Hyperbaric oxygen therapy reduces the severity of necrotizing enterocolitis in a neonatal rat model

Evaluation of oxidative stress in an experimental model of Crohn's disease treated with hyperbaric oxygen therapy

INTRODUCTION

Treatments of Inflammatory Bowel Disease (IBD) are able to control symptoms in most cases, however, a fraction of patients do not improve or have a loss of response to treatments, making it important to explore new therapeutic strategies. Hyperbaric oxygen therapy (HBO) may represent one of them. The aim of this study was to evaluate the effects of HBO therapy in an experimental model of IBD.

METHODS

Sixty male BALBc mice were divided into six groups. Group 1 was colitis-induced with trinitrobenzene sulfonic acid (TNBS) + ethanol, group 2 received TNBS + ethanol plus HBO, group 3 received only ethanol, group 4 received ethanol plus HBO, group 5 received saline solution, and group 6 received saline solution plus HBO. HBO was performed for four days, subsequently, the mice were evaluated daily. At the end of the study, samples from the intestine were collected for histological analysis as well as for measurement of antioxidant enzymes and cytokine levels.

RESULTS

HBO significantly improved the clinical and histological status of the animals. Treatment with HBO increased the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in all of the groups; moreover, the difference was only significant between the TNBS and TNBS + HBO groups and treatments promoted a reduction in the proinflammatory cytokines IFN-γ, IL-12, IL-17 and TNF-α and increased the anti-inflammatory cytokines IL-4 and IL-10, with no changes in IL-13.

CONCLUSION

HBO effectively treats TNBS-induced colitis by increasing the activity of antioxidant enzymes and modulating cytokine profiles.

What animal model should I use to study necrotizing enterocolitis?

Unfortunately, we are all too familiar with the statement: "Necrotizing enterocolitis remains the leading cause of gastrointestinal surgical emergency in preterm neonates". It's been five decades since the first animal models of necrotizing enterocolitis (NEC) were described. There remains much investigative work to be done on identifying various aspects of NEC, ranging from the underlying mechanisms to treatment modalities. Experimental NEC is mainly focused on a rat, mouse, and piglet models. Our aim is to not only highlight the pros and cons of these three main models, but to also present some of the less-used animal models that have contributed to the body of knowledge about NEC. Choosing an appropriate model is essential to conducting effective research and answering the questions asked. As such, this paper reviews some of the variations that come with each model.

Dedifferentiated fat cells administration ameliorates abnormal expressions of fatty acids metabolism-related protein expressions and intestinal tissue damage in experimental necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC) is a serious disease of premature infants that necessitates intensive care and frequently results in life-threatening complications and high mortality. Dedifferentiated fat cells (DFATs) are mesenchymal stem cell-like cells derived from mature adipocytes. DFATs were intraperitoneally administrated to a rat NEC model, and the treatment effect and its mechanism were evaluated. The NEC model was created using rat pups hand fed with artificial milk, exposed to asphyxia and cold stress, and given oral lipopolysaccharides after cesarean section. The pups were sacrificed 96 h after birth for macroscopic histological examination and proteomics analysis. DFATs administration significantly improved the survival rate from 25.0 (vehicle group) to 60.6% (DFAT group) and revealed a significant reduction in macroscopical, histological, and apoptosis evaluation compared with the vehicle group. Additionally, the expression of C-C motif ligand 2 was significantly decreased, and that of interleukin-6 decreased in the DFAT group. DFAT administration ameliorated 93 proteins mainly related to proteins of fatty acid metabolism of the 436 proteins up-/down-regulated by NEC. DFATs improved mortality and restored damaged intestinal tissues in NEC, possibly by improving the abnormal expression of fatty acid-related proteins and reducing inflammation.

Can amniotic fluid protect developing fetal lungs against the harmful effects of oxidative stress?

BACKGROUND

Preterm births cause fetuses to be born without completing the development of their organs. Due to this undesirable situation, it is the pulmonary tissue which has to be most exposed to harmful effects of extrauterine environment. Early disappearance of the prophylactic and constructive effects of amniotic fluid (AF) on developing tissues, such as pulmonary tissue, facilitates the formation of pulmonary morbidities resulting from oxygen. Setting out from this knowledge, we wanted, in addition to assessing the beneficent effects of AF on pulmonary tissue, to study the importance of AF in morbidities of this tissue thought to originate from oxygen.

METHODS

In this experimental study, while the study group was made up of the fetuses of pregnant rats exposed to hyperbaric oxygen, (hyperoxic pregnant rat fetuses-HPRF), the control group was formed of the fetuses of the rats pregnant in the usual room setting (normoxic pregnant rat fetuses-NPRF). The pulmonary and hepatic tissues taken from the fetuses of these pregnant rats on the 21st day of their pregnancy were compared biochemically and histologically. For biochemical assessment, total glutathione (tGSH), catalase (CAT), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α) values and for histopathological assessment, apoptosis, alveolar wall count (AWC), vena centralis count (VCC) were included.

