• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.193-201
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) are major causes of hospital- and community-acquired infections. The treatment of biofilm-related infections caused by these bacteria is a global healthcare challenge. Therefore, the development of alternative therapeutics is required. An essential oil extracted from Curcuma zedoaria (CZ) Rosc, also known as white turmeric, has been reported to possess various antimicrobial activities. In the present study, we evaluated the antibiofilm activities of an ethanolic extract of the CZ rhizome against MRSA and MSSA. The results showed that the CZ extract with the highest sub-minimum inhibitory concentration (sub-MIC), 1/2 MIC (0.312 mg/ml), significantly inhibited biofilm production by up to 80-90% in both tested strains. Subsequently, we evaluated the ability of the CZ extract to prevent cell-surface attachment to a 96-well plate and extracellular DNA (eDNA) release from the biofilm. The CZ extract demonstrated an inhibitory effect on bacterial attachment and eDNA release from the biofilm biomass. The CZ extract may inhibit biofilm formation by preventing eDNA release and cell-surface attachment. Therefore, this CZ extract is a potential candidate for the development of alternative treatments for biofilm-associated MRSA and MSSA infections.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.491-499
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• 2000

This study was performed to investigate the antioxidative effects of solvent extracts of eighteen curry spices. Yields of the curry spices extracted by methanol, ethylacetate and hexane were $6.4{\sim}42.9%$, $3.9{\sim}26.2%$ and $1.6{\sim}29.2%$, respectively. Methanol, ethylacetate and hexane extracts of spices were added up to 1,500 ppm in the rice bran oil and antioxidative effects of extracts were tested by Rancimat. Induction periods of spices extracted by methanol were in the order of rosemary(33.5hr)>sage(29.1hr)>ginger(28.6hr)>turmeric(26.9hr)>nutmeg(25.8hr)>oregano(25.6hr)>thyme(25.3hr)>BHT(24.5hr)>control(22.6hr). Those of ethylacetate extracts were as follows: rosemary(43.9hr)>sage(30.9hr)>oregano(29.0hr)>thyme(27.5hr)>ginger(27.1hr)>BHT(24.5hr)>control(22.6hr). Those of hexane extracts were in the order of rosemary(47.4hr)>sage(31.4hr)>oregano(27.3hr)>ginger(25.5hr)>thyme(25.1hr)>control(22.6hr). Solvent extracts of rosemary, sage, oregano, ginger and thyme showed significant antioxidative effects. Two thousands ppm hexane-extract of rosemary was the most effective. Addition of hexane-extracts of rosemary didn't show any synergism with the hexane extracts of sage, oregano, ginger, and thyme.

• Preventive Nutrition and Food Science
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• v.21 no.3
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• pp.289-295
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• 2016

Curcumin is a flavonoid found in the rhizome of the turmeric plant (Curcuma longa L.) and has recently attracted interest because it has numerous biological functions and therapeutic properties. In the present study, we attempted to incorporate curcumin into medium-chain triglyceride (MCT) nanoemulsions (0.15 wt% curcumin, 10 wt% MCT oil, and 10 wt% emulsifiers) with various emulsifiers [polyoxyethylene (20) sorbitan monolaurate (Tween-20), sorbitan monooleate (SM), and soy lecithin (SL)]. The physicochemical properties of the nanoemulsions including the Ostwald ripening stability were investigated. The initial droplet size was found to be 89.08 nm for the nanoemulsion with 10 wt% Tween-20 (control), and when Tween-20 was partially replaced with SM and SL, the size decreased: 73.43 nm with 4 wt% SM+6 wt% Tween-20 and 67.68 nm with 4 wt% SL+6 wt% Tween-20 (prepared at 15,000 psi). When the nanoemulsions were stored for 28 days at room temperature, the droplet size increased as the storage time increased. The largest increase was observed for the control nanoemulsion, followed by the 4 wt% SL+6 wt% Tween-20 and 4 wt% SM+6 wt% Tween-20 systems. The Turbiscan dispersion stability results strongly supported the relationship between droplet size and storage time. The time-dependent increase in droplet size was attributed to the Ostwald ripening phenomenon. Thus, the Ostwald ripening stability of curcumin-loaded MCT nanoemulsions with Tween-20 was considerably improved by partially replacing the Tween-20 with SM or SL. In addition, curcumin may have acted as an Ostwald ripening inhibitor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1681-1687
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• 2014

In the present study, we investigated the effect of ethyl acetate fraction from 50% ethanol extract of fermented Curcuma longa L. (FCEE) on lipid metabolism in 3T3-L1 cells. The safety range of FCEE was up to $300{\mu}g/mL$. Effects of FCEE on lipid accumulation and intracellular triglyceride (TG) content in 3T3-L1 cells were examined by Oil Red O staining and AdipoRed assay. Compared to adipocytes, lipid accumulation and intracellular TG content were significantly reduced by 10.2% and 13.7%, respectively, upon FCEE treatment at a concentration of $200{\mu}g/mL$. Glucose uptake by 3T3-L1 cells was significantly reduced by 36.6% compared to adipocytes at a concentration of $200{\mu}g/mL$. On day 8, free glycerol release into the culture medium was significantly reduced compared to adipocytes at concentrations of 50, 100, and $200{\mu}g/mL$ of FCEE. FCEE significantly stimulated RNA expression of AMP-activated protein kinase (AMPK) and suppressed mRNA expressions of sterol regulatory element-binding protein-1c (SREBP-1c), CCAAT/enhancer binding proteins ${\alpha}$ ($C/EBP{\alpha}$), and peroxisome proliferator- activated receptor ${\gamma}$ ($PPAR{\gamma}$) in 3T3-L1 cells. These results suggest that FCEE inhibits adipogenesis through activation of AMPK mRNA expressions and inhibition of SREBP-1c, $C/EBP{\alpha}$, and $PPAR{\gamma}$ mRNA expressions.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.659-666
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• 2010

Lysobacter antibioticus HS124 was isolated from rhizosphere soil in previous experiments, which produced lytic enzymes such as chitinase, gelatinase, lipase and protease. In addition, HS124 released an antibiotic compound, 4-hydroxyphenylacetic acid (4-HPAA). When larvae of P. xylostella was treated with HS124 culture broth, its body was destroyed, and degraded with the increase of incubation time, yielding glycine which was detected from HS124 culture broth. When 4-HPAA produced from HS124 was sprayed, larvae mortality increased with increasing concentration of 4-HPAA. When HS124 culture supplemented with Tween 80 was sprayed, its insecticidal activity against larvae was approximately 1.4 times higher compared to the culture without Tween 80. Insecticide (IS), HS124 culture broth (HS124), Magic-pi (MP) and HS124 culture broth+Magic-pi (HS124+MP) were each treated against larvae of P. xylostella to investigate their insecticidal effect where sterile diluted water (SDW) was used as a control. The highest mortality of larvae was found in HS124+MP, followed by IS, MP, HS124 and SDW respectively. Mortality of larvae in HS124 was 31% higher than that in SDW, but 41% lower than that in HS124+MP, meaning that both enzymes and antibiotics produced from HS124 may synergistically act as active agents with plant extract containing neem oil and turmeric in HS124+MP treatment. These results suggested that L. antibioticus HS124 together with plant extract can be one of candidates for biocontrol agents against Plutella xylostella.