Administration of Gracilariopsis lemaneiformis polysaccharide attenuates cisplatin-induced inflammation and intestinal mucosal damage in colon-26 carcinoma tumor-bearing mice

BACKGROUND

Our preliminary research revealed that the polysaccharide GP90 from Gracilariopsis lemaneiformis enhanced the antitumor effect of cisplatin, indicating that GP90 may increase the chemotherapeutic sensitivity. However, it is still necessary to fully understand whether GP90 can also improve the intestinal barrier dysfunction and systemic inflammation induced by cisplatin.

RESULTS

GP90 has been demonstrated to inhibit the excessive release of nitirc oxide, interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α induced by lipopolysaccharide in RAW264.7 cells. In vivo, GP90 effectively ameliorated the decrease in the serum CD4+ /CD8+ T-cell ratio induced by cisplatin and significantly reduced the increase in the inflammatory cytokines, CD4+ Foxp3+ , CD4+ granzyme B+ and CD4+ TNF-α induced by cisplatin. Furthermore, when combined with cisplatin, GP90 increases the protein expression levels of mucin-2 and zonula occludens-1 in the mouse small intestine. Additionally, GP90 combined with cisplatin has a modulatory effect on the intestinal microbiota by elevating the Firmicutes-to-Bacteroidetes ratio and the relative abundance of beneficial microorganisms (Lachnospiraceae bacterium), at the same time as reducing the abundance of cisplatin specific Bacteroides acidifaciens and elevating the content of butyric acid and isobutyric acid.

CONCLUSION

Collectively, these findings indicate that GP90 potentially mitigates inflammation and protects the intestinal barrier in tumor-bearing organisms undergoing chemotherapy. © 2024 Society of Chemical Industry.

Prophylactic Treatment of Intestinal Ischemia-Reperfusion Injury Reduces Mucosal Damage and Improves Intestinal Absorption

Purpose

Intestinal ischemia-reperfusion injury (i-IRI) involves a blood flow interruption in an intestinal segment followed by blood flow restoration. When blood flow is restored, oxidative and inflammatory molecules are distributed throughout the bloodstream, triggering both local and systemic damage. Our goal was to evaluate the potential of three antioxidant and/or anti-inflammatory compounds (curcumin, dexmedetomidine and α-tocopherol) to prevent or reverse local and systemic damage induced by i-IRI.

Methods

i-IRI was induced by placing a microvascular clip in the superior mesenteric artery of female WAG/RijHsd rats; the clip was removed after 1h and reperfusion was allowed for 4h. Curcumin (200 mg/kg, orally), α-tocopherol (20 mg/kg, i.p.), and dexmedetomidine (5 or 20 µg/kg, s.c.; DEX5 and DEX20, respectively) were administered. Blood and terminal ileum specimens were collected for biochemical and histological determination. Furthermore, D-xylose absorption test was performed to evaluate intestinal absorption; after completing the 1-hour ischemia and 4-hour reperfusion period, 1 mL of aqueous D-xylose solution (0.615 mg/mL) was administered orally, and one hour later, plasma D-xylose levels were quantified.

Results

The histological injury degree (HID) measured by the Chiu scale was significantly reduced when the treatments were applied (non-treated rats, 2.6 ± 0.75; curcumin, 1.54 ± 0.8; DEX5, 1.47 ± 0.7; DEX20 1.14 ± 0.5; and α-tocopherol, 1.01 ± 0.6); intestinal absorptive capacity also improved in all cases healthy rats (2.06 ± 0.07 µg/mL; non-treated, 1.18 ± 0.07 µg/mL; curcumin 1.76 ± 0.3 µg/mL; DEX5, 2.29 ± 0.2 µg/mL; DEX20, 2.25 ± 0.26 µg/mL; and α-tocopherol 1.66 ± 0.21 µg/mL). However, it failed to reduce liver enzyme levels. Finally, only dexmedetomidine significantly reduced urea and creatinine levels compared to non-treated animals.

Conclusion

All drugs were effective in reducing HID, although α-tocopherol was effective to a greater extent. Only dexmedetomidine reverted intestinal absorption to normal values of healthy animals.

6,7-Dihydroxy-2,4-Dimethoxyphenanthrene from Chinese Yam Peels Alleviates DSS-Induced Intestinal Mucosal Injury in Mice via Modulation of the NF-κB/COX-2 Signaling Pathway

