Effect of early fluid resuscitation combined with low dose cyclophosphamide on intestinal barrier function in severe sepsis rats

Malvidin alleviates LPS-induced septic intestinal injury through the nuclear factor erythroid 2-related factor 2/reactive oxygen species/NLRP3 inflammasome pathway

Emerging evidence suggests that the gastrointestinal tract plays a crucial role in the pathophysiology of sepsis, a leading cause of mortality among patients admitted to the intensive care unit (ICU). Malvidin, belonging to the flavonoid family of compounds, exhibits a range of capabilities including anti-inflammatory and antioxidant properties. Studies have demonstrated that Malvidin exhibits a dose-dependent effect in mitigating sepsis-induced intestinal injury. The advantageous impact of Malvidin in safeguarding against sepsis-induced intestinal injury is associated with its capacity to counteract oxidative stress, inhibit cellular apoptosis, diminish the secretion of pro-inflammatory cytokines, and regulate the synthesis of inflammasomes. The findings indicate that Malvidin, a natural compound, exhibits protective effects on the gut by activating the nuclear factor erythroid 2-related factor 2/reactive oxygen species/NLRP3 inflammasome pathway. These results have significant implications for potential clinical applications and offer valuable insights into the treatment of sepsis-induced intestinal injury.

Gadolinium chloride pre-treatment reduces the inflammatory response and preserves intestinal barrier function in a rat model of sepsis

The inflammatory response is closely associated with sepsis occurrence and progression. Damage to the function of the intestinal mucosal barrier is considered to be the ῾initiation factor᾿ for the development of multiple organ dysfunction syndrome, which is the most severe progression of sepsis. The aim of the present study was to investigate whether gadolinium chloride (GdCl₃) could alleviate the systemic inflammatory response and protect the function of the intestinal mucosal barrier in a rat model of sepsis. The mechanism underlying this protective effect was also explored. Sprague-Dawley rats were divided into four groups: Sham, sham + GdCl₃, cecal ligation and puncture (CLP; a model of sepsis) and CLP + GdCl₃. In each group, blood was collected from the abdominal aorta, and intestinal tissue was collected after 6, 12 and 24 h of successful modeling. Levels of tumor necrosis factor-α, interleukin (IL)-6 and IL-1β were determined using ELISA. Western blot analysis was used to determine levels of occludin, tight junction protein ZO-1 (ZO-1), myosin light chain kinase 3 (MLCK), NF-κB and caspase-3 in intestinal tissues. Hematoxylin-eosin staining was used to observe the degree of damage to intestinal tissue. The results indicated that in CLP sepsis model rats treated with GdCl₃, the release of systemic and intestinal pro-inflammatory factors was reduced and tissue damage was alleviated when compared with untreated CLP rats. Additionally, the expression of occludin and ZO-1 was increased, while that of NF-κB, MLCK, and caspase-3 was reduced in the CLP + GdCl₃ rats compared with the CLP rats. GdCl₃ may alleviate systemic and intestinal inflammatory responses and reduce the expression of MLCK through inhibition of the activation of NF-kB. The results of the present study also indicated that GdCl₃ promoted the expression of occludin and ZO-1. GdCl₃ was also demonstrated to reduce cell apoptosis through the inhibition of caspase-3 expression.

Adipose-derived mesenchymal stem cells attenuate acute lung injury and improve the gut microbiota in septic rats

Background

We hypothesized that adipose-derived mesenchymal stem cells (ADMSCs) may ameliorate sepsis-induced acute lung injury (ALI) and change microorganism populations in the gut microbiota, such as that of Firmicutes and Bacteroidetes.

Methods

A total of 60 male adult Sprague-Dawley (SD) rats were separated into three groups: the sham control (SC) group, the sepsis induced by cecal ligation and puncture (CLP) group, and the ADMSC treatment (CLP-ADMSCs) group, in which rats underwent the CLP procedure and then received 1 × 10⁶ ADMSCs. Rats were sacrificed 24 h after the SC or CLP procedures. To study the role of ADMSCs during ALI caused by sepsis and examine the impact of ADMSCs on the gut microbiome composition, rat lungs were histologically evaluated using hematoxylin and eosin (H&E) staining, serum levels of pro-inflammatory factors were detected using enzyme-linked immunosorbent assay (ELISA), and fecal samples were collected and analyzed using 16S rDNA sequencing.

Results

The serum levels of inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-6, were significantly increased in rats after the CLP procedure, but were significantly decreased in rats treated with ADMSCs. Histological evaluation of the rat lungs yielded results consistent with the changes in IL-6 levels among all groups. Treatment with ADMSCs significantly increased the diversity of the gut microbiota in rats with sepsis. The principal coordinates analysis (PCoA) results showed that there was a significant difference between the gut microbiota of the CLP-ADMSCs group and that of the CLP group. In rats with sepsis, the proportion of Escherichia–Shigella (P = 0.01) related to lipopolysaccharide production increased, and the proportion of Akkermansia (P = 0.02) related to the regulation of intestinal mucosal thickness and the maintenance of intestinal barrier function decreased. These changes in the gut microbiota break the energy balance, aggravate inflammatory reactions, reduce intestinal barrier functions, and promote the translocation of intestinal bacteria. Intervention with ADMSCs increased the proportion of beneficial bacteria, reduced the proportion of harmful bacteria, and normalized the gut microbiota.

Conclusions

Therapeutically administered ADMSCs ameliorate CLP-induced ALI and improves gut microbiota, which provides a potential therapeutic mechanism for ADMSCs in the treatment of sepsis.

Protective effects of betulinic acid on intestinal mucosal injury induced by cyclophosphamide in mice

BACKGROUND

Betulinic acid (BA) is a plant-derived pentacyclic triterpenoid with a variety of biological activities. The purpose of this study was to assess the potential protective role of BA against intestinal mucosal injury induced by cyclophosphamide (CYP) treatment.

METHODS

Mice were pretreated with BA daily (0.05, 0.5, and 5.0 mg/kg) for 14 days, then injected intraperitoneally with CYP (50 mg/kg) for 2 days.

RESULTS

BA pretreatment reduced the contents of malondialdehyde (MDA) and glutathione (GSH), decreased the activity of superoxide dismutase (SOD) in small intestine, increased villus hight/crypt depth ratio and restored the morphology of intestinal villi in CYP-induced mice. Moreover, BA pretreatment could significantly down-regulate the levels of pro-inflammatory cytokines interleukin-5 (IL-5), IL-17, IL-12 (P70) and tumor necrosis factor α (TNF-α), reduced production of chemokines macrophage inflammatory protein-1α (MIP-1α), macrophage inflammatory protein-1β (MIP-1β) and regulated upon activation, normal T-cell expressed and secreted (RANTES), and enhanced the levels of anti-inflammatory such as IL-2 and IL-10 in serum, and decreased the mRNA expressions of IL-1β and TNF-α in intestine of CYP-induced mice. Furthermore, RT-PCR demonstrated that BA improved intestinal physical and immunological barrier in CYP-stimulated mice by enhancing the mRNA expressions of zonula occluden 1 (ZO-1) and Claudin-1.

CONCLUSIONS

BA might be considered as an effective agent in the amelioration of the intestinal mucosal resulting from CYP treatment.