Rat Colon Research Articles

Anonna crassiflora suppresses colonic carcinogenesis through its antioxidant effects, bioactive amines, and phenol content in rats

Marolo (Annona crassiflora) is an underutilized Brazilian Cerrado fruit with few reports in the literature about its bioactive compounds and functional properties. In this context, the chemoprevention against the carcinogen 1,2-dimethylhydrazine (DMH)-induced pre-neoplastic lesions in Wistar rat colon was investigated and correlated with marolo’s antioxidant activity and the contents of phenolic compounds and bioactive amines. Total phenolic compounds (TPC) and total flavonoids compounds (TFC) were determined in the marolo pulp extract by spectrophotometric and Ultra-Performance Liquid Chromatography and diode array detection (UPLC-DAD) analysis. Free bioactive amines were determined by High Performance Liquid Chromatography and fluorescence detection (HPLC-FLD) after post column derivatization with o-phthalaldehyde. In addition, the in vitro antioxidant activity was determined by DPPH, and ABTS. Wistar rats were treated orally with marolo pulp at 0.7, 1.4 and 2.8 g/kg body weight (bw)/day added to a standard ration. Four subcutaneous injections of DMH (40 mg/kg bw) were used to induce a pre-neoplastic lesion that was assessed by the aberrant crypt foci (ACF) assay. The marolo pulp (fresh weigh) showed high content of total phenolic compounds (9.16 mg GAE/g), with predominance of chlorogenic acid (1.86 µg/g) and epicatechin (0.99 µg/g), and total flavonoids (7.26 mg CE/g), ∼85 % of the TPC. The marolo pulp had significant contents of tyramine (31.97 mg/kg), putrescine (20.65 mg/kg), and spermidine (6.32 mg/kg). The marolo pulp inhibited (p < 0.05) pre-neoplastic lesions induced by DMH administration at the all concentrations tested. These findings indicate that marolo pulp has a colon carcinogenesis chemopreventive effect, which could be due to, at least in parts, its antioxidant action associated with its phenolics and flavonoids content as well of spermidine.

Arctium lappa L. roots inhibit the intestinal inflammation of dietary obese rats through TLR4/NF-κB pathway

Long-term consumption of Arctium lappa L. roots can lead to weight loss. To explore the relationship between anti-obesity and anti-inflammation, the effects and mechanism of A. lappa L. root powder (ARP) on intestinal inflammation in obese rats were investigated. Dietary obese rats were successfully established by feeding a high-fat and high-sugar diet. The control group (n = 6) consumed a normal diet. The intestines were compared among the groups (each n = 6) with and without the administration of ARP (intragastric 7.5 g/kg·bw/d). Real-time quantitative reverse transcription-polymerase chain reaction and western blotting analysis revealed that ARP effectively inhibited the expression of pro-inflammatory and inflammatory cytokines in the colons of obese rats. These cytokines included interleukin (IL)-1β, IL-8, IL-6, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. The inhibition rates for all these cytokines exceeded 88 %. Moreover, ARP demonstrated the ability to down-regulate key genes involved in Toll-like receptor 4 (TLR4) complexes, namely Tlr4, myeloid differentiation protein-2 (Md2), and myeloid differentiation factor 88 (Myd88), along with downstream signaling molecules such as tumor necrosis factor receptor associated factor 6 (TRAF6) and nuclear factor-κB (NF-κB), with inhibition rates over 81 %. Additionally, ARP was observed to inhibit protein levels of TLR4, NF-κB, IL-1β, and TNF-α in the colons of obese rats, with inhibition rates of 65.6 ± 10.9 %, 84.4 ± 19.9 %, 80.8 ± 14.4 %, and 68.4 ± 17.5 %, respectively. This study confirmed the effectiveness of ARP in inhibiting intestinal inflammation through the blockade of the TLR4/NF-κB signaling pathway. It also suggested that ARP holds potential in improving intestinal health in the context of obesity, implying its possible application in the prevention and treatment of obesity and related metabolic diseases.

NGF/PI3K/TRPV1 pathway mediates the regulation of visceral pain by acupuncture at "Shangjuxu" (ST37) in irritable bowel syndrome rats with chronic visceral hyperalgesia.