In this study, we evaluated the protective effect and molecular mechanism of a dominant phenanthrene, (6,7-dihydroxy-2,4-dimethoxyphenanthrene, CYP4), from Chinese yam peels on intestinal epithelial integrity. Three doses of Chinese yam phenolic extract (CYPE) and Chinese yam phenanthrene 4 (CYP4) were administered to BALB/c mice for 7 days before dextran sulfate sodium (DSS) treatment, with berberine hydrochloride as a positive control (PC). Results showed that both disease activity indexes (DAIs), histological damage score (HDS) and survival rate in DSS mice, were improved with preintervention of CYPE and CYP4, which exhibited better efficiency than PC. Further studies showed that administration of CYP4 downregulated the oxidative stress-associated factors, MPO and NO, and improved tight junction protein occludin. Besides, the CYP4 treatment substantially downregulated the caspase-3 expression and the apoptosis rate of intestinal epithelial cells. In addition, the CYP4 treatment ameliorated the production of inflammatory cytokines including TNF-α, IFN-γ, IL-10, and IL-23 in the colon. Furthermore, the protein expression of ERK1/2, NF-κB p65, pNF-κB, and COX-2 was suppressed in CYE4 groups as compared with that in model control (MC). These findings suggested that CHP4 could effectively inhibit the activation of NF-κB/COX-2 in an experimental UC model in vivo. It was demonstrated for the first time that CYPE and CYP4 protected intestinal mucosa from damage and prevented DSS-induced colitis in mice. CYP4 was one of the active principles obligatory for the biological effect of Chinese yam in protecting intestinal health. These findings indicated that CYP4 might be a promising and useful approach for treatment of UC in humans.

Negative predictive value of the repeated absence of gluten immunogenic peptides in the urine of treated celiac patients in predicting mucosal healing: new proposals for follow-up in celiac disease

BACKGROUND

The treatment of celiac disease (CD) is a lifelong gluten-free diet (GFD). The current methods for monitoring GFD conformance, such as a dietary questionnaire or serology tests, may be inaccurate in detecting dietary transgressions, and duodenal biopsies are invasive, expensive, and not a routine monitoring technique.

OBJECTIVES

Our aim was to determine the clinical usefulness of urine gluten immunogenic peptides (GIP) as a biomarker monitoring GFD adherence in celiac patients and to evaluate the concordance of the results with the degree of mucosal damage.

METHODS

A prospective observational study was conducted involving 22 de novo CD patients, 77 celiac patients consuming a GFD, and 13 nonceliac subjects. On 3 d of the week, urine samples were collected and the GIP concentrations were tested. Simultaneously, anti-tissue transglutaminase antibodies, questionnaire results, clinical manifestations, and histological findings were analyzed.

RESULTS

Approximately 24% (18 of 76) of the celiac patients consuming a GFD exhibited Marsh II-III mucosal damage. Among this population, 94% (17 of 18) had detectable urine GIP; however, between 60% and 80% were asymptomatic and exhibited negative serology and appropriate GFD adherence based on the questionnaire. In contrast, 97% (31 of 32) of the celiac patients without duodenal damage had no detectable GIP. These results demonstrated the high sensitivity (94%) and negative predictive value (97%) of GIP measurements in relation to duodenal biopsy findings. In the de novo CD-diagnosed cohort, 82% (18 of 22) of patients had measurable amounts of GIP in the urine.

CONCLUSIONS

Determining GIP concentrations in several urine samples may be an especially convenient approach to assess recent gluten exposure in celiac patients and appears to accurately predict the absence of histological lesions. The introduction of GIP testing as an assessment technique for GFD adherence may help in ascertaining dietary compliance and to target the most suitable intervention during follow-up.

Persistence of Gut Microbiota Dysbiosis and Chronic Systemic Inflammation After Cerebral Infarction in Cynomolgus Monkeys

Background: The bidirectional interaction between the gut and brain after stroke through the immune-mediated pathway has been studied. However, the long-term effects of gut microbiota and systemic immune homeostasis after cerebral ischemia remain unclear. We examined long-term changes in the gut microbiota and systemic inflammatory cytokines after cerebral infarction in cynomolgus monkeys.

Methods: Twelve monkeys underwent successful distal M1 segment of the left middle cerebral artery occlusion (MCAO) and were randomly and equally assigned to the MCAO-1.5 m, MCAO-6 m, and MCAO-12 m groups, which were sacrificed 1.5, 6, and 12 months after cerebral infarction induction, respectively. Four monkeys that underwent a sham operation were sacrificed 12 months later. The gut microbiota and short-chain fatty acids (SCFAs) were analyzed by 16S rDNA sequencing and gas chromatography mass spectrometry, respectively. Histological examinations of the transverse colon were performed. Plasma D-lactate, zonulin, lipopolysaccharide (LPS), tumor necrosis factor (TNF-α), interferon (IFN)-γ, and interleukin (IL)-6 were detected by immunoassay kits.

Results: The levels of the Bacteroidetes phylum and Prevotella genus were significantly increased, while the Firmicutes phylum as well as the Faecalibacterium, Oscillospira, and Lactobacillus genera were decreased after cerebral infarction. Gut-originating SCFAs were significantly decreased 6 and 12 months after cerebral infarction (P < 0.05). We observed intestinal mucosal damage, evaluated by Chiu's score. Plasma D-lactate, zonulin, LPS, TNF-α, IFN-γ, and IL-6 were significantly increased after cerebral infarction (P < 0.05). Additionally, the increases in plasma LPS, TNF-α, IFN-γ, and IL-6 after cerebral infarction coincided with overgrowth of the Bacteroidetes phylum (P < 0.001).

Conclusion: Cerebral infarction induces persistent host gut microbiota dysbiosis, intestinal mucosal damage, and chronic systemic inflammation in cynomolgus monkeys.