Jeung Hee Lee

Optimized synthesis of 1,3-dioleoyl-2-palmitoylglycerol-rich triacylglycerol via interesterification catalyzed by a lipase from Thermomyces lanuginosus

1,3-Dioleoyl-2-palmitoylglycerol (OPO)-rich human milk fat substitute (HMFS) was synthesized from tripalmitin-rich fraction and ethyl oleate by a lipase-catalyzed interesterification. Response surface methodology was employed to optimize its OPO content and acyl migration with reaction factors - substrate mole ratio of PPP-rich fraction to ethyl oleate (1:4, 1:5 and 1:6), reaction temperature (50, 55 and 60 degrees C) and time (3, 7.5 and 12 hours). The predictive models for OPO content and acyl migration were adequate and reproducible. The OPO content increased with substrate ratio, and decreased with reaction time and temperature, whereas acyl migration increased with temperature and time. The optimal conditions for HMFS synthesis while maximizing OPO content (31.43% OPO) and minimizing acyl migration (6.07%) were predicted at the reaction combination of 50 degrees C, three hours and 5.5 substrate ratio. HMFS was resynthesized under the same condition, and no significant difference between the observed and predicted values was found. Further, the major fatty acid of HMFS was palmitic acid (80.6%) at sn-2 position, and oleic acid (64.9%) at sn-1,3 position.

Hepatoprotective effect of aged black garlic on chronic alcohol-induced liver injury in rats.

The hepatoprotective effect of aged black garlic (ABG) against ethanol-induced oxidative liver damage was investigated in adult male Sprague-Dawley rats for 4 weeks. Rats were divided into three groups: a saline (WT) group, an ethanol (ET) group (15 mL/kg of body weight 20% [wt/vol] ethanol), and an ethanol + ABG (ET+ABG) group (ethanol + 100 mg/kg of body weight ABG). ABG administration led to decreased epididymal and total fat pad (P<.05) and liver weights, ameliorated prominent fatty changes around the portal triad, and reduced fat accumulation in liver. ABG caused a significant decrease of the alcohol-induced increases in hepatic activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase. Cytochrome P450 2E1 activity was reduced by 55%, whereas the activities of glutathione S-transferase and quinine reductase were increased by 1.5-fold (P<.05) and fourfold (P<.05), respectively, in the ET+ABG group compared with the ET group. ABG treatment significantly decreased the thiobarbituric acid-reactive substances level in liver, heart, and plasma. Glutathione content and the activities of antioxidant enzymes such as glutathione peroxidase, glutathione reductase, and catalase in liver were significantly enhanced. Furthermore, the oxidative damage to blood lymphocyte DNA caused by chronic alcohol ingestion was significantly decreased in the ET+ABG group. In conclusion, ABG has strong antioxidative properties and may be a promising agent for protecting against chronic alcohol-induced liver damage.

Epigallocatechin-3-Gallate Suppresses IGF-I-Induced Lipogenesis and Cytokine Expression in SZ95 Sebocytes

Acne vulgaris is the most common disease of the pilosebaceous unit. The pathogenesis of this inflammatory disease is complex, involving increased sebum production and perifollicular inflammation. To identify effective agents for factors that induce acne vulgaris, we explored the pharmacological potential of epigallocatechin-3-gallate (EGCG), which has been widely investigated as an anti-proliferative and anti-inflammatory agent. In this study, we demonstrated that topical application of EGCG to rabbit auricles reduced the size of the sebaceous glands. When applied to cultured human SZ95 sebocytes, EGCG strongly suppressed cell proliferation and lipogenesis. These actions of EGCG were reproduced in IGF-I-differentiated SZ95 sebocytes. To investigate the anti-inflammatory potential of EGCG, we evaluated pro-inflammatory cytokine synthesis in IGF-I-differentiated SZ95 sebocytes and found that expression of IL-1, IL-6, and IL-8 was decreased. These results provide early evidence that EGCG is an effective candidate for acne therapy whose mechanisms of action in IGF-I-differentiated SZ95 sebocytes include the inhibition of lipogenesis and inflammation.

Spirulina improves antioxidant status by reducing oxidative stress in rabbits fed a high-cholesterol diet.

