• Korean Journal of Food Science and Technology
• /
• v.45 no.4
• /
• pp.495-500
• /
• 2013

This study was performed to identify safe natural food preservatives from medicinal herbs and to evaluate the antimicrobial effects of medicinal plants against microorganisms. Medicinal herbs were extracted 3 times with methanol at $45^{\circ}C$ for 3 h and fractionated with n-hexane. The antimicrobial effects of the fractions were determined by measuring the diameter of the inhibition zone by using an agar-well diffusion assay. The MIC of fractions for the inhibition of microorganisms was determined using a microplate reader. The antimicrobial effects of fractions were greater against gram positive bacteria than against gram negative bacteria, but the difference was not significant. The antimicrobial effects of fractions were concentration dependent. While these results have implications, the underlying mechanisms of microbial inactivation need to be further elucidated. The results showed the possibility of developing safer food preservatives.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.5
• /
• pp.676-682
• /
• 2012

The objectives of this study focused on measuring chlorophyll fluorescence related to drought stress comparing some parameters. Almost parameters were declined although they were not significant on the basis of mean values of fluorescence of total leaf area. While the ratio of fluorescence intensity variable chlorophyll ($F_V$) to fluorescence intensity maximal chlorophyll ($F_M$) was not changed, the effective quantum yield of photochemical energy conversion in photosystemII (${\Phi}PSII$) and chlorophyll fluorescence decrease ratio ($R_{fd}$) were slightly reduced, indicating inhibition of the electron transport from quinone bind protein A ($Q_A$) to quinone bind protein B ($Q_B$). Some parameters such as non-photochemical quenching rate ($NPQ_{_-LSS}$) and coefficients of non-photochemical quenching of variable fluorescence (qN) in mid-zone of leaf and near petiole zone leaf were significantly enhanced within 4 days after drought stress, which can be used as physiological stress parameters. Decrease in ${\Phi}PSII$ could was significantly measured in all leaf zones. In conclusion, three parametric evidences for chlorophyll fluorescence responses such as ${\Phi}PSII$, NPQ, and qN insinuated the possibility of photophysiological indices under drought stress.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.970-975
• /
• 2005

Based on their biological activity, phenols from rosemary extract were evaluated for inhibition of Helicobacter pylori. Contents of total phenolic compounds and inhibition zone of water and ethanol extracts from rosemary were 24.3mg/g and 25.7mg/g, and 11mm, 14mm, and, at $200{\mu}g/mL$ phenol content, 20.9% and 78.2% inhibitory activities were observed, respectively. Electron donating abilities and 2.2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid cation radicals of water and ethanol extracts were 89.1% and 62.0% and 98.4% and 96.5%, respectively. Thiobarbituric acid reactive substances values of all extracts were lower than that of control. Ethanol extract showed 98.8% angiotensin-converting enzyme inhibitory activity. Xanthin oxidase inhibitory activities of water and ethanol extracts were very high, at 84.8%, 100%, respectively. These results indicated phenolic compounds from rosemary can be utilize as a potential antioxidant, antimicrobial, anti-hypertension and anti-gout sources.

• Korean Journal of Food Science and Technology
• /
• v.48 no.5
• /
• pp.502-507
• /
• 2016

This study was designed to investigate the beneficial effects of fermented Rhus verniciflua stem bark extract (RVSBE) on the stomach. We evaluated RVSBE for its antimicrobial activity against Helicobacter pylori (H. pylori), along with its ability to reduce the viability of human gastric cancer AGS cells. In addition, its anti-inflammatory effect was examined by evaluating nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 mRNA expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. RVSBE showed antimicrobial activity, as 2.0 mg of the extract produced a clear inhibition zone of 4.0 mm. RVSBE inhibited the growth of AGS cells by 20% at concentrations ranging from 0.25-1.0 mg/mL. Regarding the anti-inflammatory effects of RVSBE, at 0.1-1.0 mg/mL, the extract showed more than 75% inhibition of NO production. In addition, cells treated with 0.25 mg/mL RVSBE showed a 25% decrease in iNOS mRNA levels compared to those in the LPS-treated cells. These results suggest that RVSBE may have significant inhibitory effects on inflammatory mediators, and therefore, may be a potential anti-inflammatory candidate.

