Gi-Hae Shin

The Antioxidant Activity and Their Major Antioxidant Compounds from Acanthopanax senticosus and A. koreanum

The antioxidant activity and chlorogenic acid and caffeic acid contents were investigated from different parts of Acanthopanax senticosus and A. koreanum. Antioxidant activity was assessed by various in vitro assays such as DPPH, ABTS, FRAP, reducing power assays and ORAC, and the chlorogenic acid and caffeic acid were validated by HPLC chromatography. Among the various extracts, the fruit extracts of A. senticosus and A. koreanum exhibited strongest antioxidant activities including ABTS, FRAP, reducing power and ORAC, however, strongest DPPH radical scavenging activity was observed from the leaf extract of A. senticosus. In addition, the antioxidant activities of various extracts were correlated with total phenolic and proanthocyanidin contents. The major phenolic contents from various parts of these plants observed that leaf extract of A. senticosus expressed higher levels of chlorogenic acid (14.86 mg/dry weigh g) and caffeic acid (3.09 mg/dry weigh g) than other parts. Therefore, these results suggest that the leaf of A. senticosus may be an excellent natural source for functional foods and pharmaceutical agents, and the validated method was useful for the quality control of A. senticosus.

Codonopsis lanceolata Extract Prevents Diet-Induced Obesity in C57BL/6 Mice

Codonopsis lanceolata extract (CLE) has been used in traditional medicine in the Asian-Pacific region for the treatment of bronchitis, cough, and inflammation. However, it is still unclear whether obesity in mice can be altered by diet supplementation with CLE. To investigate whether CLE could have preventative effects on high fat diet (HFD)-induced obesity, male C57BL/6 mice were placed on either a normal chow diet, 60% HFD, or a HFD supplemented with CLE (60, 180, and 360 mg/kg/day) for 12 weeks. CLE decreased body weight and subcutaneous and visceral fat weights in HFD-induced obese mice. CLE group mice showed lower fat accumulation and a smaller adipocyte area in the adipose tissue compared with the HFD group mice. CLE group mice exhibited lower serum levels of triglycerides, total cholesterol, low density lipoprotein (LDL), glucose, and insulin compared with the HFD group mice. In addition, CLE decreased liver weight and lowered the increase in aspartate aminotransferase (AST) and alanine transaminase (ALT) levels in HFD-induced obese mice. These results indicate that CLE can inhibit the development of diet-induced obesity and hyperlipidemia in C57BL/6 mice.

Antioxidant and anti-ageing activities of citrus-based juice mixture

The production of excessive reactive oxygen species by exposure to oxidative stress and solar radiation are primary factors in skin damage. We examined the effects of a citrus-based juice mixture and its bioactive compounds on antioxidant and anti-ageing activities in human dermal fibroblasts and hairless mice via the regulation of antioxidant enzymes and the mitogen-activated protein kinase pathway. The citrus-based juice mixture reduced H2O2-induced cell damage and intracellular reactive oxygen species production in human dermal fibroblasts. Citrus-based juice mixture pretreatment suppressed the activation of the H2O2-mediated mitogen-activated protein kinase pathway by activating the expression of activator protein 1 and matrix metalloproteinases. Moreover, it increased the expression levels of antioxidant enzymes such as glutathione reductase, catalase and manganese superoxide dismutase. In addition, oral administration of the citrus-based juice mixture decreased skin thickness and wrinkle formation and increased collagen content on an ultraviolet light B-exposed hairless mouse. These results indicate that the citrus-based juice mixture is a potentially healthy beverage for the prevention of oxidative stress-induced premature skin ageing.

Assessment and comparison of the antioxidant activities and nitrite scavenging activity of commonly consumed beverages in Korea.

In this study, the antioxidant potential of commercial beverages against a variety of radicals was determined using various antioxidant activity analytical methods. The physicochemical properties (pH value and °Brix), total phenolic content and antioxidant activities were assessed. Our results showed that the pH value and sugar content (°Brix) of commonly consumed beverages ranged from 2.4 to 3.9 and from 3.8 to 18.5, respectively. The DPPH radical scavenging activity and nitrite scavenging ability were highest in No. 45 vitamin beverage (87.5% and 86.0%, respectively). However, no clear correlation appeared between the total phenolic content and the DPPH radical scavenging activity (R=0.2565). The total phenolic content and oxygen radical absorbance capacity (ORAC) values were highest in No. 55 pomegranate beverage (183.3 mg GAE/100 mL and 1824.4 μM TE/mL, respectively). In particular, a high correlation was shown between the total phenolic content and the ORAC value (R=0.7954). Based on the results of various antioxidant activity methods, the greatest preventative antioxidant capacity of consumed beverages in Korea was found in No. 55 pomegranate. These results will enable further research on the daily phenolic compound intake as well as on the development of healthy beverages.

