertaken in pylorus-ligated rats with BPB treatment (0, 5, 15 and 45 mg/kg). Gastric and duodenal lesions in the rats were induced by ethanol and cysteamine respectively. The levels of gastric wall mucus, nonprotein sulfhydryls (NP-SH) and myeloperoxidase (MPO) were also measured in the glandular stomach of rats following ethanol induced gastric lesions.

RESULTS

BPB produced a dose-dependent inhibition of gastric acid secretion and acidity in rats. Pretreatment with BPB significantly attenuated the formation of ethanol induced gastric lesion. BPB also protected intestinal mucosa against cysteamine-induced duodenal ulcers. The antiulcer activity of BPB was associated with significant inhibition of ethanol-induced depletion of gastric wall mucus, NP-SH and MPO. These findings pointed towards the mediation of sulfhydryls in BPB induced gastrointestinal cytoprotection.

CONCLUSION

BPB possesses significant antiulcer and cytoprotective activity against experimentally induced gastroduodenal lesions.

Co-localization of TFF2 with gland mucous cell mucin in gastric mucous cells and in extracellular mucous gel adherent to normal and damaged gastric mucosa

Trefoil factor 2 (TFF2) is mucin associated peptide that has a mucosal barrier function in addition to participating in repair and healing. We examined the localization of TFF2 and gastric mucins in gastric mucous cells, the surface mucous gel layer (SMGL) adherent to normal gastric mucosa, and in the mucoid cap covering gastric erosions. Carnoy's solution, or formalin/picric acid-fixed paraffin embedded materials from resected stomachs and formalin-fixed paraffin embedded gastric biopsy materials were used. Sections were immunostained for the TFF2 and histochemically stained for gastric mucins. In addition, thick sectioned gastric mucosa fixed in Carnoy's solution were stained with FITC-labeled GSA-II lectin specific for gland mucous cell mucin and examined for three-dimensional images of the SMGL using a confocal laser scanning microscope. The TFF2 and gland mucous cell mucin were found intermixed together in the gastric gland mucous cells, in the SMGL in laminated layers, and in the mucoid cap. A laminated arrangement of continuous sheets of gland mucous cell mucin in the SMGL was demonstrated in the three-dimensional images. Co-localization of the TFF2 with gland mucous cell mucin suggests a physical interaction between the TFF2 and gland mucous cell mucin. The TFF2 trapped in the adherent mucins may be responsible for mucosal defense, healing, and repair.

Analysis of mucin composition in gastric juices of chronic rheumatic patients with upper gastrointestinal damage

Assessment of the mucin subclasses in the gastric juices of severe chronic rheumatoid arthritis (RA) patients was compared with non-RA cases which received the eradication treatment of Helicobacter pylori (H. pylori). Gastric juice samples were obtained from 8 RA patients (5 for H. pylori-negative and 3 for H. pylori-positive) and 5 control subjects in which we confirmed the successful eradication of H. pylori. The gastric luminal mucins were extracted and isolated by the ethanol precipitation method. These mucin solutions were digested with chymotrypsin, dialyzed, lyophilized, and redissolved. The obtained specimen was applied to an ion exchange column containing DEAE-Sepharose CL-6B and eluted with a discontinuous salt gradient in three salt steps. The gastric luminal mucins were divided into three fractions based on the distinctive sialic acid content. The proportion of acidic mucin rich in sialic acid from the gastric juice of RA patients without the H. pylori infection was significantly lower than those RA patients with H. pylori or the control subjects. A decrease in the acidic mucin content after eradication of H. pylori was commonly observed in all the control subjects. Our investigation raises the possibility that the gastric mucosae of RA patients have resistance against H. pylori infection. And the analysis of the composition in the gastric luminal mucin may be a very useful tool for the evaluation of gastric homeostasis in RA patients.