To investigate the effect of manual acupuncture at "Shangjuxu"(ST37) on nerve growth factor(NGF)/phosphatidylinositol 3-kinase(PI3K)/transient receptor potential vanilloid 1(TRPV1) signaling pathway in rats with chronic visceral hyperalgesia of irritable bowel syndrome (IBS), so as to explore its underlying mechanism in treating IBS chronic visceral hyperalgesia. IBS chronic visceral hyperalgesia model was established by colorectal dilation stimulation for 2 weeks for SD pups at 8 d after birth, which were fed until 8-week age after the stimulation. Then the verified successfully modeled adult rats were randomly divided into model, Shangjuxu, and non-acupoint groups, with 6 rats in each group, and 6 unmodeled rats were selected as normal group. On the next day of model evaluation, rats in the Shangjuxu group received acupuncture at right ST37 while rats in the non-acupoint group received acupuncture at the non-meridian and non-acupoint point in the right hypochondrium, both for 15 min, with manual twisting of mild reinforcing and reducing performed for 30 s at an interval of 5 min, once a day, for a total of 7 d. Abdominal withdrawal reflex(AWR) score was used to evaluate the degree of chronic visceral pain in rats. Western blot and real-time fluorescence quantitative PCR were used to detect the colonic protein and mRNA expressions of NGF, tropomyosin receptor kinase A (TrkA), PI3K and TRPV1. The positive expressions of PI3K and TRPV1 proteins in the colon of rats were detected by immunohistochemistry method. Compared with the normal group, AWR scores corresponding to 4 pressure levels of 20, 40, 60 and 80 mm Hg, mRNA and protein expressions of NGF, TrkA, PI3K and TRPV1 in colon tissue, and positive expressions of PI3K and TRPV1 in colon tissue were significantly increased(P<0.05) in the model group. After intervention, compared with the model group, rats in the Shangjuxu group had reduced AWR scores corresponding to 4 pressure levels of 20, 40, 60 and 80 mm Hg, lower colonic mRNA and protein expressions of NGF, TrkA, PI3K and TRPV1, and decreased positive expressions of PI3K and TRPV1 in colon tissue(P<0.05), while there were no significant differences in the above indexes of the non-acupoint group. Manual acupuncture at ST37 can alleviate IBS chronic visceral hyperalgesia in rat and its analgesic effect may be related to regulating NGF/PI3K/TRPV1 signaling pathway.

Fecal metabolomics combined with metagenomics sequencing to analyze the antidepressant mechanism of Yueju Wan

BackgroundYueju Wan (YJW), defined in Danxi's Mastery of Medicine, has Qi-regulating and Qi-promoting effects. YJW has frequently been applied in the clinic for the treatment of depression. Substantial evidence has shown that depression is related to metabolic abnormalities of the gut microbiota, and traditional Chinese medicine (TCM) can treat depression by adjusting gut microbiota metabolism. The antidepressant effect of YJW is well established, but thus far, whether its mechanism of action is achieved by regulating the intestinal flora has not been elucidated. MethodsIn this study, chronic unpredictable mild stress (CUMS) along with isolated feeding created a rat depression model, and YJW was administered for intervention. Rats were put through behavioral tests to determine their level of depression, and ELISA was utilized for measuring the level of monoamine neurotransmitters (MNTs) in the hippocampus. Metagenomic gene sequencing analysis was used to study the effect of depression on the intestinal flora in rats and the regulatory mechanism of YJW on the intestinal flora. Furthermore, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) was utilized for fecal metabolomics studies to further reveal the antidepressant mechanism of YJW. The antidepressant mechanism of YJW was explored and further verified by Western blot analysis. ResultsDifferent doses of YJW improved the depressive state of rats and raised the levels of MNTs in the hippocampus. The results of metagenomic sequencing indicated that the YJW recovered the structure and diversity of the intestinal flora in depressed rats. Metabolomics revealed sustained changes in 21 metabolites after the treatment of YJW, suggesting that YJW can play an antidepressant role by improving abnormal metabolic pathways. The results of correlation analysis suggested that YJW might mediate Eubacterium, Oscillibacter, Roseburia, Romboutsia and Bacterium to regulate purine metabolism, tryptophan metabolism, primary bile acid biosynthesis, and glutamate metabolism and exert antidepressant effects. Western blot analysis showed that YJW reduced the content of IL-1β in the hippocampus, inhibited the activation of the NLRP3 inflammasome in the hippocampus of rats, and increased the content of ZO-1 in the colon of rats. ConclusionYJW can alleviate depressive symptoms in depressed rats, and its mechanism is connected to improving intestinal flora and regulating body metabolism.

OR35-01 Colonic Mitochondrial Dysfunction and Sub-acute Gastrointestinal Inflammation in Two Hyperandrogenemic Rodent Models of PCOS

