Protective effect of trimetazidine in a model of ischemia-reperfusion in the rat retina

New insight of the efficacy trimetazidine in patients with peripheral arterial disease: a meta-analysis

BACKGROUND

This review aims to examine the impact of trimetazidine on skeletal muscle function in patients suffering from peripheral artery disease (PAD).

METHODS

We searched for studies, both experimental and observational research, concerning the comparison of trimetazidine administration to placebo/standard of care in patients with PAD in PubMed, ScienceDirect, and Cochrane. Meta-analyses of the included studies were performed using Review Manager v5.4. Clinical parameters [ankle-brachial index (ABI) and maximum walking distance (MWD)] were analyzed.

RESULTS

Three observational studies involving 378 participants with PAD satisfied predefined criteria. There was no substantial difference between the examined groups' on ABI (pre- and post-intervention) (MD = - 0.06 [- 0.19 to 0.07], p = 0.38, I2 = 90%). Meanwhile, MWD improvement was significantly higher (MD = 14.15 [6.05-22.25], p = 0.0006, I2 = 37%) in trimetazidine group than in the control group.

CONCLUSIONS

Current evidence from our meta-analysis suggests the beneficial role of trimetazidine's anti-ischemic effect in PAD patients by improving MWD, while it has an insignificant influence on ABI.

Bentonite-in hypromellose-poloxamer sol-gel for corneal application of trimetazidine: Study of rheology and ocular anti inflammatory potential

Bentonite is reported to be used for extending ocular drug delivery safely in a controlled manner. Bentonite combined hydroxypropyl methylcellulose (HPMC)-poloxamer based sol-to-gel formulation has been developed for the prophylactic ocular anti-inflammatory effect of trimetazidine after corneal application. HPMC-poloxamer sol formulation was prepared incorporating trimetazidine to bentonite at 1: 2*10^-5 to 1:5*10^-6 ratios using cold method, and investigations were carried out in carrageenan-induced rabbit eye model. Pseudoplastic shear thinning behavior without any yield value and high viscosity at low shear rate were the positive attribute of the tolerability of the sol formulation after ocular instillation. Presence of bentonite nanoplatelets revealed more sustained in vitro release (~79-97 %) and corneal permeation (~79-83 %) over a period of 6 h in comparison to its absence. Prominent acute inflammation has been produced in the carrageenan-induced untreated eye, whereas the absence of ocular inflammation has been noticed in the previously sol-treated eye even after carrageenan injection. HPMC-poloxamer-based formulation exhibited stronger binding affinity (5.13 kcal/mol) in the presence of bentonite rather than its absence (3.99 kcal/mol), resulting in a stable and sustained effect. HPMC-poloxamer in-situ gel of trimetazidine containing bentonite could be utilized for sustained ocular delivery and the control of ophthalmic inflammation prophylactically.

Effects of Post Ischemia-Reperfusion Treatment with Trimetazidine on Renal Injury in Rats: Insights on Delayed Renal Fibrosis Progression

Even after recovery from acute kidney injury, glomeruli remain vulnerable to further injury by way of interstitial fibrosis. This study is aimed at elucidating the effects of post ischemia-reperfusion (I/R) treatment with trimetazidine on the progression to renal fibrosis as well as short- and intermediate-term aspects. Trimetazidine 3 mg/kg or 0.9% saline was given intraperitoneally once upon reperfusion or daily thereafter for 5 d or 8 w. Renal histologic changes and related signaling proteins were assessed. After 24 h, post I/R treatment with trimetazidine significantly reduced serum blood urea nitrogen and creatinine levels and tubular injury accompanied with upregulation of hypoxia-inducible factor- (HIF-) 1α, vascular endothelial growth factor (VEGF), and Bcl-2 expression. After 5 d, post I/R treatment with trimetazidine reduced renal tubular cell necrosis and apoptosis with upregulation of HIF-1α-VEGF and tissue inhibitors of metalloproteinase activities, attenuation of matrix metalloproteinase activities, and alteration of the ratio of Bax to Bcl-2 levels. After 8 w, however, post I/R treatment with trimetazidine did not modify the progression of renal fibrosis. In conclusion, post I/R treatment with trimetazidine allows ischemic kidneys to regain renal function and structure more rapidly compared to nontreated kidneys, but not enough to resolute renal fibrosis in long-term aspect.

