• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.437-442
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• 2012

Red yeast rice (RER) has been used in China for centuries for its medicinal properties and is an increasingly popular alternative lipid-lowering treatment. This study was carried out to estimate the antioxidant properties of RER extracts. The ethyl acetate extract exhibited the DPPH radical scavenging activity of 85% at 0.2 mg/mL and $IC_{50}$ 0.13 mg/mL. A significant proportion of hydroxyl radicals in a cuvette were scavenged: 44.2% at 2.5 ${\mu}g$/mL, 74.1% at 5.0 ${\mu}g$/mL, and >100% at 10 ${\mu}g$/mL. The $HepG_2$ cells pre-treated with RER ethyl acetate extract reduced the hydroxyl radicals significantly compared to the control cells. Oxidative DNA damage was measured using a Comet assay. The RER ethyl acetate extract did not induce any DNA damage per se, and appeared to enhance the resistance to DNA damage caused by an oxidant challenge with $H_2O_2$, whereas lovastatin increased the level of DNA damage in the cells in both the unstressed (no oxidant) and those stressed with $H_2O_2$. The relative gene expression of the antioxidant enzymes in $HepG_2$ cells were also affected by the RER ethyl acetate extract. The $HepG_2$ cells were pre-incubated with the RER ethyl acetate extract, and then stressed with $H_2O_2$ or left unstressed (no oxidant). In the unstressed cells, superoxide dismutase (Cu/Zn SOD) and glutathione peroxidase (GPx) were increased significantly 3.25-fold and 2.67-fold, respectively, whereas in the stressed cells, the catalase (CAT) level was increased by 4.64-fold and 7.0-fold at 5 ${\mu}g$/mL and 10 ${\mu}g$/mL, respectively, compared to those of the control. From these results, RER appears to be effective in suppressing oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.139-147
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• 2005

The efficacy of extraction from Inonotus obliquus was examined from the points of antioxidative characteristics and some antioxidative compounds. To enhance the efficient extraction for the effective components from Inonotus obliquus, temperature-stepwise water extraction method was applied. Temperature-stepwise water extracts were prepared for 8 hrs as follows: the first extract at 8$0^{\circ}C$, the second extract from the residue of the first extract at 10$0^{\circ}C$, and the third extract from the residue of the second extract at 12$0^{\circ}C$. Antioxidativeactivities were determined by electron-donating ability of DPPR - free radical, scavenging ability of ABTS$.$$^{+}$radical cation, and by inhibiting ability of linoleic acid autoxidation. In results, the first extract showed the least antioxidant capacity, and the third extract showed the highest antioxidant capacity. The third extract also had the greatest amounts of phenolic compounds and flavonoids. Amounts of phenolic compound from each extract were almost proportional to the radical scavenging activities and linoleic acid autoxidation inhibiting ability (r=0.960∼0.980, regression analysis). Furthermore, the effect of the pooled extract of all three extractions of Inonotus obliquus on the lipid peroxidation reacted with active oxygen species (KO$_2$, $H_2O$$_2$, $.$OH) and metals (Fe$^{2+}$, CU$^{2+}$) was evaluated by measuring the formation of thiobarbituric acid reactive substances (TBARS). The pooled Inonotus obliquus extracts lowered the amounts of TBARS formed by all of the active oxygen species and metals. Especially, these lowering effects were pronounced in the reaction with $.$OH and Fe$^{2+}$. These results suggest that the pooled temperature-stepwise extract from Inonotus obliquus could be potential functional materials to reduce the oxidation of lipids and other compounds induced by free radicals.adicals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.452-458
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• 2008

The effect of fermented soybean culture of Bacillus subtilis MORI mixed with mulberry leaves on the lowering the levels of blood glucose and cholesterol was examined using neonatal streptozotocin-induced diabetic (n-STZ) rats. B. subtilis MORI produces 1-deoxynojirimycin (DNJ), an $\alpha$-glucosidase inhibitor. The content of DNJ of soybean fermented culture mixed with mulberry was higher (4.1$\pm$0.0 mg/g dry base) than that (1.5$\pm$0.0 mg/g) of mulberry. The concentration of 50% inhibition (IC50) against rat intestinal $\alpha$-glucosidase of soybean fermented culture mixed with mulberry was $5.6{\pm}0.1{\mu}g$/mL and that of mulberry was $17.0{\pm}0.5{\mu}g$/mL. Experimental groups of diabetic rats were randomly assigned to normal control group (NC group), diabetic control group (DC group) and three diabetic groups fed with DNJ food product. One of the three diabetic groups was M group (60 mg DNJ food product/kg) (DNJ food product containing 30% mulberry) and the other two were MM-60 group (60 mg/kg) and MM-120 group (120 mg/kg) (DNJ-fortified food product containing 30% fermented soybean culture mixed with mulberry leaves). The glucose in serum was significantly decreased in the MM-60 and MM-120 groups fed with DNJ-fortified food product for 4 weeks, compared with DC group. Total cholesterol and triglyceride in serum were also lower in MM-60 and MM-120 groups than the DC group. These results support that the fermented soybean culture of B. subtilis MORI mixed with mulberry leaves improved the metabolism of blood glucose and lipid in the n-STZ rat model.

• Journal of Life Science
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• v.29 no.1
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• pp.60-68
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• 2019

Limonium tetragonum, an edible halophyte that grows on salt marshes in Korea, is thought to possess various health benefits (e.g., antioxidant, antitumor, and hepatoprotective). In the present study, different solvent partitioned subfractions, water ($H_2O$), buthanol (n-BuOH), 85% aqueous methanol (85% aq. MeOH), and hexane (n-hexane), from crude extract of L. tetragonum were tested for their ability to prevent adipogenesis in differentiating 3T3-L1 preadipocytes. The treatment of differentiating 3T3-L1 preadipocytes with L. tetragonum subfractions (LTFs) resulted in suppressed adipogenesis and reduced expression of adipogenesis-related transcription factors such as peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$), CCAATT/enhancer-binding protein alpha ($C/EBP{\alpha}$), and sterol regulatory element-binding protein 1c (SREBP-1c) at both mRNA and protein levels. In addition, the LTF treatment notably decreased the levels of phosphorylated p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) pathway in association with $PPAR{\gamma}$-linked adipogenesis. Among all the tested LTFs, $H_2O$ and n-hexane were the most effective in lowering lipid accumulation and regulating the adipocyte differentiation via $PPAR{\gamma}$ pathway. Taken together, the results indicated that the $H_2O$ and n-hexane LTFs contain bioactive compounds that may exhibit significant antiadipogenesis activity by downregulation of the $PPAR{\gamma}$ pathway and inactivation of the MAPK signal pathway in 3T3-L1 preadipocytes.