RESULTS

Statistical significance was found in the pulmonary tissue values of tGSH on behalf of NPRF, and MDA on behalf of HPRF (p < 0.05). In liver tissue, statistical significance was detected in tGSH and CAT values in favor of NPRF and in MDA, and TNF-α values in favor of HPRF (p < 0.05).

DISCUSSION

: Our study has demonstrated that AF protects the pulmonary tissue from the harmful effects of oxygen in the intrauterine period. In addition, our data have suggested that the pulmonary tissue's being deprived of the useful effects of AF owing to premature birth may be an important trigger in the occurrence of the pulmonary morbidities thought to result from oxygen.

Sumac (Rhus coriaria) for the prevention and treatment of necrotizing enterocolitis

Leukotrienes, free oxygen radicals, tumor necrosis factor-alpha, and inflammatory mediators play major roles in the development of necrotizing enterocolitis (NEC). Rhus coriaria (RC: sumac) extracts may enhance cell viability by reinforcing defenses against free radical species in several progressive diseases as well as inflammatory diseases. The aim of the present study was to evaluate the effects of RC in a rat NEC model in terms of intestinal damage. Newborn pups were separated into three groups: control, NEC, and NEC treated with RC. Mortality and clinical sickness scores were evaluated. At the end of the study, ileum and proximal colon were obtained from all rats and histopathological and immunohistochemical studies were performed. In this study, the anti-inflammatory, antioxidant, immunomodulatory, and anti-apoptotic activities of RC were demonstrated in a rat NEC model, which suggests RC as a promising treatment option for preventing intestinal tissue damage. PRACTICAL APPLICATIONS: Free oxygen radicals, tumor necrosis factor-alpha, and inflammatory mediators play major roles in the development of NEC. Intestinal tissue damage is caused by necrosis and apoptosis as a result of intestinal inflammation and release of pro-inflammatory cytokines. Anti-inflammatory, antioxidant, immunomodulatory, and anti-apoptotic activities of RC are especially due to its phenolic compounds. In this study, the anti-inflammatory, antioxidant, immunomodulatory, and anti-apoptotic activities of RC were demonstrated in a rat NEC model. RC can suggest as a new treatment option for preventing intestinal injury.

Hyperbaric Oxygen Increases Stem Cell Proliferation, Angiogenesis and Wound-Healing Ability of WJ-MSCs in Diabetic Mice

Hyperbaric oxygen therapy (HBOT) is effective for the medical treatment of diverse diseases, infections, and tissue injury. In fact, in recent years there is growing evidence on the beneficial effect of HBOT on non-healing ischemic wounds. However, there is still yet discussion on how this treatment could benefit from combination with regenerative medicine strategies. Here we analyzed the effects of HBOT on three specific aspects of tissue growth, maintenance, and regeneration: (i) modulation of adult rodent (Mus musculus) intestinal stem cell turnover rates; (ii) angiogenesis dynamics during the development of the chorio-allantoic membrane (CAM) in Gallus gallus embryos; (iii) and wound-healing in a spontaneous type II diabetic mouse model with a low capacity to regenerate skin. To analyze these aspects of tissue growth, maintenance, and regeneration, we used HBOT alone or in combination with cellular therapy. Specifically, Wharton Jelly Mesenchymal Stem cells (WJ-MSC) were embedded in a commercial collagen-scaffold. HBOT did not affect the metabolic rate of adult mice nor of chicken embryos. Notwithstanding, HBOT modified the proliferation rate of stem cells in the mice small intestinal crypts, increased angiogenesis in the CAM, and improved wound-healing and tissue repair in diabetic mice. Moreover, our study demonstrates that combining stem cell therapy and HBOT has a collaborative effect on wound-healing. In summary, our data underscore the importance of oxygen tension as a regulator of stem cell biology and support the potential use of oxygenation in clinical treatments.

Melatonin's role as a co-adjuvant treatment in colonic diseases: A review

Melatonin is produced in the pineal gland as well as many other organs, including the enterochromaffin cells of the digestive mucosa. Melatonin is a powerful antioxidant that resists oxidative stress due to its capacity to directly scavenge reactive species, to modulate the antioxidant defense system by increasing the activities of antioxidant enzymes, and to stimulate the innate immune response through its direct and indirect actions. In addition, the dysregulation of the circadian system is observed to be related with alterations in colonic motility and cell disruptions due to the modifications of clock genes expression. In the gastrointestinal tract, the activities of melatonin are mediated by melatonin receptors (MT2), serotonin (5-HT), and cholecystokinin B (CCK2) receptors and via receptor-independent processes. The levels of melatonin in the gastrointestinal tract exceed by 10-100 times the blood concentrations. Also, there is an estimated 400 times more melatonin in the gut than in the pineal gland. Gut melatonin secretion is suggested to be influenced by the food intake. Low dose melatonin treatment accelerates intestinal transit time whereas high doses may decrease gut motility. Melatonin has been studied as a co-adjuvant treatment in several gastrointestinal diseases including irritable bowel syndrome (IBS), constipation-predominant IBS (IBS-C), diarrhea-predominant IBS (IBS-D), Crohn's disease, ulcerative colitis, and necrotizing enterocolitis. The purpose of this review is to provide information regarding the potential benefits of melatonin as a co-adjuvant treatment in gastrointestinal diseases, especially IBS, Crohn's disease, ulcerative colitis, and necrotizing enterocolitis.

