Differential regulation of TNF alpha, IL-1 beta, IL-6, IL-8, TNF beta, and IL-10 by pentoxifylline

The regulatory role of Epinephelus Coioides miR-21 in the infection and replication of iridovirus SGIV

Iridovirus SGIV is a highly pathogenic virus of fish that can cause more than 90% mortality in Epinephelus coioides, a marine farmed fish in South China. miRNAs can be involved in regulating the development of virus-induced diseases. In this study, SGIV infection could significantly inhibit the expression of E. coioides miR-21. And, overexpressing miR-21 could inhibit the expressions of viral key genes (ICP18, VP19, LITAF and MCP), SGIV-induced CPE, and viral titers. Overexpression of miR-21 promoted the promoter activity of AP-1/NF-κB, SGIV-induced apoptosis, and activities of caspase 3/9. Inhibiting miR-21 could produce the opposite results. E. Coioides PDCD4 is a targeting gene of miR-21, and we speculate that PDCD4 downregulation may, at least in part, explain the observed antiviral effects. These studies indicate that miR-21 could inhibit the infection and replication of SGIV, which might provide a molecular basis for further exploring the mechanism of SGIV invasion.

Pentoxifylline in COVID-19 and considerations for its research in long COVID

INTRODUCTION

Pentoxifylline (PTX) affects most blood components and the blood vessels, potentially modulating various conditions. Due to its impact on markers linked to COVID-19 severity, research has explored PTX for acute COVID-19. Following the widespread administration of COVID-19 vaccinations, there has been a notable and consistently growing increase in research focusing on long COVID. Consequently, our examination of relevant acute COVID-19 data shall additionally be contextualized into long COVID research.

METHODS

Various Databases were searched until July 2024 for all primary clinical studies on Pentoxifylline (PTX) in COVID-19.

RESULTS

Studies were on acute infection with SARS-CoV-2 where PTX was an adjuvant to standard therapy for ethical and practical reasons under the circumstance. PTX generally reduced hospitalization duration and improved some inflammatory markers, but its impact on mortality was inconsistent. Adverse events were minimal. Meta-analysis revealed a significant reduction in hospitalization duration.

CONCLUSION

This systematic review and meta-analysis suggest that adding pentoxifylline (PTX) to standard COVID-19 therapy may significantly reduce hospitalization duration and improve some inflammatory markers. However, its impact on mortality rates is inconclusive. Adverse events are minimal. PTX can be favorable as an add-on in managing acute COVID-19 and could reduce the risk of long COVID, as well as assist in managing many of its most common symptoms.

A neuroprotective effect of pentoxifylline in rats with diabetic neuropathy: Mitigation of inflammatory and vascular alterations

BACKGROUND

Treatment of diabetic neuropathic pain does not change the natural history of neuropathy. Improved glycemic control is the recommended treatment in these cases, given that no specific treatment for the underlying nerve damage is available, so far. In the present study, the potential neuroprotective effect of pentoxifylline in streptozotocin (50 mg/kg) induced diabetic neuropathy in rats was investigated.

METHODS

Pentoxifylline was administered at doses equivalent to 50, 100 & 200 mg/kg, in drinking water, starting one week after streptozotocin injection and for 7 weeks. Mechanical allodynia, body weight and blood glucose level were assessed weekly. Epidermal thickness of the footpad skin, and neuroinflammation and vascular alterations markers were assessed.

RESULTS

Tactile allodynia was less in rats that received pentoxifylline at doses of 100 and 200 mg/kg (60 % mechanical threshold increased by 48 % and 60 %, respectively). The decrease in epidermal thickness of footpad skin was almost completely prevented by the same doses. This was associated with a decrease in spinal tumor necrosis factor alpha (TNFα) and nuclear factor kappa B levels and a decrease in microglial ionized calcium binding adaptor molecule 1 immunoreactivity, compared to the control diabetic group. In sciatic nerve, there was decrease in TNF-α and vascular endothelial growth factor levels and intercellular adhesion molecule immunoreactivity.

CONCLUSION

Pentoxifylline showed a neuroprotective effect in streptozotocin-induced diabetic neuropathy, which was associated with a suppression of both the inflammatory and vascular pathogenic pathways that was not associated with a hypoglycemic effect. Thus, it may represent a potential neuroprotective drug for diabetics.

Parsimonious Effect of Pentoxifylline on Angiogenesis: A Novel Pentoxifylline-Biased Adenosine G Protein-Coupled Receptor Signaling Platform

Angiogenesis is the physiological process of developing new blood vessels to facilitate the delivery of oxygen and nutrients to meet the functional demands of growing tissues. It also plays a vital role in the development of neoplastic disorders. Pentoxifylline (PTX) is a vasoactive synthetic methyl xanthine derivative used for decades to manage chronic occlusive vascular disorders. Recently, it has been proposed that PTX might have an inhibitory effect on the angiogenesis process. Here, we reviewed the modulatory effects of PTX on angiogenesis and its potential benefits in the clinical setting. Twenty-two studies met the inclusion and exclusion criteria. While sixteen studies demonstrated that pentoxifylline had an antiangiogenic effect, four suggested it had a proangiogenic effect, and two other studies showed it did not affect angiogenesis. All studies were either in vivo animal studies or in vitro animal and human cell models. Our findings suggest that pentoxifylline may affect the angiogenic process in experimental models. However, there is insufficient evidence to establish its role as an anti-angiogenesis agent in the clinical setting. These gaps in our knowledge regarding how pentoxifylline is implicated in host-biased metabolically taxing angiogenic switch may be via its adenosine A2BAR G protein-coupled receptor (GPCR) mechanism. GPCR receptors reinforce the importance of research to understand the mechanistic action of these drugs on the body as promising metabolic candidates. The specific mechanisms and details of the effects of pentoxifylline on host metabolism and energy homeostasis remain to be elucidated.

Effectiveness of pentoxifylline in severe early-onset fetal growth restriction: A randomized double-blinded clinical trial

OBJECTIVE

Management of pregnancy complicated by severe early-onset fetal growth restriction (FGR) is one of the most challenging obstetrical issues. So far, there has not been a proven option for the treatment or improvement of this condition. Improper immune response during placentation leads to inadequate trophoblast invasion and impaired utero-placental perfusion. Pentoxifylline improves the endothelial function and induces vasodilation by reducing the inflammatory-mediated cytokines. We have evaluated the effect of Pentoxifylline on fetal-placental perfusion, neonatal outcome, and the level of oxidative stress markers before and after the intervention in the setting of severe early-onset FGR.

MATERIALS AND METHODS

This study is a pilot randomized clinical trial on 40 pregnant women who had developed early-onset growth restricted fetus. Pentoxifylline and placebo were given with a dose of 400 mg per os two times daily until delivery. Serial ultrasound examination regarding fetal weight, amniotic fluid and also utero-placenta-fetal Doppler's were done. For the assessment of serum Antioxidant level, blood sampling was done once at the beginning of the study and again, at least, three weeks after the investigation. After delivery, umbilical-cord blood gas analysis, APGAR score at 1 and 5 min, NICU admission, and neonatal death were recorded and compared between the two groups.

RESULTS

Utero-placenta-fetal Doppler's in the Pentoxifylline group did not significantly change compared to the control group. Fetal weight gain was significantly higher in the Pentoxifylline group before (996.33 ± 317.41) and after (1616.89 ± 527.90) treatment (P = 0.002). Total serum antioxidant capacity significantly increased in the Pentoxifylline group (p < 0.036). Average 5 min Apgar score was significantly higher (P < 0.036) and the percentage of babies admitted to NICU was significantly lower (P < 0.030) in the treated group.

CONCLUSION

Using Pentoxifylline in pregnancy affected by FGR might show promising effects. In this study, Pentoxifylline improved the neonatal outcome, increased fetal weight gain, and reduced neonatal mortality by decreasing the level of oxidative stress markers and cutting down the inflammatory cascade.

