Ethyl-pyruvate reduces lung injury matrix metalloproteinases and cytokines and improves survival in experimental model of severe acute pancreatitis

Ethyl pyruvate and analogs as potential treatments for acute pancreatitis: A review of in vitro and in vivo studies

Ethyl pyruvate (EP) has been shown to improve outcomes from multiple organ dysfunction syndrome (MODS) in experimental animal models of critical illness. This review aimed to summarise in vitro and in vivo effects of EP analogs on acute pancreatitis (AP) with the objective of proposing medicinal chemistry modifications of EP for future research. In vitro studies showed that both sodium pyruvate and EP significantly reduced pancreatic acinar necrotic cell death pathway activation induced by multiple pancreatic toxins. In vivo studies using different murine AP models showed that EP (usually at a dose of 40 mg/kg every 6 h) consistently reduced pain, markers of pancreatic injury, systemic inflammation and MODS. There was also a significant increase in survival rate, even when EP was administered 12 h after disease induction (compared with untreated groups or those treated with Ringer's lactate solution). Experimental studies suggest that EP and analogs are promising drug candidates for treating AP. EP or analogs can undergo medicinal chemistry modifications to improve its stability and deliverability. EP or analogs could be evaluated as a supplement to intravenous fluid therapy in AP.

Ethyl pyruvate treatment ameliorates pancreatic damage: evidence from a rat model of acute necrotizing pancreatitis

INTRODUCTION

Ethyl pyruvate (EP), a natural flavoring and fragrance agent, has been shown to exert anti-inflammatory and antioxidant actions. We tested the potential beneficial effects of EP in a rat model of acute necrotizing pancreatitis (ANP), a serious condition with a significant inflammatory explosion and oxidative stress.

MATERIAL AND METHODS

Fifty-two adult male Sprague-Dawley rats were divided into four groups: sham + saline, sham + EP, ANP + saline, and ANP + EP. The ANP was induced by glycodeoxycholic acid and cerulein. Animals were sacrificed at 48 h and biochemical, hematological, and histological markers of ANP and inflammation were assessed. The extent of mortality, systemic cardiorespiratory variables, pancreatic microcirculation, renal/hepatic functions, acinar cell injury and enzyme markers for pancreas and lung tissues were investigated.

RESULTS

The EP-treated ANP group presented significantly lower mortality than the untreated ANP group (44% (7/16) vs. 19% (3/16), respectively, p < 0.05). Administration of EP resulted in significantly lower levels of IL-6 (ANP + saline: 5470 ±280 vs. ANP + EP: 2250 ±180 pg/ml, p < 0.05). Compared with the ANP group, the ANP + EP group had a lower pancreatic necrosis score (1.45 ±0.2 vs. 0.96 ±0.2, p < 0.05). Moreover, intraperitoneal EP administration had a positive effect on most indices of pancreatitis (amylase and alanine transaminase levels) and lung damage (except lung malondialdehyde levels) as they decreased towards baseline values.

CONCLUSIONS

The results from this experimental study indicate that EP, a nontoxic chemical approved by the Food and Drug Administration as a food additive, provides positive effects on the course of pancreatitis, suggesting potential usefulness in management of ANP.

Ethyl pyruvate is a novel anti-inflammatory agent to treat multiple inflammatory organ injuries

Ethyl pyruvate (EP) is a simple derivative of pyruvic acid, which is an important endogenous metabolite that can scavenge reactive oxygen species (ROS). Treatment with EP is able to ameliorate systemic inflammation and multiple organ dysfunctions in multiple animal models, such as acute pancreatitis, alcoholic liver injury, acute respiratory distress syndrome (ARDS), acute viral myocarditis, acute kidney injury and sepsis. Recent studies have demonstrated that prolonged treatment with EP can ameliorate experimental ulcerative colitis and slow multiple tumor growth. It has become evident that EP has pharmacological anti-inflammatory effect to inhibit multiple early inflammatory cytokines and the late inflammatory cytokine HMGB1 release, and the anti-tumor activity is likely associated with its anti-inflammatory effect. EP has been tested in human volunteers and in a clinical trial of patients undergoing cardiac surgery in USA and shown to be safe at clinical relevant doses, even though EP fails to improve outcome of the heart surgery, EP is still a promising agent to treat patients with multiple inflammatory organ injuries and the other clinical trials are on the way. This review focuses on how EP is able to ameliorate multiple organ injuries and summarize recently published EP investigations.