Oxidative Stress Related Diseases in Newborns

We review oxidative stress-related newborn disease and the mechanism of oxidative damage. In addition, we outline diagnostic and therapeutic strategies and future directions. Many reports have defined oxidative stress as an imbalance between an enhanced reactive oxygen/nitrogen species and the lack of protective ability of antioxidants. From that point of view, free radical-induced damage caused by oxidative stress seems to be a probable contributing factor to the pathogenesis of many newborn diseases, such as respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia, necrotizing enterocolitis, patent ductus arteriosus, and retinopathy of prematurity. We share the hope that the new understanding of the concept of oxidative stress and its relation to newborn diseases that has been made possible by new diagnostic techniques will throw light on the treatment of those diseases.

Hyperbaric oxygen therapy stimulates colonic stem cells and induces mucosal healing in patients with refractory ulcerative colitis: a prospective case series

BACKGROUND

Hyperbaric oxygen (HBO) is used as part of treatment in a variety of clinical conditions. Its use in the treatment of ulcerative colitis has been reported in few clinical reports.

OBJECTIVE

We report the effect of HBO on refractory ulcerative colitis exploring one potential mechanism of action.

DESIGN

A review of records of patients with refractory ulcerative colitis who received HBO was conducted. Clinical and histopathological scoring was utilised to evaluate the response to HBO therapy (HBOT).

RESULTS

All patients manifested clinical improvement by the 40th cycle of HBOT. The median number of stool frequency dropped from seven motions/day (range=3-20) to 1/day (range=0.5-3), which was significant (z=-4.6, p<0.001). None of the patients manifested persistent blood passage after HBOT (z=-3.2, p=0.002). The severity index significantly improved after HBOT (z=-4.97, p<0.001). Histologically, a significant reduction of the scores of activity was recorded accompanied by a significant increase in the proliferating cell nuclear antigen labelling index of the CD44 cells of the colonic mucosa (p=0.001).

CONCLUSIONS

HBOT is effective in the setting of refractory ulcerative colitis. The described protocol is necessary for successful treatment. HBOT stimulates colonic stem cells to promote healing.

Medical ozone therapy reduces shock wave therapy-induced renal injury

OBJECTIVES

Extracorporeal shock wave (ESW) lithotripsy is the preferred treatment modality for uncomplicated kidney stones. More recently free oxygen radical production following ESW application has been considered to be crucial in shock wave-induced renal damage. It has been shown that ozone therapy (OT) has ameliorative and preventive effects against various pathological conditions due to increased nitro-oxidative stress. In current study, we aimed to evaluate the efficacy of OT against ESW-induced renal injury.

METHODS

Twenty-four male Sprague-Dawley rats were divided into three groups: sham-operated, ESW, and ESW + OT groups. All groups except sham-operated group were subjected to ESW procedure. ESW + OT group received 1 mg/kg/day of oxygen/ozone mixture intraperitoneally at 2 h before ESW, and OT was continued once a day for consecutive three days. The animals were killed at the 4th day, and kidney tissue and blood samples were harvested for biochemical and histopathologic analysis.

RESULTS

Serum ALT and AST levels, serum neopterin, tissue nitrite/nitrate levels, and tissue oxidative stress parameters were increased in the ESW group and almost came close to control values in the treatment group (p < 0.05, ESW vs. ESW + OT). Histopathological injury scores were significantly lower in treatment group than the ESW group (p < 0.05, ESW vs. ESW + OT). Immunohistochemical iNOS staining scores in ESW group were higher than those of sham-operated group (p < 0.05, ESW vs. sham-operated), iNOS staining scores in OT group were significantly lower than the ESW group (p < 0.05, ESW + OT vs. ESW).

CONCLUSION

OT ameliorates nitro-oxidative stress and reduces the severity of pathological changes in the experimental ESW-induced renal injury of rat model.

A spectrum of intestinal injury models in neonatal mice

PURPOSE

To compare the degree of necrotizing enterocolitis (NEC)-like damage under different stress conditions in neonatal mice.

METHODS

5-day-old C57BL/6 mice were assigned to: (A) breastfed and no stress factors; (B) breastfed+maternal separation (3 h daily); (C) breastfed+hypoxia+lipopolysaccharide (LPS-4 mg/kg/day); (D) hyperosmolar formula+hypoxia+LPS. Mice were killed at 9 days of life. Ileum and colon were stained for hematoxylin/eosin and blindly assessed. A scoring ≥2 was considered NEC. Data were compared using one-way ANOVA and reported as median (range).

