Siponimod As a Novel Inhibitor of Retinal Angiogenesis: In Vitro and In Vivo Evidence of Therapeutic Efficacy.

Sphingosine-1-phosphate (S1P) receptors control endothelial cell proliferation, migration, and survival. Evidence of the ability of S1P receptor modulators to influence multiple endothelial cell functions suggests their potential use for antiangiogenic effect. The main purpose of our study was to investigate the potential of siponimod for the inhibition of ocular angiogenesis in vitro and in vivo. We investigated the effects of siponimod on the metabolic activity (thiazolyl blue tetrazolium bromide assay), cell toxicity (lactate dehydrogenase release), basal proliferation and growth factor-induced proliferation (bromodeoxyuridine assay), and migration (transwell migration assay) of human umbilical vein endothelial cells (HUVEC) and retinal microvascular endothelial cells (HRMEC). The effects of siponimod on HRMEC monolayer integrity, barrier function under basal conditions, and tumor necrosis factor alpha (TNF-α)-induced disruption were assessed using the transendothelial electrical resistance and fluorescein isothiocyanate-dextran permeability assays. Siponimod's effect on TNF-α-induced distribution of barrier proteins in HRMEC was investigated using immunofluorescence. Finally, the effect of siponimod on ocular neovascularization in vivo was assessed using suture-induced corneal neovascularization in albino rabbits. Our results show that siponimod did not affect endothelial cell proliferation or metabolic activity but significantly inhibited endothelial cell migration, increased HRMEC barrier integrity, and reduced TNF-α-induced barrier disruption. Siponimod also protected against TNF-α-induced disruption of claudin-5, zonula occludens-1, and vascular endothelial-cadherin in HRMEC. These actions are mainly mediated by sphingosine-1-phosphate receptor 1 modulation. Finally, siponimod prevented the progression of suture-induced corneal neovascularization in albino rabbits. In conclusion, the effects of siponimod on various processes known to be involved in angiogenesis support its therapeutic potential in disorders associated with ocular neovascularization. SIGNIFICANCE STATEMENT: Siponimod is an extensively characterized sphingosine-1-phosphate receptor modulator already approved for the treatment of multiple sclerosis. It inhibited retinal endothelial cell migration, potentiated endothelial barrier function, protected against tumor necrosis factor alpha-induced barrier disruption, and also inhibited suture-induced corneal neovascularization in rabbits. These results support its use for a novel therapeutic indication in the management of ocular neovascular diseases.

Failure of the vascular hypothesis of multiple sclerosis in a rat model of chronic cerebrospinal venous insufficiency.

Chronic cerebrospinal venous insufficiency (CCSVI) is a series of stenotic malformations in the cerebrospinal venous outflow routes, which is postulated to cause multiple sclerosis (MS). The hypotheses assumed that CCSVI leads to iron deposition which triggers inflammation and demyelination in MS. Invasive endovascular treatment of CCSVI was initiated based on the previous theory. The present study was designed to validate this hypothesis using a rat model of CCSVI. Bilateral jugular vein ligation (JVL) was performed on female albino rats (n = 15), and sham-operated rats (n = 15) were used as a control group. The rats were followed clinically for eight months and neurological examination detected no weakness or paralysis in the operated rats. At the end of the experiment, the rats were sacrificed and the brains were processed for histopathological examination of tissue sections stained by hematoxylin and eosin, myelin stain, silver impregnation, iron stain and immunohistochemical preparations for GFAP, CD68 and CD45. Semithin sections stained with toluidine blue were also examined. In the JVL group, increased iron deposition in the white matter was detected. An increase in the size and number of astrocytes along with increased GFAP immunoreactivity denoting reactive gliosis was also noted in the JVL group. However, no signs of demyelination, inflammation or axonopathy were detected. This study revealed that iron deposition in the JVL group as a model for CCSVI was not associated with cardinal histopathological findings of MS. It is therefore recommended that the invasive endovascular treatment of CCSVI should be reconsidered and further controlled clinical studies be carried out to provide a better understanding of the pathogeneses of MS..

An electron microscopic study of the antifertility potential of rosemary (Rosmarinus officinalis L) in male albino rats / Estudio de microscopía electrónica del potencial antifertilidad del Romero (Rosmarinus officinalis L) en ratas macho albinas

The present work was aimed at studying the antifertility potential of the commonly used herb, rosemary in the male albino rats using electron microscopy as the method of investigation. Ethanolic extract of the rosmary prepared and administered orally in two different doses for a period of three months to the animals. At the end of the experiment animals were sacrificed and testes removed. Sections for the electrone microscopy prepared and changes were observed. The present results showed evident microscopic changes in the testis of the animals received higher dose of the drug. Most of the seminiferous tubules were compressed, having irregular basement membrane and devoid of any spermatogenic cells. The present work revealed a clear morphological evidence of the dose dependent antifertility potential of the rosemary in the male albino rats.

El trabajo tuvo como objetivo estudiar el potencial anti-fertilidad de la hierba de uso común, el romero, en ratas albinas macho utilizando microscopía electrónica como método de investigación. El extracto etanólico del romero se preparó y administró por vía oral a los animales en dos dosis diferentes durante un período de tres meses. Los animales experimentales se sacrificaron y se retiraron sus testículos. Se prepararon secciones para microscopía electrónica y se observaron los cambios. Los resultados mostraron cambios microscópicos evidentes en los testículos de los animales que recibieron una dosis mayor del medicamento. La mayoría de los túbulos seminíferos se observaron comprimidos, con una membrana basal irregular y carente de células espermatogénicas. El presente trabajo revela una clara evidencia morfológica de una posible anti-fertilidad dependiente de la dosis del romero administrada en las ratas albinas macho.