Neuroprotective Activity of Methanolic Extract of Lysimachia christinae against Glutamate Toxicity in HT22 Cell and Its Protective Mechanisms

Purpose. Excessive glutamate amount can give oxidative stress to neuronal cells, and the accumulation of cell death can trigger the neurodegenerative disorders. In this study, we discovered the neuroprotective effect of Lysimachia christinae Hance in the mouse hippocampal HT22 cell line. Method. Overnight incubated HT22 cells were pretreated with L. christinae extract dose dependently (1, 10, and 100 μg/ml). Followed by then, glutamate was treated. These treated cells were incubated several times again, and cell viability, accumulation of reactive oxygen species (ROS) and Ca2+, mitochondrial membrane potential (MMP), and glutathione-related enzyme amount were measured. Results. As a result, L. christinae increases the cell viability by inhibiting the ROS and Ca2+ formation, recovering the level of MMP and enhancing the activity of glutathione production compared with only vehicle-treated groups. Conclusion. These draw that L. christinae may remarkably decelerate the neurodegeneration by minimizing neuronal cell damage via oxidative stress

Simultaneous Determination of Four Compounds in a Nelumbo nucifera Seed Embryo by HPLC-DAD

Nelumbo nucifera has a variety of biological activities. So it was importantly used as various herbal medicines since traditional times. A simple, fast, and sensitive high-performance liquid chromatographic (HPLC) method was developed in this study for efficient quality control of N. nucifera. Four different compounds, including neferine, 1,2,3,4-tetrahydro-1-[(4-hydroxyphenyl) methyl]-2-methyl-7-isoquinolinol, 1-hydroxy-2-methylpropene, and 3-(prop-1-enyl)benzene-1,2,4,5-tetrol, were simultaneously determined. The four compounds were isolated through a Dionex C18 column by gradient elution with 0.1% TFA-water and methanol. The flow rate was 1.0 mL/min, and the wavelength was detected at 205, 254, 280, and 330 nm. The chromatograms were acquired at 205 nm. The four compounds showed good linear relationships (r2>0.96) over five different concentrations, and an average recovery of the method ranged from 96.27% to 108.78%. Through the analysis validation test and application of the method, the optimized conditions verified that it is efficient to isolate the compounds of N. nucifera seed embryos

Neuroprotective effect of Aronia melanocarpa extract against glutamate-induced oxidative stress in HT22 cells

Abstract Background Glutamate (an endogenous excitatory neurotransmitter) at high concentrations contributes to the development of neurodegenerative diseases. Aronia melanocarpa (A. melanocarpa) berries contain anthocyanins and have high antioxidant activities. In this study, we evaluated whether A. melanocarpa berries could protect neuronal cells against glutamate-induced oxidative stress. Method A. melanocarpa berries exerted a protective effect against cytotoxicity in HT22 mouse hippocampal cells by MTT assay. We evaluated oxidative stress parameters including ROS level, intracellular Ca2+ level, glutathione level and antioxidant enzyme activity in HT22 cells to elucidate the mechanism of its neuroprotective effect. Results A. melanocarpa berries decreased glutamate-induced death of HT22 cells. In addition, A. melanocarpa berries reduced ROS and intracellular Ca2+ levels. Glutathione level, antioxidant enzymes, glutathione reductase and glutathione peroxide activities and mitochondrial membrane potential were also increased in HT22 cells. Conclusion These results suggested that A. melanocarpa berries protected HT22 cells by exerting an antioxidant effect

Visual function restoration in a mouse model of Leber congenital amaurosis via therapeutic base editing

Leber congenital amaurosis (LCA), an inherited retinal degen-eration, causes severe visual dysfunction in children and adoles-cents. In patients with LCA, pathogenic variants, such as RPE65, are evident in specific genes, related to the functions of retinal pigment epithelium and photoreceptors. In contrast to the orig-inal Cas9, base editing tools can correct pathogenic substitu-tions without generation of DNA double-stranded breaks (DSBs). In this study, dual adeno-associated virus (AAV) vec-tors containing split adenine base editors (ABEs) with trans- splicing intein were prepared for in vivo base editing in retinal degeneration of 12 (rd12) mice, an animal model of LCA, pos-sessing a nonsense mutation of C to T transition in the Rpe65 gene (p.R44X). Subretinal injection of AAV-ABE in retinal pigment epithelial cells of rd12 mice resulted in an A to G transition. The on-target editing was sufficient for recovery of wild-type mRNA, RPE65 protein, and light-induced electrical responses from the retina. Compared with our previous thera-peutic editing strategies using Cas9 and prime editing, or with the gene transfer strategy shown in the current study, our results suggest that, considering the editing efficacy and functional recovery, ABEs could be a strong, reliable method for correction of pathogenic variants in the treatment of LCA.Y