Abstract Disclosure: N. Hoang: None. S. Rezq: None. J. Basnet: None. A.M. Huffman: None. K. Brooks: None. L.L. Yanes Cardozo: None. D.G. Romero: None. K.S. Edwards: None. Introduction: Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women during their reproductive years. Approximately 80% of PCOS women suffer from hyperandrogenemia. PCOS women often exhibited symptoms of irritable bowel syndrome (IBS) that is associated with sub-acute gastrointestinal (GI) inflammation. However, the underlying pathophysiology for the development of IBS is unknown. Mitochondrial dysfunction is associated with the development of inflammation and hyperandrogenemia can alter mitochondrial function. This study aims to investigate the mechanisms linking PCOS and mitochondrial dysfunction to the development of IBS symptoms. Methods: The hyperandrogenemic female (HAF) rodent models exhibit characteristics similar to PCOS women such as increased body weight, fat mass, and food intake. At 4 weeks of age, female rats received dihydrotestosterone (DHT, 7.5mg/90 days) pellets. At 3 weeks of age female mice were implanted with Silastic tubes filled with DHT (8mg) or vehicle. At 15 weeks of age, colon tissues were collected for histology (H&amp;E staining) and mitochondria isolation. Intact mitochondrial respiration, mitochondrial reactive oxygen species (mtROS), and complex IV activity, a marker for oxidative phosphorylation capacity, were measured using the Oroboros O2k-FluoRespirometer. Data was normalized to mitochondrial content using citrate synthase (CS) activity. Results: Histology from the colon of HAF rats showed an increase in immune cell infiltration and structural derangement. Both HAF rodent models showed an increase in GI inflammation and alterations to colon mitochondrial function. Complex I-driven respiration showed a significant (p&amp;lt;0.05) decrease (60%) in both rats and mice. Both rats and mice showed a significant (p&amp;lt;0.05) decrease (50%) in complex II-driven respiration. Quality of mitochondria is determined by the respiratory control ratio (RCR). A significant (p&amp;lt;0.05) decrease in RCR was observed for both rats (40%) and mice (20%). Both rats and mice showed a 2-fold increase in mtROS (p&amp;lt;0.05). Complex IV activity was significantly (p&amp;lt;0.05) decreased in both rats (3.91±0.97 vs. 5.22±1.13 nmol e-/CS activity) and mice (0.03±0.01 vs. 0.05±0.01 nmol e-/CS activity) compared to control. Conclusions: The observed colonic inflammation and associated mitochondrial dysfunction in both rodent models of PCOS suggests that mitochondrial dysfunction is involved in the development of IBS symptoms in PCOS. This study provides a better understanding of the role of mitochondria in the development of IBS with PCOS and an avenue for the development of strategies to re-establish normal mitochondrial function. This could provide options for preventive and therapeutic interventions for IBS where there are limited treatment options in PCOS women. Supported by NIH grants: P20PGM121334 Presentation Date: Sunday, June 18, 2023

Effect of Tangshen formula on the remodeling of small intestine and colon in Zucker diabetic fatty rats

Background and aimPrevious study have demonstrated that Tangshen Formula (TSF) could attenuate colonic histomorphological remodeling in the diabetic rat model induced by high fat diet plus low dosage streptozotocin (STZ). However, it is not clear whether TSF has same effect on small intestine and the effect on biomechanical properties of bowel. The aim of this study is to investigate the effect of TSF on histomorphological and biomechanical remodeling of small intestine and colon by using Zucker Diabetic Fatty (ZDF) Rat model. Materials and methodsZDF rats (obese fa/fa) with blood glucose higher than 11.7 mmol/L were divided into ZDF group (diabetic control group) and ZDF + TSF group (TSF treatment group), the later were intragastrically administered TSF. The ZDF rats (lean fa/+) were served as normal control (ZL) group. The rats in the ZL and ZDF groups were administered with saline. The experimental period covered from 8 weeks to 24 weeks. At the end of experiment, the ileal and colonic segments were studied in vitro. The histomorphometry and biomechanical parameters were measured. ResultsCompared with ZL group histomorphologically, the wet weight per unit length, wall thickness, wall area and fractions of total and type I and type III collagen in different layers for both ileum and colon increased in ZDF group. Those increasing parameters were partially inhibited in ZDF + TSF group. Compared with ZL group biomechanically, ZDF and ZDF + TSF groups had smaller opening angle and residual strain in ileum, and bigger opening angle and residual strain in colon. Whereas the wall became softer in circumferential direction and stiffer in longitudinal direction for both ileum and colon. However, no difference of biomechanical parameters was found between ZDF and ZDF + TSF groups. ConclusionThe histomorphological and biomechanical remodeling of ileum and colon were happened in ZDF rats （obese fa/fa）. TSF could partly attenuate ileal and colonic histomorphological remodeling rather than biomechanical remodeling.

Creation of a oblique colon valve: a new methods to wake up the stem cell of colon

Objective: To find out a similar and better methods to increase colon absorptive function. Methods: Oblique colon valves were created in colons of rats with the massive resection of the small bowels, and the rats were compared with group with traditional colon valves, and short bowel syndrome (SBS) group. The rats were observed for 30 weeks.Results:The rats in groups with colon valves were heavier than that in control group. And rats with oblique colon valves had less obstruction. Conclusions: Oblique colon valve was a better methods to increase the absorptive function of colon.

Resveratrol alleviates perinatal methylmercury-induced neurobehavioral impairments by modulating the gut microbiota composition and neurotransmitter disturbances.

