Adjuvant potential of selegiline in attenuating organ dysfunction in septic rats with peritonitis

Deprenyl reduces inflammation during acute SIV infection

In the era of antiretroviral therapy, inflammation is a central factor in numerous HIV-associated comorbidities, such as cardiovascular disease, cognitive impairment, and neuropsychiatric disorders. This highlights the value of developing therapeutics that both reduce HIV-associated inflammation and treat associated comorbidities. Previous research on monoamine oxidase inhibitors (MAOIs) suggests this class of drugs has anti-inflammatory properties in addition to neuropsychiatric effects. Therefore, we examined the impact of deprenyl, an MAOI, on SIV-associated inflammation during acute SIV infection using the rhesus macaque model of HIV infection. Our results show deprenyl decreased both peripheral and CNS inflammation but had no effect on viral load in either the periphery or CNS. These data show that the MAOI deprenyl may have broad anti-inflammatory effects when given during the acute stage of SIV infection, suggesting more research into the anti-inflammatory effects of this drug could result in a beneficial adjuvant for antiretroviral therapy.

Selegiline Protects Against Lipopolysaccharide (LPS)-Induced Impairment of the Blood-Brain Barrier Through Regulating the NF-κB/MLCK/p-MLC Signaling Pathway

Disruption of the blood-brain barrier (BBB) is an important hallmark of sepsis-associated encephalopathy (SAE). Selegiline, a selective and irreversible inhibitor of monoamine oxidase type B, has been applied for the treatment of nervous disorders. In this study, we aimed to investigate whether selegiline has a protective capacity in the impairment of the BBB in both in vivo and in vitro experiments. In a sepsis mouse model, administration of selegiline ameliorated lipopolysaccharide (LPS)-induced impairment of BBB integrity. Additionally, treatment with selegiline increased the expression of the tight junction protein junctional adhesion molecule A (JAM-A) against LPS. Also, we found that selegiline inhibited the production of the proinflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β. In an in vitro experimental model, bEnd.3 brain endothelial cells were exposed to LPS. Results indicate that stimulation with LPS significantly increased the permeability of bEnd.3 cells and reduced the expression of JAM-A, both of which were rescued by treatment with selegiline. Additionally, selegiline prevented the activation of the NF-κB/MLCK/p-MLC signaling pathway in LPS-challenged bEnd.3 cells. These results indicate that selegiline exerted a protective effect on BBB dysfunction, which might be attributed to the inhibition of the NF-κB/MLCK/p-MLC signaling pathway. These findings provide a basis for further research into the neuroprotective mechanism of selegiline.

Neuroprotective effects of selegiline on rat neural stem cells treated with hydrogen peroxide

Oxidative stress and reactive oxygen species generation have been implicated in the pathogenesis of several neurological disorders including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis and multiple sclerosis. In the present study, the neuroprotective effects of selegiline against hydrogen peroxide-induced oxidative stress in hippocampus-derived neural stem cells (NSCs) were evaluated. NSCs isolated from neonatal Wistar rats were pretreated with different doses of selegiline for 48 h and then exposed to 125 µM H2O2 for 30 min. Using MTT and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays, acridine orange/ethidium bromide staining and reverse transcription-quantitative polymerase chain reaction, the effects of selegiline on cell survival, apoptosis and the expression of B-cell lymphoma 2 (Bcl-2) and heat shock protein 4 (Hspa4) in pretreated stem cells were assessed compared with a control group lacking pretreatment. The results indicated that the viability of cells pretreated with 20 µM selegiline was significantly increased compared with the control group (P<0.05). Additionally, 20 µM selegiline increased the mRNA expression of Bcl-2 and Hspa4 (P<0.05 vs. control) and suppressed oxidative stress-induced cell death (apoptosis and necrosis; P<0.05 vs. control and 10 µM groups). From these findings, it was concluded that selegiline may be a therapeutic candidate for the treatment of neurological diseases mediated by oxidative stress.

