Akkermansia muciniphila improves chronic colitis-induced enteric neuroinflammation in mice

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic diseases that are not fully understood. Drugs in use can only be applied for a short time due to their side effects. Therefore, research is needed to develop new treatment approaches. In addition, it has been proven that IBD causes degeneration in the enteric nervous system (ENS). In recent years, it has been discussed that probiotics may have positive effects in the prevention and treatment of inflammatory enteric degeneration. Akkermansia muciniphila (A. muciniphila) is an anaerobic bacterium found in the mucin layer of the intestinal microbiota. It has been found that the population of A. muciniphila decreases in the case of different diseases. In light of this information, the curative effect of A. muciniphila application on colitis-induced inflammation and enteric degeneration was investigated.

METHODS

In this study, 5 weeks of A. muciniphila treatment in Trinitro-benzene-sulfonic acid (TNBS)-induced chronic colitis model was investigated. Colon samples were examined at microscopic, biochemical, and molecular levels. Fecal samples were collected before, during, and after treatment to evaluate the population changes in the microbiota. Specific proteins secreted from the ENS were evaluated, and enteric degeneration was examined.

RESULTS

As a result of the research, the ameliorative effects of A. muciniphila were shown in the TNBS colitis model-induced inflammation and ENS damage.

DISCUSSION

In light of these results, A. muciniphila can potentially be evaluated as a microbiome-based treatment for IBD with further clinical and experimental studies.

Ferulic acid attenuates pancreaticobiliary duct occlusion-induced inflammation in both pancreas and liver

INTRODUCTION

Acute pancreatitis is a systemic inflammatory disorder characterized by the hyperactivation of digestion enzymes and the release of proinflammatory cytokines. Ferulic acid (FA) is a hydroxycinnamic acid derivative that has recently been shown to have antioxidant and anti-inflammatory properties.

AIM

The anti-inflammatory effects of FA were investigated in the pancreaticobiliary duct ligation (PBDL)-induced pancreatitis model.

METHODS

Wistar albino rats (250-300 g; female = male) were divided into sham operation and PBDL groups. Some PBDL-performed animals were given intragastric saline or 250 mg/kg FA or 500 mg/kg FA 30 min before the PBDL and for 3 consecutive days. Moreover, the control group received saline. Blood samples are collected at the 24th, 48th, and 72nd hours to measure serum tumor necrosis factor (TNF)-α, liver, and pancreatic enzymes. At the 72nd hour, rats were euthanized; pancreas, lung, and liver samples were collected, scored microscopically, and analyzed for myeloperoxidase activity, malondialdehyde, and glutathione levels. One-way ANOVA with Tukey-Kramer tests were used for statistical analysis.

RESULTS

FA treatment reduced myeloperoxidase activity and prevented the depletion of glutathione in all three tissues. With FA treatments, high malondialdehyde levels in the pancreas and liver were reduced, as were serum TNF- α, amylase, lipase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels. Additionally, FA ameliorated microscopic damage in the pancreas and liver significantly.

CONCLUSION

According to the findings, FA protects endogenous antioxidant content, prevents neutrophil infiltration, and decreases lipid peroxidation in PBDL-induced pancreatitis. Furthermore, FA improves tissue damage induced by pancreatitis with its anti-inflammatory effects.

Ferulic Acid Treats Gastric Ulcer via Suppressing Oxidative Stress and Inflammation

(1) Background: The aim of the present study was to evaluate the gastroprotective potential of ferulic acid (FA) on indomethacin-induced gastric ulcers in rats with macroscopic and microscopic examinations along with biochemical assays. (2) Methods: After 24 h starvation, the ulcer was induced in male Sprague-Dawley rats by subcutaneous indomethacin (25 mg/kg) injection. Fifteen minutes after ulcer induction, rats were treated with either tween 80 or FA. FA was given by oral gavage at 100 mg/kg, 250 mg/kg, and 500 mg/kg. In the fourth hour, rats were euthanized and collected gastric samples were evaluated macroscopically and microscopically. Antioxidant parameters including malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and inflammatory parameters comprising of myeloperoxidase (MPO), Tumor Necrosis Factor (TNF)-α, Interleukin (IL)-1β, IL-6 and Nuclear Factor Kappa-B (NF-κB) p65 levels were also determined. (3) Results: Indomethacin injection significantly increased the macroscopic and microscopic scores. In addition, it increased the gastric MDA, MPO, TNF-α, IL-1β, IL-6, and NF-κB p65 levels but reduced SOD and GSH content. Treatment with FA significantly improved the gastric injury macroscopically and microscopically. Moreover, FA displayed a marked decrease in the gastric levels of MDA, MPO, TNF-α, IL-1β, IL-6, and NF-κB p65 and a significant increase in SOD and GSH compared to the INDO group. Ultimately, 250 mg/kg FA was determined as the most effective dose. (4) Conclusion: Our results revealed that FA has a gastroprotective effect against indomethacin-induced gastric ulcers in rats due to its antioxidant and anti-inflammatory properties. As a result, FA may be a potential treatment choice for gastric ulcers.