Methylmercury (MeHg), a potent neurotoxic substance, causes adverse health outcomes by modulating metabolites through altered gut microbiota patterns. Among the many metabolites, neurotransmitters play a particularly important role in the nervous system and behavior. Resveratrol (RSV) has been investigated as an antiaging, antioxidant, anti-inflammatory, and neuroprotective agent. The current study evaluated that RSV is protective of neurodevelopmental toxicity induced by MeHg and further explored the underlying mechanisms. Sprague-Dawley rats were treated with 1.2 mg/kg/d of MeHg, and the effects were evaluated after supplementation with RSV (20 mg/kg/d). The results indicated that MeHg had adverse effects on early neurodevelopmental indicators in the experimental group offspring as compared to control pups. Interestingly, RSV significantly improved the MeHg-induced delays in the neurobehavioral reflexes and reduced the total mercury (THg) concentration in the colons of the offspring rats. In agreement, RSV administration improved the gut microbiota diversity and structure by increasing the abundance of probiotics and upregulating the expression of tight junction proteins. It also ameliorated the MeHg-induced abnormalities in the expression profiles of neurotransmitters. Furthermore, eight key bacteria that were strongly linked with the neurotransmitters and neuroreflex parameters were identified. Taken together, these results demonstrate that RSV treatment effectively reduces the occurrence of neurodevelopmental toxicity caused by perinatal MeHg exposure by modulating the intestinal flora and neurotransmitter metabolism. These findings provide a new therapeutic approach for treating MeHg-induced neurotoxicity. The cover image is based on the Research Article Resveratrol alleviates perinatal methylmercury-induced neurobehavioral impairments by modulating the gut microbiota composition and neurotransmitter disturbances by Fang Chen et al., https://doi.org/10.1002/tox.23973.

Antioxidant potential of ethanol extract of Annona muricata leaves and its inhibitory effect on lipid peroxidation in 1,2-dimethylhydrazine induced colon carcinogenesis

Annona muricata, as it is scientifically called but known in most parts of Nigeria as soursop. A fruit tree with various therapeutic uses, the plant belongs to the family of Annonaceae and has several medicinal properties. The medicinal properties of Annona muricata are well known, and they can be used to treat a variety of illnesses and conditions. Effects of ethanol extract of Annona muricata leaves (EEAML) on the enzymatic antioxidants of the kidney and colon in Wistar rats induced with 1, 2 Dimethylhydrazine (DMH) at 25 mg/kg bodyweight s.c. were investigated in this study. Thirty-six male Wistar rats weighing 110–170g were acclimated for two weeks and randomized into six groups (six per group). Group A (control), Group B (extract; 120 mg/kg body weight of ethanolic extract of A. muricata), Group C (DMH only), Group D (DMH + EXTRACT), Group E (pretreatment), and Group F (posttreatment). The extract was administered daily via oral gavage, while the DMH was given subcutaneously at a dosage of 25 mg/kg bodyweight. This study reveals the carcinogenic effect of DMH induced oxidative stress were ameliorated by the administration of this leaf extract of EEAML at a dose of 120mg/kg b.w. The colon and kidney homogenates of rats administered EEAML (co-treated, pretreatment and post- treatment) showed increased enzymatic antioxidant; glutathione peroxidase, catalase activities and SOD activities. But a reduction in malondialdehyde levels was observed. These findings validate the use of Annona muricata in traditional medicine by showing that the ethanolic extract of the leaves can reduce DMH-induced oxidative stress and alter the enzymatic antioxidant profile in colon carcinogenesis.

The non-conventional edible plant foroba (Parkia biglobosa) has anti-obesity effect, improves lipid peroxidation and reverses colon and hippocampal lesions in healthy and obese rats

We evaluated the Parkia biglobosa pulp (PB) effects on food intake, body composition and oxidative and inflammatory parameters related to gut and brain of rats. A total of 32 male Wistar rats were randomised into four groups: healthy (HG), obese (OG); and healthy (HPB) and obese (OPB) groups with PB (400 mg/kg body weight). The rats consumed a control or cafeteria diet for 16 weeks. Body weight, food intake, bacteria count, organic acids in faeces were quantified. NF-κB and oxidative parameters were evaluated in the colon and hippocampus. PB contains fibres, 3,4-dihydroxybenzoic acid, catechin, and myricetin. PB treatment decreased fat mass and energy intake; increased the count of lactic acid bacteria and faecal organic acids, improved lipid peroxidation and reversed colon and hippocampal lesions, with reduction the NF-κB in OPB colon. PB has anti-obesity effect with potential to modulation gut-brain axis, mainly via blocking the activation of NF-κB.

Estrogen increases the expression of BKCa and impairs the contraction of colon smooth muscle via upregulation of sphingosine kinase 1.