Electroacupuncture Ameliorates Acute Renal Injury in Lipopolysaccharide-Stimulated Rabbits via Induction of HO-1 through the PI3K/Akt/Nrf2 Pathways

Electroacupuncture at select acupoints have been verified to protect against organ dysfunctions during endotoxic shock. And, heme oxygenase (HO)-1 as a phase II enzyme and antioxidant contributed to the protection of kidney in septic shock rats. The phosphatidylinositol 3-kinase (PI3K)-Akt pathway mediated the activation of NF-E2 related factor-2 (Nrf2), which was involved in HO-1 induction. To understand the efficacy of electroacupuncture stimulation in ameliorating acute kidney injury (AKI) through the PI3K/Akt/Nrf2 pathway and subsequent HO-1 upregulation, a dose of LPS 5mg/kg was administered intravenously to replicate the rabbit model of AKI induced by endotoxic shock. Electroacupuncture pretreatment was handled bilaterally at Zusanli and Neiguan acupoints for five consecutive days while sham electroacupuncture at non-acupoints as control. Results displayed that electroacupuncture stimulation significantly alleviated the morphologic renal damage, attenuated renal tubular apoptosis, suppressed the elevated biochemical indicators of AKI caused by LPS, enhanced the expressions of phospho-Akt, HO-1protein, Nrf2 total and nucleoprotein, and highlighted the proportions of Nrf2 nucleoprotein as a parallel. Furthermore, partial protective effects of elecroacupuncture were counteracted by preconditioning with wortmannin (the selective PI3K inhibitor), indicating a direct involvement of PI3K/Akt pathway. Inconsistently, wortmannin pretreatment made little difference to the expressions of HO-1, Nrf2 nucleoprotein and total protein, which indicated that PI3K/Akt may be not the only pathway responsible for electroacupuncture-afforded protection against LPS-induced AKI. These findings provide new insights into the potential future clinical applications of electroacupuncture for AKI induced by endotoxic shock instead of traditional remedies.

Preservation of renal blood flow by the antioxidant EUK-134 in LPS-treated pigs

Sepsis is associated with an increase in reactive oxygen species (ROS), however, the precise role of ROS in the septic process remains unknown. We hypothesized that treatment with EUK-134 (manganese-3-methoxy N,N'-bis(salicyclidene)ethylene-diamine chloride), a compound with superoxide dismutase and catalase activity, attenuates the vascular manifestations of sepsis in vivo. Pigs were instrumented to measure cardiac output and blood flow in renal, superior mesenteric and femoral arteries, and portal vein. Animals were treated with saline (control), lipopolysaccharide (LPS; 10 µg·kg-1·h-1), EUK-134, or EUK-134 plus LPS. Results show that an LPS-induced increase in pulmonary artery pressure (PAP) as well as a trend towards lower blood pressure (BP) were both attenuated by EUK-134. Renal blood flow decreased with LPS whereas superior mesenteric, portal and femoral flows did not change. Importantly, EUK-134 decreased the LPS-induced fall in renal blood flow and this was associated with a corresponding decrease in LPS-induced protein nitrotyrosinylation in the kidney. PO2, pH, base excess and systemic vascular resistance fell with LPS and were unaltered by EUK-134. EUK-134 also had no effect on LPS-associated increase in CO. Interestingly, EUK-134 alone resulted in higher CO, BP, PAP, mean circulatory filling pressure, and portal flow than controls. Taken together, these data support a protective role for EUK-134 in the renal circulation in sepsis.

An explorative study regarding the effect of l-deprenyl on cognitive and functional recovery in patients after stroke

INTRODUCTION

Selegiline (l-deprenyl) is a selective monoamine oxidase type B inhibitor that has been shown to have neurotrophic and anti-apoptotic properties and to protect neurons in different experimental models of cerebral ischaemia. The aim of this explorative study was to investigate whether selegiline could enhance cognitive and functional recovery in stroke survivors.

METHODS

This was a randomized controlled study in which patients enrolled within two weeks of stroke underwent a clinical and functional evaluation and a neuropsychological assessment. The patients were given selegiline (10mg/day) or matched placebo once a day for six weeks in addition to standard rehabilitation care.

RESULTS

Of 137 stroke survivors, 47 patients met the inclusion criteria and were randomly assigned to the Study Group (n=23) or the Control Group (n=24). The statistical analysis showed a significant improvement in most neuropsychological tests after two and six weeks in the study group; these improvements were not replicated in the control group. The between-group analysis revealed that the domains of attention and executive functions benefited most from the drug treatment. With regard to functional status, comparison of clinical scores at admission and discharge showed a statistically significant enhancement in both groups without statistically significant differences between the groups.

CONCLUSIONS

These preliminary results suggest that selegiline administered in the subacute phase can promote cognitive functioning in stroke patients. Further studies will elucidate whether and how this enhancement can impact on functional recovery in the short and in the long term.