RESULTS

Ileum-Mucosal injury was mild in group B (0.0-1). Hypoxia+LPS induced greater injury in group C (1.6, 1-2.5; p < 0.0001 to B) and D (2, 0.5-3.5; p < 0.0001 to B). There were no differences between group C and D (p = n.s.). There were no cases of NEC in group A or B, whereas NEC was present in 36 % group C and 68 % group D mice. Colon-a similar degree of mucosal injury was observed among group B (2, 1-3), C (1.7, 0-3) and D (1.5, 1-3; p = n.s.). NEC was present in 75 % of group B, 50 % of group C and 86 % of group D.

CONCLUSION

These models establish a spectrum of intestinal injury and are useful to investigate the variability of neonatal intestinal diseases, such as NEC.

Effects of hypothermia on skeletal ischemia reperfusion injury in rats

OBJECTIVE

The aim of this study was to investigate the effect of hypothermia (H) on skeletal ischemia-reperfusion (IR) injury in rats by measuring malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), nitric oxide (NO), and interleukin-1 beta (IL-1β) in muscle, and measureing immunohistochemical-inducible nitric oxide synthase (iNOS) staining of skeletal muscle.

MATERIALS AND METHODS

Eighteen Wistar Albino rats were divided randomly into three groups (sham, IR, hypothermia) (n=6). The sham group had all procedures without the IR period. The lower right extremity of rats in the IR and hypothermia groups was subjected to 2 hours of ischemia and 22 hours of reperfusion by applying a clamp on the common iliac artery and a rubber-band at the level of the lesser trochanter under general anesthesia. Rats in the hypothermia group underwent 4 hours of hypothermia during the first four hours of reperfusion in addition to a 2-hour ischemia and 22-hour reperfusion period. All rats were sacrificed at end of the IR period using a high dose of anesthesia. The tibialis anterior muscles were preserved. Immunohistochemical iNOS staining was performed, and MDA, SOD, GSH-Px, NO, and IL-1β were measured in the muscle.

RESULTS

The level of MDA, NO, and IL-1β in muscle was increased in the IR group compared with that in the sham group, but these parameters were decreased in the hypothermia group compared with the IR group. The activities of SOD and GSH-Px in muscle were decreased in the IR group; however, these parameters were increased in the hypothermia group. The score and intensity of iNOS staining of skeletal muscle was dens in IR group, mild in hypothermia group, and weak in sham group.

CONCLUSION

The present study has shown that hypothermia reduced IR injury in the skeletal muscle by decreasing the levels of MDA, NO, and IL-1β, and increasing the activities of SOD and GSH-Px. In addition, hypothermia attenuated the score and intensity of iNOS staining.

Beneficial effects of Etanercept on experimental necrotizing enterocolitis

PURPOSE

Tissue damage in necrotizing enterocolitis (NEC) of infants occurs as a result of an uncontrolled inflammatory response. The aim of this study was to investigate any potential anti-inflammatory effects that Etanercept may have on the inflammatory response in an experimental NEC model in newborn rats.

METHODS

Newborn pups were randomized into three groups immediately after birth (Control, NEC + Placebo and NEC + Etanercept). Pups in the NEC + Placebo and NEC + Etanercept groups were subjected to an NEC-inducing protocol (hypercarbia, hypothermia and hyperoxia) twice a day for 3 days. Pups in the NEC + Etanercept group were given an intraperitoneal injection of Etanercept. Rats were harvested for biochemical and histopathological examinations.

RESULTS

The histopathological injury score of rats in the NEC + Placebo group was significantly higher compared to the NEC + Etanercept and Control groups (p < 0.05 for both comparisons). Tissue levels of tumor necrosis factor-α, interleukin-1β, and malondialdehyde were higher in the placebo group compared to the Etanercept group.

CONCLUSION

Our results suggest that Etanercept attenuates intestinal tissue damage in NEC by reducing inflammation and blocking the production of free-oxygen radicals, while also reducing tissue levels of tumor necrosis factor-α and interleukin-1β.

Hyperbaric oxygen treatment and N-acetylcysteine ameliorate acetaminophen-induced liver injury in a rat model

An overdose of acetaminophen (APAP) produces centrilobular hepatocellular necrosis. We aimed to investigate the hepatoprotective effects of N-acetylcysteine (NAC) only and hyperbaric oxygen (O(2)) treatment (HBOT) combined with NAC, and their anti-inflammatory properties in liver tissue. In the current study, a total of 32 male Sprague Dawley rats were divided into 4 groups: sham, APAP, NAC, and NAC + HBOT. In the APAP, NAC, and NAC + HBOT groups, liver injury was induced by oral administration of 1 g/kg APAP. The NAC group received 100 mg/kg NAC per day. NAC + HBOT group received intraperitoneal injection of 100 mg/kg/day NAC and were given HBOT at 2.8 ATA pressure with 100% O(2) inhalation for 90 min every 12 h for 5 days. Rats in the sham group received distilled water only by gastric tube. All animals were killed on day 6 after APAP or distilled water administration. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, hepatic neopterin, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) levels were measured. There was a significant increase in serum AST and ALT activities in the APAP group compared with the sham group (in both p = 0.001). NAC and NAC + HBOT groups had significant decreases in hepatic neopterin, TNF-α, and IL-6 levels compared with the APAP group. APAP administration caused extensive hepatic necrosis. NAC and NAC + HBO treatments significantly reduced APAP-induced liver injury. Our results showed that the liver damage in APAP toxicity was attenuated by NAC and NAC + HBO treatments. NAC + HBOT exhibit hepatoprotective activity against APAP-induced liver injury in rats.