Defining the role of trimetazidine in the treatment of cardiovascular disorders: some insights on its role in heart failure and peripheral artery disease

Trimetazidine is a cytoprotective drug whose cardiovascular effectiveness, especially in patients with stable ischemic heart disease, has been the source of much controversy in recent years; some have gone so far as to treat the medication as a ‘placebo drug’ whose new side effects, such as Parkinsonian symptoms, outweigh its benefits. This article is an attempt to present the recent key studies, including meta-analyses, on the use of trimetazidine in chronic heart failure, also in patients with diabetes mellitus and arrhythmia, as well as in peripheral artery disease. This paper also includes the most recent European Society of Cardiology guidelines, including those of 2013, on the use of trimetazidine in cardiovascular disease.

The effects of trimetazidine and sildenafil on bilateral cavernosal nerve injury induced oxidative damage and cavernosal fibrosis in rats

AIM

The aim of this study was to compare the effects of sildenafil and trimetazidine on bilateral cavernosal nerve injury-induced oxidative damage and fibrotic changes in cavernosal tissue in rat model.

MATERIAL AND METHODS

A total of 32 male Sprague-Dawley rats were randomly divided into 4 groups; each group consist 8 rats (control, BCI, BCI + TMZ, and BCI + sildenafil groups). Tissue superoxide dismutase (SOD), malondialdehyde (MDA), and protein carbonyl (PC) levels were determined biochemically and distribution of cavernosal fibrosis density among groups was performed histopathologically.

RESULTS

Tissue SOD levels in BCI group were significantly lower than the control group (P < 0.05). Tissue MDA and PC levels in BCI group were significantly higher than the control group (P < 0.05). TMZ and sildenafil administration significantly increased tissue SOD levels (P < 0.05) and reduced tissue MDA and PC levels (P < 0.05). Histologically, the degree of cavernosal fibrosis and collagen density was higher in BCI group in comparison to control, TMZ-treated, and sildenafil-treated groups.

CONCLUSION

BCI caused oxidative damage and increased cavernosal fibrosis in rat penis. TMZ and sildenafil treatment decreased oxidative damage and reduced the degree of fibrosis in penile tissue due to BCI.

Randomized clinical trial France DMLA2: effect of trimetazidine on exudative and nonexudative age-relatedmacular degeneration

PURPOSE

To evaluate the effect of trimetazidine (TMZ) in a randomized, double-blind, placebo-controlled clinical trial on the occurrence of choroidal neovascularization or geographic atrophy in age-related macular degeneration.

METHODS

A total of 1,086 patients from France, Belgium, and Spain with soft drusen and/or retinal pigment epithelium abnormalities in the study eye and choroidal neovascularization in the contralateral eye were randomly assigned to receive orally placebo or TMZ 70 mg daily (35 mg × 2) and followed-up for 3 years to 5 years.

RESULTS

Treatment duration ranged between 0.4 months and 67.8 months with a mean ± SD of 38 ± 16 months. Three hundred and fifty-eight patients developed choroidal neovascularization (incidence per 100 patient-years: TMZ 10.86; placebo 11.13). Trimetazidine did not prevent the choroidal neovascularization (hazard ratio = 0.97; 95% confidence interval, 0.77-1.20; P = 0.781). However, there was a trend favoring TMZ for retinal atrophy, a secondary endpoint (HR = 0.76; 95% confidence interval, 0.56-1.02; P = 0.069). Overall, the difference in atrophy incidence between TMZ and placebo was not statistically different. Differences within some prespecified subgroups of patients showed superiority of TMZ in men (HR = 0.50; 95% confidence interval, 0.28-0.89; p = 0.016), in patients aged ≤75 years (HR = 0.58; 95% confidence interval, 0.38-0.88; p = 0.010), or in patients presenting with isolated pigmentary changes (HR = 0.19; 95% confidence interval, 0.05-0.70; p = 0.005).

