• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.341-346
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• 2011

The objective of this study was to evaluate antioxidant activities of Rehmannia glutinosa (Raw Jihwang) by traditional method. The total phenol content of Rehmannia radix Preparata (the final cycle of Jihwang) was increased to 205%, compared with Rehmannia glutinosa. Antioxidant activities, determined by ferric-reducing antioxidant potential (FRAP), 2,2'-azinobis(3 ethybenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrydrazyl (DPPH) and hydroxyl radical scavenging activities, increased remarkably as the number of steaming-drying cycles increased. Especially, FRAP value increased 285%. Also, $IC_{50}$ values for DPPH and hydroxyl radical scavenging activities of the final 9th-cycling product, decreased 48.4% and 76%, respectively, compared with those of Rehmannia glutinosa. Our result was suggested that antioxidant activities of Rehmannia radix Preparata improve according to the increasing number of steaming-drying cycles.

• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.311-314
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• 2007

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are the most important angiogenic molecules associated with tumor-induced neovascularization. This study was carried out to investigate inhibitory effect of extracts from root of Rehmannia glutinosa LIBOSCHITZ (Rehmannia Radix and Rehmannia Radix Preparata) on endothelial cell proliferation. The methanol extracts from the medicinal herb were fractionated into n-hexane, ethyl acetate, n-butanol and aqueous fractions. Among the four fractions, the n-butanol fraction from R. Radix on exhibited highly effective inhibition (${\approx}79%$ inhibition) on the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ and then ethyl acetate fraction from R. Radix (${\approx}45%$ inhibition) at the concentration of $100\;{\mu}g/ml$. The n-butanol fraction efficiently blocked the VEGF- and bFGF-induced HUVEC proliferation in a dose-dependent manner, but did not affect the growth of HT1080 human fibrosarcoma cells. The n-butanol fraction more efficiently blocked the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ and VEGF- and bFGF-induced human umbilical vein endothelial cell proliferation than the fraction from R. Radix Preparata. Our results suggest that Rehmannia Radix may be used as a candidate for developing anti-angiogenic agent.

• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.257-262
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• 1999

We investigated the biological activities on ethanol extracts of R. glutinosa and R. glutinosa Preparata. The result of anti-mutagenicity suggested that the ethanol extract of R. glutinosa Preparata showed stronger activity than that of R. glutinosa ethanol extract. All of the ethanol extracts showed over 50% growth inhibition of several cancer cell lines. Especially, 61% of the cell growth of Hep3B was inhibited by adding 1g/ l of ethanol extract of R. glutinosa Preparata. In hypoglycemic activities and controlling blood pressure, 63.69% of ${\alpha}-glucosidase$ and 56.58% of ACE activities were inhibited by adding 1g/ l of ethanol extract of R. glutinosa Preparata. In general, the ethanol extract of R. glutinosa Preparata showed higher biological activities than those of R. glutinosa.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.5
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• pp.624-633
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• 2012

This study was performed to evaluate the physiochemical and sensory quality characteristics as well as the antioxidant activities of steamed rib sauce prepared with different amounts of Rehmannia glutinosa preparata concentrate(0, 6, 12, 18%). The moisture content and salinity of control were 80% and 0.8%, respectively, but those of sauces added with Sookjihwang concentrate were not significantly different from those of control. The acidity and reducing sugar content increased according to the amount of Sookjihwang concentrate. Hunter's color L (lightness) and b (yellowness) values decreased according to the amount of Sookjihwang concentrate, whereas a (redness) value was not significantly different among the treatments. Viscosity increased according to the amount of Sookjihwang concentrate. Total phenol and flavonoid contents increased according to the amount of Sookjihwang concentrate. Antioxidant activities (DPPH and hydroxyl radical scavenging activities) also increased according to the amount of Sookjihwang concentrate. Results of sensory preference test revealed that the scores for color, glossiness, and overall preference were the highest in sauce added with 12% Sookjihwang concentrate. It can be suggested that sauce added with Sookjihwang concentrate may be a functional sauce with high antioxidant activity.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.136-143
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• 2015

The aim of this study was to evaluate the quality characteristics and anti-oxidative activities in the rice cookies with R. glutinosa Preparata (0%, 4%, 8%, 12%) and bean flour (10%). The moisture of cookies was increased depending on amount of R. glutinosa Preparata (RRP). The pH of cookies with RRP was lower than that of the control cookies. Sugar content and reducing sugar of cookies were increased according to the amount of RRP. L-value and b-value of cookies with 12% RRP were lower than the control, whereas a-value was higher than the control. Spread factor of cookies with RRP was lower than the control, and hardness of cookies was increased depending on amount of RRP added. The antioxidant activity such as DPPH radical and hydroxyl radical scavenging activity was significantly increased in the cookies with RRP, compared with that of the control. Also, total phenol content of cookies was increased according to the amount of RRP. In sensory test, cookies with 8% RRP received the highest score for overall preference. As a result, the optimum amount of RRP concentrate to be added in the cookies was found to be 8%.