Exercise improves testicular morphology and oxidative stress parameters in rats with testicular damage induced by a high-fat diet

Obesity and male infertility are problems that affect population. Exercise is a nonpharmacological way to reduce the negative health effects of obesity. The purpose of this study was to examine the effects of exercise on hormone levels, blood-testis barrier, and inflammatory and oxidative biomarkers in rats that became obese due to a high-fat diet (HFD). Male rats received a standard diet (STD group) or a HFD (HFD group) for 18 weeks. During the final 6 weeks of the experiment, swimming exercises (1 h/5 days/week) were given to half of these animals (STD + EXC and HFD + EXC groups). Finally, blood and testicular tissues were analysed by biochemical and histological methods. Body weight, leptin, malondialdehyde, interleukin-6, TNF-alpha and myeloperoxidase levels, apoptotic cells and DNA fragmentation were increased, and testis weight, insulin, FSH, LH, testosterone, glutathione and superoxide dysmutase levels, proliferative cells, ZO-1, occludin, and gap junction protein Cx43 immunoreactivity were decreased in the HFD group. All these hormonal, morphological, oxidative and inflammatory biomarkers were enhanced in the HFD + EXC group. It is thought that exercise protected testicular cytotoxicity by regulating hormonal and oxidant/antioxidant balances and testicular function, inhibiting inflammation and apoptosis, as well as preserving blood-testis barrier.

Morphological evaluation of the effects of exercise on high-fat-diet-induced liver damage in rats

BACKGROUND/AIMS

This study was aimed to investigate the protective effects of swimming exercise on nonalcoholic fatty liver disease (NAFLD) associated with high fat diet-induced obesity, using microscopical and biochemical parameters.

MATERIALS AND METHODS

Sprague Dawley male rats were fed either standard chow (STD group; 6% fat) or high-fat diet (HFD group; 45% fat) for 18 weeks. Animals were divided into four groups, STD, STD + EXC, HFD, HFD + EXC. Exercise groups were submitted to swimming training 5 days of week and 1h of per day, during the last 6 weeks of the experiment. At the end of the experiment, liver samples were evaluated for morphologically and ultrastructurally. Moreover, malondialdehyde (MDA) and glutathione (GSH) levels were evaluated in liver samples.

RESULTS

Normal morphology of liver parancyma with hepatocytes and sinusoids was observed in the STD and STD+EXC groups. Steatosis, lipid accumulation, ballooned hepatocytes, decrease of glycogen deposits and fibrosis in periportal area were observed in HFD group. Liver MDA level was increased and GSH level was decreased in HFD group. Exercise treatment ameliorated these morphological and oxidative changes in HFD induced liver damage.

CONCLUSION

Based on morphological and biochemical analysis, we could conclude that swimming training ameliorated obesity-induced liver damage by regulating lipid accumulation and oxidative damage.

Anti-inflammatory effects of nesfatin-1 on acetic acid-induced gastric ulcer in rats: involvement of cyclo-oxygenase pathway