Treatment of Poor Sperm Quality and Erectile Dysfunction With Oral Pentoxifylline: A Systematic Review

Background: Pentoxifylline (PTX) is a member of methylxanthine chemicals and a type of non-selective phosphodiesterase-5 inhibitors, which has been used in male infertility treatment to improve sperm quality and erectile dysfunction (ED) treatment. Mutually tight associations existed between ED and male infertility. Using PTX might kill two birds with one stone by improving sperm quality and erectile function in infertile men with ED. Methods: PubMed, Cochrane Library, EMBASE, and Web of Science were searched by October 2021. Based on available evidence from observational studies and randomized-controlled trials (RCTs), we conducted a systematic review to summarize the efficacy and safety of PTX in treating ED and male infertility. The protocol of the article was registered and updated in PROSPERO (CRD42021291396). Results: From 202 records, eight studies (7 RCTs) evaluating the role of PTX in ED and three studies (2 RCTs) assessing the efficacy of PTX in male infertility were included in the systematic review. Three studies (100.00%) and two studies (100.00%) reported the beneficial role of PTX in improving sperm progressive motility and normal sperm morphology rate, respectively. In contrast, only one study (33.33%) indicated the favorable role of PTX in enhancing sperm concentration. As for ED, three (60.00%) studies supported the treatment role of PTX alone in ED, and two studies (66.67%) favored the combination use of PTX and selective PDE5Is compared with selective PDE5Is alone. Safety analysis showed that PTX was a well-tolerated drug in ED and male infertility treatment. Conclusion: Given the association between ED and male infertility and satisfying findings from available evidence, PTX administration for the simultaneous treatment of poor sperm quality and mild ED in infertile men will highly enhance the treatment compliance. However, the finding should be treated carefully until validated by further studies.

Efficacy and safety of pentoxifylline combination therapy in major depressive disorder: a randomized, double-blind, placebo-controlled clinical trial

In this randomized, double-blind, placebo-controlled clinical trial, we assessed the efficacy and safety of pentoxifylline combination therapy with sertraline in treatment of major depressive disorder (MDD). A total of 56 patients with MDD were assigned into two parallel groups to receive sertraline (100 mg/day) plus placebo or sertraline (100 mg/day) plus pentoxifylline (400 mg three times daily) for six weeks. Patients were evaluated with the Hamilton rating scale for depression (HAM-D) at baseline and weeks 2, 4 and 6. The sertraline plus pentoxifylline group demonstrated greater improvement in HAM-D scores from baseline to all three study time points (P = 0.013, 0.007 and 0.016 for week 2, 4 and 6, respectively). Response to treatment rate was also significantly higher in the sertraline plus pentoxifylline group compared to the sertraline plus placebo group at week 4 [57.1 vs. 21.4%, P = 0.013] and the study endpoint [96.4 vs. 57.1%, P = 0.001]. However, the remission rate, time to remission and time to treatment response did not show any significant difference between trial groups. Our findings support the efficacy and safety of pentoxifylline combination therapy in patients with MDD.

A Neonatal Murine Escherichia coli Sepsis Model Demonstrates That Adjunctive Pentoxifylline Enhances the Ratio of Anti- vs. Pro-inflammatory Cytokines in Blood and Organ Tissues

Introduction: Neonatal sepsis triggers an inflammatory response that contributes to mortality and multiple organ injury. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses pro-inflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that administration of PTX in addition to antibiotics decreases live bacteria-induced pro-inflammatory and/or enhances anti-inflammatory cytokine production in septic neonatal mice without augmenting bacterial growth.

Methods: Newborn C57BL/6J mice (< 24 h old) were injected intravenously with 10⁵ colony forming units (CFUs)/g weight of a bioluminescent derivative of the encapsulated clinical isolate Escherichia coli O18:K1. Adequacy of intravenous injections was validated using in vivo bioluminescence imaging and Evans blue. Pups were treated with gentamicin (GENT), PTX, (GENT + PTX) or saline at 0, 1.5, or 4 h after sepsis initiation, and euthanized after an additional 4 h. CFUs and cytokines were measured from blood and homogenized organ tissues.

Results: GENT alone inhibited bacterial growth, IL-1β, and IL-6 production in blood and organs. Addition of PTX to GENT profoundly inhibited E. coli-induced TNF and enhanced IL-10 in blood of newborn mice at all timepoints, whereas it primarily upregulated IL-10 production in peripheral organs (lung, spleen, brain). PTX, whether alone or adjunctive to GENT, did not increase microbial colony counts in blood and organs.

Conclusion: Addition of PTX to antibiotics in murine neonatal E. coli sepsis promoted an anti-inflammatory milieu through inhibition of plasma TNF and enhancement of IL-10 production in plasma and organs without increasing bacterial growth, supporting its utility as a potential adjunctive agent for newborn sepsis.

Current and Future Treatments in the Fight Against Non-Alcoholic Fatty Liver Disease

Obesity is recognised as a risk factor for many types of cancers, in particular hepatocellular carcinoma (HCC). A critical factor in the development of HCC from non-alcoholic fatty liver disease (NAFLD) is the presence of non-alcoholic steatohepatitis (NASH). Therapies aimed at NASH to reduce the risk of HCC are sparse and largely unsuccessful. Lifestyle modifications such as diet and regular exercise have poor adherence. Moreover, current pharmacological treatments such as pioglitazone and vitamin E have limited effects on fibrosis, a key risk factor in HCC progression. As NAFLD is becoming more prevalent in developed countries due to rising rates of obesity, a need for directed treatment is imperative. Numerous novel therapies including PPAR agonists, anti-fibrotic therapies and agents targeting inflammation, oxidative stress and the gut-liver axis are currently in development, with the aim of targeting key processes in the progression of NASH and HCC. Here, we critically evaluate literature on the aetiology of NAFLD-related HCC, and explore the potential treatment options for NASH and HCC.

Pentoxifylline Alone or in Combination with Gentamicin or Vancomycin Inhibits Live Microbe-Induced Proinflammatory Cytokine Production in Human Cord Blood and Cord Blood Monocytes In Vitro

Neonatal sepsis and its accompanying inflammatory response contribute to substantial morbidity and mortality. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses transcription and production of proinflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that PTX decreases live microbe-induced inflammatory cytokine production in newborn blood. Cord blood was stimulated with live microorganisms commonly encountered in newborn sepsis (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, or Candida albicans) and simultaneously treated with antimicrobial agents (gentamicin, vancomycin, or amphotericin B) and/or clinically relevant concentrations of PTX. Microbial colony counts were enumerated by plating, supernatant cytokines were measured by multiplex assay, intracellular cytokines and signaling molecules were measured by flow cytometry, and mRNA levels were measured by quantitative reverse transcription-PCR. PTX inhibited concentration-dependent E. coli-, S. aureus-, S. epidermidis-, and C. albicans-induced tumor necrosis factor (TNF) and E. coli-induced interleukin-1β (IL-1β) production in whole blood, with greater suppression of proinflammatory cytokines in combination with antimicrobial agents. Likewise, PTX suppressed E. coli-induced monocytic TNF and IL-1β, whereby combined PTX and gentamicin led to significantly greater reduction of TNF and IL-1β. The anti-inflammatory effect of PTX on microbe-induced proinflammatory cytokine production was accompanied by inhibition of TNF mRNA expression and was achieved without suppressing the production of the anti-inflammatory IL-10. Of note, microbial colony counts in newborn blood were not increased by PTX. Our findings demonstrated that PTX inhibited microbe-induced proinflammatory cytokine production, especially when combined with antimicrobial agents, without enhancing microbial proliferation in human cord blood in vitro, thus supporting its utility as candidate adjunctive agent for newborn sepsis.