• Korean Journal of Medicinal Crop Science
• /
• v.9 no.4
• /
• pp.251-258
• /
• 2001

Medicinal plant extracts including Rubus coreanus, Sanguisorba officinalis, Eriobotrya japonica, Prunus mume, Crataegus pinnatifida, Rosa leavaigate Prunus persica, Prunus japonica var. nakaii and Spiraea blumei were prepared for the test of antibacterial activity. Tryptic soy broth (TSB) containing $0{\sim}10mg/ml$ of medicinal plant extracts was inoculated with $10^6$ cells/ml of Staphylococcus aureus and incubated at $35^{\circ}C$ for 24 hours. The plate counting method and clear zone test were used to test inhibitory effect of the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was derived from the survival curves of S. aureus. The order of antibacterial activities of medicinal plant extracts on the S. aureus was Rubus coreanus > Sanguisorba officinalis > Eriobotrya japonica > Prunus mume > Crataegus pinnatfida. Minimum inhibitory concentration of Sanguisorba ofEcmalis on the Staphylococcus aureus was 2.5mg/ml and minimum bactericidal concentration of Rubus coreanus was 1.0%. Inhibition zone of Rubus coreanus, Sanguisorba officinalis, Eriobotrya japonica, Prunus mume, and Crataegus pinnatifida was 16.5mm, 14.3mm 11.0mm, 14.0mm and 12.7mm, respectively. The morphology of S. aureus cells treated with medicinal plant extracts showed damage of cell wall and cytoplasmic membrane. Severely damaged cells of S. aureus lost electron dense material and cytoplasm. This result suggests that medicinal plant extracts can be used as an effective natural antibacterial agent in food.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.3
• /
• pp.389-394
• /
• 2005

This study was performed to investigate the antimicrobial activity of the Rubia akane Nakai extract against food-borne pathogens. First, the Rubia akane Nakai was extracted with methanol at room temperature and the fractionation of the methanol extract was carried out by using petroleum ether, chloroform, and ethyl acetate, and methanol. The antimicrobial activity of the Rubia akane Nakai extract was determined by using a paper disc method against food-borne pathogens and food spoilage bacteria. The methanol extract of Rubia akane Nakai showed the highest antimicrobial activity against Bacillus cereus and Pseudomonas aeruginosa. Synergistic antimicrobial effect was observed when Rubia akane Nakai extract was mixed with Viscum album var. coloratum extract as compared to each extract alone. Finally, the growth inhibition curves were determined by using methanol extract of Rubia akane Nakai against Bacillus cereus and Pseudomonas aeruginosa. The methanol extract of Rubia akane Nakai had strong antimicrobial activity against Pseudomonas aeruginosa at the concentration of 4,000 ppm. At this concentration, the growth of Pseudomonas aeruginosa was retarded more than 72 hours and up to 48 hours for Bacillus cereus. From these results, it was concluded that the methanol extract of Rubia akane Nakai inhibited effectively Bacillus cereus and Pseudomonas aeruginosa.

• Journal of Applied Biological Chemistry
• /
• v.51 no.6
• /
• pp.296-301
• /
• 2008

The extracts from Salvia officinalis were studied for antioxidative activities and inhibitory activities against angiotensin converting enzyme(ACE) and xanthine oxidase (XOase). Total phenolic compounds were found as 22.28, 26.3, 24.63, and 28.22 mg/g in the water, 60% ethanol, 60% methanol and 60% acetone extracts, respectively. The antioxidant activities of Salvia officinalis extracts were measured as $64.4{\pm}1.5%$ at $200\;{\mu}g/ml$ on EDA, inhibition rate on ABTS of $96.9{\pm}0.2%$, antioxidant protection factor of $2.30{\pm}0.16$ PF and TBARS was $0.6{\pm}0.05$ (${\times}100\;{\mu}M$) in the control and $0.28{\pm}0.02$ (${\times}100\;{\mu}M$) in 60% ethanol extracts. Inhibitory activities was the ACE of 75.50% and XOase 100% in 60% ethanol extracts. The 60% ethanol extracts from Salvia officinalis exhibited antimicrobial activities against Helicobacter pylori such as 13 mm of clear zone and inhibition rate of 63.4% with $200\;{\mu}g/ml$ of phenolics content. Rosemarinic acid was the most abundant phenolic compounds as analyzed by HPLC. The results suggest that the 60% ethanol extracts from Salvia officinalis L. will be useful as natural antioxidants and functional foods.