Estrogen (E2) may impair the contraction of colonic smooth muscle (SM) leading to constipation. Large conductance Ca2+ -activated K+ channels (BKCa ) are widely expressed in the smooth muscle cells (SMCs) contributing to hyperpolarization and relaxation of SMCs. Sphingosine kinase 1 (SphK1) is known to influence the expression of BKCa . We aimed to elucidate the potential underlying molecular mechanism of BKCa and SphK1 that may influence E2-induced colonic dysmotility. In ovariectomized rats, SMcontraction and expression of BKCa , SphK1, sphingosine-1-phosphate receptor (S1PR) were analyzed after the treatment with vehicle, BSA-E2, E2, and E2receptor antagonist. The role of BKCa , SphK1, and S1PR in E2-induced SMdysmotility was investigated in rat colonic SMCs. The effect of SphK1 on SMcontraction as well as on the expression of BKCa and S1PR was analyzed in SphK1 knock-out mutant mice and wild-type (WT) mice treated with or without E2. The E2-treated group exhibited a weak contraction of colonic SMand a delayed colonic transit. The treatment with E2 significantly upregulated the expression of BKCa , SphK1, S1PR1, and S1PR2, but not S1PR3, in colon SMand SMCs. Inhibition of BKCa , SphK1, S1PR1, and S1PR2 expression attenuated the effect of E2 on Ca2+ mobilization in rat colon SMCs. WTmice treated with E2 showed impaired gastrointestinal motility and enhanced expression of BKCa , S1PR1, and S1PR2 compared with those without E2 treatment. Conversely, in SphK1 knock-out mice treated with E2, these effects were partially reversed. E2 increased the release of S1P which in turn could have activated S1PR1 and S1PR2. Loss of SphK1 attenuated the effect of E2 on the upregulation of S1PR1 and S1PR2 expression. These findings indicated that E2 impaired the contraction of colon SMthrough activation of BKCa via the upregulation of SphK1 and the release of S1P. In the E2-induced BKCa upregulation, S1PR1 and S1PR2 might also be involved. These results may provide further insights into a therapeutic target and optional treatment approaches for patients with constipation.

Effects of moxibustion at "Tianshu"（ST25） and "Shangjuxu" （ST37） on colonic metabolites and inflammatory factors in rats with Crohn's disease

To observe the effects of moxibustion at "Tianshu"（ST25） and "Shangjuxu"（ST37） on the colonic metabolites and inflammatory factors in rats with Crohn's disease（CD）, so as to explore the mechanisms of moxibustion in protecting colon of CD rats based on metabolomics. Twelve rats were first randomly selected from 36 male SD rats as a normal group（NG）. The CD model was induced by 2, 4, 6 trinitrobenzene sulfonic acid（TNBS） enema on the rest 24 rats. After successful modeling, rats were randomly divided into model（TNBS） and moxibustion（TNBS+MOX） groups（n=10 rats/group）. Moxibustion was applied at bilateral ST25 and ST37 for 30 min, once daily for 7 consecutive days in the TNBS+MOX group, while rats in the NG and TNBS groups did not receive any interventions. Body weight of rats was recorded and disease activity index（DAI） was assessed during the experiment. After interventions, HE staining was performed to observe pathological damage of colon. Serum levels of inflammatory factors were measured by ELISA. NMR hydrogen spectroscopy was used to detect colonic metabolites of each group, and orthogonal partial least squares discriminant analysis（OPLS-DA） was used to screen differential colonic metabolites between groups, followed by pathway analysis using MetaboAnalyst 5.0 platform. After modeling, compared with the NG group, the body weight of the rats in the TNBS group was significantly decreased（P<0.05）, the DAI score was increased （P<0.05）, the colon had obvious inflammatory damage and the pathological injury index was increased（P<0.05）, and levels of serum tumor necrosis factor-α（TNF-α）, interleukin（IL）-1β and interferon-γ（IFN-γ） were significantly increased（P<0.05）. After moxibustion intervention, compared with the TNBS group, the body weight was significantly increased（P<0.05）, while the levels of serum TNF-α, IL-1β, IFN-γ, and DAI score of the rats in the TNBS+MOX group were significantly decreased（P<0.05）, with alleviated colonic inflammatory injury detected by HE staining. Compared with the NG group, the relative expressions of colonic hypoxanthine, betaine, creatine, inositol, taurine, uracil, and methanol of the TNBS group were decreased（P<0.05）, while the relative expressions of histidine, leucine, proline, lysine, isoleucine, phenylalanine, tyrosine, propionic acid, and valine were increased（P<0.05） in the TNBS group, among which, relative expressions of hypoxanthine, leucine, lysine, isoleucine, betaine, tyrosine, and taurine were reversed in the TNBS+MOX group relevant to the TNBS group, mainly involving phenylalanine, tyrosine and tryptophan biosynthesis, and taurine and subtaurine metabolism pathway. The mechanism of moxibustion at ST25 and ST37 for CD may be related to improving colon metabolic disorder state by regulating multiple metabolic metabolites and metabolic pathways, and reducing the level of inflammatory factors, so as to maintain intestinal immune homeostasis.

