The relative efficacy of aminoguanidine and pentoxifylline in modulating endotoxin-induced cardiac stress

Effect of pentoxifylline on endothelial dysfunction, oxidative stress and inflammatory markers in STEMI patients

Aim: ST-elevation myocardial infarction (STEMI) patients suffer higher mortality and adverse outcomes linked to endothelial dysfunction (ED). Methods: 43 patients were randomized to pentoxifylline (PTX) 400 mg thrice daily (n = 22) or placebo (n = 21). Soluble vascular cell adhesion molecule-1, malondialdehyde, interleukin-1 (IL-1), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-α (TNF-α) were assessed at baseline and 2 months. Results: After 2 months, no significant difference was observed in markers' levels between the 2 groups. However, a within-group comparison revealed a statistically significant change in hs-CRP in the PTX group (10.057 (9.779-10.331) versus 9.721 (6.102-10.191)), p = 0.032. Conclusion: PTX for 2 months in STEMI patients was safe and well-tolerated but had no significant detectable effect on ED, oxidative stress or inflammatory markers. Clinical Trial Registration: NCT04367935 (ClinicalTrials.gov).

The cardioprotective effects of perindopril in a model of polymicrobial sepsis: The role of radical oxygen species and the inflammation pathway

Mortality rates associated with myocardial dysfunction due to sepsis and septic shock are generally high across the world. The present study focused on the antioxidant and anti-inflammatory effects of perindopril (PER) for the purpose of preventing the adverse effects of sepsis on the myocardium and developing new alternatives in treatment. The control group received only saline solution via the oral route for 4 days. The second group underwent cecal ligation puncture (CLP), and the third underwent CLP and received PER (2 mg/kg). Rats in the third group received 2 mg/kg PER per oral (p.o.) from 4 days before induction of sepsis. Thiobarbituric acid reactive species (TBARS), total thiol (-SH), interleukin-1 beta (IL-1β), IL-6, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and nuclear factor kappa B (NF-κB/p65) levels increased in the CLP groups. In contrast, PER (2 mg/kg) decreased the levels of biochemical parameters other than total-SH and decreased 8-OHdG, NF-κB/p65 immunopositivity in rat heart tissues. The data from this study show that impairment of the oxidant/antioxidant balance and inflammatory cytokine levels in favor of inflammation in heart tissue under septic conditions results in severe tissue damage. PER administration before sepsis was shown to exhibit antioxidant and anti-inflammatory properties by reducing these effects. This in turn increased the importance of PER as new evidence of its protective effects in heart tissue.

Nitric oxide synthase in diabetic rat testicular tissue and the effects of pentoxifylline therapy

Diabetes is known to be associated with erectile dysfunction, retrograde ejaculation, level of testicular hormone, and a decrease in semen quality, respectively. In this project, we aimed to investigate at the molecular level, the effects of NOS on testes pathology in diabetes and examine the effects of pentoxifylline on healing. A total of 50 Wistar albino male rats were divided into five groups: Group I control; Group II only diabetes; Group III and IV diabetes + pentoxifylline; Group V only pentoxifylline. Group III rats received 50 mg/kg/day pentoxifylline during two months. In comparison, Group IV rats received saline in the first month followed by 50 mg/kg/day of pentoxifylline for the following month. NOS expression in testicular tissue was assessed using qRT-PCR, western blot, and immunohistochemistry. The mean seminiferous tubule diameter, Johnsen's testicular biopsy score, and serum testosterone levels decreased compared to controls. In contrast, the number of apoptotic cells, the levels of nNOS, iNOS and eNOS mRNA, and protein increased when compared to the control. Upon pentoxifylline therapy NOS decreased suggesting that it contributes to this damage and treatment with pentoxifylline may be effective in reversing this damage.

Therapeutic effects of pentoxifylline on diabetic heart tissue via NOS

Objective:

Diabetes mellitus causes a decrease in cardiac output, arterial blood pressure, and heart rate. In this study, we aimed to investigate, at the molecular level, the effect of nitric oxide synthase (NOS) on heart pathology in type 1 diabetes and look at the therapeutic effect of pentoxifylline on this pathology.