In order to elucidate the contribution of cycloxygenase (COX) enzymes in the anti-oxidant and anti-inflammatory mechanisms of nesfatin-1, which improves the healing process of chronic gastric ulcers, either acetic acid (80%; ulcer groups; n = 40) or saline (control groups; n = 40) was applied to the serosal surface of male Sprague Dawley rats' stomachs for 1 min. Both the control and ulcer groups were treated daily with either i.p. saline or nesfatin-1 (0.3 μg/kg; for 3 days). Nesfatin-1-treatment was preceded with i.p. saline, COX-2 inhibitor NS-398 (2 mg/kg), COX-1 inhibitor ketorolac (3 mg/kg) or non-selective COX inhibitor indomethacin (5 mg/kg) for 3 days. The rats were decapitated at the end of the third day, and their trunk blood was collected for the measurements of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-10 using ELISA. The induction of ulcers resulted in increased macroscopic scores, along with elevated gastric malondialdehyde, luminol- and lucigenin-enhanced chemiluminescence levels and myeloperoxidase activity. On the other hand, nesfatin-1 treatment abolished these elevations. Depleted glutathione, superoxide dismutase and catalase activity levels in the saline-treated ulcer group were preserved in the nesfatin-1-treated ulcer group. Increased levels of serum TNF-α, IL-1β, IL-10 in the saline-treated ulcer group, as compared to control group, were significantly decreased in the nesfatin-1-treated ulcer group. The inhibition of COX-1, and/or COX-2 reversed most of the alterations induced with nesfatin-1, but COX-2-blockade was consistently more effective to abolish all nesfatin-1-induced changes. Our results suggest that nesfatin-1 ameliorates ulcer-induced inflammatory response through the modulation of oxidant-antioxidant balance. As selective pharmacological inhibition of COX-1 or COX-2 suppresses the antioxidant/anti-inflammatory effects of nesfatin-1, it appears that nesfatin-1 decreases inflammatory mediators and neutrophil migration by a COX-dependent mechanism, especially by a COX-2- dependent mechanism, during the ulcer healing stage.

Neuroprotective Effect of Erythropoietin on Phenylhydrazine-Induced Hemolytic Hyperbilirubinemia in Neonatal Rats

Neonatal unconjugated hyperbilirubinemia might cause severe bilirubin neurotoxicity in especially hemolytic conditions. The study aimed to elucidate the potential neuroprotective effects of erythropoietin (EPO) in hemolysis-induced hyperbilirubinemia. In newborn rats, hyperbilirubinemia secondary to hemolysis was induced by injecting with phenylhydrazine hydrochloride (PHZ) and rats were injected with either vehicle or EPO. At 54th hour of the PHZ injection, rats were decapitated. Serum levels of TNF-α, IL-1β, IL-10, brain-derived neurotrophic factor (BDNF) and S100-B and brain malondialdehyde, glutathione levels and myeloperoxidase activities were measured. TUNEL staining and NF-κB expression were evaluated. As compared to control pups, in vehicle-treated PHZ group, TNF-α and IL-1β levels, malondialdehyde level and myeloperoxidase activity were increased with concomitant decreases in IL-10 and glutathione. All EPO regimens reversed PHZ-induced alterations in IL-10, TNF-α, malondialdehyde and glutathione levels. Three-day-treatment abolished increases in myeloperoxidase activity and IL-1β levels, while BDNF and S100-B were elevated. Increased TUNEL (+) cells and NF-κB expressions in the brain of PHZ group were reduced in the 3-day-treated group. EPO exerted anti-inflammatory effects on PHZ-induced neural damage in newborn rats, while the neuroprotection was more obvious when the treatments were repeated successively. The results suggest that EPO treatment may have a therapeutic potential in supporting neuroplasticity in the hyperbilirubinemic neonates.

The neuroprotective and anti-apoptotic effects of melatonin on hemolytic hyperbilirubinemia-induced oxidative brain damage

Melatonin exerts protection in several inflammatory and neurodegenerative disorders. To investigate the neuroprotective effects of melatonin in an experimental hemolysis-induced hyperbilirubinemia, newborn Sprague-Dawley rats (25-40 g, n = 72) were injected with phenylhydrazine hydrochloride (PHZ; 75 mg/kg) and the injections were repeated at the 24th hour. Rats were treated with saline or melatonin (10 mg/kg) 30 min before the first and second PHZ injections and 24 h after the 2nd PHZ injections. Control rats (n = 24) were injected with saline, but not PHZ. At sixth hours after the last injections of saline or melatonin, all rats were decapitated. Tumor necrosis factor (TNF)-α, IL-1β, IL-10 and brain-derived neurotrophic factor (BDNF) and S100B levels in the plasma were measured. Brain tissue malondialdehyde (MDA), glutathione (GSH) levels and myeloperoxidase (MPO) activities were measured, and brain tissues were evaluated for apoptosis by TUNEL method. In the saline-treated PHZ group, hemoglobin, hematocrit levels were reduced, and total/direct bilirubin levels were elevated when compared to control group. Increased plasma TNF-α, IL-1β levels, along with decreased BDNF, S100B and IL-10 values were observed in the saline-treated PHZ group, while these changes were all reversed in the melatonin-treated group. Increased MDA levels and MPO activities in the brain tissues of saline-treated hyperbilirubinemic rats, concomitant with depleted brain GSH stores, were also reversed in the melatonin-treated hyperbilirubinemic rats. Increased TUNEL(+) cells in the hippocampus of saline-treated PHZ group were reduced by melatonin treatment. Melatonin exerts neuroprotective and anti-apoptotic effects on the oxidative neuronal damage of the newborn rats with hemolysis and hyperbilirubinemia.