Effects of moxibustion at "Tianshu"（ST25） and "Shangjuxu" （ST37） on colonic metabolites and inflammatory factors in rats with Crohn's disease

To observe the effects of moxibustion at "Tianshu"（ST25） and "Shangjuxu"（ST37） on the colonic metabolites and inflammatory factors in rats with Crohn's disease（CD）, so as to explore the mechanisms of moxibustion in protecting colon of CD rats based on metabolomics. Twelve rats were first randomly selected from 36 male SD rats as a normal group（NG）. The CD model was induced by 2, 4, 6 trinitrobenzene sulfonic acid（TNBS） enema on the rest 24 rats. After successful modeling, rats were randomly divided into model（TNBS） and moxibustion（TNBS+MOX） groups（n=10 rats/group）. Moxibustion was applied at bilateral ST25 and ST37 for 30 min, once daily for 7 consecutive days in the TNBS+MOX group, while rats in the NG and TNBS groups did not receive any interventions. Body weight of rats was recorded and disease activity index（DAI） was assessed during the experiment. After interventions, HE staining was performed to observe pathological damage of colon. Serum levels of inflammatory factors were measured by ELISA. NMR hydrogen spectroscopy was used to detect colonic metabolites of each group, and orthogonal partial least squares discriminant analysis（OPLS-DA） was used to screen differential colonic metabolites between groups, followed by pathway analysis using MetaboAnalyst 5.0 platform. After modeling, compared with the NG group, the body weight of the rats in the TNBS group was significantly decreased（P<0.05）, the DAI score was increased （P<0.05）, the colon had obvious inflammatory damage and the pathological injury index was increased（P<0.05）, and levels of serum tumor necrosis factor-α（TNF-α）, interleukin（IL）-1β and interferon-γ（IFN-γ） were significantly increased（P<0.05）. After moxibustion intervention, compared with the TNBS group, the body weight was significantly increased（P<0.05）, while the levels of serum TNF-α, IL-1β, IFN-γ, and DAI score of the rats in the TNBS+MOX group were significantly decreased（P<0.05）, with alleviated colonic inflammatory injury detected by HE staining. Compared with the NG group, the relative expressions of colonic hypoxanthine, betaine, creatine, inositol, taurine, uracil, and methanol of the TNBS group were decreased（P<0.05）, while the relative expressions of histidine, leucine, proline, lysine, isoleucine, phenylalanine, tyrosine, propionic acid, and valine were increased（P<0.05） in the TNBS group, among which, relative expressions of hypoxanthine, leucine, lysine, isoleucine, betaine, tyrosine, and taurine were reversed in the TNBS+MOX group relevant to the TNBS group, mainly involving phenylalanine, tyrosine and tryptophan biosynthesis, and taurine and subtaurine metabolism pathway. The mechanism of moxibustion at ST25 and ST37 for CD may be related to improving colon metabolic disorder state by regulating multiple metabolic metabolites and metabolic pathways, and reducing the level of inflammatory factors, so as to maintain intestinal immune homeostasis.

Antioxidant potential of acerola by-product along the enterohepatic axis of rats fed a high-fat diet

Acerola (Malpighia emarginata DC) by-product (ABP) has bioactive compounds that can provide antioxidant and hypolipidemic effects in vivo. In this study we aimed to evaluate the antioxidant potential of ABP on oxidative damage along the enterohepatic axis of rats fed a high-fat diet for 7 weeks. In addition, we analysed the phenolic compound profile in the enterohepatic axis, and the lipid accumulation in the liver, colon and liver tissue structure of high-fat diet-fed rats treated with fenofibrate drug (100 mg/kg) or ABP (400 mg/kg) via orogastric administration in the 4th to 7th weeks of the experiment. ABP had increased antioxidant potential in vitro and presented ascorbic acid (2022.06 μg/g), carotenoid (2.63 μg/g), and total phenolic compound (5366.44 μg/g) contents. The high-fat diet-fed rats that received ABP (compared to fenofibrate treatment) presented a non-significant reduction of 9.87% in guanine oxidation product, lower relative liver weight, degree of hepatic steatosis, and aspartate aminotransferase level in their blood. ABP also provided high-fat diet-fed rats: an increased amount of total phenolic compounds in caecal digesta (946.42 µg/g), faeces (3299.07 µg/g), colon (256.15 µg/g) and hepatic tissues (454.80 µg/g); higher total antioxidant capacity in plasma and colon; and lower lipid peroxidation in plasma, colonic and hepatic tissues. The results point to the potential antioxidant activity of ABP against oxidative damage along the enterohepatic axis caused by high-fat diet intake. The ABP had a greater protective effect on the healthy liver compared to fenofibrate treatment due to its bioactive compound content.