Misoprostol Inhibits Lipopolysaccharide-Induced Pro-inflammatory Cytokine Production by Equine Leukocytes

Pro-inflammatory cytokines including tumor necrosis factor α (TNFα), IL-1β, IL-6, and IL-8 are potent immune mediators that exacerbate multiple equine diseases such as sepsis and laminitis. Unfortunately, safe and effective cytokine-targeting therapies are lacking in horses; therefore, novel mechanisms of inhibiting cytokine production are critically needed. One potential mechanism for inhibiting cytokine synthesis is elevation of intracellular cyclic AMP (cAMP). In human leukocytes, intracellular cAMP production is induced by activation of E-prostanoid (EP) receptors 2 and 4. These receptors can be targeted by the EP2/4 agonist and prostaglandin E1 analog, misoprostol. Misoprostol is currently used as a gastroprotectant in horses but has not been evaluated as a cytokine-targeting therapeutic. Thus, we hypothesized that misoprostol treatment would inhibit pro-inflammatory cytokine production by lipopolysaccharide (LPS)-stimulated equine leukocytes in an in vitro inflammation model. To test this hypothesis, equine leukocyte-rich plasma (LRP) was collected from 12 healthy adult horses and used to model LPS-mediated inflammatory signaling. LRP was treated with varying concentrations of misoprostol either before (pretreated) or following (posttreated) LPS stimulation. LRP supernatants were assayed for 23 cytokines using an equine-specific multiplex bead immunoassay. Leukocytes were isolated from LRP, and leukocyte mRNA levels of four important cytokines were evaluated via RT-PCR. Statistical differences between treatments were determined using one-way RM ANOVA (Holm-Sidak post hoc testing) or Friedman's RM ANOVA on Ranks (SNK post hoc testing), where appropriate (p < 0.05, n = 3-6 horses). These studies revealed that misoprostol pre- and posttreatment inhibited LPS-induced TNFα and IL-6 protein production in equine leukocytes but had no effect on IL-8 protein. Interestingly, misoprostol pretreatment enhanced IL-1β protein synthesis following 6 h of LPS stimulation, while misoprostol posttreatment inhibited IL-1β protein production after 24 h of LPS stimulation. At the mRNA level, misoprostol pre- and posttreatment inhibited LPS-induced TNFα, IL-1β, and IL-6 mRNA production but did not affect IL-8 mRNA. These results indicate that misoprostol exerts anti-inflammatory effects on equine leukocytes when applied before or after a pro-inflammatory stimulus. However, the effects we observed were cytokine-specific and sometimes differed at the mRNA and protein levels. Further studies are warranted to establish the inhibitory effects of misoprostol on equine cytokine production in vivo.

Effects of pentoxifylline on inflammatory markers and blood pressure: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Pentoxifylline is a xanthine derivative with potential cardiovascular benefits.

AIM

To evaluate the impact of pentoxifylline on blood pressure (BP) and plasma TNF-α, C-reactive protein (CRP) and IL-6 through a systematic review and meta-analysis of randomized controlled trials.

METHODS

The protocol was registered (PROSPERO: CRD42016035988). The search included PUBMED, ProQuest, Scopus and EMBASE until 1 September 2015 to identify trials reporting BP or inflammatory markers during pentoxifylline therapy. Quantitative data synthesis was performed using a random-effects model, with weighted mean difference (WDF) and 95% confidence intervals (CIs) as summary statistics.

RESULTS

Fifteen studies (16 treatment arms) were found to be eligible for inclusion. Meta-analysis did not suggest any effect of pentoxifylline on either SBP or DBP. Pentoxifylline treatment was associated with a significant reduction in plasma concentrations of TNF-α (WDF: -1.03 pg/ml, 95% CI: -1.54, -0.51; P < 0.001, 11 treatment arms) and CRP (WDF: -1.39 mg/l, 95% CI: -2.68, -0.10; P = 0.034, five treatment arms). No alteration in plasma IL-6 concentration was observed. The impact of pentoxifylline on plasma TNF-α levels was found to be positively associated with treatment duration (slope: 0.031; 95% CI: 0.004, 0.057; P = 0.023) but independent of pentoxifylline dose (slope: -0.0003; 95% CI: -0.002, 0.001; P = 0.687).

CONCLUSION

Pentoxifylline did not alter BP or plasma IL-6 concentration, but significantly reduced circulating TNF-α and CRP concentrations.

The effect of pentoxifylline on L-1 sarcoma tumor growth and angiogenesis in Balb/c mice

Methyloxantines are present in many herbs and vegetal foods, among them in tea, coffee and chocolate. Previous studies revealed that theophylline and theobromine have anti-angiogenic properties. Anti-tumor properties of theobromine were also described. Pentoxifylline (3,7-dimethyl-1-(5-oxohexyl)xanthine, PTX) is a synthetic xanthine derivative. It is a phosphodiesterase inhibitor and has various anti-inflammatory abilities. Pentoxifylline is widely used in therapy of inflammatory arterial diseases such as intermittent claudication of upper and lower limbs as well as in coronary heart disease. The aim of our research was to evaluate the effect of pentoxifylline (individually and in combination with non-steroidal anti-inflammatory drug sulindac), on L-1 sarcoma angiogenic activity and tumor formation in syngeneic Balb/c mice. Pre-incubation of tumor cells for 90 min with various PTX concentrations resulted in dose-dependent decrease of their ability to induce newly-formed blood vessels after transplantation into the skin of recipient mice. Administration of PTX to mice, recipients of tumor cells, slows tumor growth and reduces its volume. Synergistic inhibitory effect of PTX and sulindac, expressed as % of tumors sixth and thirteen day after subcutaneous grafting of L-1 sarcoma into syngeneic Balb/c mice, was observed.

Pentoxifylline modulates LPS-induced hyperinflammation in monocytes of preterm infants in vitro

BackgroundPentoxifylline (PTX), a methylxanthine derivate with immunomodulating properties, has been used as adjunctive treatment in severe neonatal sepsis. The aim of the study was to investigate the anti-inflammatory effects of PTX on Lipopolysaccharides (LPS)-stimulated monocytes of preterm neonates in vitro compared with monocytes of term infants and adult controls.MethodsWhole cord blood samples and control adult blood samples were incubated with LPS and PTX. The expression of surface markers, phagocytosis, cytokine secretion, and Toll-like receptor (TLR)4 signaling of monocytes were assessed by flow cytometry. Changes of TLR4-messenger RNA (mRNA) levels were confirmed by reverse-transcriptase PCR.ResultsThe expression of CD14, CD11b, CD64, CD71, and CD80 was downregulated by PTX in a dose-dependent manner; the greatest effect was observed on CD14 and CD11b in preterm infants. PTX markedly downregulated LPS-induced tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 levels in all age groups. Early IL-10 production was significantly downregulated by PTX in term and preterm neonates, while remaining unchanged in adults. Moreover, PTX downregulated TLR4 expression of monocytes on cellular and mRNA level, decreased signaling, and suppressed phagocytosis.ConclusionPTX downregulated TLR4 expression and signaling, thereby leading to strong anti-inflammatory properties in monocytes. Age-dependent differences were identified for CD14 and CD11b expression and IL-10 production.

Pentoxifylline inhibits TLR- and inflammasome-mediated in vitro inflammatory cytokine production in human blood with greater efficacy and potency in newborns

BACKGROUND

Toll-like receptor (TLR)-mediated inflammation may contribute to neonatal sepsis, for which pentoxifylline (PTX), a phosphodiesterase inhibitor that raises intracellular cAMP, is a candidate adjunctive therapy. We characterized the anti-inflammatory effects of PTX toward TLR-mediated production of inflammatory (tumor necrosis factor (TNF) and interleukin (IL)-1β) and proresolution (IL-6 and IL-10) cytokines in human newborn and adult blood.

METHODS

Newborn cord and adult blood were treated with PTX (50-400 µmol/l) before, during or after stimulation with LPS (TLR4 agonist), R848 (TLR7/8 agonist) or LPS/ATP (inflammasome activation). Cytokines were measured by multiplex assay (supernatants), intracellular cytokines and signaling molecules by flow cytometry, and mRNA by quantitative real-time PCR.

RESULTS

Whether added 2 h pre-, simultaneously to, or 2 h post-TLR stimulation, PTX inhibited TLR-mediated cytokine production in a concentration-dependent manner, with greater efficacy and potency in newborn blood, decreasing intracellular TNF and IL-1β with relative preservation of IL-10 and IL-6. PTX decreased TLR-mediated TNF mRNA while increasing IL-10 mRNA. Neonatal plasma factors contributed to the anti-inflammatory effects of PTX in newborn blood that were independent of soluble TNF receptor concentrations, p38 MAPK phosphorylation and IĸB degradation.

CONCLUSION

PTX is a potent and efficacious inhibitor of TLR-mediated inflammatory cytokines in newborn cord blood and a promising neonatal anti-inflammatory agent.