Nesfatin-1 alleviates gastric damage via direct antioxidant mechanisms

BACKGROUND

Indomethacin is a nonsteroidal anti-inflammatory drug, which is known to produce serious side effects, causing ulcerative lesions. Nesfatin-1, a newly identified anorexigenic peptide, was recently shown to have neuroprotective effects. The aim of the study was to investigate the anti-inflammatory effects of nesfatin-1 on indomethacin-induced gastric ulcer.

MATERIALS AND METHODS

After a 24-h starvation period, ulcer was induced in Sprague-Dawley rats by subcutaneous administration of indomethacin (25 mg/kg), whereas control group received vehicle. Fifteen minutes after ulcer induction, rats were treated with either saline or nesfatin-1 (0.1, 0.3, or 1 μg/kg, intraperitoneally). At the fourth hour, all rats were decapitated and their trunk blood was collected for tumor necrosis factor (TNF)-α and interleukin (IL)-6 measurements. Stomach samples were examined microscopically and analyzed for myeloperoxidase (MPO) activity, malondialdehyde (MDA), glutathione (GSH), luminol-, and lucigenin-enhanced chemiluminescence (CL) levels.

RESULTS

Ulcer induction increased serum TNF-α; and IL-6 levels, gastric CL and MDA levels and MPO activity but decreased gastric GSH content (P < 0.05-0.001). On the other hand, 0.1 μg/kg dose of nesfatin-1 reduced microscopic and macroscopic damage scores, decreased MPO activity and MDA levels, CL and IL-6 levels, whereas gastric GSH was replenished (P < 0.01). However, indomethacin-induced increase in TNF-α level was abolished at only 1 μg/kg dose of nesfatin-1 (P < 0.01).

CONCLUSIONS

Nesfatin-1 alleviated indomethacin-induced gastric injury, suggesting that the anti-inflammatory and gastroprotective effects of nesfatin-1 on oxidative gastric damage could be implemented by supporting the balance in oxidant and antioxidant systems while inhibiting the generation of pro-inflammatory mediators.

The role of cholinergic anti-inflammatory pathway in acetic acid-induced colonic inflammation in the rat

The "cholinergic anti-inflammatory pathway" provides neurological modulation of cytokine synthesis to limit the magnitude of the immune response. This study aimed to evaluate the impact of the cholinergic anti-inflammatory pathway on the extent of tissue integrity, oxidant-antioxidant status and neutrophil infiltration to the inflamed organ in a rat model of acetic acid-induced colitis. Colitis was induced by intrarectal administration of 5% acetic acid (1ml) to Sprague-Dawley rats (200-250g; n=7-8 per group). Control group received an equal volume of saline intrarectally. The rats were treated with either nicotine (1mg/kg/day) or huperzine A (0.1mg/kg/day) intraperitoneally for 3 days. After decapitation, the distal colon was scored macroscopically and microscopically. Tissue samples were used for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, and myeloperoxidase (MPO) activity. Formation of reactive oxygen species was monitored by using chemiluminescence (CL). Nuclear factor (NF)-κB expression was evaluated in colonic samples via immunohistochemical analysis. Trunk blood was collected for the assessment of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-10, resistin and visfatin levels. Both nicotine and huperzine A reduced the extent of colonic lesions, increased colonic MDA level, high MPO activity and NF-κB expression in the colitis group. Elevation of serum IL-1β level due to colitis was also attenuated by both treatments. Additionally, huperzine A was effective to reverse colitis-induced high lucigenin-enhanced CL values and serum TNF-α levels. Colitis group revealed decreased serum visfatin levels compared to control group which was completely reversed by nicotine. In conclusion, modulation of the cholinergic system either by nicotine or ACh esterase inhibition improved acetic acid-induced colonic inflammation as confirmed by macroscopic and microscopic examination and biochemical assays.

Alpha-lipoic acid modulates gut inflammation induced by trinitrobenzene sulfonic acid in rats

BACKGROUND AND AIM

Alpha-lipoic acid (ALA) has been shown to combat oxidative stress by quenching a variety of reactive oxygen species. It is involved in the regeneration of exogenous and endogenous antioxidants, chelation of metal ions, and repair of oxidized proteins. This study aimed to evaluate the potential beneficial effect of ALA on trinitrobenzenesulfonic acid (TNBS)-induced gut ileitis and colitis in rats.

