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Objectives: In multiple sclerosis, an autoimmune inflammatory disease, oligodendroglia are primarily affected and play an important role in the onset and process of the degeneration of neuronal axons. High-dose therapy with glucocorticoids like 6α-methylprednisolone (MP) as well as the application of immunomodulatory agents like glatiramer acetate (GA) are commonly used in the treatment of MS. The purpose of our study was to examine, in an adequate cell culture model, the effect of MP and GA on oligodendroglial activation induced by pro-inflammatory stimuli. Methods: In the present study, we measured the mRNA (real-time RT-PCR) and protein (Western blot) expression of inducible nitric oxide synthase (iNOS) and the release of nitric oxide (NO; Griess reagent) of rat oligodendroglial progenitor cell line OLN-93 after pro-inflammatory stimulation, and searched for influences of MP and GA on these parameters. OLN-93 cells were treated either with a combination of TNF-α and IFN-γ alone, or additionally with MP or GA. Cell viability and cell protein contents were determined in parallel. Results: Our results show that TNF-α and IFN-γ increased iNOS mRNA and protein expression and the NO production in OLN-93 cells. The elevated production of NO and iNOS protein was reduced in the presence of MP, whereas under treatment with GA, the cytokine-induced overproduction of NO did not change significantly. Conclusions: The presented data suggest an active role of oligodendroglial cells in inflammatory processes like multiple sclerosis and indicate different properties of MP and GA regarding immunosuppression. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Different culture types (shoot culture, callus culture, and cell suspension culture) of Rosmarinus officinalis L. were established and their ability to biosynthesize the phytochemicals carnosic acid, carnosol, and rosmarinic acid were assessed and compared with subcultures of the same stem plant over time. Furthermore, we examined the antioxidative effect of extracts from different culture types by measuring their scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals as well as their anti-inflammatory potential on neonatal microglial rat cells activated by means of the inflammogen lipopolysaccharide (LPS) taking nitric oxide (NO) as parameter. Our results show that during an investigation period of 17 months, the shoot culture accumulated varying amounts of carnosic acid and carnosol, which were also present in callus culture but about 20- to 80-fold lower than in the shoot culture. In suspension culture, only carnosic acid and no carnosol could be detected. The level of carnosic acid in suspension culture was threefold less than detected for the callus culture on average. The amount of rosmarinic acid produced in shoot culture and callus culture were comparable, whereas in suspension culture higher concentrations of rosmarinic acid could be measured than in shoot and callus culture. Thus, the content of carnosic acid, carnosol, and rosmarinic acid in the extracts depended on the differentiation grade of the cell culture type. The DPPH radical-scavenging activity of the extracts depended on the amount of all three phytochemicals, in particular of rosmarinic acid. The anti-inflammatory character of the extracts was mainly based on their carnosic acid content. [ABSTRACT FROM AUTHOR]

Purpose: Recent studies have reported neuroprotective effects of erythropoietin (EPO) and vascular endothelial growth factor (VEGF). The purpose of the present study was to clarify their influence on neurite outgrowth and regeneration of rat retinal ganglion cells (RGCs) in vitro and to elucidate the expression of corresponding receptors in the rat retina in vivo., Methods: Retinal explants from postnatal rats were stimulated with VEGF alone; VEGF in combination with anti-VEGF-receptor (VEGF-R)-2 antibody or T-type Ca2+ channel blocker ethosuximide (ESX); EPO alone; or EPO in combination with anti-EPO-receptor antibody or ESX. The presence of the corresponding receptors in the rat retina was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and by immunohistochemistry., Results: EPO induced a stable improvement of neurite outgrowth of RGCs in a dose-dependent manner (5 x 10(-15) M to 5 x 10(-13) M) up to 169% (P < 0.05). Treatment of the explants with anti-EPO-R antibody (1:80 dilution) and with ESX (5 microM) totally inhibited EPO-mediated effects on RGCs. In comparison, VEGF (50 ng/mL), induced neurite outgrowth of retina explants up to 167% (P < 0.05), which again was inhibited in the presence of anti-VEGF-R2 antibody or ESX. Transcripts of EPO-R, VEGF-R1, and VEGF-R2 were detected by RT-PCR. Intense immunoreactivity for VEGF-R1, VEGF-R2, and EPO-R were found in the RGC layer of the retina., Conclusions: The data demonstrate for the first time that EPO and VEGF have a significant and specific biological effect on neurite regrowth of axotomized RGCs. Therefore, these results imply that EPO and VEGF have not only a neuroprotective but also a neuroregenerative role in ischemic retinal conditions.