Methods:

In this experimental study, 50 Wistar albino male rats were used. The rats were divided into 5 groups: group C, control; group D, only diabetes; group D+PI and D+PII, diabetes + pentoxifylline; group P, only pentoxifylline. Group D+PI rats received 50 mg/kg/day pentoxifylline over two months. However, group D+PII rats received saline in the first month and 50 mg/kg/day of pentoxifylline over the following month. At the end of two months, NOS expressions in heart tissue were assessed through immunohistochemistry analysis. The data were compared by one-way ANOVA.

Results:

At the end of the experiments, there was increased cytoplasmic vacuolization, myofibrillar loss, cytoplasmic eosinophilia, and degeneration of cardiomyocytes; nNOS and iNOS expressions in group D decreased compared with that in group C. In group D+PI and group D+PII, nNOS and iNOS expressions improved compared with group D.

Conclusion:

As a result, we found that diabetes, a known chronic disease, causes serious damage in heart tissue. NOS plays a role in this damage, and pentoxifylline aided in improving nNOS and iNOS expression in this damage.

6-Hydroxydopamine and lipopolysaccharides induced DNA damage in astrocytes: involvement of nitric oxide and mitochondria

The present study was conducted to investigate the effect of the neurotoxins 6-hydroxydopamine and lipopolysaccharide on astrocytes. Rat astrocyte C6 cells were treated with different concentration of 6-hydroxydopamine (6-OHDA)/lipopolysaccharides (LPS) for 24 h. Both neurotoxins significantly decreased the viability of astrocytes, augmented the expression of inducible nitric oxide synthase (iNOS) and the astrocyte marker--glial fibrillar acidic protein. A significantly decreased mitochondrial dehydrogenase activity, mitochondrial membrane potential, augmented reactive oxygen species (ROS) level, caspase-3 mRNA level, chromatin condensation and DNA damage was observed in 6-OHDA/LPS treated astroglial cells. 6-OHDA/LPS treatment also caused the significantly increased expression of iNOS and nitrite level. Findings showed that 6-OHDA/LPS treatment caused mitochondrial dysfunction mediated death of astrocytes, which significantly involve the nitric oxide. Since we have observed significantly increased level of iNOS along with mitochondrial impairment and apoptotic cell death in astrocytes, therefore to validate the role of iNOS, the cells were co-treated with iNOS inhibitor aminoguanidine (AG, 100 μM). Co-treatment of AG significantly attenuated the 6-OHDA/LPS induced cell death, mitochondrial activity, augmented ROS level, chromatin condensation and DNA damage. GFAP and caspase-3 expression were also inhibited with co-treatment of AG, although the extent of inhibition was different in both experimental sets. In conclusion, the findings showed that iNOS mediated increased level of nitric oxide acts as a key regulatory molecule in 6-OHDA/LPS induced mitochondrial dysfunction, DNA damage and apoptotic death of astrocytes.

The NO/ONOO-cycle as the central cause of heart failure

The NO/ONOO-cycle is a primarily local, biochemical vicious cycle mechanism, centered on elevated peroxynitrite and oxidative stress, but also involving 10 additional elements: NF-κB, inflammatory cytokines, iNOS, nitric oxide (NO), superoxide, mitochondrial dysfunction (lowered energy charge, ATP), NMDA activity, intracellular Ca(2+), TRP receptors and tetrahydrobiopterin depletion. All 12 of these elements have causal roles in heart failure (HF) and each is linked through a total of 87 studies to specific correlates of HF. Two apparent causal factors of HF, RhoA and endothelin-1, each act as tissue-limited cycle elements. Nineteen stressors that initiate cases of HF, each act to raise multiple cycle elements, potentially initiating the cycle in this way. Different types of HF, left vs. right ventricular HF, with or without arrhythmia, etc., may differ from one another in the regions of the myocardium most impacted by the cycle. None of the elements of the cycle or the mechanisms linking them are original, but they collectively produce the robust nature of the NO/ONOO-cycle which creates a major challenge for treatment of HF or other proposed NO/ONOO-cycle diseases. Elevated peroxynitrite/NO ratio and consequent oxidative stress are essential to both HF and the NO/ONOO-cycle.