Protective effects of hydrogen-rich saline on necrotizing enterocolitis in neonatal rats

PURPOSE

The aim of this study was to test the hypothesis that hydrogen-rich saline (HRS) might have protective effects on the development of necrotizing enterocolitis (NEC) in a neonatal rat model.

METHODS

NEC was induced in male newborn Sprague-Dawley rats by formula feeding, exposure to asphyxia and cold stress. Sixty-four rat pups were divided randomly into four groups: C+NS (n=11), C+H2 (n=11), NEC+NS (n=20), and NEC+H2 (n=22). Rats in the former two groups were mother-fed. Pups received intra-peritoneal injection of HRS (10 ml/kg, 10 min before asphyxia stress twice a day) or the same dose of normal saline. Rats were monitored until 96 h after birth. Body weight, histological NEC score, survival time, malondialdehyde, antioxidant capacity, inflammatory mediators, and mucosal integrity were assessed.

RESULTS

HRS treatment maintained the body weight, reduced the incidence of NEC from 85% (17/20) to 54.5% (12/22), increased the survival rate from 25% (5/20) to 68.2% (15/22), and attenuated the severity of NEC. In addition, HRS inhibited the mRNA expression of pro-inflammatory mediators (inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin-6), down-regulated lipid peroxidation, enhanced total antioxidant capacity, and prevented the increase of diamine oxidase in serum. However, no significant influence of HRS on the interleukin-10 mRNA expression was observed.

CONCLUSIONS

HRS showed beneficial effects on neonatal rats with NEC via decreasing oxidative stress, increasing antioxidant capacity, suppressing inflammation, and preserving mucosal integrity.

What really causes necrotising enterocolitis?

Background. One of the most serious gastrointestinal disorders occurring in neonates is necrotising enterocolitis (NEC). It is recognised as the most common intra-abdominal emergency and is the leading cause of short bowel syndrome. With extremely high mortality and morbidity, this enigmatic disease remains a challenge for neonatologists around the world as its definite aetiology has yet to be determined. As current medical knowledge stands, there is no single well-defined cause of NEC. Instead, there are nearly 20 risk factors that are proposed to increase the likelihood of developing NEC. Aims and Objectives. The aim of this project was to conduct a comprehensive literature review around the 20 or so well-documented and less well-documented risk factors for necrotising enterocolitis. Materials and Methods. Searches of the Medline, Embase, and Science direct databases were conducted using the words "necrotising enterocolitis + the risk factor in question" for example, "necrotising enterocolitis + dehydration." Search results were ordered by relevance with bias given to more recent publications. Conclusion. This literature review has demonstrated the complexity of necrotising enterocolitis and emphasised the likely multifactorial aetiology. Further research is needed to investigate the extent to which each risk factor is implicated in necrotising enterocolitis.

CDP-choline reduces severity of intestinal injury in a neonatal rat model of necrotizing enterocolitis

BACKGROUND

Cytidine 5'-diphosphocholine (CDP-choline) is an endogenous intermediate in the biosynthesis of phosphatidylcholine, a contributor to the mucosal defense of the intestine. The aim of this study was to evaluate the possible cytoprotective effect of CDP-choline treatment on intestinal cell damage, membrane phospholipid content, inflammation, and apoptosis in a neonatal rat model of necrotizing enterocolitis (NEC).

METHODS

We divided a total of 30 newborn pups into three groups: control, NEC, and NEC + CDP-choline. We induced NEC by enteral formula feeding, exposure to hypoxia-hyperoxia, and cold stress. We administered CDP-choline intraperitoneally at 300 mg/kg/d for 3 d starting from the first day of life. We evaluated apoptosis macroscopically and histopathologically in combination with proinflammatory cytokines in the gut samples. Moreover, we determined membrane phospholipid levels as well as activities of xanthine oxidase, superoxide dismutase, glutathione peroxidase, and myeloperoxidase enzymes and the malondialdehyde content of intestinal tissue.