Effect of bucladesine, pentoxifylline, and H-89 as cyclic adenosine monophosphate analog, phosphodiesterase, and protein kinase A inhibitor on acute pain

The aim of this study was to determine the effects of cyclic adenosine monophosphate (cAMP) and its dependent pathway on thermal nociception in a mouse model of acute pain. Here, we studied the effect of H-89 (protein kinase A inhibitor), bucladesine (Db-cAMP) (membrane-permeable analog of cAMP), and pentoxifylline (PTX; nonspecific phosphodiesterase (PDE) inhibitor) on pain sensation. Different doses of H-89 (0.05, 0.1, and 0.5 mg/100 g), PTX (5, 10, and 20 mg/100 g), and Db-cAMP (50, 100, and 300 nm/mouse) were administered intraperitoneally (I.p.) 15 min before a tail-flick test. In combination groups, we injected the first and the second compounds 30 and 15 min before the tail-flick test, respectively. I.p. administration of H-89 and PTX significantly decreased the thermal-induced pain sensation in their low applied doses. Db-cAMP, however, decreased the pain sensation in a dose-dependent manner. The highest applied dose of H-89 (0.5 mg/100 g) attenuated the antinociceptive effect of Db-cAMP in doses of 50 and 100 nm/mouse. Surprisingly, Db-cAMP decreased the antinociceptive effect of the lowest dose of H-89 (0.05 mg/100 g). All applied doses of PTX reduced the effect of 0.05 mg/100 g H-89 on pain sensation; however, the highest dose of H-89 compromised the antinociceptive effect of 20 mg/100 g dose of PTX. Co-administration of Db-cAMP and PTX increased the antinociceptive effect of each compound on thermal-induced pain. In conclusion, PTX, H-89, and Db-cAMP affect the thermal-induced pain by probably interacting with intracellular cAMP and cGMP signaling pathways and cyclic nucleotide-dependent protein kinases.

Therapies in non-alcoholic steatohepatitis (NASH)

The hallmark of non-alcoholic fatty liver disease (NAFLD) is excessive fatty accumulation in the hepatocytes, which may be an isolated event (non-alcoholic fatty liver, NAFL) or accompanied by evidence of inflammation and cell injury with or without fibrosis (non-alcoholic steatohepatitis, NASH). NASH, the more aggressive form of NAFLD, may progress to cirrhosis and hepatocellular carcinoma. Since NASH is estimated to overtake hepatitis C virus infection as the leading cause of liver transplantation in the US in the coming decade, and there are no current FDA-approved therapies for this disease, the need to find appropriate therapeutic targets is now more urgent than ever before. Diet and other lifestyle modifications have always been difficult to maintain and this approach alone has not slowed the rising tide of the disease. While the results of traditional therapies such as vitamin E and pioglitazone have been significant for steatosis and inflammation, they have had no effect on fibrosis, which is the strongest indicator of mortality in this condition. However, the understanding of the pathogenesis and progression of NASH has evolved and several promising novel therapies to target and possibly reverse fibrosis are being evaluated, making the future outlook of NASH therapy more optimistic.

Hypothesis: Pentoxifylline explores new horizons in treatment of preeclampsia

Preeclampsia, the leading cause of maternal morbidity and perinatal mortality, initiates as inappropriate immune response to trophoblastic invasion impairs placentation and placental circulation. A poorly perfused placenta generates superoxide anions as well as anti-angiogenic factors and this series of events result in impairment of endothelial function, followed by maternal morbidities such as hypertension, kidney injury and proteinuria. Renal loss of anti-coagulant proteins and subsequent hyper-coagulable state along with endothelial dysfunction accelerates progression of the disease toward eclampsia. Since Pentoxifylline, a methyl-xanthine derivative known for enhancement of vascular endothelial function, down-regulation of many inflammatory cytokines increased during preeclampsia, improvement of placental circulation, reduction of ischemia-reperfusion injury, enhancement of vasodilatation and endothelial function, ameliorating proteinuria, inhibition of platelet aggregation and decreasing risk of preterm labor, which are all amongst morbidities of preeclampsia, here it is hypothesized that Pentoxifylline prevents development of preeclampsia and/or decelerate progression of the disease.

Lipoic acid and pentoxifylline mitigate nandrolone decanoate-induced neurobehavioral perturbations in rats via re-balance of brain neurotransmitters, up-regulation of Nrf2/HO-1 pathway, and down-regulation of TNFR1 expression

Behavioral perturbations associated with nandrolone decanoate abuse by athletes and adolescents may be attributed to oxidative stress and inflammation. However, the underlying mechanisms are not yet fully explored. On the other hand, the natural antioxidant lipoic acid can pass the blood brain barrier and enhance Nrf2/HO-1 (nuclear factor erythroid-2 related factor 2/heme oxygenase-1) pathway. In addition, the phosphodiesterase-IV inhibitor xanthine derivative pentoxifylline has a remarkable inhibitory effect on tumor necrosis factor-alpha (TNF-α). Therefore, this study aimed at investigation of the possible protective effects of lipoic acid and/or pentoxifylline against nandrolone-induced neurobehavioral alterations in rats. Accordingly, male albino rats were randomly distributed into seven groups and treated with either vehicle, nandrolone (15mg/kg, every third day, s.c.), lipoic acid (100mg/kg/day, p.o.), pentoxifylline (200mg/kg/day, i.p.), or nandrolone with lipoic acid and/or pentoxifylline. Rats were challenged in the open field, rewarded T-maze, Morris water maze, and resident-intruder aggression behavioral tests. The present findings showed that nandrolone induced hyperlocomotion, anxiety, memory impairment, and aggression in rats. These behavioral abnormalities were accompanied by several biochemical changes, including altered levels of brain monoamines, GABA, and acetylcholine, enhanced levels of malondialdehyde and TNF-α, elevated activity of acetylcholinesterase, and up-regulated expression of TNF-α receptor-1 (TNFR1). In addition, inhibited catalase activity, down-regulated Nrf2/HO-1 pathway, and suppressed acetylcholine receptor expression were observed. Lipoic acid and pentoxifylline combination significantly mitigated all the previously mentioned deleterious effects mainly via up-regulation of Nrf2/HO-1 pathway, inhibition of TNF-α and down-regulation of TNFR1 expression. In conclusion, the biochemical and histopathological findings of this study revealed the protective mechanisms of lipoic acid and pentoxifylline against nandrolone-induced behavioral changes and neurotoxicity in rats.

Ex vivo host and parasite response to antileishmanial drugs and immunomodulators

Background

Therapeutic response in infectious disease involves host as well as microbial determinants. Because the immune and inflammatory response to Leishmania (Viannia) species defines the outcome of infection and efficacy of treatment, immunomodulation is considered a promising therapeutic strategy. However, since Leishmania infection and antileishmanial drugs can themselves modulate drug transport, metabolism and/or immune responses, immunotherapeutic approaches require integrated assessment of host and parasite responses.

Methodology

To achieve an integrated assessment of current and innovative therapeutic strategies, we determined host and parasite responses to miltefosine and meglumine antimoniate alone and in combination with pentoxifylline or CpG 2006 in peripheral blood mononuclear cells (PBMCs) of cutaneous leishmaniasis patients. Parasite survival and secretion of TNF-α, IFN-γ, IL-10 and IL-13 were evaluated concomitantly in PBMCs infected with Luc-L. (V.) panamensis exposed to meglumine antimoniate (4, 8, 16, 32 and 64 μg Sb^V/mL) or miltefosine (2, 4, 8, 16 and 32 μM HePC). Concentrations of 4 μM of miltefosine and 8 μg Sb^V/mL were selected for evaluation in combination with immunomodulators based on the high but partial reduction of parasite burden by these antileishmanial concentrations without affecting cytokine secretion of infected PBMCs. Intracellular parasite survival was determined by luminometry and cytokine secretion measured by ELISA and multiplex assays.