The beneficial effect of Spirulina (Spirulina platensis) on tissue lipid peroxidation and oxidative DNA damage was tested in the hypercholesterolemic New Zealand White rabbit model. After hypercholesterolemia was induced by feeding a high cholesterol (0.5%) diet (HCD) for 4 weeks, then HCD supplemented with 1% or 5% Spirulina (SP1 or SP5, respectively) was provided for an additional 8 weeks. Spirulina supplementation significantly reduced the increased lipid peroxidation level in HCD-fed rabbits, and levels recovered to control values. Oxidative stress biomarkers such as glutathione, glutathione peroxidase, glutathione reductase, and glutathione S-transferase were significantly improved in the liver and red blood cells of rabbits fed SP1. Furthermore, SP5 induced antioxidant enzyme activity by 3.1-fold for glutathione, 2.5-fold for glutathione peroxidase, 2.7-fold for glutathione reductase, and 2.3-fold for glutathione S-transferase in liver, compared to the HCD group. DNA damage in lymphocytes was significantly reduced in both the SP1 and SP5 groups, based on the comet assay. Findings from the present study suggest that dietary supplementation with Spirulina may be useful to protect the cells from lipid peroxidation and oxidative DNA damage.

Optimisation of tripalmitin-rich fractionation from palm stearin by response surface methodology.

BACKGROUND Solvent fractionation is effective in improving separation at low temperature, resulting in higher yield and purity of the final product. Tripalmitin (PPP) is an important substrate for the synthesis of human milk fat substitute (HMFS). In this study a fraction rich in PPP was separated from palm stearin by solvent fractionation. RESULTS The PPP-rich fraction was concentrated from palm stearin by acetone fractionation. Response surface methodology (RSM) was employed to optimise PPP purity (Y(1), %) and PPP content (Y(2), g kg(-1) palm stearin) with the independent variables fractionation temperature (X(1), 25, 30 and 35 degrees C) and weight ratio of palm stearin to acetone (X(2), 1:3, 1:6 and 1:9). The predictive models for PPP purity and PPP content of the solid fraction were adequate and reproducible, with no significant lack of fit and satisfactory levels of R(2). PPP purity showed a positive correlation with temperature and acetone ratio, whereas PPP content exhibited a negative correlation. The optimised fractionation condition for a targeted PPP-rich fraction with > 92% PPP purity and > 225 g kg(-1) PPP content from palm stearin was predicted. CONCLUSION The RSM model for optimising PPP purity and PPP content in the PPP-rich fraction from palm stearin by acetone fractionation was valid. The scaled-up PPP-rich fraction obtained can be used as a substrate for the synthesis of 1,3-dioleoyl-2-palmitoylglycerol, which is a main component of HMFS in infant formulas.

Multicenter study of preservative sensitivity in patients with suspected cosmetic contact dermatitis in Korea

As many new cosmetic products are introduced into the market, attention must be given to contact dermatitis, which is commonly caused by cosmetics. We investigate the prevalence of preservative allergy in 584 patients with suspected cosmetic contact dermatitis at 11 different hospitals. From January 2010 to March 2011, 584 patients at 11 hospital dermatology departments presented with cosmetic contact dermatitis symptoms. These patients were patch‐tested for preservative allergens. An irritancy patch test performed on 30 control subjects using allergens of various concentrations showed high irritancy rates. Preservative hypersensitivity was detected in 41.1% of patients. Allergens with the highest positive test rates were benzalkonium chloride (12.1%), thimerosal (9.9%) and methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) (5.5%). Benzalkonium chloride and chlorphenesin had the highest irritancy rate based on an irritancy patch test performed using various concentrations. Seven of 30 normal subjects had a positive irritant patch reading with 0.1% benzalkonium chloride and eight of 30 normal subjects had a positive irritant patch reading at 4 days with 0.5% chlorphenesin in petrolatum. Although benzalkonium chloride was highly positive for skin reactions in our study, most reactions were probably irritation. MCI/MI and thimerosal showed highly positive allergy reactions in our study. The optimum concentration of chlorphenesin to avoid skin reactions is less than 0.5%.

Butterbur (Petasites japonicus Max.) Extract Improves Lipid Profiles and Antioxidant Activities in Monosodium l-Glutamate-Challenged Mice

We investigated the effect of the butanol fraction from the methanol extract of butterbur (Petasites japonicus Max.) (BMP) on the plasma lipid profiles and oxidative damage of liver in mice challenged with monosodium l-glutamate (MSG). ICR mice (6-8 weeks old, male) were fed BMP (0.1% or 0.3%) for 1 week, and on day 7, MSG (4 mg/g) was administered intraperitoneally to the mice. Administration of MSG resulted in a significant decrease of antioxidant biomarkers such as total glutathione level and antioxidant enzyme activities such as glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), and quinone reductase (NQO1), whereas the thiobarbituric acid-reactive substances (TBARS) value was increased in liver tissue. However, BMP supplementation markedly enhanced the hepatic antioxidant enzyme activities, including GPx, GR, GST, and NQO1, whereas it lowered TBARS, compared to the MSG-treated group. Moreover, BMP supplementation decreased total cholesterol, atherogenic index, and low-density lipoprotein-cholesterol, compared to the MSG-treated group. Based on these results, it was proposed that BMP improve the plasma lipid profiles and decrease the oxidative stress by up-regulating the hepatic antioxidant enzymes in mice challenged with MSG.