CONCLUSION

Trimetazidine failed to prevent choroidal neovascularization. Subgroup analyses suggest that this drug could be tested as preventive therapy for geographic atrophy, although the overall comparison showed no statistically significant differences in the progression of geographic atrophy.

Trimetazidine revisited: a comprehensive review of the pharmacological effects and analytical techniques for the determination of trimetazidine

Trimetazidine (TMZ) is an effective and well-tolerated antianginal drug that possesses protective properties against ischemia-induced heart injury. Growing interest in metabolic modulation in recent years urged an up-to-date review of the literature on TMZ. This review consists of two major sections: (1) comprehensive and critical information about the pharmacological effects, mechanism of action, pharmacokinetics, side effects, and current usage of TMZ, and (2) developments in analytical techniques for the determination of the drug in raw material, pharmaceutical dosage forms, and biological samples.

The protective effects of trimetazidine on testicular ischemia and reperfusion injury in rats

This study was designed to investigate the protective effect of trimetazidine [TMZ; 1-(2, 3, 4-trimethhoxibenzyl)-piperazine dihydrochloride], as an antioxidant agent, on torsion-detorsion-induced biochemical and histopathological changes in experimental testicular ischemia/reperfusion injury in rats. Twenty-seven male Wistar rats weighing 180-220 g were divided into five groups: control (C, n = 4), sham-operated (S, n = 4), ischemia (I, n = 6), ischemia-reperfusion (I/R, n = 6) and ischemia-reperfusion + trimetazidine (I/R + TMZ; n = 7). Control rats were used for basal normal values. In group I, 2 h torsion of the left testis was performed. In I/R and I/R + TMZ groups, following 2 h of torsion, 4 h detorsion of the testis was performed. In ischemia and I/R groups, physiologic saline was administered orally for 7 days, and the rats in I/R + TMZ group were pretreated orally with 5 mg/kg day TMZ for 7 days before inducing ischemia. At the end of each experiment, ipsilateral orchiectomies were performed for the tissue levels of malondialdehyde (MDA), glutathione peroxidase (GPx) enzyme activities and histopathological examinations in all groups. MDA levels were significantly reduced and GPx enzyme activities were significantly increased in testes in I/R+TMZ pretreated group compared to group I and I/R. The mean seminiferous tubular diameter (MSTD) and Johnsen's score were significantly better in I/R+TMZ group than groups I and I/R. Pretreatment with TMZ decreased germ cell apoptosis and caspase-3 expression in the ischemic testis. The present results show that TMZ has a protective activity in the testicular injury caused by I/R, and provide the first evidence of the role of TMZ for the prevention of I/R-induced testicular injury.

Trimetazidine modulates AMPA/kainate receptors in rat vestibular ganglion neurons

Trimetazidine (1[2,3,4-trimethoxy-benzyl] piperazine, 2 HCl) is an anti-ischemic agent frequently administered as a prophylactic treatment for episodes of angina pectoris and chorioretinal disturbances. It is also employed as a symptomatic treatment of vertigo but its mechanism of action is yet to be defined. Using Fura-2 fluorescence photometry and whole-cell patch-clamp recordings we investigated the effect of trimetazidine on the [Ca(2+)](i) and current responses induced by the application of non-N-methyl-D-aspartate (NMDA) receptor agonists on low density vestibular ganglion neuronal cultures explanted from 3 day s postnatal rats. Trimetazidine blocked the [Ca(2+)](i) and current responses induced by 100 microM applications of both kainate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA). These responses were dependent on external Ca(2+) and were blocked by the voltage-dependent Ca(2+) channel blockers Ni(2+) and Cd(2+) . Trimetazidine only acts on the AMPA/kainate receptors and had no effect on K(+)-induced depolarizations. Dose-dependent curves were obtained for the inhibition by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and trimetazidine (IC(50) 7 microM and 0.7 microM) of kainate stimulations. After AMPA stimulation, dose-response inhibition curves showed an IC(50) of 3 microM for CNQX and 25 microM for trimetazidine. These results indicate that trimetazidine could be a potent antagonist of AMPA/kainate receptors in vestibular ganglion neurons. This may explain the protective role of trimetazidine in the inner ear suggesting an anti-excitotoxic activity.

