• Korean Journal of Food Science and Technology
• /
• v.49 no.2
• /
• pp.222-227
• /
• 2017

Red ginseng prepared from fresh 6-year-old ginseng treated with colloidal gold nanoparticles was extracted using hot water to evaluate its total phenolic and flavonoid contents, antioxidant capacity, and neuroprotective effects. Water extract of red ginseng treated with gold nanoparticles (WERGGN) had total phenolic and total flavonoid contents of 212.2 mg gallic acid equivalents/$^{\circ}Bx$ and 3.5 mg catechin equivalents/$^{\circ}Bx$, respectively. The antioxidant capacities of WERGGN measured using ABTS, DPPH, and ORAC assays were 272.3, 141.2, and 868.4 mg vitamin C equivalents/$^{\circ}Bx$, respectively. The WERGGN showed protective effects on the viability of neuron-like PC-12 cells against oxidative stress induced by hydrogen peroxide in a dose-dependent manner, partly because of a reduction in intracellular oxidative stress. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission, were inhibited by treatment with WERGGN. These results suggest that WERGGN is useful as a functional material to decrease oxidative stress and neuronal damage.

• Korean Journal of Food Science and Technology
• /
• v.48 no.1
• /
• pp.86-91
• /
• 2016

Oxidative stress caused by reactive oxygen species is ascribed to many neurodegenerative diseases like Alzheimer's disease. Phenolic antioxidants can reduce the oxidative stress. In this study, ripe fruits of Opuntia ficus-indica var. saboten (OFS) were extracted using 80% (v/v) aqueous ethanol. Total phenolic and flavonoid contents of the OFS fruits (100 g) were 409.9 mg gallic acid equivalents and 72.2 mg catechin equivalents, respectively. The OFS fruits had antioxidant capacity at 381.2, 298.2, and 3,219.9 mg vitamin C equivalents/100 g in ABTS, DPPH, and ORAC assays, respectively. The OFS fruits showed protective effects on PC-12 cells against oxidative stress in a dose-dependent manner, partly due to decrease of intracellular oxidative stress. Furthermore, the OFS fruits inhibited both acetylcholinesterase and butyrylcholinesterase. Consequently, these results suggest that the OFS fruits might be served as a source of functional materials to reduce oxidative stress in neuronal cells and to inhibit cholinesterases.

• Journal of the Mineralogical Society of Korea
• /
• v.5 no.2
• /
• pp.109-121
• /
• 1992

For the purpose of mineralogical and chemical study on the topazes from various localities of world(Brzail, China, India, Nigeria and Sri Lanka), electron microprobe analysis(EPMA), neutron activation analysis(NAA), X-ray diffractometry, Raman spectroscopy, etch test, scanning electron microscopy, refractive index, specific gravity, fluid inclusion were performed. The chemical composition in topaz was discussed along with its physical and structural properties. Variations in the unit-cell dimension and physical properties of topaz were found to have a close relations in the unit-cell dimension and physical properties of topaz were found to have a close relationship with extent of substitution of $OH^-\;for\;F^-$. According to neutron activation analyses, the trace elements had no effects on the physical properties of topaz. Raman spectra showed that the peaks of topaz were different in intensity from one locality to another. Etching defects in topaz includes negative crystal defect o point-bottom pit(India, Nigeria) and net work defect of curl-bottom pit(Brazil, China). Fluid inclusions in topaz may be classiffied into liquid $CO_2$-bearing inclusion, gaseous inclusion, halite, sylvite-bearing inclusion and liquid inclusion. The results of this study can be useful to devising artificial coloring methods for topaz with different mineralogical compositions.