Exposure to okadaic acid could disrupt the colonic microenvironment in rats

Okadaic acid (OA) is one of the most prevalent marine phycotoxin with complex toxicity, which can lead to toxic symptoms such as diarrhea, vomiting, nausea, abdominal pain, and gastrointestinal discomfort. Studies have shown that the main affected tissue of OA is digestive tract. However, its toxic mechanism is not yet fully understood. In this study, we investigated the changes that occurred in the epithelial microenvironment following OA exposure, including the epithelial barrier and gut bacteria. We found that impaired epithelial cell junctions, mucus layer destruction, cytoskeletal remodeling, and increased bacterial invasion occurred in colon of rats after OA exposure. At the same time, the gut bacteria decreased in the abundance of beneficial bacteria and increased in the abundance of pathogenic bacteria, and there was a significant negative correlation between the abundance of pathogenic bacteria represented by Escherichia/Shigella and animal body weight. Metagenomic analysis inferred that Escherichia coli and Shigella spp. in Escherichia/Shigella may be involved in the process of cytoskeletal remodeling and mucosal layer damage caused by OA. Although more evidence is needed, our results suggest that opportunistic pathogens may be involved in the complex toxicity of OA during OA-induced epithelial barrier damage.

Proanthocyanidin and sodium butyrate synergistically modulate rat colon carcinogenesis by scavenging free radicals and regulating the COX-2 and APC pathways

BackgroundThe purpose of this study was to explore the effects of sodium butyrate (NaB), grape seed proanthocyanidin extract (GSPE), or their combination against dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) formation, which is a proxy for colon carcinogenesis in the rat colon.ResultsAfter inducing colon cancer, all treatments markedly decreased the overall numbers of ACF, with the NaB–GSPE combination eliciting the most pronounced reduction. All the treatments significantly inhibited cell proliferation as indicated by the lower percentages of Ki67-positive cells in the colonic mucosa. Also, caspase-3-immunolabeled cells were found to be significantly increased after all treatments, indicating more apoptotic activity in the initiated colonocytes. Further, the treatments significantly modulated the levels of antioxidant biomarkers, including malondialdehyde, superoxide dismutase, reduced glutathione, and total antioxidant capacity, suggesting a potently induced antioxidant activity, especially after the combination treatment. All treatments, especially the combination, dramatically downregulated the expression of COX-2 and APC, both of which are directly linked to colon cancer.ConclusionsNaB and GSPE exert potent anti-carcinogenic effects, both alone but more effectively in combination, in a rat colon cancer model. They could be important for colon cancer treatment and for adjuvant therapy in humans.

Oral administration of Bifidobacterium longum WHH2270 ameliorates type 2 diabetes in rats.

Accumulating evidence suggests that specific probiotic strains exert hypoglycemic effects on type 2 diabetes mellitus (T2DM), and probiotic strains within Bifidobacterium exhibit potential beneficial effects on T2DM. In this study, α-glucosidase inhibitory activities of 14 Bifidobacterium strains were assessed in vitro. The hypoglycemic effects of Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity (42.03%) were then investigated in a high-fat diet/streptozotocin-induced T2DM rat model. Oral administration of WHH2270 (4 × 109 CFU/kg/day) for 8weeks significantly reversed the reduced body weight and ameliorated the levels of fasting blood glucose, serum triglyceride, serum total cholesterol, glucose tolerance, and insulin resistance in T2DM rats. Using 16S rRNA high-throughput sequencing of feces, WHH2270 was revealed to reshape the gut microbiome composition by increasing the abundances of Lactobacillus and Bifidobacterium and decreasing the abundances of UCG_005, Clostridium, and Faecalibacterium in T2DM rats. Besides, the fecal levels of short-chain fatty acids (SCFAs) including acetate, propionate, and butyrate were also elevated after WHH2270 administration. Moreover, the gene expressions of SCFA receptors FFAR2 and FFAR3 in the colon and pancreas of T2DM rats were restored by WHH2270 administration, accompanied by increased levels of serum acetate. In summary, these results provide evidence that WHH2270 has the potential to improve T2DM symptoms by alleviating hyperglycemia, which was associated with changes in the gut microbiome composition and SCFA production. PRACTICAL APPLICATION: Bifidobacterium longum WHH2270 with high α-glucosidase inhibitory activity may serve as a promising hypoglycemic agent for the treatment of T2DM.

Exclusive Enteral Nutrition Alleviates Th17-Mediated Inflammation via Eliminating Mechanical Stress-Induced Th17-Polarizing Cytokines in Crohn's-like Colitis.

