• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.138-146
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• 2016

In this study, we report the optimal extraction conditions for obtaining organosulfur compounds, such as cycloalliin, from garlic by using principal component analysis (PCA). Extraction variables including temperature ($40{\sim}80^{\circ}C$), time (0.5~12 h), and pH (4~12) were investigated for the highest cycloalliin yields. The cycloalliin yield (5.5 mmol/mL) at pH 10 was enhanced by ~40% relative to those (~3.9 mmol/mL) at pH 4 and pH 6. The cycloalliin level at $80^{\circ}C$ showed the highest yield among the tested temperatures (5.05 mmol/mL). Prolonged extraction times also increased cycloalliin yield; the yield after 12 h was enhanced ~2-fold (4 mmol/mL) compared to the control. Isoalliin and cycloalliin levels were inversely correlated, whereas a direct correlation between polyphenol and cycloalliin levels was observed. In storage for 30 days, garlic stored at $60^{\circ}C$ (11 mmol/mL) showed higher levels of cycloalliin and polyphenols than those at $40^{\circ}C$, with the maximum cycloalliin level (13 mmol/mL) on day 15. Based on the PCA analysis, the isoalliin level depended on the extraction time, while cycloalliin amounts were influenced not only by extraction time, but also by pH and temperature. Taken together, extraction of garlic at $80^{\circ}C$, with an incubation time of 12 h, at pH 10 afforded the maximum yield of cycloalliin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1725-1731
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• 2016

This study was carried out to investigate the effects of steam-drying on antioxidant compounds and antioxidant activity of Alliun hookeri root (AHR). The yield of methanolic extracts, total phenolic content (TPC), browning intensity (280 nm and 420 nm), and organosulfur compound contents (alliin and cycloalliin) in raw and steam-dried AHRs were 10.71~37.40%, $15.53{\sim}36.36{\mu}g/mg$, 0.48~2.09, 0.01~0.25, $1.46{\sim}700.61{\mu}g/mg$, and $1,173.95{\sim}2,182.60{\mu}g/mg$, respectively. Yield, TPC, and browning intensity of AHRs increased by steam-drying, whereas organosulfur compound contents decreased. Of all methanolic extracts from raw and steam-dried AHRs, four-time steam-drying showed the lowest $EC_{50}$ values (0.43, 7.53, 0.34, and 0.48 mg/mL, respectively) for DPPH radical scavenging activity, ABTS radical scavenging activity, SOD-like activity, and reducing power, whereas four-time steam-drying resulted in the highest TPC ($36.36{\mu}g/mg$) and browning intensity (2.09 and 0.25 at 280 and 420 nm, respectively). The antioxidant activities of methanolic extracts from raw and steam-dried AHRs were closely correlated with their TPC, browning intensity, and organosulfur compound content, showing correlation determination coefficient ($R^2$) values higher than 0.82. As a result, four-time steam-drying of AHRs could be useful as potential antioxidant sources.

• Journal of Life Science
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• v.27 no.5
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• pp.553-560
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• 2017

Fermented garlic extract (FGE) is a well-known functional food containing cycloalliin. Here we tested if FGE has an effect on the vascular system. We found that FGE had an effect on monocytic adhesion to endothelial cells, which occurs at the initial step of processes of inflammation. From dose-dependent experiments, 0.1 to $1{\mu}g/ml$ of FGE appeared to inhibit lipopolysaccharide (LPS)-enhanced heterotypic cell adhesion between THP-1 and BAECs. This result indicates that FGE blocks vascular inflammation. Then we found that FGE activates eNOS and Akt in BAECs. The phosphorylation of eNOS was maximally elevated 10 min after FGE treatment. Parallely, the phosphorylation of Akt was also maximally increased 10 min after FGE treatment. Consistently, it was found that FGE enhanced the production of nitric oxide. We then examined whether NO mediates THP-1 cell adhesion to BAECs. Both Akt and eNOS inhibitors appeared to reverse an inhibitory effect of FGE. These findings indicate that FGE inhibits LPS-enhanced heterotypic cell adhesion via Akt and eNOS. In conclusion, FGE plays an important role in prevention of inflammatory diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.342-347
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• 2013

In this study, we investigated changes in the organosulfur compounds of garlic (by fermentation with lactic acid bacteria) and the effects of these fermented garlic extracts on alcohol-induced cytotoxicity in CYP2E1-transfected HepG2 cells. Lactobacillus plantarum has the highest growth rate in a garlic medium and the S-allyl-L-cysteine (SAC) in fermented garlic extracts with Lactobacillus plantarum and Pediococcus pentosaceus were significantly higher compared to other lactic acid bacteria strains (p<0.05). The SAC, S-ethyl cysteine (SEC) and S-methyl cysteine (SMC) in garlic extracts were all increased by fermentation with lactic acid bacteria. However, alliin in the fermented garlic extracts with lactic acid bacteria strains was lower than the original garlic extract and the contents of cycloalliin in the garlic extracts did not change with fermentation (p<0.05). The electron donating ability of the fermented garlic extracts increased with dose. The electron donating ability of the fermented garlic extract with L. plantarum and P. pentosaceus was over 90% efficient at 5 mg/g. The fermented garlic extracts (with lactic acid bacteria) and garlic extract were not influenced, up to $100{\mu}g/mL$, in CYPE1-transfected HepG2 cells. The CYPE1-transfected HepG2 cell viabilities were 92.60% and 92.23% when treated with both alcohol (200 mM) and fermented garlic extract ($100{\mu}g/mL$) with lactic acid bacteria respectively, for 6 days.