Principal Findings

Anti- and pro-inflammatory cytokines characteristic of L. (V.) panamensis infection were evaluable concomitantly with viability of Leishmania within monocyte-derived macrophages present in PBMC cultures. Both antileishmanial drugs reduced the parasite load of macrophages; miltefosine also suppressed IL-10 and IL-13 secretion in a dose dependent manner. Pentoxifylline did not affect parasite survival or alter antileishmanial effects of miltefosine or meglumine antimoniate. However, pentoxifylline diminished secretion of TNF-α, IFN-γ and IL-13, cytokines associated with the outcome of infection by species of the Viannia subgenus. Exposure to CpG diminished the leishmanicidal effect of meglumine antimoniate, but not miltefosine, and significantly reduced secretion of IL -10, alone and in combination with either antileishmanial drug. IL-13 increased in response to CpG plus miltefosine.

Conclusions and Significance

Human PBMCs allow integrated ex vivo assessment of antileishmanial treatments, providing information on host and parasite determinants of therapeutic response that may be used to tailor therapeutic strategies to optimize clinical resolution.

Host determinants of the response to infection have increasingly been recognized as therapeutically relevant targets. Despite the pathogenesis of dermal leishmaniasis being mediated by the immune and inflammatory response, in vitro anti-leishmanial drug screening has been based on antimicrobial effect without consideration of effects on the host response. The results of this study show that peripheral blood mononuclear cells from patients allow an integrated evaluation of both antimicrobial efficacy and host response to drugs, immunomodulatory agents, and their combinations. This integrated approach to defining treatment strategies based on host and parasite responses opens the way for the optimization and tailoring of treatment to different clinical circumstances.

Medical treatments for endometriosis-associated pelvic pain

The main sequelae of endometriosis are represented by infertility and chronic pelvic pain. Chronic pelvic pain causes disability and distress with a very high economic impact. In the last decades, an impressive amount of pharmacological agents have been tested for the treatment of endometriosis-associated pelvic pain. However, only a few of these have been introduced into clinical practice. Following the results of the controlled studies available, to date, the first-line treatment for endometriosis associated pain is still represented by oral contraceptives used continuously. Progestins represent an acceptable alternative. In women with rectovaginal lesions or colorectal endometriosis, norethisterone acetate at low dosage should be preferred. GnRH analogues may be used as second-line treatment, but significant side effects should be taken into account. Nonsteroidal anti-inflammatory drugs are widely used, but there is inconclusive evidence for their efficacy in relieving endometriosis-associated pelvic pain. Other agents such as GnRH antagonist, aromatase inhibitors, immunomodulators, selective progesterone receptor modulators, and histone deacetylase inhibitors seem to be very promising, but there is not enough evidence to support their introduction into routine clinical practice. Some other agents, such as peroxisome proliferator activated receptors-γ ligands, antiangiogenic agents, and melatonin have been proven to be efficacious in animal studies, but they have not yet been tested in clinical studies.

Pentoxifylline does not alter the concentration of hepcidin in chronic kidney disease patients undergoing hemodialysis

INTRODUCTION

Anemia is a frequent condition in patients with chronic kidney disease due to a reduction in the production of erythropoietin. Patients with inflammation respond less well to treatment with erythropoietin, possibly because the increased production of hepcidin reduces the availability of iron for hematopoiesis. Some studies suggest that pentoxifylline has anti-inflammatory properties and could be used as adjuvant therapy in the treatment of anemia.

OBJECTIVE

The aim of this study was to analyze the effect of pentoxifylline on serum hepcidin in chronic hemodialysis patients with inflammation.

METHODS

71 adult patients on hemodialysis with C-reactive protein (CRP) ≥0.5 mg/dl in screening tests; patients were randomized to the treatment group (oral pentoxifylline 400 mg/thrice-weekly) or the control group for 3 months follow-up.

RESULTS

During the study, a decrease in hemoglobin, transferrin saturation, and hepcidin was observed in both groups. However, these reductions were related to the time and not to the drug. There was no difference in the concentrations of CRP, ferritin, and albumin over time in either group.

CONCLUSIONS

The use of this amount of pentoxifylline did not modify the serum levels of hepcidin in this population.

Antibacterial and anti-inflammatory effects of Syzygium jambos L. (Alston) and isolated compounds on acne vulgaris

BACKGROUND

Acne vulgaris is a chronic skin disorder leading to inflammation as a result of the production of reactive oxygen species due to the active involvement of Propionibacterium acnes (P. acnes) in the infection site of the skin. The current study was designed to assess the potential of the leaf extract of Syzygium jambos L. (Alston) and its compounds for antibacterial and anti-inflammatory activity against the pathogenic P. acnes.

METHODS

The broth dilution method was used to assess the antibacterial activity. The cytotoxicity investigation on mouse melanocyte (B16-F10) and human leukemic monocyte lymphoma (U937) cells was done using sodium 3'-[1-(phenyl amino-carbonyl)-3,4-tetrazolium]-bis-[4-methoxy-6-nitrobenzene sulfonic acid hydrate (XTT) reagent. The non-toxic concentrations of the samples was investigated for the suppression of cytokines interleukin 8 (IL 8) and tumour necrosis factor (TNF α) by testing the supernatants in the co-culture of the human U937 cells and heat killed P. acnes using enzyme immunoassay kits (ELISA). The statistical analysis was done using the Graph Pad Prism 4 program.

RESULTS

Bioassay guided isolation of ethanol extract of the leaves of S. jambos led to the isolation of three known compounds namely; squalene, an anacardic acid analogue and ursolic acid which are reported for the first time from this plant. The ethanol extract of S. jambos and one of the isolated compound namely, anacardic acid analogue were able to inhibit the growth of P. acnes with a noteworthy minimum inhibitory concentration (MIC) value of 31.3 and 7.9 μg/ml, respectively. The ethanol extract and three commercially acquired compounds namely; myricetin, myricitrin, gallic acid exhibited significant antioxidant activity with fifty percent inhibitory concentration (IC50) ranging between 0.8-1.9 μg/ml which was comparable to that of vitamin C, the reference antioxidant agent. The plant extract, compounds ursolic acid and myricitrin (commercially acquired) significantly inhibited the release of inflammatory cytokines IL 8 and TNF α by suppressing them by 74 - 99%. TEM micrographs showed the lethal effects of selected samples against P. acnes.

CONCLUSIONS

The interesting antibacterial, antioxidant and anti-inflammatory effects of S. jambos shown in the present study warrant its further investigation in clinical studies for a possible alternative anti-acne agent.

Preventive and therapeutic anti-TNF-α therapy with pentoxifylline decreases arthritis and the associated periodontal co-morbidity in mice

AIMS

The association between rheumatoid arthritis (RA) and periodontal disease (PD) has long been studied and some reports suggest that treating RA may improve the associated PD, and vice versa. This study aimed to evaluate the effects of an anti-tumor necrosis factor (TNF)-α therapy with pentoxifylline (PTX) in an experimental model of RA-associated PD.

MAIN METHODS

Male C57BL/6 mice were subjected to chronic antigen-induced arthritis (AIA) and daily treated with PTX (50mg/kg, i.p.) using preventive (Pre-PTX) or therapeutic (The-PTX) strategies. Fourteen days after the antigen challenge, mice were euthanized and knee joints, maxillae and serum were collected for microscopic and/or immunoenzymatic analysis.

KEY FINDINGS

AIA triggered significant leukocyte recruitment to the synovial cavity, tissue damage and proteoglycan loss in the knee joint. Pre-PTX and The-PTX regimens decreased these signs of joint inflammation. The increased levels of TNF-α and IL-17 in periarticular tissues of AIA mice were also reduced by both PTX treatments. Serum levels of C-reactive protein, which were augmented after AIA, were reduced by the PTX regimens. Concomitantly to AIA, mice presented alveolar bone loss, and recruitment of osteoclasts and neutrophils to periodontal tissues. Pre-PTX and The-PTX prevented and treated these signs of PD. PTX treatment also decreased TNF-α and increased IL-10 expression in the maxillae of AIA mice, although it did not affect the expression of IFN-γ and IL-17.

SIGNIFICANCE

The current study shows the anti-inflammatory and bone protective effects of preventive and therapeutic PTX treatments, which decreased the joint damage triggered by AIA and the associated periodontal co-morbidity.

