Ethacrynic acid decreases expression of proinflammatory intestinal wall cytokines and ameliorates gastrointestinal stasis in murine postoperative ileus

OBJECTIVES: Several compounds characterized by an olefin linkage conjugated to a carbonyl group have anti-inflammatory properties. The diuretic ethacrynic acid (EA) is a compound of this type. Herein, we tested the hypothesis that ethacrynic acid can modulate the development of ileus after bowel manipulation. METHODS: Groups (n=9) of male C57Bl/6 mice underwent surgical manipulation of the small intestine using a pair of cotton-tipped applicators (MAN). Control animals (CONT) did not undergo any surgical intervention or receive treatment. MAN mice were pre- and post-treated with four intraperitoneal doses of phosphate buffered saline (PBS), EA1 (1mg/kg per dose), or EA10 (10mg/kg per dose). Gastrointestinal transit of non-absorbable FITC-labeled dextran was assessed by gavaging the mice with the tracer 24h after operation and assessing FD70 concentration 120 min later in the bowel contents from the stomach, 10 equally long segments of small intestine, cecum, and two equally long segments of colon. The geometric center for the tracer was calculated for each animal. Expression of interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) transcripts in the ileal muscularis propria was assessed using semiquantitative reverse transcriptase-polymerase chain reaction. RESULTS: In control animals, the mean (±SE) geometric center for the transit marker was 9.89±0.47, whereas it was 4.59±0.59 for PBS-treated animals (p<0.05 vs CONT). The geometric center for pre- post treatment with low (1mg/kg) and high (10mg/kg) doses of ethacrynic acid were 7.23±0.97 and 5.15±0.57, respectively. Compared to PBS, treatment with ethacrynic acid (1mg/kg) significantly decreased manipulation-induced IL-6 and iNOS mRNA expression in the wall of the small bowel. CONCLUSIONS: Pre- and post-treatment with ethacrynic acid ameliorates ileus and modulates inflammation in the gut wall induced by bowel manipulation.

Ethacrynic acid promotes apoptosis in lung cancer A549 cells when combined with cisplatin chemotherapy / 第三军医大学学报

Objective To investigate the killing effect of ethacrynic acid (EA) on lung cancer A549 cells derived spheres and explore the underlying mechanism.Methods A549 spheres were cultured in serum-free medium,and the protein expression of CD133,SOX2,EpCAM and ABCG2 was detected by Western blotting.MTT assay was used to evaluate the cell viability of A549 spheres and A549 cells after treated by 1,2,5,10 and 20 mg/mL cisplatin (DDP) for 48 h.The activity of glutathione S-transferase (GST) was measured by colorimetric method after A549 spheres were treated with 10,50,100 and 200 μmol/L EA,respectively.Flow cytometry,Western blotting,real-time PCR and luciferase assay were used to analyze the levels of cellular reactive oxygen species (ROS),formation of A549 spheres,mRNA and protein expression levels of β-catenin,Sox2 and ABCG2,and promoter activity of β-catenin upon 200 μmol/L EA treated cells for 48 h.A549 sphere was infected with β-catenin adenovirus for 24 h,followed by 200 μmol/L EA treatment (in presence or absence of 5 mg/mL DDP) for 24 h.The expression of β-catenin,Sox2 and ABCG2 at mRNA and protein levels was detected by real-time PCR and Western blotting,and cell growth of A549 spheres was evaluated by MTT assay.Results The A549 spheres,with high expression of tumor stem cells markers CD133,SOX2,EpCAM and drug resistance related molecule ABCG2,and resistance to DDP at different doses,were successfully derived.After 200 μmol/L EA had treated A549 sphere for 48 h,the levels of ROS were significantly increased (P ＜ 0.05),and the mRNA and protein levels of β-catenin,Sox2 and ABCG2,and promoter activity of β-catenin were notably decreased (P ＜ 0.05).The treatment of 200 μmol/L EA enhanced the inhibitory effect on proliferation and the promoting effect on apoptosis in A549 spheres induced by 5 mg/mL DDP (P ＜ 0.05).Up-regulation of β-catenin by adenoviral infection partly reversed the effects of 200 μmol/L EA on suppressing the expression levels of β-catenin,Sox2 and ABCG2,compared to the spheres infected with blank adenovirus.Additionally,β-catenin over-expression significantly remitted the inhibitory effect of 200 μmol/L EA and 5 mg/mL DDP on the proliferation in A549 spheres.Conclusion EA exerts inhibitory effect on the proliferation and stemness of A549 spheres through suppressing GST activity and β-catenin expression,and then promotes cell apoptosis.EA might be a novel drug in treatment of lung cancer and cancer stem cells.

Ethacrynic Acid Inhibits Sphingosylphosphorylcholine-Induced Keratin 8 Phosphorylation and Reorganization via Transglutaminase-2 Inhibition

Sphingosylphosphorylcholine (SPC) is significantly increased in the malicious ascites of tumor patients and induces perinuclear reorganization of keratin 8 (K8) filaments in PANC-1 cells. The reorganization contributes to the viscoelasticity of metastatic cancer cells resulting in increased migration. Recently, we reported that transglutaminase-2 (Tgase-2) is involved in SPC-induced K8 phosphorylation and reorganization. However, effects of Tgase-2 inhibitors on SPC-induced K8 phosphorylation and reorganization were not clearly studied. We found that ethacrynic acid (ECA) concentration-dependently inhibited Tgase-2. Therefore, we examined the effects of ECA on SPC-induced K8 phosphorylation and reorganization. ECA concentration-dependently suppressed the SPC-induced phosphorylation and perinuclear reorganization of K8. ECA also suppressed the SPC-induced migration and invasion. SPC induced JNK activation through Tgase-2 expression and ECA suppressed the activation and expression of JNK in PANC-1 cells. These results suggested that ECA might be useful to control Tgase-2 dependent metastasis of cancer cells such as pancreatic cancer and lung cancers.

Correlation between Dose of Ethacrynic Acid and Weight of Cat in the Cat Deafening Procedure / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Co-administration of kanamycin (KM) with the loop diuretic ethacrynic acid (EA) has been known to produce a rapid and profound hearing loss in adult animals. The objective of this study was to see if monitoring the hearing status during intravenous infusion of EA could minimalize individual variability and to evaluate the correlation between the dose of EA and the body weight (wt). MATERIALS AND METHOD: Twenty cats with the mean age of 24 weeks+/-3.7 (range, 20.6-28.3 weeks) and the mean weight of 3.27 kg+/-0.75 (range 2.4-4.75 kg) received a subcutaneous injection of KM (300 mg/kg) followed by an intravenous infusion of EA (1 mg/min). Click evoked auditory brainstem responses (ABRs) were recorded to monitor the hearing during the infusion. When the ABR thresholds rose to levels in excess of 90 dB SPL, the infusion of EA was stopped. The histopathologies for sections of apex, middle, base of cochlea were examined after 6 months. RESULTS: There was a significant positive correlation (p<.001, r2=.583) between the EA dose and body weight. Cochlear histopathology showed an absence of organ of Corti and decrease of spiral ganglion cells in the majority of cochleas, especially in the basal turn. The extent of loss of spiral ganglion cells was dependent on their distance from the round window. CONCLUSION: Monitoring the animal's hearing status during the procedure ensured that the dose of EA was optimized for individual animals. Thus, the positive correlation between the EA dose and body weight should be considered should in designing the animal models of controlled high frequency hearing loss.