Effect of Glycine, Pyruvate, and Resveratrol on the Regeneration Process of Postischemic Intestinal Mucosa

Artemisinin Alleviates Intestinal Inflammation and Metabolic Disturbance in Ulcerative Colitis Rats Induced by DSS

Objective

This study is aimed to reveal the possible mechanisms of artemisinin in the treatment of ulcerative colitis (UC) through bioinformatics analysis and experimental verification in UC model rats.

Methods

Firstly, we searched two microarray data of the Gene Expression Omnibus (GEO) database to explore the differentially expressed genes (DEGs) between UC samples and normal samples. Then, we selected DEGs for gene ontology (GO) function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The acute UC model of rats was established by using 3.5% dextran sulfate sodium (DSS) for 10 days to verify the core pathway. Finally, we evaluated the therapeutic effect of artemisinin at the molecular level and used metabonomics to study the endogenous metabolites in the rat serum.

Results

We screened in the GEO database and selected two eligible microarray datasets, GSE36807 and GSE9452. We performed GO function and KEGG pathway enrichment analyses of DEGs and found that these DEGs were mainly enriched in the inflammatory response, immune response, and IL-17 and NF-κB signaling pathways. Finally, we verified the IL-17 signaling pathway and key cytokines, and ELISA and immunohistochemical results showed that artemisinin could downregulate the expression of proinflammatory cytokines such as IL-1β and IL-17 in the IL-17 signaling pathway and upregulate the expression of the anti-inflammatory cytokine PPAR-γ. Metabolomics analysis showed that 33 differential metabolites were identified in the artemisinin group (AG) compared to the model group (MG). Differential metabolites were mainly involved in alanine, aspartate, and glutamate metabolism and synthesis and degradation of ketone bodies.

Conclusion

In this study, we found that artemisinin can significantly inhibit the inflammatory response in UC rats and regulate metabolites and related metabolic pathways. This study provides a foundation for further research on the mechanism of artemisinin in the treatment of UC.

Synergistic Effect of β-alanine and Aprotinin on Mesenteric Ischemia

BACKGROUND

Acute mesenteric ischemia arises through sudden interruption of mesenteric blood flow, mostly due to an occlusion of the superior mesenteric artery and is associated with a high mortality of approximately 50% to 90%. In previous studies, the single application of β-alanine or aprotinin caused an ameliorated intestinal damage but without any systemic effects.

METHODS

To analyze the combined effect of β-alanine and aprotinin on acute ischemia and reperfusion of the small intestine, a model with anesthetized rats was used. Ischemia and reperfusion were initiated by occluding and reopening the superior mesenteric artery. After 120 min of ischemia and 180 min of reperfusion, the intestine was analyzed for tissue damage, the activity of the saccharase, and accumulation of granulocytes. In addition, systemic and metabolic as well as inflammatory parameters were measured in blood at certain points in time.

RESULTS

The combination of β-alanine and aprotinin resulted in a clearly stabilized mean arterial blood pressure and blood glucose level during the reperfusion period. Furthermore, the combined administration resulted in significantly reduced tissue damage parameters, cytokine and cell-free hemoglobin concentrations in blood plasma. In addition, the damage to the small intestine was significantly attenuated, so that the animals ultimately survived the entire test period because of the administration of both substances.

CONCLUSIONS

Overall, the simultaneous application of both substances leads to a synergistic protection without the occurrence of undesirable side effects. The combined usage of β-alanine and aprotinin can be seen as a promising approach to inhibit the onset of acute mesenteric ischemia.

Protective Effects of Sodium Pyruvate during Systemic Inflammation Limited to the Correction of Metabolic Acidosis

Protective effects by exogenous sodium pyruvate already have been described in various experimental models of injury, among others during intestinal ischemia-reperfusion injury, hemorrhagic shock, and shock secondary to systemic inflammation (endotoxemic shock). Low doses of sodium pyruvate reduced signs of inflammation, enhanced systemic blood pressure, and ameliorated metabolic acidosis when administered in a prophylactic manner during endotoxemic shock. In the present study, we investigated whether low-dosed infusions of sodium pyruvate exhibited beneficial effects when applied therapeutically after the induction of systemic inflammation. Lipopolysaccharide was infused at a rate of 0.5 mg/kg × h over a period of 360 min to induce systemic inflammation in male Wistar rats. Sodium pyruvate (single dose 50 mg/kg × 15 min) was administered intravenously 180 and 270 min after starting of the lipopolysaccharide infusion. Systemic/vital parameters (e.g., systemic blood pressure and breathing rate) and blood/plasma parameters (e.g., acid-base parameters; electrolytes; glucose and lactate concentration; hemolysis; aminotransferase activities; and parameters of coagulation) were determined in regular intervals. Lipopolysaccharide infusion led to metabolic acidosis, hypoglycemia, electrolyte as well as hemostatic disturbances, and hemolysis. Except for the acid-base status (amelioration of metabolic acidosis) and the plasma chloride concentration (reduction of hyperchloremia), the additional infusion of sodium pyruvate failed in significantly improving lipopolysaccharide-dependent alterations (e.g. vital, blood and plasma parameters). Protective effects of a delayed administration of the metabolizable anion pyruvate during systemic inflammation, hence, are limited to its function as alkalizer to counteract metabolic acidosis.