Novel therapeutic targets in mood disorders: Pentoxifylline (PTX) as a candidate treatment

Efficacy of pentoxifylline for the treatment of bipolar I/II patients with treatment-resistant depression: A proof-of-concept, randomized, double-blind, placebo-controlled trial

BACKGROUND

Immune dysregulation can play a role in depression pathophysiology, and immunological antagonists can improve depressive symptoms in treatment-resistant bipolar depression (TRD) patients according to studies.

OBJECTIVE

To evaluate the anti-depressant effects of the anti-inflammatory drug, pentoxifylline (PTX) in TRD bipolar I/II adult subjects.

METHODS

This 12-week, randomized, double-blind, placebo-controlled, parallel-group trial of 60 participants was conducted at Hawler Psychiatric Hospital and Private Clinic in Erbil, Iraq. Participants were confirmed as being qualified for bipolar I/II depression based on DSM-5 criteria. Data were analyzed using modified intent-to-treat analysis.

RESULTS

There were no significant differences between the two groups in Hamilton Rating Scale for Depression-17 (HAM-D-17) scores (χ2=1.9, P =.48) or a significant time × treatment interaction (χ2=7.1, P=.54). Nevertheless, a significant effect of time was observed with both groups' reduction in HAM-D-17 scores from the start to the endpoint (χ2= 2.11, P=.002). Besides, a significant time × treatment × CRP interaction was found (χ2=3.1, P=0.016), where there was more reduction in HAM-D-17 score in PTX-treated subjects with CRP> 7.1 mg/L. The response rate difference between PTX and the placebo group did not reach a significance level (χ2=0.84, p=0.43). Furthermore, serum concentrations of TNF-α, CRP, and IL-6 significantly reduced at week 12 in the PTX group (P=.007,.04, and <.001, respectively).

CONCLUSION

The current proof of concept study found that in terms of overall anti-depressant effectiveness in bipolar patients with TRD, PTX is not superior to placebo. However, it may improve depressive mood in a subpopulation of subjects with a higher pretreatment inflammatory profile.

MSK1 is required for the experience- and ampakine-dependent enhancement of spatial reference memory and reversal learning and for the induction of Arc and BDNF

There is considerable interest in the development of nootropics, pharmacological agents that can improve cognition across a range of both cognitive modalities and cognitive disabilities. One class of cognitive enhancers, the ampakines, has attracted particular attention by virtue of improving cognition associated with animal models of neurodevelopmental, neurodegenerative, and psychiatric conditions, as well as in age-related cognitive impairment. Ampakines elevate CNS levels of BDNF, and it is through this elevation that their beneficial actions are believed to occur. However, what transduces the elevation of BDNF into long-lasting cognitive enhancement is not known. We have previously shown that MSK1, by virtue of its ability to regulate gene transcription, converts the elevation of BDNF associated with environmental enrichment into molecular, synaptic, cognitive and genomic adaptations that underlie enrichment-induced enhanced synaptic plasticity and learning and memory, a property that MSK1 retains across the lifespan. To establish whether MSK1 similarly converts ampakine-induced elevations of BDNF into cognitive enhancement we tested an ampakine (CX929) in male WT mice and in male mice in which the kinase activity of MSK1 was inactivated. We found that MSK1 is required for the ampakine-dependent improvement in spatial reference memory and cognitive flexibility, and for the elevations of BDNF and the plasticity-related protein Arc associated with ampakines and experience. These observations implicate MSK1 as a key enabler of the beneficial effects of ampakines on cognitive function, and furthermore identify MSK1 as a hub for BDNF-elevating nootropic strategies.

Pentoxifylline as a Novel Add-on Therapy for Major Depressive Disorder in Adult Patients: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Evidence indicates an association between immune dysregulation and major depressive disorder (MDD). Pentoxifylline (PTX), a phosphodiesterase inhibitor, has been shown to reduce pro-inflammatory activities. The aim of this study was to evaluate changes in depressive symptoms and pro-inflammatory markers after administration of PTX as an adjunctive agent to citalopram in patients with MDD.

METHODS

One hundred patients were randomly assigned to either citalopram (20 mg/day) plus placebo (twice daily) (n=50) or citalopram (20 mg/day) plus PTX (400 mg) (twice daily) (n=50). The Hamilton Depression Rating Scale-17 (HAM-D-17) scores at baseline, weeks 2, 4, 6, 8, 10, and 12 and serum levels of interleukin1-β (IL-1-β), tumor necrosis factor-α, C-reactive protein, IL-6, serotonin, IL-10, and brain-derived neurotrophic factor (BDNF) at baseline and week 12 were evaluated.

RESULTS

HAM-D-17 score in the PTX group significantly reduced in comparison to the control group after weeks 4, 6, 8,10, and 12 ((LSMD): - 2.193, p=0.021; - 2.597, p=0.036; - 2.916, p=0.019; - 4.336, p=0.005; and - 4.087, p=0.008, respectively). Patients who received PTX had a better response (83%) and remission rate (79%) compared to the placebo group (49% and 40%, p=0.006 and p=0.01, respectively). Moreover, the reduction in serum concentrations of pro-inflammatory factors and increase in serotonin and BDNF in the PTX group was significantly greater than in the placebo group (p<0.001).

CONCLUSION

These findings support the safety and efficacy of PTX as an adjunctive antidepressant agent with anti-inflammatory effects in patients with MDD.

