• Journal of Nutrition and Health
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• v.52 no.5
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• pp.413-421
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• 2019

Purpose: Astragalus membranaceus (AM) is an important traditional medicinal herb. Pharmacological research has indicated that AM has various physiological activities such as antioxidant, anti-inflammatory, immunoregulatory, anticancer, hypolipidemic, antihyperglycemic, and hepatoprotective activities. The bioactive substances responsible for the physiological activities in AM, including many antioxidant substances, change during the roasting process. This study investigated and compared the changes in the antioxidant constituents of AM caused by roasting. Methods: DPPH (1,1-diphenyl-2-picryl hydrazyl) and $ABTS^+$ (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging activities and their total phenolic content (TPC) were measured. High-performance liquid chromatography (HPLC) analysis was performed to confirm any changes in the isoflavonoids of roasted AM (R-AM),. The cell viability of UVB-induced HDF (Human dermal fibroblast) cells treated with AM and R-AM extracts was investigated. The comet assay was used to examine the inhibitory effects of R-AM extracts on DNA damage caused by oxidative stress. Results: The DPPH and $ABTS^+$ radical scavenging activities were $564.6{\pm}20.9$ and $108.2{\pm}3.1$ ($IC_{50}$ value) respectively, from the 2R-AM. The total phenol content was $47.80{\pm}1.40mg$ GAE/g from the 1R-AM. The values of calycosin and formononetin, which are the known isoflavonoid constituents of AM, were $778.58{\pm}2.72$ and $726.80{\pm}3.45{\mu}g/g$ respectively, from the 2R-AM. Treatment of the HDF cells with R-AM ($50{\sim}200{\mu}g/mL$) did not affect the cell viability. Furthermore, the R-AM extracts effectively protected against UVB-induced DNA damage. Conclusion: The findings of this study indicate that R-AM increases its isoflavonoid constituents and protects against UVB-induced DNA damage in HDF cells.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.473-481
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• 2012

This study was conducted to investigate the contents of ginsenosides and physiochemical properties of Panax ginseng after 9 times steaming and drying treatment by using the new auto steamer which is more fast and simple than previous report. In the process of steaming and drying, the content of six major ginsenosides such as Rg1, Re, Rb1, Rc, Rb2 and Rd were gradually decreased. On the other hand, the content of seven minor ginsenosides includes Rh1, 20(S)-Rg2, 20(R)-Rg2, 20(S)-Rg3, 20(R)-Rg3, Rk1 and Rg5 were gradually increased. We observed the protopanxadiol ginsenosides such as Rb1, Rb2, Rc and Rd were converted into 20(S)-Rg3, 20(R)-Rg3, Rk1 and Rg5; similarly protopanxatriol ginsenosides of Rg1 and Re were converted into Rh1, 20(S)-Rg2 and 20(R)-Rg2. Based on the result of fresh ginseng, the contents of reducing sugar, acidic polysaccharide and total phenolic compounds were gradually increased and reached to maximum at 7 times repetitive steaming process of the fresh ginseng. Whereas DPPH radical scavenging activities were gradually decreased to 68% at 7 times steaming. New auto 9 repetitive steaming and drying process has similar production with original methods, but content of benzo(a)pyrene were not almost detected comparatively taking less time. The present results suggested that this method is best for the development of value-added ginseng industry related products.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.508-514
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• 2016

Effects of the ethyl acetate fraction from gomchwi (Ligularia fischeri) extract against high $glucose/H_2O_2-induced$ oxidative stress and in vitro neurodegeneration were investigated to confirm the physiological property of the extract. The ethyl acetate fraction of gomchwi extract showed the highest total phenolic contents than the other solvent fractions. An anti-hyperglycemic activity of the ethyl acetate fraction was evaluated using the ${\alpha}-glucosidase$ inhibitory assay, and the half maximal inhibitory concentration ($IC_{50}$) value for ${\alpha}-glucosidase$ was found to be $727.64{\mu}g/mL$. In addition, the ethyl acetate fraction showed excellent 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt radical scavenging activity, and inhibition of malondialdehyde production. The ethyl acetate fraction also decreased intracellular reactive oxygen species, whereas neuronal cell viability against high glucose/$H_2O_2$-induced cytotoxicity was found to be increased. Finally, 3,5-dicaffeoylquinic acid as a main phenolic compound in the ethyl acetate fraction was analyzed by high-performance liquid chromatography. These results suggest that gomchwi might be a good natural source of functional materials to prevent diabetic neurodegeneration.