• Korean Journal of Plant Resources
• /
• v.12 no.1
• /
• pp.20-26
• /
• 1999

To investigate phytotoxic substances in Equisetum arvense, the aqueous extracts(25 and 8$0^{\circ}C$) or the freeze-drying matter from aqueous extracts($25^{\circ}C$) of E. arvense were tested at different concentrations for biological activities on callus induction and growth, seed germination, seedling growth and antibacterial function. Callus induction and growth of Oryza sativa and Brassica campestris ssp. pekinensis were inhibited by the aqueous extracts at 8$0^{\circ}C$ than at $25^{\circ}C$ and the higher concentrations. Callus growth of four receptor species was inhibited in order of Platycodon grandiflorum, Sesamum indicum, Brassica campestris ssp. pekinensis and Oryza sativa. Seed germination of Ο. sativa, S. indicum, and B. campestris ssp. pekinensis was not affected at low concentration, but it was proportionally inhibited by the higher concentrations. The greatest inhibition of seed germination was 28.3% compared to control, when 2,000$\mu\textrm{g}$/ml of freeze-drying matter was applied to B. campestris ssp. pekinensis. Shoot growth was stimulated by 500$\mu\textrm{g}$/ml of freeze-drying matter, but it was inhibited by the higher concentrations. Root growth was significantly inhibited compare to control at all concentrations. Antibacterial activity of freeze-drying matter didn't showed against Xantomonas oryzae and Eschrichia coli, but a small clear zone was formed by 500$\mu\textrm{g}$ of freeze-drying matter against Erwinia carotovora ssp. carotovora.

• Applied Biological Chemistry
• /
• v.51 no.3
• /
• pp.153-158
• /
• 2008

An actinomycetes F-97 producing tyrosinase inhibitor was isolated from soil samples. Isolation and purification of tyrosinase inhibitor produced by F-97 was performed as follows: IRC-120 ($NH_4^+$ type) column chromatography, silica gel column chromatography, $C_{18}$ column chromatography and Sephadex LH-20 column chromatography were used successively after the centrifuged supernatant was adjusted to pH 4.0. To identify the purity of the inhibitor, octadecylsilyl(ODS) HPLC was carried out with 5% methanol as a mobile phase. Finally, the purification yield of a tyrosinase inhibitor was 5.24%. The inhibitor was very soluble in water, methanol and ethanol but insoluble in acetone, butanol, ethylacetate and chloroform. The ${\lambda}_{max}$ value of this inhibitor in water was 194nm under UV light. The biochemical test of the inhibitor was positive in Molish, Benedict, cone. $H_2SO_4$, and $KMnO_4$ tests but negative in iodine, ninhydrin, Million, Sakaguchi, xanthoproteic and Emerson tests. The tyrosinase inhibitor was stable against heat treatment of $100^{\circ}C$ for 50 minutes and pH $4{\sim}9$. The $IC_{50}$ value of this inhibitor was $19.2{\mu}g/ml$ for mushroom tyrosinase. In $1,000{\mu}g/ml$ inhibitor concentration, inhibition zone was 27 mm for Streptomyces bikiniensis NRRL B-1049. The inhibition of F-97 against mushroom tyrosinase was competitive with tyrosine.

• Journal of Applied Biological Chemistry
• /
• v.52 no.2
• /
• pp.65-69
• /
• 2009

In this study, we tried to find the subject to inhibit H. pylori from Cheongmoknosang mulberry leaves extracts and to purify and identify them. Total phenolic compounds of hot water and 80% ethanol extracts are 17.6 and 16.1 mg/g. The activity of H. pylori inhibition at 80% ethanol extracts was determined as 15mm clear zone. The purification of inhibitory compounds were carried on $C_{18}$ column and MCI-gel CHP-20 column chromatography which were used a gradient procedure as increasing ethanol in $H_2O$. The chemical structure of purified inhibitory compounds on H. pylori were identified chlorogenic acid, caffeic acid, and rosmarinic acid by FAB-MS, $^1H-NMR$, $^{13}C-NMR$ and IR spectrum.