METHOD

After 48 h of fasting, Sprague-Dawley rats underwent a laparotomy under ether anesthesia. TNBS solution 30 mg/mL in 40% ethanol (1 mL) was injected into the lumen, 10 cm proximal to the ileocolonic junction to induce ileitis or intrarectally 8 cm proximal to the anal sphincter to induce colitis. ALA (25 mg/kg intraperitoneally, twice a day) was given after induction of inflammation and continued for 3 days. All animals were decapitated 3 days after induction of the inflammation. The mucosal lesions of the ileum and colon were scored macroscopically and microscopically. Samples were taken for the measurement of malondialdehyde (MDA) and glutathione (GSH) levels, tissue-associated myeloperoxidase (MPO) activity and luminol- or lucigenin-enhanced chemiluminescence (CL).

RESULTS

Macroscopic scores, morphological changes and increased tissue lipid peroxidation with a concomitant reduction in GSH of the ileitis or colitis groups were all reversed by treatment with ALA. ALA treatment was also effective in improving tissue MPO activity and CL values, which were elevated in untreated ileitis or colitis groups.

CONCLUSION

ALA is beneficial in TNBS-induced gut inflammation in rats via suppression of neutrophil accumulation, preservation of endogenous glutathione and inhibition of reactive oxidant generation.

The effect of alpha-melanocyte stimulating hormone on gentamicin-induced acute nephrotoxicity in rats

The effect of alpha-melanocyte stimulating hormone (alpha-MSH) was investigated on gentamicin-induced acute renal injury in rats. Sprague-Dawley rats (200-250 g; n = 8-10) were treated with gentamicin sulphate (GEN; 80 mg kg(-1)) or saline intraperitoneally for 7 consecutive days. alpha-MSH was administered at a dose of 25 microg rat(-1) day(-1) following GEN or saline injections. On day 8, all animals were decapitated. Trunk blood and 24 h urine were collected to measure the serum creatinine levels, blood urea nitrogen (BUN) levels and to calculate the creatinine clearance values. The kidneys were excised for histological evaluation and for the measurement of malondialdehyde (MDA) levels, glutathione (GSH) contents and myeloperoxidase (MPO) activity. Treatment with alpha-MSH reduced the severity of the renal lesions microscopically, decreased MDA content and MPO activity and restored GSH in kidney samples. However, it did not restore the impaired renal function tests due to GEN challenge. In conclusion, alpha-MSH treatment has a beneficial effect on GEN-induced acute nephrotoxicity, as confirmed by histological evaluation and biochemical assays; but it does not improve GEN-induced renal dysfunction. The mechanism of the protective effect could be attributed, at least in part, to decreased tissue leukocyte infiltration and thus, to decreased oxygen-derived reactive metabolite production.

Resveratrol Reduces Renal and Lung Injury Caused by Sepsis in Rats

Resveratrol (3,5,4'-trans-trihydroxystilbene), a natural phytoalexin, has various pharmacological effects, including anti-inflammatory properties via inhibition of oxidation, leukocyte priming, and expression of inflammatory mediators. The present study was aimed to investigate the possible beneficial activities of resveratrol on lung and kidney damage in a rat model of sepsis.

MATERIALS AND METHODS

Sepsis was induced to Sprague-Dawley rats of both sexes (200-250 g) by cecal ligation and perforation. The rats were treated with resveratrol (30 mg/kg; i.p.) or saline after induction of sepsis and at 16 h. Twenty-four hours after the sepsis-induction, all rats were decapitated. Blood was collected for the measurement of tumor necrosis factor-alpha level and lactate dehydrogenase activity. Lung and kidney samples were taken for histological assessment and for the measurement of malondialdehyde, glutathione level, myeloperoxidase activity, and collagen content.

RESULTS

Sepsis caused a significant increase in malondialdehyde levels, myeloperoxidase activity, and collagen content of the lung and kidney tissues with a concomitant reduction in glutathione levels. Microscopic examination revealed severe destruction of regular morphology in both lung and kidney tissues. Serum tumor necrosis factor-alpha and lactate dehydrogenase levels also were higher in rats with sepsis compared to those of the sham group. Resveratrol treatment reversed these biochemical parameters and preserved tissue morphology as evidenced by histological evaluation.

CONCLUSIONS

Resveratrol, a phenolic compound, reduces sepsis-induced remote organ injury, at least in part, through its ability to balance oxidant-antioxidant status, to inhibit neutrophil infiltration and to regulate the release of inflammatory mediators.