Graphical Abstract

Intratracheal instillation of ethyl pyruvate nanoparticles prevents the development of shunt-flow-induced pulmonary arterial hypertension in a rat model

Purpose

To investigate whether inhalation of ethyl pyruvate (EP) encapsulated with poly(ethylene glycol)-block-lactide/glycolide copolymer nanoparticles (EP-NPs) can prevent the development of shunt-flow-induced hyperkinetic pulmonary arterial hypertension (PAH) in a rat model.

Materials and methods

Rats were separated into five groups: blank (ie, no treatment after shunt flow), normal control (ie, no shunt flow or treatment), EP-NP instillation, EP-only instillation, and vehicle. The animals received intratracheal instillation of EP-NPs or other treatments immediately after a shunt flow, and treatment continued weekly until the end of the experiment. Hemodynamic data were recorded, pulmonary arterial remodeling was assessed, and levels of inflammatory mediators and ET1 expression in the lung and serum were analyzed. In addition, retention of EP in the lungs of rats in the EP-NP and EP-only groups was measured using high-performance liquid chromatography.

Results

After 12 weeks, hemodynamic abnormalities and pulmonary arterial remodeling were improved in the EP-NP instillation group, compared with the blank, EP-only, and vehicle groups (P<0.05). In addition, the EP-NP group showed significantly decreased levels of HMGB1, IL-6, TNFα, reactive oxygen species, and ET1 in the lung during PAH development (P<0.05). Furthermore, EP-NP instillation was associated with reduced serum levels of inflammatory factors and ET1. High-performance liquid-chromatography measurement indicated that EP retention was greater in the lungs of the EP-NP group than in the EP-only group.

Conclusion

EP-NP instillation attenuated inflammation and prevented pulmonary arterial remodeling during the development of PAH induced by shunt flow. In the future, EP-NP delivery into the lung might provide a novel approach for preventing PAH.

Effects of Ringer's sodium pyruvate solution on serum tumor necrosis factor-α and interleukin-6 upon septic shock

Objective:

To study the effects of Ringer’s sodium pyruvate solution on tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) upon septic shock.

Methods:

Ninety emergency patients with septic shock were divided into a treatment group and a control group by random draw. The control group was resuscitated with 50 ml of compound sodium chloride (Ringer’s solution), and the treatment group was given 50 ml of Ringer’s sodium pyruvate solution. Both groups were basically treated.

Results:

All patients were successfully resuscitated. After treatment, extravascular lung water index, intrathoracic blood volume index, systemic vascular resistance index and cardiac index of the two groups were significantly improved compared with those before treatment (P<0.05). However, there were no significant inter-group differences at different time points (P>0.05). Blood lactic acid level, central venous oxygen saturation index and urine output were also improved after treatment, with significant inter-group differences (P<0.05). Serum TNF-α and IL-6 levels of both groups significantly decreased after treatment (P<0.05), and the levels of the treatment group were significantly lower than those of the control group (P<0.05). During 28 days of follow-up, the mortality rate of the treatment group (4.4%) was significantly lower than that of the control group (20.0%) (P<0.05).

Conclusion:

Patients with septic shock are complicated with disordered expressions of inflammatory factors. During resuscitation, Ringer’s sodium pyruvate solution can effectively promote blood circulation, mitigate inflammation and maintain acid-base equilibrium, thus decreasing the prognostic mortality rate.