Trans fatty acids content and fatty acid profiles in the selected food products from Korea between 2005 and 2008.

Since a high intake of trans fatty acids (TFA) has been associated with the increased risk of developing cardiovascular disease, food regulation worldwide has been amended with respect to nutrition labeling and health claims on TFA. In the present study, the TFA levels of Korean food products were investigated to assess the regulation effect of TFA labeling. Same Korean food products within 7 different categories were purchased in years 2005 and 2008, and the contents of TFA and lipid and fatty acid composition were investigated. Lipid and TFA contents decreased in all food products manufactured in 2008. TFA levels were 0.01 to 6.88 g/100 g food in 2005, but the levels remarkably decreased to nondetectable level or up to 0.5 g TFA/100 g food in 2008. The foods from 2005 contained a various level of TFA ranging 0.6% to 44.6% of total fatty acids; however, the TFA level significantly decreased in most foods up to 3.8% from year 2008. For TFAs, trans C18:1 levels were greater than trans isomers of C18:2, and the levels in 2005 were significantly reduced in 2008 (P < 0.05). TFA levels at the sn-2 position were up to 48.3% of total fatty acids in 2005, but the level considerably decreased up to 5.4% in 2008. The considerably decreased content of TFA in 2008 suggested that food manufacturers recognized the adverse effect of TFA on human health and followed the compulsory trans fat labeling rule by Korean Food and Drug Administration (KFDA), which started December 2007.

Red beet (Beta vulgaris L.) leaf supplementation improves antioxidant status in C57BL/6J mice fed high fat high cholesterol diet

The effect of diet supplemented with red beet (Beta vulgaris L.) leaf on antioxidant status of plasma and tissue was investigated in C57BL/6J mice. The mice were randomly divided into two groups after one-week acclimation, and fed a high fat (20%) and high cholesterol (1%) diet without (control group) or with 8% freeze-dried red beet leaf (RBL group) for 4 weeks. In RBL mice, lipid peroxidation determined as 2-thiobarbituric acid-reactive substances (TBARS value) was significantly reduced in the plasma and selected organs (liver, heart, and kidney). Levels of antioxidants (glutathione and β-carotene) and the activities of antioxidant enzyme (glutathione peroxidase) in plasma and liver were considerably increased, suggesting that antioxidant defenses were improved by RBL diet. Comet parameters such as tail DNA (%), tail extent moment, olive tail moment and tail length were significantly reduced by 25.1%, 49.4%, 35.4%, and 23.7%, respectively, in plasma lymphocyte DNA of RBL mice compared with control mice, and indicated the increased resistance of lymphocyte DNA to oxidative damage. In addition, the RBL diet controlled body weight together with a significant reduction of fat pad (retroperitoneal, epididymal, inguinal fat, and total fat). Therefore, the present study suggested that the supplementation of 8% red beet leaf in high fat high cholesterol diet could prevent lipid peroxidation and improve antioxidant defense system in the plasma and tissue of C57BL/6J mice.

Effects of dietary supplementation with red-pigmented leafy lettuce (Lactuca sativa) on lipid profiles and antioxidant status in C57BL/6J mice fed a high-fat high-cholesterol diet

The present study was undertaken to assess the beneficial effects of a daily consumption of 8 % freeze-dried red-pigmented leafy lettuce (Lactuca sativa) on CVD. C57BL/6J mice were fed a high-fat high-cholesterol diet supplemented with or without red-pigmented leafy lettuce for 4 weeks. The present results showed that the red-pigmented leafy lettuce-supplemented diet significantly decreased the level of total and LDL-cholesterol and TAG in the plasma of the mice. The atherosclerotic index was calculated to be 46 % lower in the mice fed with the lettuce diet compared with the control diet. Lipid peroxidation measured by 2-thiobarbituric acid-reactive substances was markedly reduced in the plasma, liver, heart and kidney of the mice fed the lettuce diet. The content of antioxidants (total glutathione and beta-carotene) was significantly increased by lettuce supplementation. The antioxidant defence system by antioxidant enzymes including glutathione S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase and paraoxanase in blood or liver tissues was also increased, and showed the improved oxidative stress in the mice fed the lettuce diet. The measurement of tail DNA (%), tail extent moment and olive tail moment indicated that the lettuce diet increased the resistance of hepatocyte and lymphocyte DNA to oxidative damage. The present study showed that the supplementation of a high-cholesterol high-fat diet with 8 % red-pigmented leafy lettuce resulted in an improvement of plasma cholesterol and lipid levels, prevention of lipid peroxidation and an increase of the antioxidant defence system and, therefore, could contribute to reduce the risk factors of CVD.