Method validation and measurement uncertainty for the simultaneous determination of synthetic phenolic antioxidants in edible oils commonly consumed in Korea

This study investigated a method for the validation and determination of measurement uncertainty for the simultaneous determination of synthetic phenolic antioxidants (SPAs) such as propyl gallate (PG), octyl gallate (OG), dodecyl gallate (DG), 2,4,5-trihydroxy butyrophenone (THBP), tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in edible oils commonly consumed in Korea. The validated method was able to extract SPA residues under the optimized HPLC-UV and LC-MS/MS conditions. Furthermore, the measurement of uncertainty was evaluated based on the precision study. For HPLC-UV analysis, the recoveries of SPAs ranged from 91.4% to 115.9% with relative standard deviations between 0.3% and 11.4%. In addition, the expanded uncertainties of the SPAs ranged from 0.15 to 5.91. These results indicate that the validated method is appropriate for the extraction and determination of SPAs and can be used to verify the safety of edible oil products containing SPAs residues.

Acute and subchronic (28 days) oral toxicity studies of Codonopsis lanceolata extract in Sprague–Dawley rats

Codonopsis lanceolata is a perennial plant that has been used as a food and in traditional medicine for the treatment of cough, bronchitis, and inflammation in East Asia including Korea, Japan, and China. However, information regarding its toxicity is limited. Therefore, we performed a safety evaluation of aqueous C. lanceolata root extract (CLE) in Sprague-Dawley rats. Assessment of acute toxicity revealed that CLE did not influence mortality, clinical appearance, body weight gain, or necropsy findings at a dose of 5000 mg/kg body weight. In the subchronic oral toxicity, data revealed that several significant alteration in food consumption, water consumption, protein excretion, WBCs levels, TGs, BUN levels, and the absolute and relative weights in the liver, spleen and lungs. However, these changes were transient and were not considered treatment related because they showed no apparent dose dependent. These results suggest that CLE (1250, 2500, and 5000 mg/kg body weight/day) administered orally does not cause acute or subchronic toxicity to male or female rats. The 50% lethal dose (LD50) of CLE was determined to be greater than 5000 mg/kg.

Antioxidant and Anti-adipogenic Effects of Kohlrabi and Radish Sprout Extracts

Korea Food Research InstituteAbstract Common cruciferous vegetables, kohlabi (Brassica oleracea) and radish (Raphanus sativus), containphytochemicals such as glucosinolates and carotenoids. Therefore, this study investigated the antioxidant and anti-adipogenic effects of kohlrabi sprout extract (KSE) and radish sprout extract (RSE). The total carotenoid and glucosinolatecontents of KSE and RSE were 39.50±0.67 and 76.73±2.75 mg/g, respectively. The total glucosinolate contents of KSEand RSE were 2.65±0.02 and 8.13±0.54 mg/g, respectively. The in vitro-antioxidative activities of KSE and RSE weresignificantly increased in a dose-dependent manner. Furthermore, β-carotene and glucosinolate-enriched KSE and RSEsignificantly inhibited lipid accumulation and reactive oxygen species production during the adipogenesis of 3T3-L1preadipocytes. These results suggest that glucosinolate-enriched KSE and RSE, especially RSE, can be used in thetreatment of obesity and as a natural source of antioxidants.Keyword

Comparative Analysis of γ-Oryzanol, β-Glucan, Total Phenolic Content and Antioxidant Activity in Fermented Rice Bran of Different Varieties

Rice bran, a by-product derived from processing rice, is a rich source of bioactive compounds. Recent studies have suggested that the fermentation can improve their biological activities. This study aimed to determined the level of γ-oryzanol, β-glucan and total phenol contents of fermented rice bran from 21 Korean varieties, as well as to evaluate their antioxidant activities. We also assessed the validation of the analytical method for determining γ-oryzanol content in fermented rice brans. Among the fermented rice brans, the Haedam rice bran contained the highest level of total phenol content (156.08 mg gallic acid equivalents/g), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (71.30%) and ORAC (Oxygen radical absorbance capacity) value (1101.31 μM trolox equivalents/g). Furthermore, the fermented Migwang rice bran showed the highest level of γ-oryzanol content (294.77 ± 6.74 mg/100 g).