RESULTS

Mean clinical sickness score, macroscopic gut assessment score, and intestinal injury score were significantly improved, whereas mean apoptosis score and caspase-3 levels were significantly reduced in pups in the NEC + CDP-choline group compared with the NEC group. Tissue proinflammatory cytokine (interleukin-1β, interleukin-6, and tumor necrosis factor-α) levels as well as tissue malondialdehyde content and myeloperoxidase activities were reduced, whereas glutathione peroxidase and superoxide dismutase activities were preserved in the NEC + CDP-choline group. In addition, NEC damage reduced intestinal tissue membrane phospholipids, whereas CDP-choline significantly enhanced total phospholipid and phosphatidylcholine levels. Long-term follow-up in additional experiments revealed increased body weight, decreased clinical sickness scores, and enhanced survival in CDP-choline-receiving versus saline-receiving pups with NEC lesions.

CONCLUSIONS

Our study reports, for the first time, beneficial effects of CDP-choline treatment on intestinal injury in a neonatal rat model of NEC. Our data suggest that CDP-choline may be used as an effective therapeutic agent to prevent NEC.

Effect of hyperbaric oxygen therapy on the intestinal ischemia reperfusion injury

PURPOSE

Adequate tissue oxygenation is essential for healing. Hyperbaric oxygen therapy (HBOT) has potential clinical applications to treat ischemic pathologies, however the exact nature of any protective effects are unclear at present. We therefore investigated the potential role of HBOT in modulating the ischemia/reperfusion (I/R) injury response in intestinal model of I/R injury.

METHODS

Male Wistar rats were subjected to surgery for the induction of intestinal ischemia followed by reperfusion. HBOT was provided before and/or after intestinal ischemia. Cell viability in the intestinal tissue was assessed using the MTT assay and by measuring serum malondealdehyde (MDA). Microvascular density and apoptosis were evaluated by immunohistochemistry.

RESULTS

The results indicate that HBOT treatment pre- and post-ischemia reduces lesion size to the intestinal tissue. This treatment increases cell viability and reduces the activation of caspase-3, which is associated with increased number of tissue CD34 cells and enhanced VEGF expression.

CONCLUSION

The hyperbaric oxygen therapy can limit tissue damage due to ischemia/reperfusion injury, by inducing reparative signaling pathways.

Hyperbaric oxygen treatment for inflammatory bowel disease: a systematic review and analysis

Background

Traditionally, hyperbaric oxygen treatment (HBOT) has been used to treat a limited repertoire of disease, including decompression sickness and healing of problem wounds. However, some investigators have used HBOT to treat inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis.

Methods

Comprehensive searches were conducted in 8 scientific databases through 2011 to identify publications using HBOT in IBD. Human studies and animal models were collated separately.

Results

Thirteen studies of HBOT in Crohn's disease and 6 studies in ulcerative colitis were identified. In all studies, participants had severe disease refractory to standard medical treatments, including corticosteroids, immunomodulators and anti-inflammatory medications. In patients with Crohn's disease, 31/40 (78%) had clinical improvements with HBOT, while all 39 patients with ulcerative colitis improved. One study in Crohn's disease reported a significant decrease in proinflammatory cytokines (IL-1, IL-6 and TNF-alpha) and one study in ulcerative colitis reported a decrease in IL-6 with HBOT. Adverse events were minimal. Twelve publications reported using HBOT in animal models of experimentally-induced IBD, including several studies reporting decreased markers of inflammation or immune dysregulation, including TNF-alpha (3 studies), IL-1beta (2 studies), neopterin (1 study) and myeloperoxidase activity (5 studies). HBOT also decreased oxidative stress markers including malondialdehyde (3 studies) and plasma carbonyl content (2 studies), except for one study that reported increased plasma carbonyl content. Several studies reported HBOT lowered nitric oxide (3 studies) and nitric oxide synthase (3 studies) and one study reported a decrease in prostaglandin E₂ levels. Four animal studies reported decreased edema or colonic tissue weight with HBOT, and 8 studies reported microscopic improvements on histopathological examination. Although most publications reported improvements with HBOT, some studies suffered from limitations, including possible publication and referral biases, the lack of a control group, the retrospective nature and a small number of participants.

Conclusions

HBOT lowered markers of inflammation and oxidative stress and ameliorated IBD in both human and animal studies. Most treated patients were refractory to standard medical treatments. Additional studies are warranted to investigate the effects of HBOT on biomarkers of oxidative stress and inflammation as well as clinical outcomes in individuals with IBD.

Melatonin ameliorates necrotizing enterocolitis in a neonatal rat model

INTRODUCTION

We designed the present study to evaluate the efficacy of melatonin (M) on the severity of necrotizing enterocolitis (NEC) in a neonatal rat model.

MATERIALS AND METHODS

Immediately after birth, pups were weighed and randomized into 3 groups: NEC, NEC + M, and control. Necrotizing enterocolitis was induced by enteral formula feeding and exposure to hypoxia after cold stress at 4°C and oxygen. The NEC + M group received 10 mg/kg M daily for 3 days after the first day of the NEC procedure. The pups were killed on the fourth day, and their intestinal tissues were harvested for biochemical and histopathologic analysis. Blood samples were also obtained from the pups.

