Rhus chinensis Mill. fruits prevent necrotizing enterocolitis in rat pups via regulating the expressions of key proteins involved in multiple signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Based on ancient records and previous studies, many parts of Rhus chinensis Mill., including the fruits, have good preventive and therapeutic effects on inflammation, malaria, diarrhea, and gastrointestinal diseases. Rhus plants and Galla chinensis produced from R. chinensis leaves can also prevent or cure intestinal diseases. However, the preventive effect and molecular mechanisms of R. chinensis fruits on necrotizing enterocolitis (NEC) have not been comprehensively studied.

AIM OF THE STUDY

This article aims to estimate the effect of the 80% ethanol extract of R. chinensis fruits (RM) on alleviating NEC in rat pups and illustrate the potential molecular mechanisms.

MATERIALS AND METHODS

Rat pups were subjected to formula feeding, intermittent hypoxic, and cold stresses to establish the NEC model. The preventive effects of RM on NEC were evaluated through survival rate; clinical sickness index; macroscopic conditions; histopathology; and expression levels of inflammatory markers (i.e., tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6]), oxidative stress indicators (i.e., total antioxidant status [TAS], total oxidant status [TOS], superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], myeloperoxidase [MPO], malondialdehyde [MDA]), and tight junction proteins (i.e., Zonula Occludens 1 [ZO-1], Occludin). Moreover, the expression levels of several key proteins involved in oxidative stress (i.e., nuclear factor erythroid 2-related factor 2 [Nrf2], NAD(P)H-quinone oxidoreductase-1 [NQO1]), inflammation (i.e., Toll-like receptor 4 [TLR4], phosphorylated-nuclear factor kappa-B [p-NF-κB], inducible nitric oxide synthase [iNOS]), and apoptosis (i.e., cleaved cysteinyl aspartate specific proteinase-3 [cleaved Caspase-3], Bcl-2-associated X [Bax], B-cell lymphoma-2 [Bcl-2]) in intestinal tissues were analyzed to clarify the molecular mechanisms.

RESULTS

The extract particularly high doses (400 mg RM/kg body weight) could remarkably reduce the mortality and clinical sickness score and improve the macroscopic condition and histopathological injury of the intestine in NEC pups. After RM administration, the levels of TOS, TNF-α, IL-6, MPO, and MDA in the bowel tissue decreased, whereas the levels of TAS, SOD, and GSH-Px were significantly enhanced. The expression levels of ZO-1 and Occludin proteins were dramatically augmented in RM-treated groups to maintain intestinal barrier integrity. Further analyses revealed that RM might prevent NEC pups by improving some pivotal proteins involved in oxidative stress, inflammation, and apoptosis of enterocytes, namely, by down-regulating the levels of TLR4, p-NF-κB, iNOS, cleaved Caspase-3, and Bax and up-regulating the levels of Bcl-2, NQO1, and Nrf2.

CONCLUSIONS

The RM prevented the intestinal inflammation and damage caused by NEC by regulating the expression of several pivotal proteins involved in oxidative stress, inflammation, and apoptosis. This study might provide a scientific basis for R. chinensis fruits as a traditional herbal medicine to prevent and/or alleviate NEC.

Consumption of Butylated Starch Alleviates the Chronic Restraint Stress-Induced Neurobehavioral and Gut Barrier Deficits Through Reshaping the Gut Microbiota

The beneficial effect of short-chain fatty acids (SCFAs) on host health has been well recognized based on the booming knowledge from gut microbiome research. The role of SCFA in influencing psychological function is highlighted in recent years but has not been fully elucidated. In this study, the SCFA-acylated starches were used to accomplish a sizeable intestine-targeted release of the SCFAs, and the neurobehavioral, immunological, and microbial effects were further investigated. Acetylated-, butylated-, and isobutylated-starch could attenuate the depression-like behaviors and excessive corticosterone production in chronically stressed mice. Butylated- starch significantly reduced the colonic permeability via increasing the tight junction proteins (including ZO-1, Claudin, and Occludin) gene expression and reduced the level of the inflammatory cytokines (including IL-1β and IL-6). The butylated starch's neurological and immunological benefits may be derived from the gut microbiome modifications, including normalizing the abundance of certain beneficial microbes (Odoribacter and Oscillibacter) and metabolomic pathways (Tryptophan synthesis and Inositol degradation). The present findings further validate the brain-beneficial effect of butyrate and offer novel guidance for developing novel food or dietary supplements for improving mental health.

Chemical composition and anti-inflammatory activity of n-butanol extract of Piper sarmentosum Roxb. In the intestinal porcine epithelial cells (IPEC-J2)

ETHNOPHARMACOLOGICAL RELEVANCE

Piper sarmentosum Roxb. (PS) is a terrestrial herb primarily distributed in tropical and subtropical regions of Asia. It is widely used in folk medicine in certain countries of Southeast Asia for the treatment of fever, toothache, coughing and pleurisy, which showed the anti-inflammatory activity of PS.

