• Journal of Life Science
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• v.20 no.5
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• pp.736-744
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• 2010

The root of Playtcodon grandiflorum, called Platycodi radix, has been a favorite edible plant in Asia and contains a large amount of saponins. Melanoma cells (B16F10) were used to investigate the inhibitory effect of aged black Platycodi radix extract (ABPRE) on oxidative stress and matrix metalloproteinases (MMPs). Platycodon radix has been known to have a variety of medicinal effects such as prevention of gastric ulcers, antiallergenic activities, histamine release inhibition, and antioxidant effects. However, the mechanism of its action remains unclear in humans. ABPRE was prepared using ethanol extraction of aged black Platycodi radix. In an antioxidant effect study of ABPRE, it was observed that ABPRE specifically exhibited the scavenging activity of DPPH radical, but did not inhibit the production of malondialdehyde from lipid peroxidation. DNA oxidation was also blocked in the presence of ABPRE. In addition, ABPRE decreased the expression and activation of MMP-2 stimulated by phenazine methosulfate. Furthermore, ABPRE revealed the inhibitory effect on melanin production induced by L-dopa via antioxidant effect and the reduction of tyrosinase expression. Especially, the expression of antioxidant enzymes such as SOD-1 and SOD-2 regulated by Nrf2 was increased in the presence of ABPRE. Therefore, it appears that ABPRE may be a possible chemopreventive agent for the prevention of metastasis related to oxidative stress.

• Resources Recycling
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• v.32 no.6
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• pp.45-53
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• 2023

This study discussed the trend and future strategy of adsorption technology R&D to effectively recover ammonia emitted from the livestock fields. A proper ammonia adsorbent should incorporate acidic or hydrogen bonding functional groups on the surface, as well as a high specific surface area and a good surface structure appropriate for ammonia adsorption. Activated carbon and minerals such as zeolite have widely been used as ammonia adsorbents, but their adsorption effects are generally low, so any improvement through surface modification should be necessary. For example, incorporation of metal chloride included in a porous adsorbent can promote ammonia adsorption effectiveness. Recently, new types of adsorbents such as MOFs (Metal-Organic Frameworks) and POPs (Porous Organic Polymers) have been developed and utilized. They have shown very high ammonia adsorption capacity because of adjustable and high specific surface area and porosity. In addition, Prussian Blue exhibited high ammonia adsorption and desorption performance and selectivity. This looks relatively advantageous in relation to the recovery of ammonia from livestock waste discharge. In the future, further research should be made to evaluate ammonia adsorption/desorption efficiency and purity using various adsorbents under conditions suitable for livestock sites. Also, effective pre- and/or post-treatment processes should be integrated to maximize ammonia recovery.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.765-773
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• 2000

The degradation of humic acid using $TiO_2$ coatings was studied, $TiO_2$ coatings were prepared by dip-coating method. Sol solutions for coating were prepared by mixing the gel, which can be produced by the reaction of $TiOCl_2$ and $NH_4OH$ solution, and hydrogen peroxide solution, and hydrolysis of titanium tetraisopropoxide (TTIP). It was shown from XRD that coatings from sol aged at $100^{\circ}C$ for 18h with titanium peroxo solution were crystallized to anatase in the range of temperatures of $25^{\circ}C$ to $500^{\circ}C$. In contrast, those coated from TTIP were crystallized to anatase at temperature above $400^{\circ}C$. So the sols originated from $TiCl_4$ can be applied for not only on the heat-resistance substrates but on the plastic substrates. Thickness and the quality of the films were dependent on the withdrawing speed, the concentration of sol, and the number of coating. The films showed various interference colors depending on the thickness of them. In the case that the films coated 2 times at withdrawing speed of 2.5cm per minute by 0.2M sol, the films had a transparent light blue color with thickness of around 50nm. It was known from the result of photo-degradation by $TiO_2$ coatings using humic acid that the removal efficiency of $COD_{cr}$ was over 85% after illumination of $UV/H_2O_2$ for 40min. and that of UV/VIS absorbable materials was over 95%.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.66-72
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• 2009

Diabetic Retinopathy (DR) is a leading cause of blindness among adults in the western countries. Hyperglycemia is a condition, that induces apoptotic cell death in a variety of cell types in diabetes, but the mechanism remains unclear. The aim of the study is to understand the effects of high Glucose on Human Retinal Endothelial Cells. Retinal endothelial cells were cultured in Iscove's Modified Dulbecco's Medium (IMDM) containing 5, 25 and 50 mM Glucose, incubated for 24, 36 and 48 hours in humidified 5 % CO$_2$ incubator at 37$^{\circ}C$. Human Retinal Endothelial Cell Line (HREC) were characterized for morphology with different treatment by phase contrast microscopic analysis. Number of dead and viable cells was counted by trypan blue exclusion and supported by MTT assay. The intracellular Hydrogen peroxide (H$_2$O$_2$), a Reactive Oxygen Species (ROS) generation in high glucose conditions was assessed by FOX II assay and apoptosis by caspase-3 assay. The high glucose treated cells undergoing DNA fragmentation was witnessed by Agarose gel electrophoresis. We found that the cells incubated with 25 and 50 mM glucose containing medium for 48 hours altered the morphology of the cell, induced apoptosis and DNA fragmentation. The dead cell number were high in 25 and 50 mM when compared to the cells incubated with 5 mM glucose for 24, 36, and 48 hours. Also, the H$_2$O$_2$ levels and the activity of caspase-3 were increased in high glucose treated cells. Conclusions/interpretation: Our results demonstrated that elevated glucose induces apoptosis in cultured HREC. The hyperglycemia-induced increase in apoptosis may be dependent on caspase activation. The association between ROS generation and caspase-3 activation on high glucose treated cells is yet to be investigated.