Pentoxifylline inhibits phosgene-induced lung injury via improving hypoxia

Inhalation of high concentrations of phosgene often causes pulmonary edema, which obstructs the airway and causes tissue hypoxia. There is currently no specific antidote. This study was performed to investigate the effect behind pentoxifylline (PTX) treatment for phosgene-induced lung injury in rat models. Rats were exposed to phosgene. The protein levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and occludin proteins in lung tissue were determined. The effect of both prophylactic and therapeutic administration of PTX (50 mg/kg and 100 mg/kg) was evaluated. The lung permeability index and HIF-1α protein level increased, the arterial blood oxygenation index (PaO2/FIO2 ratio) and occludin protein level decreased significantly 6 h after phosgene exposure (P < 0.05). PTX exerted protective effects by HIF-1α-VEGF-occludin signaling pathway to some extent. Moreover, prophylactic, but not therapeutic administration of PTX (100 mg/kg), exhibited a significant protective effect. Pretreatment with PTX protected against phosgene-induced lung injury, possibly by inhibiting differential expression of HIF-1α, VEGF, and occludin.

Pentoxifylline as adjunctive therapy in cognitive deficits and symptoms of schizophrenia: A randomized double-blind placebo-controlled clinical trial

BACKGROUND

Due to the inflammatory factors in the pathophysiology of schizophrenia, Pentoxifylline, as anti-inflammatory medication, seems to improve the symptoms of schizophrenia. This study aims to evaluate the efficacy of Pentoxifylline as an adjunctive therapy on cognitive deficits and symptoms of schizophrenia.

METHODS

This randomized double-blind placebo-controlled clinical trial was conducted on 52 patients diagnosed with chronic schizophrenia. All patients were divided into two, treatment and control groups. They received a 400 mg dose of Pentoxifylline and the placebo in the treatment and control groups, respectively, twice a day for 8 weeks. Then, they were tested with the Positive and Negative Syndrome Scale (PANSS), Wisconsin Card Sorting Test (WCST), digit span, Stroop test, and Rey Auditory and Verbal Learning Test at baseline and the end of the weeks 4 and 8. Data analysis was done by Kolmogorov-Smirnov test, t-test, Mann-Whitney test, chi-square test, and generalized estimating equation model.

RESULTS

After analyzing the data, it was revealed that the positive symptoms of PANSS, the number of errors in the incongruent Stroop test, and reaction time in the congruent Stroop test were significantly lower in the treatment group (p < 0.05). Moreover, the number of categories of WCST was significantly higher in the treatment group (p < 0.05). There was no statistically significant difference in other parameters between the control and treatment groups (p > 0.05).

CONCLUSIONS

As evidenced by the results of this study, Pentoxifylline can help alleviate schizophrenia cognitive deficits and can reduce psychotic symptoms. Therefore, it can potentially be useful for schizophrenia treatment.

Second messengers and their importance for novel drug treatments of patients with bipolar disorder

Second messenger systems, like the cyclic nucleotide, glycogen synthase kinase-3β, phosphoinositide, and arachidonic acid cascades, are involved in bipolar disorder (BD). We investigated their role on the development of novel therapeutic drugs using second messenger mechanisms. PubMed search and narrative review. We used all relevant keywords for each second messenger cascade combining it with BD and related terms and combined all with novel/innovative treatments/drugs. Our search produced 31 papers most were reviews, and focussed on the PI3K/AKT-GSK-3β/Nrf2-NF-ĸB pathways. Only two human randomized clinical trials were identified, of ebselen, an antioxidant, and celecoxib, a cyclooxygenase-2 inhibitor, both with poor unsatisfactory results. Despite the fact that all second messenger systems are involved in the pathophysiology of BD, there are few experiments with novel drugs using these mechanisms. These mechanisms are a neglected and potentially major opportunity to transform the treatment of bipolar illness.

Management of Severe Oral Inflammatory Conditions in Dogs and Cats

Severe oral inflammatory disease is not uncommon in the mouths of canine and feline patients. An approach to oral diagnosis is offered. This article discusses a brief review of important points in the oral diagnosis and management of main canine (canine chronic ulcerative stomatitis (CCUS), eosinophilic stomatitis, and Wegener's granulomatosis (WG)) and feline diseases (feline gingivostomatitis/caudal stomatitis, oral eosinophilic lesions, pyogenic granuloma, and autoimmune diseases with oral manifestations), and-whereby possible-information about the current understanding of disease pathogenesis and treatment is offered.

Pentoxifylline for treatment of major depression after percutaneous coronary intervention or coronary artery bypass grafting: A randomized, double-blind, placebo-controlled trial

INTRODUCTION

Near one-fifth of patients with coronary artery disease (CAD) develop major depressive disorder (MDD), an independent risk factor of mortality in these patients. We investigated the efficacy of oral pentoxifylline in treating MDD in CAD patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in a 6-week trial.

METHODS

We only included patients with mild to moderate MDD (having a score between 14 and 17 on the Hamilton depression rating scale (HAM-D)). Sixty-four CAD patients undergoing PCI or CABG aged 40-60 years were randomly assigned to either the pentoxifylline (800 mg daily) or the placebo group. The outcome was assessed with the HAM-D at weeks 2, 4, and 6.

RESULTS

Patients receiving pentoxifylline had greater improvement in HAM-D scores from baseline at each follow-up than patients receiving placebo (p-value = 0.036 at week 2, p-value < 0.001 at week 4, and p-value < 0.001 at week 6). We found a significant effect for treatment, time, and time×treatment interaction in depression improvement (p-value < 0.001). Rate of remission, treatment response, and adverse effects did not differ between the two groups.

DISCUSSION

Our study supports the safety and efficacy of pentoxifylline in treatment of MDD in CAD patients. However, further investigations are required to confirm the generalizability of our results since the results need to be interpreted cautiously because of the imitated range of disease severity for inclusion. This trial was registered with the Iranian Registry of Clinical Trials (www.irct.ir; No. IRCT20090117001556N132).