AIM OF THE STUDY

This study aimed to investigate the chemical constituents and the molecular mechanism and related metabolic pathway by which n-butanol extract of PS (PSE-NB) exerts its anti-inflammatory effects.

MATERIALS AND METHODS

Chemical constituents of PSE-NB was analyzed using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique. Anti-inflammatory effects of PSE-NB were investigated in lipopolysaccharide (LPS)-induced IPEC-J2 cells.

RESULTS

In total, 218 compounds, including 94 alkaloids and 26 phenolics were tentatively identified, which indicating alkaloids and phenolics were the main constituents of PSE-NB. In addition, the current cell experiment in vitro showed that PSE-NB (10-500 μg/mL) pre-treatment before LPS stimulation significantly decreased mRNA expression of IL-1β, IL-6 and TNF-α in IPEC-J2 cells compared with LPS treatment (p < 0.05). PSE-NB improved mRNA expression of tight junction proteins (ZO-1 and Occludin) and NHE3, which were reduced by LPS stimulation (p < 0.05). Moreover, PSE-NB (10 μg/mL) alleviated LPS-induced protein expression of p65 and p-p65 (p < 0.05), and reduced p65 translocation into the nucleus induced by LPS. At the same time, metabolic pathway analysis indicated that PSE-NB exerts anti-inflammatory effects mainly via augmentation of methionine metabolism in IPEC-J2 cells.

CONCLUSIONS

Taken together, the results suggested that alkaloids and phenolics were the main constituents in PSE-NB. PSE-NB might attenuate LPS-induced inflammatory responses in IPEC-J2 cells by regulating NF-κB signaling pathway and intracellular metabolic pattern.

The dynamic process of dietary soybean β-conglycinin in digestion, absorption, and metabolism among different intestinal segments in grass carp (Ctenopharyngodon idella)

The present study aimed to investigate the dynamic process of soybean β-conglycinin in digestion, absorption, and metabolism in the intestine of grass carp (Ctenopharyngodon idella). Fish fed with 80 g β-conglycinin/kg diet for 7 weeks, the intestinal digestive enzyme was extracted to hydrolyze β-conglycinin in vitro, the free amino acid and its metabolism product contents in intestinal segments were analyzed. The present study first found that β-conglycinin cannot be thoroughly digested by fish intestine digestive enzyme and produces new products (about 60- and 55-kDa polypeptides). The indigestible β-conglycinin further caused the free amino acid imbalance, especially caused free essential amino acid deficiency in the proximal intestine but excess in the distal intestine. Moreover, these results might be partly associated with the effect of β-conglycinin in amino acid transporters and tight junction-regulated paracellular pathway. Finally, dietary β-conglycinin increased the content of amino acid catabolism by-product ammonia while decreased the amino acid anabolism product carnosine content in the proximal intestine and distal intestine. Thus, the current study first and systemically explored the dynamic process of β-conglycinin in digestion, absorption, and metabolism, which further supported our previous study that dietary β-conglycinin suppressed fish growth and caused intestine injure.

Acrolein Disrupts Tight Junction Proteins and Causes Endoplasmic Reticulum Stress-Mediated Epithelial Cell Death Leading to Intestinal Barrier Dysfunction and Permeability

Increasing evidence suggests that environmental and dietary factors can affect intestinal epithelial integrity leading to gut permeability and bacterial translocation. Intestinal barrier dysfunction is a pathogenic process associated with many chronic disorders. Acrolein is an environmental and dietary pollutant and a lipid-derived endogenous metabolite. The impact of acrolein on the intestine has not been investigated before and is evaluated in this study, both in vitro and in vivo. Our data demonstrate that oral acrolein exposure in mice caused damage to the intestinal epithelial barrier, resulting in increased permeability and subsequently translocation of bacterial endotoxin-lipopolysaccharide into the blood. Similar results were seen in vitro using established Caco-2 cell monolayers wherein acrolein decreased barrier function and increased permeability. Acrolein also caused the down-regulation and/or redistribution of three representative tight junction proteins (ie, zonula occludens-1, Occludin, Claudin-1) that critically regulate epithelial paracellular permeability. In addition, acrolein induced endoplasmic reticulum stress-mediated death of epithelial cells, which is an important mechanism contributing to intestinal barrier damage/dysfunction, and gut permeability. Overall, we demonstrate that exposure to acrolein affects the intestinal epithelium by decrease/redistribution of tight junction proteins and endoplasmic reticulum stress-mediated epithelial cell death, thereby resulting in loss of barrier integrity and function. Our findings highlight the adverse consequences of environmental and dietary pollutants on intestinal barrier integrity/function with relevance to gut permeability and the development of disease.