Curbing the focal adhesion kinase and its associated signaling events by pentoxifylline in MDA-MB-231 human breast cancer cells

Pentoxifylline (PTX) is a methylxanthine derivative currently being used in the treatment of peripheral vascular diseases. Recently, we had evaluated its action in human MDA-MB-231 breast cancer cells. PTX exhibited anti-metastatic activity by affecting key processes such as proliferation, adhesion, migration, invasion and apoptosis. In light of the preliminary findings, the present work accounts for the possible mechanistic insights of the pathways affected by PTX. Aberrant Focal Adhesion Kinase (FAK) signaling forms a key determinant in breast cancer and in view of this fact we had investigated downstream processes regulated by FAK. PTX at sub-toxic doses lowers the level of activated FAK, Extracellular Regulated Kinase or Mitogen Activated Protein Kinase (ERK/MAPK), Protein Kinase B (PKB/Akt) affecting cellular proliferation and survival. It blocks G1/S phase of cell cycle by inhibiting the expression of Cyclin D1/Cdk6. Further, it modulates the activities of RhoGTPases and alters actin organization resulting in decreased motility. PTX also delays tumor growth and inhibited blood vessel formation in vivo. In purview of these findings, PTX surely qualifies as a suitable prospect in the intervention of breast cancer.

Immunomodulatory properties of pentoxifylline are mediated via adenosine-dependent pathways

The phosphodiesterase inhibitor pentoxifylline (PTX) exerts multiple beneficial immunomodulatory effects in states of hyperinflammation. However, the exact mechanism of action still remains elusive, and the clinical effects of PTX cannot be reliably predicted. In immune cells, the G protein-coupled adenosine A2A receptor (A2AR) exerts strong anti-inflammatory effects. As PTX amplifies signaling pathways downstream of Gs protein-coupled receptors, the A2AR-signaling pathway might be involved in the mediation of immune-suppressive effects of PTX. Here, we investigated this assumption in LPS-stimulated human polymorphonuclear (PMN) leukocytes and in anti-CD3/CD28-stimulated human T cells. In stimulated PMN leukocytes, PTX treatment led to a 4.5-fold decrease of the 50% inhibitory concentrations of adenosine on the H2O2 production; i.e., for adenosine plus PTX (in clinically relevant concentrations), an overadditive increase of inhibitory effects from less than 20% (estimated for each) to 56% (+/-5%) was found. In T cells, adenosine plus PTX revealed similar synergistic inhibitory effects on proinflammatory cytokine production. Inhibition of interferon gamma and TNF-alpha production increased from 7% (+/-1%) and 31% (+/-6%) (PTX alone) to 49% (+/-2%) and 69% (+/-6%), respectively. In T cells and PMN leukocytes, mRNA transcription of the A2AR was significantly increased upon stimulation, which was not influenced by PTX. In human PMN leukocytes and T cells, clinically relevant anti-inflammatory effects of PTX can be achieved only in the presence of sufficient adenosine concentrations. Sufficient adenosine levels might be a prerequisite for the accessibility of sepsis patients to treatment with PTX.

Effect of pentoxifylline on semen parameters, reproductive hormones, and seminal plasma antioxidant capacity in men with idiopathic infertility: a randomized double-blind placebo-controlled study

OBJECTIVE

To determine the safety and efficacy of oral pentoxifylline (PTX) administration in improving semen parameters in infertile men with idiopathic OAT.

PATIENTS AND METHODS

The study included 254 infertile men who underwent double-blind therapy with 400 mg PTX (Apotex Inc., Toronto, Canada) twice daily (group 1, n = 127), or similar regimen of placebo (group 2, n = 127). The study consisted of a 4-week screening phase, a 24-week treatment phase, and a 12-week treatment-free period. The effects of treatment on semen parameters, serum hormones including testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin B, seminal plasma catalase-like and superoxide dismutase (SOD)-like activity, and acrosome reaction test were evaluated.

RESULTS

A significant increase in sperm concentration (mean value, 26.4 ± 4.6 × 10(6)/ml vs. 16.2 ± 3.4 × 10(6)/ml), sperm motility (mean value, 35.8 ± 4.2% vs. 26.4 ± 2.4%), and sperm with normal morphology (mean value, 25.4 ± 4.3% vs. 17.4 ± 4.2%) was observed after PTX administration when compared with baseline (all P = 0.001); in contrast, a subtle decreased values were observed after placebo (median values, 16.4 ± 4.1 × 10(6)/ml vs. 16.7 ± 3.6 × 10(6)/ml, P = 0.1; 25.7 ± 3.6% vs. 26.8 ± 2.5%, P = 0.08; and 16.9 ± 4.1% vs. 17.6 ± 4.4%, P = 0.08, respectively). Mean SOD-like and catalase-like activity in the semen of PTX group was significantly greater than in the semen of placebo group (46.4 ± 2.4 vs. 36.3 ± 1.3 U/ml and 371 ± 44 vs. 301 ± 14 U/ml, respectively, both P = 0.003). The acrosome reaction was observed to be increased in PTX group (P = 0.01). Levels of reproductive hormones were also affected.

CONCLUSIONS

PTX administration significantly improves semen parameters in infertile men with idiopathic OAT.

Involvement of phosphodiesterases in autoimmune diseases

We have previously shown that several phosphodiesterase (PDE) subtypes are up-regulated in muscles and lymph node cells (LNC) of rats with experimental autoimmune myasthenia gravis (EAMG). In the present study we investigated PDE expression during the course of EAMG and experimental allergic encephalomyelitis (EAE) and found that the up-regulated expression of selected PDE subtypes in both experimental models is correlated with disease severity. In EAMG, PDE expression is correlated also with muscle damage. A similar up-regulation of PDE was also observed in the respective human diseases, MG and multiple sclerosis (MS). Our findings suggest that change in PDE expression levels is a general phenomenon in autoimmune diseases and may also be used as a marker for disease severity.

Inhibition of brain proinflammatory cytokine synthesis reduces hypothalamic excitation in rats with ischemia-induced heart failure

The expression of proinflammatory cytokines increases in the hypothalamus of rats with heart failure (HF). The pathophysiological significance of this observation is unknown. We hypothesized that hypothalamic proinflammatory cytokines upregulate the activity of central neural systems that contribute to increased sympathetic nerve activity in HF, specifically, the brain renin-angiotensin system (RAS) and the hypothalamic-pituitary-adrenal (HPA) axis. Rats with HF induced by coronary ligation and sham-operated controls (SHAM) were treated for 4 wk with a continuous intracerebroventricular infusion of the cytokine synthesis inhibitor pentoxifylline (PTX, 10 microg/h) or artificial cerebrospinal fluid (VEH). In VEH-treated HF rats, compared with VEH-treated SHAM rats, the hypothalamic expression of proinflammatory cytokines was increased, along with key components of the brain RAS (renin, angiotensin-converting enzyme, angiotensin type 1 receptor) and corticotropin-releasing hormone, the central indicator of HPA axis activation, in the paraventricular nucleus (PVN) of the hypothalamus. The expression of other inflammatory/excitatory mediators (superoxide, prostaglandin E(2)) was also increased, along with evidence of chronic neuronal excitation in PVN. VEH-treated HF rats had higher plasma levels of norepinephrine, ANG II, interleukin (IL)-1beta, and adrenocorticotropic hormone, increased left ventricular end-diastolic pressure, and increased wet lung-to-body weight ratio. With the exception of plasma IL-1beta, an indicator of peripheral proinflammatory cytokine activity, all measures of neurohumoral excitation were significantly lower in HF rats treated with intracerebroventricular PTX. These findings suggest that the increase in brain proinflammatory cytokines observed in rats with ischemia-induced HF is functionally significant, contributing to neurohumoral excitation by activating brain RAS and the HPA axis.

Comparative effects of several therapatic agents on hepatic damage induced by acute experimental pancreatitis

PURPOSE

The prognosis of acute pancreatitis (AP) depends upon the degree of pancreatic necrosis and the intensity of multisystem organ failure. The liver contributes to the systemic manifestations of AP by releasing some cytokines. This study was undertaken to examine comparative effects of melatonin, antioxidant mixture containing L(+)-ascorbic acid and N-acetyl cysteine, pentoxifylline and L-arginine on hepatic damage induced by caerulein-pancreatitis.