Anti-excitotoxic activity of trimetazidine in the retina

The purpose of this study was to investigate the mechanism of the neuroprotective activity of trimetazidine in animal retina stressed by ischemia or kainate. Flash electroretinograms were recorded in guinea pigs after ischemia, induced by an acute increase in the intraocular pressure (IOP), or after an intravitreal injection of kainate. Treatment with trimetazidine per os afforded a significant protection of the electroretinogram against the ischemic as well as the excitotoxic insult as an antioxidant (dimethylthiourea) and a nitric oxide synthase inhibitor (nitroarginine) did. The effect of the drug on the extracellular accumulation of glutamate induced by chemical ischemia was studied by incubating rat retina in vitro. Trimetazidine was able to inhibit the extracellular glutamate accumulation, which represents the first step of the excitotoxic phenomenon. Then the compound activity on the glial uptake of glutamate was studied in a rat Müller cell line (rMC-1) in culture. Chemical ischemia inhibited the active 3H-glutamate transport, an effect that was reversed by trimetazidine, at micromolar concentrations. These results demonstrate that trimetazidine which is recognized as an efficient drug against ischemic injuries, is also capable of protecting the retina against excitotoxicity by reducing ischemia-induced accumulation of glutamate due in particular to glial transporter inhibition.

Augmentation of Ischemia/Reperfusion Injury to Endothelial Cells by Cyclosporin A

Ischemia/reperfusion (I/R) carries significant injury to endothelial cells in transplanted organs and is an important factor in chronic rejection. Immunosuppressive drugs, notably cyclosporin A (CyA) and FK506, can potentially augment this injury. Here, our goal was to determine the combined effects of I/R and CyA or FK506 on endothelial cells. Transformed mouse endothelial cells (SVEC 4–10) were subjected to ischemia or I/R for 2–24 hours by incubating cells in 100 per cent N2 (ischemia) followed by 5 per cent CO2 and 95 per cent O2 (reperfusion) for 24 hours. In separate experiments, CyA or FK506 was added to cells subjected to ischemia or I/R. Nonviable cells were determined by Trypan blue exclusion assay. All experiments (done in triplicate) were analyzed by Student's t test. Increasing ischemia times resulted in a greater number of nonviable cells (2% nonviable cells at 0 hours and 57% at 24 hours of I/R). Addition of CyA significantly increased the number of nonviable cells when compared with the control (I/R only) group ( P = 0.014). Interestingly, FK506 did not increase the percentage of nonviable cells compared with the control group ( P = 0.2). Unlike FK506, CyA augments I/R injury to endothelial cells in vitro. These findings could be relevant in chronic rejection and transplantation.

Retinal ischemia: mechanisms of damage and potential therapeutic strategies

Retinal ischemia is a common cause of visual impairment and blindness. At the cellular level, ischemic retinal injury consists of a self-reinforcing destructive cascade involving neuronal depolarisation, calcium influx and oxidative stress initiated by energy failure and increased glutamatergic stimulation. There is a cell-specific sensitivity to ischemic injury which may reflect variability in the balance of excitatory and inhibitory neurotransmitter receptors on a given cell. A number of animal models and analytical techniques have been used to study retinal ischemia, and an increasing number of treatments have been shown to interrupt the "ischemic cascade" and attenuate the detrimental effects of retinal ischemia. Thus far, however, success in the laboratory has not been translated to the clinic. Difficulties with the route of administration, dosage, and adverse effects may render certain experimental treatments clinically unusable. Furthermore, neuroprotection-based treatment strategies for stroke have so far been disappointing. However, compared to the brain, the retina exhibits a remarkable natural resistance to ischemic injury, which may reflect its peculiar metabolism and unique environment. Given the increasing understanding of the events involved in ischemic neuronal injury it is hoped that clinically effective treatments for retinal ischemia will soon be available.