Effects of cello-oligosaccharide on intestinal microbiota and epithelial barrier function of weanling pigs

A total of 144 piglets (Duroc × Landrace × Yorkshire; average initial weight of 6.13 kg weaned at 21 ± 1 d age) were allotted to 4 treatments for 2 wk, each of which had 6 pens with 6 pigs per pen. After the feeding experiment, 6 pigs per treatment were slaughtered to investigate the effects of cello-oligosaccharide (COS) on intestinal microbiota and epithelial barrier function. The COS was added to the basal diet at 0, 1.5, 3.0, and 4.5 g/kg diet at the expense of corn, respectively. Plasma -lactate, diamine oxidase (DAO), and the Ussing chamber technique were used to determine the intestinal barrier function. 16S rRNA-based methods were used for intestinal microbiota analysis. The results showed that incremental levels of COS had no effect ( > 0.05) on growth performance. Incremental levels of COS increased lactobacilli in jejunal and colonic contents ( < 0.05); decreased in jejunal contents ( < 0.05) and and in colonic contents ( < 0.05); reduced plasma DAO (linear, = 0.013, and quadratic, = 0.037); increased jejunal mucosa DAO (linear, = 0.003, and quadratic, = 0.008); decreased fluorescein isothiocyanate dextran 4 kDa flux of jejunum and colon ( < 0.05); and increased transepithelial electrical resistance (TER) in colon ( < 0.05), claudin-1 protein expression in jejunal mucosa (linear, = 0.001, and quadratic, = 0.003), and protein expressions of claudin-1 and zonula occludens-1 (ZO-1) in colonic mucosa linearly ( = 0.001 and = 0.001, respectively) and quadratically ( = 0.001 and = 0.002, respectively). The results indicated that the improved microbial ecosystem in the presence of COS might contribute to improvement in intestinal barrier function and tight junction proteins. Results also showed that the appropriate dietary COS supplementation level was 3.0 g/kg in weaned pig diets under our trial conditions.

Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-β1, ERK1/2, and Akt in piglets after acetic acid challenge

The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P < 0.05) ADG, ADFI, and transepithelial electrical resistance and decreased (P < 0.05) fecal scores, crypt depth, and fluorescein isothiocyanate-dextran 4 kDa (FD4) influx as compared with ACA group. Moreover, DS-ZnO increased (P < 0.05) occludin, claudin-1, and zonula occluden-1 expressions; reduced (P < 0.05) caspase-9 and caspase-3 activity and Bax expression; and improved (P < 0.05) Bcl2, XIAP, and PCNA expression. Diosmectite-zinc oxide composite supplementation also increased (P < 0.05) TGF-β1 expression and ERK1/2 and Akt activation. These results suggest that DS-ZnO attenuates the acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-β1 and ERK1/2 and Akt signaling pathway.

Oral administration of putrescine and proline during the suckling period improves epithelial restitution after early weaning in piglets

Polyamines are necessary for normal integrity and the restitution after injury of the gastrointestinal epithelium. The objective of this study was to investigate the effects of oral administration of putrescine and proline during the suckling period on epithelial restitution after early weaning in piglets. Eighteen neonatal piglets (Duroc × Landrace × Large Yorkshire) from 3 litters (6 piglets per litter) were assigned to 3 groups, representing oral administration with an equal volume of saline (control), putrescine (5 mg/kg BW), and proline (25 mg/kg BW) twice daily from d 1 to weaning at 14 d of age. Plasma and intestinal samples were obtained 3 d after weaning. The results showed that oral administration of putrescine or proline increased the final BW and ADG of piglets compared with the control (P < 0.05). Proline treatment decreased plasma D-lactate concentration but increased the villus height in the jejunum and ileum, as well as the percentage of proliferating cell nuclear antigen (PCNA) positive cells and alkaline phosphatase (AKP) activity in the jejunal mucosa (P < 0.05). The protein expressions for zonula occludens (ZO-1), occludin, and claudin-3 (P < 0.05) but not mRNA were increased in the jejunum of putrescine- and proline-treated piglets compared with those of control piglets. The voltage-gated K+ channel (Kv) 1.1 protein expression in the jejunum of piglets administrated with putrescine and the Kv1.5 mRNA and Kv1.1 protein levels in the ileum of piglets administrated with proline were greater than those in control piglets (P < 0.05). These findings indicate that polyamine or its precursor could improve mucosal proliferation, intestinal morphology, as well as tight junction and potassium channel protein expressions in early-weaned piglets, with implications for epithelial restitution and barrier function after stress injury.