RESULTS

The liver specimens of all groups showed histopathological alterations such as hepatocyte necrosis, intracellular vacuolization, vascular congestion, sinusoidal dilatation and inflammatory infiltration. TEM studies revealed vacuole formation, mitochondrial degeneration, lysosome accumulation and necrosis. The mean histopathological score of the caerulein group was significantly different from that of each treatment group.

CONCLUSION

L-Arginine and antioxidant administration be important for reducing hepatic damage induced by AP. Improvement of hepatic damage, in turn, might be beneficial for the prognosis of AP.

Pentoxifylline reduces pro-inflammatory and increases anti-inflammatory activity in patients with coronary artery disease—A randomized placebo-controlled study

The balance between different immunological stimuli is essential in the progression and stabilization of atherosclerotic plaques. Immune regulation has been suggested as potential target for the treatment of atherosclerotic disease. We sought to determine whether treatment with pentoxifylline, a phosphodiesterase inhibitor with immunomodulating properties, could reduce the pro-inflammatory response observed in patients with acute coronary syndromes (ACS) and increase anti-inflammatory activity. In a double-blind, prospective, placebo-controlled study, 64 patients with ACS were randomized to receive pentoxifylline 400mg TID or placebo for 6 months. Analysis of the pro-inflammatory markers, C-reactive protein (CRP), interleukin (IL)-6, IL-12, interferon-gamma and tumor necrosis factor (TNF)-alpha and the anti-inflammatory cytokines, transforming growth factor (TGF)-beta1 and IL-10 were done at baseline, 1 and 6 months. Pentoxifylline treatment significantly reduced the adjusted levels of CRP and TNF-alpha compared to placebo after 6 months (P=0.04 and P<0.01, respectively). IL-12 increase was significantly less pronounced with pentoxifylline (P=0.04). The levels of the anti-inflammatory cytokine, IL-10, also declined significantly less in the pentoxifylline group compared to placebo (P<0.01) with a trend towards a higher increase of TGF-beta1 in the former group (P=0.16). Pentoxifylline reduces pro-inflammatory and increases anti-inflammatory response in patients with ACS and may have beneficial clinical effects on cardiovascular events.

Hypertonic saline and pentoxifylline attenuates gut injury after hemorrhagic shock: the kinder, gentler resuscitation

BACKGROUND

We have previously demonstrated that postshock resuscitation with Hypertonic saline and Pentoxifylline (HSPTX) attenuates pulmonary and histologic gut injury when compared with Ringer's lactate (RL). In this study, we hypothesized that the decrease in gut injury observed with HSPTX is associated with the attenuation of inducible nitric oxide synthase (iNOS) activity and production of ileal proinflammatory mediators after hemorrhagic shock.

METHODS

In a rat model of hemorrhagic shock, resuscitation was conducted with RL (32 mL/kg; n = 7) or HSPTX (4 mL/kg 7.5% NaCl + PTX 25 mg/kg; n = 7). Sham animals that did not undergo shock were also studied. Four hours after resuscitation, the terminal ileum was collected for evaluation of nitrite, tumor necrosis factor (TNF)-alpha, Interleukin (IL)-6, and cytokine-induced neutrophil chemoattractant (CINC) by enzyme immunoassay. Heme oxygenase-1 (HO-1), iNOS, cytoplasmic inhibitor of kappa B (Ikappa B) phosphorylation, and nuclear factor (NF)kappa B p65 nuclear translocation were determined by Western blot.

RESULTS

HSPTX resuscitation resulted in a 49% decrease in iNOS when compared with RL (p < 0.05). Similar results were obtained when examining nitrite (882 +/- 59 vs. 1,435 +/- 177 micromol/L; p < 0.01), and HO-1 content (p < 0.05). RL resuscitation resulted in markedly higher levels of TNF-alpha (83 +/- 27 vs. 9 +/- 5 pg/mL; p < 0.01), IL-6 (329 +/- 58 vs. 118 +/- 43 pg/mL; p < 0.05), and CINC (0.43 +/- .06 vs. 0.19 +/- .08 ng/mL; p < 0.05) than HSPTX. The increase in cytokines observed with RL was also associated with an increase in I-kappaB phosphorylation (p < 0.01) and NF-kappaB p65 nuclear translocation (p < 0.001).

CONCLUSION

The attenuation in gut injury after postshock resuscitation with HSPTX is associated with downregulation of iNOS activity and subsequent proinflammatory mediator synthesis. HSPTX has the potential to be a superior resuscitation fluid with significant immunomodulatory properties.

Pentoxifylline attenuates the development of hyperalgesia in a rat model of neuropathic pain

Pentoxifylline, a non-specific cytokine inhibitor, has shown to be beneficial in inflammatory pain in both experimental and clinical studies. The present study demonstrates for the first time, to our knowledge, the antihyperalgesic effect of pentoxifylline in the neuropathic pain using L5 spinal nerve transection rat model. In a preventive paradigm, pentoxifylline (12.5, 25, 50, or 100mg/kg intraperitoneally) was administered systemically daily, beginning 1h prior to nerve transection. Pentoxifylline (50, or 100mg/kgi.p.) produced significant decrease in the mechanical and thermal hyperalgesia. However, pentoxifylline (100mg/kgi.p.) did not influence the paw pressure thresholds and paw withdrawal latency in sham-operated rats. In order to understand the possible antinocicieptive effect of pentoxifylline in neuropathic pain, we examined the level of TNFalpha, IL-1beta, IL-6 and IL-10 protein in the contralateral brain on day 7 post-transection. Pentoxifylline administration resulted in a dose-dependent reduction of the production of proinflammatory cytokines like TNFalpha, IL-1beta and IL-6, and enhancement of IL-10. Furthermore, we investigated the activity of nuclear factor kappa B (NF-kappaB) in the contralateral brain on days 7 after surgery. In accordance with the change of proinflammatory cytokines, Pentoxifylline (50 or 100mg/kg) significantly inhibited the activation of NF-kappaB in the brain. This research supports a growing body of literature emphasizing the importance of neuroinflammation and neuroimmune activation in the development of neuropathic pain states, and the potential preventive value of pentoxifylline in the treatment of neuropathic pain.

Pharmacokinetics of Intranasal and Intratracheal Pentoxifylline in Rabbits

STUDY OBJECTIVE

To evaluate the disposition of pentoxifylline and its metabolite, lisofylline, in New Zealand rabbits after two alternative routes of administration, intranasal and intratracheal.

DESIGN

Pharmacokinetics study in an animal model.

SETTING

University-affiliated animal care facility.

SUBJECTS

Twenty New Zealand white rabbits divided into four groups of five rabbits each: group 1 did not receive study drug (control group), and groups 2, 3, and 4 evaluated intravenous, intranasal, and intratracheal routes of administration, respectively.

INTERVENTION

Each rabbit in groups 2-4 received pentoxifylline as a single 20-mg/kg dose by their respective route of administration.

MEASUREMENTS AND MAIN RESULTS

Blood samples were collected over a 24-hour period and were analyzed by using high-performance liquid chromatography-tandem mass spectrometry. The pharmacokinetic parameters evaluated were area under the concentration-time curve from time zero extrapolated to infinity (AUC(0-infinity)), maximum concentration (Cmax), time to maximum concentration (Tmax), elimination rate constant (k(el)), and half-life (t1/2). Median pentoxifylline pharmacokinetic parameters after intravenous administration were AUC(0-infinity) 5420 ng x hr/ml, Cmax 16,727 ng/ml, Tmax 5 minutes, k(el) 0.036 minute(-1), and t1/2 19 minutes. Median pharmacokinetic parameters after intranasal and intratracheal administration, respectively, were AUC(0-infinity) 4224 and 6824 ng x hr/ml, Cmax 11,181 and 16,758 ng/ml, Tmax 5 and 5 minutes, k(el) 0.028 and 0.032 minute(-1), and t1/2 25 and 22 minutes. The metabolite, lisofylline, displayed a similar disposition after the three different routes of administration.

CONCLUSION

The pharmacokinetic profiles after intranasal and intratracheal administration of pentoxifylline appear similar to those after intravenous administration. These data provide support for development of pentoxifylline intranasal and intratracheal dosage formulations that would be suitable for use in premature neonates.