• Korean Journal of Oriental Medicine
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• v.4 no.1 s.4
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• pp.115-127
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• 1998

To improve the quality control of frequently used oriental medicinal plants, the storage, cutting, processing and decokting methods of Rehmannia glutinosa Libosch. var. purpurea Makino(熟地黃) were examined. The contents of 5-hydroxymethyl-2- furaldehyde(5-HMF) of Rehmannia glutinosa Libosch. var. purpurea Makino were analysed by HPLC at various conditions as the standard component. Raw materials were classified into 3 groups with their specific gravity(天 地 人黃) and determined the ding weights and the contents of water, the solid component of Ji-Hwang(地黃) was the most. Rehmannia glutinosa Libosch. var purpurea Makino was steamed and dried nine times and analysed the content of 5-HMF on every time. In the case of Ji-Hwang, the standard component of the ninth sample was produced the most. But which of the tenth samples of Chun-Hwang and Yin-Hwang(天黃 人黃) were the most. The best decokting conditions which were determined by the yield of 5-HMF were as follows : non cutting, soaking time was 0 minutes, decokting time was 75 minutes after boiling. The contents of sugar on each of samples were determined. The contents of standard component increased by steaming number and the contents of sugar decreased.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.5
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• pp.1349-1355
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• 2005

The steamed root of Rehmannia glutinosa has been used for treatment of inner ear diseases, such as tinnitus and hearing loss in traditional Oriental Medicine. In the present study, we investigated the effect of ethanol extract of steamed root R. glutinosa (SRG) on cisplatin cytotoxicity of HEI-OC1 auditory cells. In addition, to investigate the mechanism of SRG on cisplatin cytotoxicity, the effects of SRG on lipid peroxidation as well as scavenging activities against various free radicals were measured in cisplatin-treated cells. Treatment of SRG protected cells from cisplatin and reduced lipid peroxidation in a dose-dependent manner. Furthermore, SRG demonstrated significant scavenging activity against various free radicals, including superoxide radical, hydroxyl radical, hydrogen peroxide, and DPPH radical. These results indicate that SRG protects cisplatin-induced damages of HEI-OC1 cells through inhibition of lipid peroxidation and augmenting scavenging activities against free radials.

• The Korea Journal of Herbology
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• v.36 no.6
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• pp.47-61
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• 2021

Objectives : 'Steaming and drying' is a traditional processing method that has been used to produce Suk-ji-hwang (熟地黃; Rehmanniae Radix Preparata) from Ji-hwang (地黃, the fresh root of Rehmannia glutinosa Liboschitz ex Steudel; Rehmanniae Radix). The steaming and drying process, which is proceeded in heating and moisturizing conditions, plays a crucial role in the change of therapeutic effect of Ji-hwang, presumably due to the modification of its chemical constituents. In this article, the chemical influence of the 'Steaming and drying' process was investigated for understanding the underlying mechanism of chemical modification of Ji-hwang. Methods : The articles regarding the modifications of chemical constituents of Ji-hwang during the 'Steaming and drying' process were collected and analyzed to investigate the influence of the processing to Ji-hwang. Results : The results indicated that iridoid glycosides were degraded to their aglycones and sugars, and such degradations occurred faster at a high pressure than at an atmospheric pressure during the process. The contents of catalpol, ajugol, and acteoside were decreased, while those of rehmannioside A and D were slightly increased during the repeated processing. The contents of oligosaccharides, namely sucrose, maltose, raffinose, and stachyose (except for manninotriose), were decreased, while those of monosaccharides, glucose and fructose, were increased by the repeated processing. Conclusions : These results demonstrate that the 'Steaming and drying' process influenced the chemical constituents of Ji-hwang and provide probable basis for the therapeutic modification of Suk-ji-hwang after the processing of Ji-hwang.

• Korean Journal of Medicinal Crop Science
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• v.26 no.1
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• pp.1-7
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• 2018

Background: Rehmanniae radix preparata (RRP) has been used as a traditional medicine and is one of the most important oriental herbal medicines. However, the physical characteristics of RRP are not suitable for use in industry. The present study was under-taken to determined the preparation method of RRP powder and the physicochemical characteristics of RRP powder by milling under different pre-freezing temperatures. Methods and Results: Moisture content, powder yield, particle size, bulk density, compressive stress, extraction yield, and 5-HMF content of PRR powders by milling with pre-freezing temperatures (-20, -40, -60, and $-80^{\circ}C$) were analyzed, and correlation among these factors was determined. Powder yield increased and particle size decreased in a pre-freezing temperature-dependent manner from -20 to $-60^{\circ}C$. The Hausner ratio increased from 1.186 to 1.225 with decreasing temperature from -20 to $-80^{\circ}C$, whereas compressive stress showed the opposite trend. Extraction yield and 5-HMF content were not significantly different between RRP powder. Significant correlations were observed among pre-freezing temperature and physical characteristics (e.g., yield, particle size, Hausner ratio, and compressive stress). Conclusions: These results suggest that the pre-freezing temperature is an important factor affecting the physical characteristics of PRR powder and applicable to the industrial production of RRP powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1518-1524
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• 2011

This study was investigated the quality characteristics and antioxidant activities of the Rehmanniae radix (Rehmannia glutinosa Libosch. var. purpurea Makino) paste (RRP) and Rehmanniae radix preparata extract (RRPP). RRP and RRPP were made from vacuum concentrates of hot water extracts. The sugar contents of RRP and RRPP were 65.3 and 72.0$^{\circ}Brix$, respectively, whereas the reducing sugar contents were 2.4% and 44.9%. The pH level was lowest in the RRPP. The DPPH and hydroxyl radical scavenging activity of RRPP were much higher than those of RRP. Total phenol contents of RRP and RRPP were 2.15 mg/mL and 12.36 mg/mL, respectively. FRAP values of RRP and RRPP were 0.55 mg/mL and 2.02 mg/mL, respectively. Based on these results, it can be concluded that RRPP was the most appropriate in terms of both physicochemical and antioxidative activities.