RESULTS

The mortality rate and weight loss were highest in the NEC group. Malondialdehyde and protein carbonyl content were significantly increased, whereas superoxide dismutase and glutathione peroxidase were decreased in the NEC-treated pups. Melatonin prevented these changes, with these values being similar to control levels in the NEC + M group. Nitrate plus nitrite levels and serum tumor necrosis factor α and interleukin-1β were increased in the NEC group, and histopathologic injury score in the NEC group was significantly higher than that in the NEC + M group.

CONCLUSION

Melatonin significantly reduced the severity of NEC in our study.

Total oxidant status and oxidative stress are increased in infants with necrotizing enterocolitis

BACKGROUND

Oxidative stress has been implicated in the pathogenesis of necrotizing enterocolitis (NEC). In this study, we compared the global oxidant/antioxidant status by measuring total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in preterm infants with NEC and with control preterms.

METHODS

Forty-one preterm neonates with NEC (stage 1 [group 1; n = 23] and stages 2 and 3 [group 2; n = 18]) and age-matched 36 healthy preterm controls (group 3) were included in this study. Blood samples were obtained both at the time of NEC diagnosis and 72 hours after for the evaluation of TAC and TOS. Serum levels of TAC, TOS, and OSI in patients with NEC were compared with controls.

RESULTS

Demographic characteristics were comparable in all 3 groups. Preterm neonates in group 2 (with stages 2 and 3 NEC) had the highest TOS levels and OSI (P < .001 vs both groups 1 and 3). There was no difference in TAC levels among the groups (P = .26).

CONCLUSIONS

Our findings demonstrated that although TAC levels were similar in all 3 groups, oxidant stress mechanisms were activated in preterm neonates with definite NEC (stages 2 and 3 NEC). Premature neonates with increased levels of TOS and OSI were associated with severity of NEC.

Beneficial effects of N-acetylcysteine and ebselen on renal ischemia/reperfusion injury

INTRODUCTION

It has been demonstrated that peroxynitrite accompanies acute renal ischemia and contributes to the pathophysiology of renal damage. Therefore, we aimed to investigate the roles of N-acetylcysteine (NAC), a well-known powerful antioxidant, and ebselen (E), a scavenger of peroxynitrite, on renal injury induced by renal ischemia/reperfusion injury (IRI) of rat kidney.

MATERIALS AND METHODS

Forty male Sprague-Dawley rats were divided into five groups: sham, renal IRI, renal IRI+NAC, renal IRI+E, and renal IRI+NAC+E. IR injury was induced by 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood samples were obtained for histopathological and biochemical evaluations.

RESULTS

Renal IR resulted in increased malondialdehyde and nitrite/nitrate levels suggesting increased lipid peroxidation and peroxynitrite production and decreased superoxide dismutase and glutathione peroxidase activities. Both NAC and E alone significantly decreased malondialdehyde and nitrite/nitrate levels and increased superoxide dismutase and glutathione peroxidase activities. Additionally in the renal IRI+NAC+E group, all biochemical results were quite close to those of sham group. Histopathologically, the kidney injury in rats treated with combination of NAC and E was found significantly less than the other groups.

CONCLUSIONS

Both NAC and E are able to ameliorate IRI of the kidney by decreasing oxidative and nitrosative stresses and increasing free radical scavenger properties. Additionally, combination of NAC and E prevents kidney damage more than when each drug is used alone, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing renal IRI.

Comparative effects of probiotics, prebiotics, and synbiotics on growth factors in the large bowel in a rat model of formula-induced bowel inflammation

OBJECTIVES

Supplementation with probiotics has been shown to prevent gastrointestinal damage possibly through preservation of growth factors. We tested the hypothesis that probiotics, prebiotics, or synbiotics supplementation preserves intestinal insulin-like growth factors (IGFs) and epidermal growth factors (EGFs) in formula-fed neonatal rats.

MATERIALS AND METHODS

At birth (postnatal day 0 [P0]), neonatal rat pups (n = 18 pups/group) were either maternally fed or hand-gavaged with formula supplemented with probiotics (Pro-Fed), prebiotics, or synbiotics from P0 to P3. A formula-fed control group received formula without supplementation. At P4, large bowel samples were assessed histologically and assayed for vascular endothelial growth factor (VEGF), soluble VEGF receptor-1, IGF-I, IGF-II, and EGF.

RESULTS

All formula-fed groups were severely growth suppressed with comparable mortalities. Moderate preservation of bowel integrity was noted in the Pro-Fed group. In contrast, severe inflammation was seen in all of the other formula groups. This was associated with significant increases in VEGF levels in all of the formula groups (P < 0.05) except the Pre-Fed group. Similar elevations in soluble VEGF receptor-1 (P < 0.05), IGF-I (P < 0.05), and EGF (P < 0.05) were noted, but statistical significance was achieved only in the Pro-Fed group.

CONCLUSIONS

Induction of IGF-I and EGF with moderate bowel integrity may represent a protective effect of probiotics against formula-induced inflammation. These data, taken collectively, suggest that probiotics may provide more beneficial effects on the developing large bowel than prebiotics and synbiotics.