Inflammation and Oxidative Stress Markers by Pentoxifylline Treatment in Rats with Chronic Renal Failure and High Sodium Intake

BACKGROUND

Inflammation is a risk factor for mortality in patients with chronic renal failure (CRF). Prevention of extracellular fluid volume expansion and the use of certain drugs such as pentoxifylline (PF) may reduce inflammation and oxidative stress. The aim of this study is to analyze the effect of dietary sodium and PF treatment on the levels of inflammation and oxidative stress markers in rats with CRF.

METHODS

CRF was induced in rats by 5/6 nephrectomy. Different groups of rats with CRF received low sodium (LNa, 0.01% sodium chloride [NaCl] in the diet), normal sodium (NNa, 0.05% NaCl in the diet), or high sodium diet (HNa, as in NNa plus 0.015% NaCl in the drinking water). An additional group received HNa plus PF treatment (25 mg/kg in the drinking water) for 60 days. Circulating creatinine, tumor necrosis factor alpha (TNF-alpha), nitrites, thiols, malondialdehyde (MDA), and advanced oxidation protein products (AOPP) were measured.

RESULTS

Higher sodium intake was associated with higher serum creatinine levels (median; interquartile range), LNa, 1.255; 0.715, NNa, 1.305; 0.495, HNa, 2.015; 1.115 mg/dL (p < 0.05), TNF-alpha levels, LNa, 2.7; 23.6, NNa, 36.7; 47.7, HNa, 263.7; 126.5 pg/mL, and AOPP, LNa, 31.72; 7.55, NNa, 45.89; 9.38, HNa, 60.41; 37.42 microg/mL. MDA was not modified by sodium intake. PF treatment decreased serum TNF-alpha (151.7 pg/mL, p < 0.5) and AOPP (49.83 micromol/L, p < 0.03), and increased nitrites and thiols levels when compared with HNa rats.

CONCLUSIONS

High sodium intake increases the serum concentration of inflammation and oxidative stress markers; these changes are prevented by PF treatment.

Novel effect of mineralocorticoid receptor antagonism to reduce proinflammatory cytokines and hypothalamic activation in rats with ischemia-induced heart failure

Blocking brain mineralocorticoid receptors (MRs) reduces the high circulating levels of tumor necrosis factor (TNF)-alpha in heart failure (HF) rats. TNF-alpha and other proinflammatory cytokines activate neurons in the paraventricular nucleus (PVN) of hypothalamus, including corticotropin-releasing hormone (CRH) neurons, by inducing cyclooxygenase (COX)-2 activity and synthesis of prostaglandin E2 by perivascular cells of the cerebral vasculature. We tested the hypothesis that systemic treatment with a MR antagonist would reduce hypothalamic COX-2 expression and PVN neuronal activation in HF rats. Rats underwent coronary ligation to induce HF, confirmed by echocardiography, or sham surgery, followed by 6 weeks treatment with eplerenone (30 mg/kg per day, orally) or vehicle (drinking water). Eplerenone-treated HF rats had lower plasma TNF-alpha, interleukin (IL)-1beta and IL-6, less COX-2 staining of small blood vessels penetrating PVN, fewer PVN neurons expressing Fra-like activity (indicating chronic neuronal activation), and fewer PVN neurons staining for TNF-alpha, IL-1beta, and CRH than vehicle-treated HF rats. COX-2 and CRH protein expression in hypothalamus were 1.7- and 1.9-fold higher, respectively, in HF+vehicle versus sham+vehicle rats; these increases were attenuated (26% and 25%, respectively) in HF+eplerenone rats. Eplerenone-treated HF rats had less prostaglandin E2 in cerebrospinal fluid, lower plasma norepinephrine levels, lower left ventricular end-diastolic pressure, and lower right ventricle/body weight and lung/body weight ratios, but no improvement in left ventricular function. Treatment of HF rats with anticytokine agents, etanercept or pentoxifylline, produced very similar results. This study reveals a previously unrecognized effect of MR antagonism to minimize cytokine-induced central neural excitation in rats with HF.

Pentoxifylline and its major oxidative metabolites exhibit different pharmacological properties

Previous investigations indicate that some of the metabolites of the hemorheological agent pentoxifylline (PTX), namely 1-(5-hydroxyhexyl)-3,7-dimethylxanthine (M1), 1-(4-carboxybutyl)-3,7-dimethylxanthine (M4) and 1-(3-carboxypropyl)-3,7-dimethylxanthine (M5), concur to some of the biological effects of the drug. However, information on the bioactivity of the major circulating oxidative metabolites of PTX (M4 and M5) is scanty. Here, we compared the effects of M4 and M5 with that of PTX and its major reductive metabolite, M1, on TNF-alpha production and cytotoxicity, endothelial cell proliferation and on the ATPase activity related to some ATP-binding cassette (ABC) transporters. Unlike PTX and M1, M4 and M5 poorly inhibited lipopolysaccaride-stimulated tumor necrosis factor-alpha (TNF-alpha) release by RAW 264.7 murine macrophages, and did not affect at all cell proliferation and upregulation of TNF-alpha-induced vascular cell adhesion molecule-1 (VCAM-1) in H5V endothelioma cells. By contrast, M4 and M5 were more effective than PTX and M1 in protecting WC/1 murine fibrosarcoma cells from TNF-alpha cytotoxicity. Moreover, results from ATP hydrolase assays indicated that neither PTX nor its tested metabolites interacted significantly with the human multidrug resistance transporters p-glycoprotein/multidrug resistance 1 (MDR1), multidrug resistance-related protein 1 (MRP1), and breast cancer resistance protein (BCRP). Based on these results and literature data, M5, retaining some of the PTX effects but lacking in significant inhibition of TNF-alpha production, may be a promising candidate drug for certain pathologic conditions.

Pharmacokinetics and oral bioavailability of pentoxyfylline in broiler chickens

The pharmacokinetic properties of pentoxyfylline and its metabolites were determined in healthy chickens after single intravenous and oral dosage of 100 mg/kg pentoxyfylline. Plasma concentrations of pentoxyfylline and its metabolites were determined by a validated high-performance liquid chromatographic method. After intravenous (i.v.) and oral (p.o.) administration, the plasma concentration-time curves were best described by a one-compartment open model. The mean elimination half-life (t(1/2el)) of pentoxyfylline was 1.05 h, total body clearance 1.90 L/h x kg, volume of distribution 2.40 L/kg and the mean residence time was 2.73 h, after i.v. administration. After oral dosing, mean maximal plasma concentration of pentoxyfylline was 4.01 microg/mL and the interval from p.o. administration until maximum concentration was 1.15 h. The mean oral bioavailability was found to be 28.2%. Metabolites I, IV and V were present in chicken plasma after both i.v. and p.o. administration, with metabolite V being the most dominant.

Effects of the tumour necrosis factor-alpha inhibitors pentoxifylline and thalidomide in short-term experimental oral mucositis in hamsters

Oral mucositis is a frequent side-effect of cancer therapy. A definitive method of prophylaxis or treatment is not yet available. As pentoxifylline (PTX) and thalidomide (TLD) have been shown to inhibit cytokine synthesis, we studied the effects of these cytokine inhibitors in an experimental oral mucositis model. Oral mucositis was induced in Golden hamsters by the administration of 5-fluorouracil (5-FU) followed by mechanical trauma of the cheek pouch. On days 4, 5, 10, 12, 14 and 16, lesions induced by 5-FU were examined macroscopically and microscopically, and the presence and intensity of hyperemia, erythema, edema, inflammatory cell infiltration, hemorrhagic areas, ulcers and abscesses were recorded. Saline (control), PTX (5, 15, 45 mg kg(-1)) or TLD (10, 30, 90 mg kg(-1)) were administered daily and animals were killed on day 10 for macroscopic and histological analysis and assay of myeloperoxidase (MPO) activity. Animals were weighed daily, and total and differential leukocyte counts were performed on peripheral blood. PTX and TLD were found to reduce the macroscopic and histological parameters of oral mucositis and MPO activity. PTX and TLD also reversed peripheral neutrophilia, but only PTX prevented weight loss. The results indicate a protective effect of PTX and TLD, suggesting an important role for tumour necrosis factor-alpha (TNF-alpha) in the pathophysiology of 5-FU induced-oral mucositis in hamsters.