Efficacy and safety evaluation of safinamide as an add-on treatment to levodopa for parkinson's disease

Safinamide as adjunctive therapy to levodopa monotherapy for patients with Parkinson's disease with wearing-off: The Japanese observational J-SILVER study

BACKGROUND

Safinamide is an effective adjunctive therapy for wearing-off in Parkinson's disease (PD); however, evidence is lacking in older patients and those in the early stages of wearing-off. This study evaluated the efficacy and safety of safinamide as adjunctive therapy in patients with PD treated with levodopa monotherapy in clinical practice.

METHODS

This multicentre, open-label observational study was conducted at five sites in Japan. Patients diagnosed with PD and wearing-off initiated safinamide as adjunctive therapy with levodopa monotherapy. Efficacy endpoints were mean changes in Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part I, III, and IV scores; daily ON-time without dyskinesia using 24-h patient symptom diaries; and 39-item Parkinson's Disease Questionnaire (PDQ-39) scores at 18 weeks of treatment.

RESULTS

In total, 24 patients initiated safinamide (66.7% were aged ≥75 years); the mean duration of wearing-off was 1.2 years. MDS-UPDRS Part III total score, Part IV total score, and PDQ-39 summary index decreased significantly from baseline (mean change -7.0 [p = 0.012], -2.4 [p = 0.007] and - 5.3 [p = 0.012], respectively). There was a non-statistically significant increase of 1.55 h in mean daily ON-time without dyskinesia. Numerical Rating Scale total score for pain (p = 0.015), and scores for OFF-period pain (p = 0.012) and nocturnal pain (p = 0.021) subdomains were significantly improved in the subgroup with pain. Most reported adverse events were classified as mild.

CONCLUSION

Safinamide improved motor and non-motor symptoms and quality of life-related measures in older patients with PD in the early stages of wearing-off without new safety concerns.

STUDY REGISTRATION

University Hospital Medical Information Network in Japan; study ID: UMIN000044341.

Safinamide, an inhibitor of monoamine oxidase, modulates the magnitude, gating, and hysteresis of sodium ion current

BACKGROUND

Safinamide (SAF), an α-aminoamide derivative and a selective, reversible monoamine oxidase (MAO)-B inhibitor, has both dopaminergic and nondopaminergic (glutamatergic) properties. Several studies have explored the potential of SAF against various neurological disorders; however, to what extent SAF modulates the magnitude, gating, and voltage-dependent hysteresis [Hys(V)] of ionic currents remains unknown.

METHODS

With the aid of patch-clamp technology, we investigated the effects of SAF on voltage-gated sodium ion (NaV) channels in pituitary GH3 cells.

RESULTS

SAF concentration-dependently stimulated the transient (peak) and late (sustained) components of voltage-gated sodium ion current (INa) in pituitary GH3 cells. The conductance-voltage relationship of transient INa [INa(T)] was shifted to more negative potentials with the SAF presence; however, the steady-state inactivation curve of INa(T) was shifted in a rightward direction in its existence. SAF increased the decaying time constant of INa(T) induced by a train of depolarizing stimuli. Notably, subsequent addition of ranolazine or mirogabalin reversed the SAF-induced increase in the decaying time constant. SAF also increased the magnitude of window INa induced by an ascending ramp voltage Vramp. Furthermore, SAF enhanced the Hys(V) behavior of persistent INa induced by an upright isosceles-triangular Vramp. Single-channel cell-attached recordings indicated SAF effectively increased the open-state probability of NaV channels. Molecular docking revealed SAF interacts with both MAO and NaV channels.

CONCLUSION

SAF may interact directly with NaV channels in pituitary neuroendocrine cells, modulating membrane excitability.

Ginsenoside Rg1 attenuates D-galactose-induced neural stem cell senescence via the Sirt1-Nrf2-BDNF pathway

With the ageing of society's population, neurodegenerative diseases have become an important factor affecting the quality of life and mortality in the elderly. Since its physiopathological processes are complex and the authorized medications have recently been shown to have several adverse effects, the development of safe and efficient medications is urgently needed. In this study, we looked at how ginsenoside Rg1 works to postpone neural stem cell ageing and brain ageing, giving it a solid scientific foundation for use as a therapeutic therapy for neurodegenerative diseases.

Neuroprotective effect of Ginsenoside Re against neurotoxin‑induced Parkinson's disease models via induction of Nrf2

The aim of the present study was to examine the neuroprotective effects of a panel of active components of ginseng and to explore their molecular mechanisms of action in two rotenone (Rot)-induced models of Parkinson's disease: An in vitro model using the human neuroblastoma cell line SH-SY5Y and an in vivo model using Drosophila. Ginsenoside Re (Re) was identified as the most potent inhibitor of Rot-induced cytotoxicity in SH-SY5Y cells by Cell Counting kit-8 assay and lactate dehydrogenase release assay. Flow cytometry, Hoechst staining, Rhodamine 123 staining, ATP and cytochrome c release revealed that Re rescue of Rot-induced mitochondrial dysfunction and inhibition of the mitochondrial apoptotic pathway. Western blot analysis demonstrated that Re alleviated Rot-induced oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) anti-oxidant pathway, and these effects were abolished by RNA interference-mediated knockdown of Nrf2. Re enhanced phosphorylation of components of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and extracellular regulated protein kinase (ERK) pathways, and pharmacological inhibition of these pathways reduced Re-mediated Nrf2 activation and neuroprotection. In the Drosophila model, Immunofluorescence microscopy, reactive oxygen species (ROS), hydrogen peroxide and knockdown analysis revealed that Re reversed Rot-induced motor deficits and dopaminergic neuron loss while concomitantly alleviating Rot-induced oxidative damage. The findings of the present study suggest that Re protects neurons against Rot-induced mitochondrial dysfunction and oxidative damage, at least in part, by inducing Nrf2/heme oxygenase-1 expression and activation of the dual PI3K/AKT and ERK pathways.