Exclusive enteral nutrition (EEN) with a liquid diet is the only established dietary treatment for Crohn's' disease (CD). However, the mechanism of action of EEN in CD is unclear. T helper 17 (Th17) immune response plays a critical role in CD. We hypothesized that EEN alleviates Th17 response by eliminating mechanical stress-induced expression of Th17-polarizing cytokines. A rat model of Crohn's-like colitis was established by intracolonic instillation of TNBS (65 mg/kg in 250 µL of 40% ethanol). Control rats were treated with saline. We characterized immunophenotypes and molecular changes of the colon in control and colitis rats with and without EEN treatment. Th17 differentiation was determined using coculture assays. TNBS instillation induced transmural inflammation with stenosis in the inflammation site and a marked increase of Th17-polarizing cytokines interleukin (IL)-6 and osteopontin and the Th17 cell population in the mechanically distended preinflammation site (P-site). EEN treatment eliminated mechanical distention and the increase of IL-6, osteopontin, and Th17 response in the P-site. IL-6 and osteopontin expression was found mainly in the muscularis externa. Mechanical stretch of colonic smooth muscle cells in vitro induced a robust increase of IL-6 and osteopontin. When naïve T cells were cultured with conditioned media from the P-site tissue or stretched cells, Th17 differentiation was significantly increased. Inhibition of IL-6, but not deletion of osteopontin, blocked the increase of Th17 differentiation. Mechanical stress induces Th17-polarizing cytokines in the colon. EEN attenuates Th17 immune response by eliminating mechanical stress-induced IL-6 in Crohn's-like colitis.

2,4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone from Cleistocalyx nervosum var. paniala seeds attenuated the early stage of diethylnitrosamine and 1,2-dimethylhydrazine-induced colorectal carcinogenesis

BackgroundDichloromethane extract of Cleistocalyx nervosum var. paniala seeds exhibited an anticarcinogenicity against chemically-induced the early stages of carcinogenesis in rats. This study aimed to identify anticarcinogenic compounds from C. nervosum seed extract (CSE). MethodsSalmonella mutation assay was performed to determine mutagenicity and antimutagenicity of partially purified and purified compounds of CSE. The anticarcinogenic enzyme-inducing activity was measured in Hepa1c1c7. Moreover, the anticancer potency was examined on various human cancer cell lines. The anticarcinogenicity of DMC was investigated using dual-organ carcinogenicity model. The number of preneoplastic lesions was evaluated in the liver and colon. The inhibitory mechanisms of DMC on liver- and colorectal carcinogenesis were investigated. ResultsSix partially purified fractions (MK1 – MK6) and purified compounds, including 2,4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) and hariganetin, were obtained from CSE. Among these fractions, MK4 and DMC presented the greatest antimutagenicity against indirect mutagens in bacterial model. Moreover, MK5 possessed an effective anticarcinogenic enzyme inducer in Hepa1c1c7. The MK4, DMC and CSE showed greater anticancer activity on all cell lines and exhibited the most effective toxicity on colon cancer cells. Furthermore, DMC inhibited the formation of colonic preneoplastic lesions in carcinogens-treated rats. It reduced PCNA-positive cells and frequency of BCAC in rat colon. DMC also enhanced the detoxifying enzyme, GST, in rat livers. ConclusionsDMC obtained from CSE may be a promising cancer chemopreventive compound of colorectal cancer process in rats. It could increase detoxifying enzymes and suppress the cell proliferation process resulting in prevention of post-initiation stage of colorectal carcinogenesis.

Moringa oleifera Lam. Leaf improves constipation of rats induced by low-fiber-diet: A proteomics study

Ethnopharmacological relevanceThe leaf of Moringa oleifera Lam., a medicinal and edible herb for thousands of years in Ayurveda, is used as Pancha (na) karma (purgative) during and after the body cleansing process, to treat constipation, reduce cholesterol and body weight. Aim of studyThe aim was to investigate the diarrhea effects and possible mechanism of M. oleifera leaves in constipation rats. Materials and methodsThe hot water extract of M. oleifera leaves (WEMOL) was prepared and analyzed using LC-20AT HPLC system. The constipated rat model was induced by feeding with low fiber diet for 21 days. After oral administration of WEMOL for 7 days, the excretion parameter analysis, gastro-intestinal propulsion, histological analysis by HE and Alcian blue staining, and gastrointestinal hormone in rat's digestive tract through ELISA were used to evaluate the laxative effect of WEMOL. Label-free quantitation (LFQ) with LC-MS/MS, bioinformatics and Western blot were used to discover and verify the signal pathways and key proteins of WEMOL related to diarrhea. ResultsThe contents of isoquercitrin and astragalin were 2.7 mg/g and 1.7 mg/g, respectively in WEMOL. The stool number, weight, and water content of constipation rats were significantly reduced, indicating model had been established successfully. WEMOL (1.25 and 2.5 g/kg) increased water content of feces and the levels of Gas, MTL, NPY in gastric antrum and VIP, SP in colon of constipation rats, improved the muscle layer thickness and mucin secretion of colon. The proteomics revealed a total of 1731 differential proteins and 9 signaling pathways, WEMOL increased the expression of Vamp2, Gnai3, and Prkacb. ConclusionsThe laxative mechanism of WEMOL maybe modulate the signaling pathways mediated by 5-HT and Ach receptors, related to gastrointestinal motility and intestinal fluid secretion. It can be considered as the scientific connotation of Pancha (na) karma of M. oleifera leaves in ayurveda.