Bee venom phospholipase A2 ameliorates motor dysfunction and modulates microglia activation in Parkinson's disease alpha-synuclein transgenic mice

α-Synuclein (α-Syn) has a critical role in microglia-mediated neuroinflammation, which leads to the development of Parkinson's disease (PD). Recent studies have shown that bee venom (BV) has beneficial effects on PD symptoms in human patients or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxin-induced PD mice. This study investigated whether treatment with BV-derived phospholipase A2 (bvPLA2) would improve the motor dysfunction and pathological features of PD in human A53T α-Syn mutant transgenic (A53T Tg) mice. The motor dysfunction of A53T Tg mice was assessed using the pole test. The levels of α-Syn, microglia and the M1/M2 phenotype in the spinal cord were evaluated by immunofluorescence. bvPLA2 treatment significantly ameliorated motor dysfunction in A53T Tg mice. In addition, bvPLA2 significantly reduced the expression of α-Syn, the activation and numbers of microglia, and the ratio of M1/M2 in A53T Tg mice. These results suggest that bvPLA2 could be a promising treatment option for PD.

Protective Effect of Coriolus versicolor Cultivated in Citrus Extract Against Nitric Oxide-Induced Apoptosis in Human Neuroblastoma SK-N-MC Cells

Nitric oxide (NO) is a reactive free radical and a messenger molecule in many physiological functions. However, excessive NO is believed to be a mediator of neurotoxicity. The medicinal plant Coriolus versicolor is known to possess anti-tumor and immune-potentiating activities. In this study, we investigated whether Coriolus versicolor possesses a protective effect against NO donor sodium nitroprusside (SNP)-induced apoptosis in the human neuroblastoma cell line SK-N-MC. We utilized 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis, and caspase-3 enzyme activity assay in SK-N-MC cells. MTT assay showed that SNP treatment significantly reduces the viability of cells, and the viabilities of cells pre-treated with the aqueous extract of Coriolus versicolor cultivated in citrus extract (CVEcitrus) was increased. However, aqueous extract of Coriolus versicolor cultivated in synthetic medium (CVEsynthetic) showed no protective effect and aqueous citrus extract (CE) had a little protective effect. The cell treated with SNP exhibited several apoptotic features, while those pre-treated for 1 h with CVEcitrus prior to SNP expose showed reduced apoptotic features. The cells pre-treated for 1 h with CVEcitrus prior to SNP expose inhibited p53 and Bax expressions and caspase-3 enzyme activity up-regulated by SNP. We showed that CVEcitrus exerts a protective effect against SNP-induced apoptosis in SK-N-MC cells. Our study suggests that CVEcitrus has therapeutic value in the treatment of a variety of NO-induced brain diseases.

Neuroprotective Effect of Fucoidan against N-methyl-D-aspartate-Induced Excitotoxicity in Rat Hippocampus

Fucoidan, a sulfated polyanionic polymer of L-fucose, is obtained from brown marine macroalgae. In the present study, neuroprotective effect of fucoidan against N-methyl- D-aspartate (NMDA)-induced excitotoxicity in the hippocampus was investigated. The patch clamp study revealed that fucoidan significantly inhibited NMDA receptor-activated ion current in the acutely dissociated hippocampal CA1 neurons. In an organotypic hippocampal slice culture, fucoidan inhibited NMDA-induced neuronal cell death in a dose-dependent manner. The present study showed that fucoidan possesses a neuroprotective effect against NMDA-induced excitotoxicity, and that the suppressive effect of fucoidan on the NMDA-induced ion current can be suggested as being the underlying neuroprotective mechanism of fucoidan.

Effects of Armeniacae Semen and Amygdalin on the Lipopolysaccaride-induced Prostaglandin E2 Synthesis and Nitric Oxide Production in Mouse BV2 Microglial Cells

Armeniacae semen has been used in traditional medicine for the treatment of pain and inflammatory diseases. Amygdalin is the major compound of Armeniacae semen, and it is used for treatment of pain and cancers. In the present study, we compared the effects of aqueous extract of Armeniacae semen and a solution of amygdalin extracted from Armeniacae semen on the lipopolysaccharide (LPS)-stimulated cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA expressions in mouse BV2 microglial cells. We also compared the effects of these compounds on the prostaglandin E2 synthesis and the nitric oxide production in mouse BV2 microglial cells. In the present results, Armeniacae semen and amygdalin suppressed prostaglandin E2 synthesis and nitric oxide production by inhibiting the LPS-induced enhancement of COX-2 mRNA and iNOS mRNA expressions in mouse BV2 cells. For the COX-1 expression, Armeniacae semen showed more potent suppression effect compared to the amygdalin. However, amygdalin more potently suppressed the LPS-induced COX-2 mRNA expression compared to aqueous extract of Armeniacae semen. In the case of iNOS mRNA expression, Armeniacae semen and amygdalin showed similar suppressing effects. For the LPS-induced PGE2 synthesis, amygdalin showed more potent suppressing effect, meanwhile, Armeniacae semen and amygdalin showed similar suppressing effect on NO production. Based on the present results, amygdalin may exert anti-inflammatory and analgesic effect though mainly the inhibition of COX-2 pathway, in contrast Armeniacae semen may exert such effect though both the inhibition of COX-2 and iNOS pathways.