Comparison of the efficacy of melatonin and 1400W on renal ischemia/reperfusion injury: a role for inhibiting iNOS

INTRODUCTION

We investigated the roles of melatonin (a powerful antioxidant, iNOS inhibitor, and a scavenger of peroxynitrite) and 1400W (a strong and selective inhibitor of inducible nitric oxide) on renal dysfunction and injury induced by ischemia/reperfusion (I/R) of rat kidney, since oxidative and nitrosative injury are believed to be the major causes.

MATERIALS AND METHODS

Thirty-two male Sprague-Dawley rats were divided into four groups of sham-operated, I/R, I/R + Melatonin and I/R + 1400W. Rats were given either melatonin (10 mg/kg) or 1400W (10 mg/kg) in the I/R + Melatonin and I/R + 1400W groups respectively at 6 h prior to ischemia and at the beginning of reperfusion via intraperitoneal route. I/R injury was induced by 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood were obtained for histopathologic and biochemical evaluation.

RESULTS

Melatonin and 1400W had an ameliorative effect on both oxidative and nitrosative stress in the kidneys against renal I/R injury in rats. In addition, melatonin significantly reduced elevated nitro-oxidative stress product, restored decreased antioxidant enzymes and attenuated histological alterations when compared with 1400W.

CONCLUSIONS

Both Melatonin and 1400W were efficient in ameliorating experimental I/R injury of the kidneys. Moreover, melatonin was more effective than 1400W possibly through inhibiting iNOS as well as scavenging free oxygen radicals and peroxynitrite.

Efficacy of hyperbaric oxygen therapy and medical ozone therapy in experimental acute necrotizing pancreatitis

OBJECTIVES

Our aims were to evaluate the efficacy of ozone therapy (OT) in an experimental rat model of acute necrotizing pancreatitis (ANP) and to compare its effects with hyperbaric oxygen (HBO) therapy in this entity.

METHODS

Forty Sprague-Dawley rats were divided into sham-operated, ANP, ANP + HBO, and ANP + OT groups. Acute necrotizing pancreatitis was induced by infusing 1-mL/kg 3% sodium taurocholate into the common biliopancreatic duct. Hyperbaric oxygen was administered twice daily at a 2.8-atm pressure for 90 minutes. Ozone therapy was set as daily intraperitoneal injections of 0.7-mg/kg ozone/oxygen gas mixture. Hyperbaric oxygen and OT were continued for 3 days after the induction of ANP. The surviving animals were killed at the fourth day, and their pancreases were harvested for biochemical, microbiological, and histopathologic analyses.

RESULTS

Serum amylase/lipase and neopterin levels and tissue oxidative stress parameters were similar to sham's values in both the ANP + HBO and the ANP + OT groups. Histopathologic injury scores were significantly lower in the treatments groups than in the ANP group. When compared with the ANP group, the number of infected rats was significantly lesser in the ANP + HBO and the ANP + OT groups.

CONCLUSIONS

Hyperbaric oxygen and OT reduce the severity and the mortality in the experimental rat model of ANP, and a greater benefit was received for OT comparing with HBO.

Medical ozone therapy reduces oxidative stress and intestinal damage in an experimental model of necrotizing enterocolitis in neonatal rats

PURPOSE

Necrotizing enterocolitis (NEC) remains a major cause of morbidity and death in neonates. Evidence suggests that an imbalance between activated proinflammatory response with inadequate antiinflammatory protection results in NEC. Ozone has been proposed as an antioxidant enzyme activator, immunomodulator, and cellular metabolic activator. Therefore, this study was designed to investigate whether medical ozone therapy is effective on neonatal rat model of NEC.

MATERIALS AND METHODS

Thirty-eight newborn Sprague-Dawley pups were randomly divided into 3 groups of NEC, NEC + ozone, and control (left to breast feed). Necrotizing enterocolitis was induced by enteral formula feeding and exposure to 100% carbon dioxide inhalation for 10 minutes after +4 degrees C cold exposures for 5 minutes and 97% oxygen for 5 minutes 2 times daily. The NEC + ozone group received 0.7 mg/kg per day ozone/oxygen mixture intraperitoneally for a total of 3 days after first day of NEC procedure. The pups were killed at fourth day, and their intestinal tissues were harvested for biochemical and histopathologic analysis. Blood sample from pups were also obtained.

RESULTS

The mortality rate and the weight loss were significantly higher in NEC group than control and treatment groups. Oxidative stress markers (malondialdehyde and protein carbonyl content) significantly increased and antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) were significantly decreased in NEC group. All these biochemical changes were ameliorated in NEC + ozone group. Nitrate plus nitrite levels and serum tumor necrosis factor alpha were elevated in NEC group and reduced in treatment group. In addition, histopathologic injury score of NEC group was significantly higher than NEC + ozone group.

CONCLUSION

Ozone treatment significantly reduced the severity of NEC by modulating antioxidative defense and antiinflammatory protection in our experimental animal model.