• Research in Plant Disease
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• v.10 no.4
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• pp.349-352
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• 2004

Antimicrobial activity of garlic extracts of four local cultivars (Namdo, Goheung, Danyang and garlic imported from China) against several plant pathogenic bacteria and fungi was investigated. The garlic extracts exhibited marked in vitro antimicrobial activities against the Gram-positive and -negative bacteria as well as fungal pathogens. Of the four cultivars, two cultivars (Namdo and garlic imported from China) showed relatively good antimicrobial activities. Gram-positive bacteria, Clavibater michiganensis was most sensitive, whereas Burkholderia cepacia was the strong resistant towards garlic extracts. Results from the planta bioassays under greenhouse conditions indicated that garlic extracts significantly reduced the cucumber powdery mildew disease showing control value 59.7-61.9% compared with the nontreated controls.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.436-444
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• 2010

Methanol extracts of the aerial and rhizome parts obtained from ten species of ferns has been screened for antimicrobial activities against Bacillus subtilis, Escherichia coli, Listeria monocytogenes, Propionibacterium acnes, Streptococcus mutans and Streptococcus sobrinus. Antimicrobial activities were carried out using broth microdilution method and paper disc diffusion assay and the extracts which showed clear zones more than 15mm in concentration of 2 mg/disc were tested for its antimicrobial activities at the $0.125{\sim}2\;mg{\cdot}mL^{-1}$ concentration of each extract for three days. The non-sterilized crude methanol extracts of Osmunda cinnamomea var. fokiensis rhizome showed the highest antimicrobial activities on B. subtilis(39%), E. coli (33%) and L. monocytogenes(58%) at the concentration of $2\;mg{\cdot}mL^{-1}$ after 72 hours. In P. acnes, frond extract of O. cinnamomea var. fokiensis showed most vigorous antimicrobial activities in the all extracts but it showed weak activity(clear zone diameters below 15 mm). All extracts has the antimicrobial activities on Streptococcus, but they exhibited weak activity. At the concentration of $2\;mg{\cdot}mL^{-1}$, only Osmunda japonica rhizome extracts showed 28 and 39% of antimicrobial activities on S. mutans and S. sobrinus after 72 hours and the other extracts showed below 10% of antimicrobial activities on S. mutans and S. sobrinus.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.3
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• pp.201-207
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• 2008

In this study, we investigated the antimicrobial and antifungal activity from the wild seaweeds of Jeju island. The active ingredients of the seaweeds were prepared by 80% methanol extraction. Antimicrobial and antifungal activity of seaweed extracts was examined. We found that 6 plant extracts among 45 plants, namely, Codium contractum, Undaria pinnatifida, Ishige sinicola, Ishige okamurai, Ishige okamuriai, Ecklonia cava, Hizikia fusiformis, Ulva fasciata, Ulva pertusa, Sargassum siliquastrum, Ecklonia kurome, Gracilaria textorii, significantly inhibited growth of harmful microorganisms. Additionally, according to DPPH assay. 2 plant extracts were found to have antioxidant activities. Taken together, these results suggest the possibility that 11 plant extracts can be utilized as an antimicrobial agent.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.300-306
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• 2002

141 methanol extracts from 125 plant species which populate in Korea were screened for antimicrobial activity against various food-borne pathogens and food spoilage microorganisms. Those plants were selected from 3 different plant groups: traditional herbs, edible plants and flowers. The methanol extracts were tested by using the disk diffusion assay against five bacteria: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli. From the evaluation of the inhibition zone diameter of microbial growth, the most significant antimicrobial activity against Bacillus subtilis, Staphylococcus auresus, Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli was observed from the extract of Schizandra chinensis (Turcz.) Baill., Rheum officinale Baill., Schizandra chinensis (Turcz.) Baill., Koelreuteria paniculata Lax and Crataegus pinnatifida Bunge, respectively. The extract from many plants - Koelreuteria paniculata Lax, Chaenomeles sinensis Koehne, Scutellaria bacicalensis Georgi, Castanea crenata Sieb. et Zucc., Rosa centifolia L., Allium fistulosum L. var. giganteum Makino, Crataegus pinnatifida Bunge, Schizandra chinensis (Turcz.) Baill., Lonicera japonica - showed antimicrobial activity all four tested bacteria.

• The Korean Journal of Community Living Science
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• v.15 no.1
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• pp.85-90
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• 2004

To classify the physiological activity by habitat and part of Dandelion (Taraxacum officinale), antioxidative and antimicrobial activities were investigated from methanol extracts of Dandelion. Dandelion was taken from Uiryeong (in Kyungnam province) and from Seoul, and antioxidative and antimicrobial activities were measured for three different parts of the dandelion: the flower, leaf and root. Antioxidative activities of methanol extracts from Dandelion were examined by a DPPH test, and antimicrobial activities were examined against 5 microorganisms: Bacillus subtilis and Bacillus cereus as G(+) microorganisms, and Salmonella typhimurium, Staphylococcus aureus and Eschrichia coli as G(-) microorganisms. No significant differences were found in terms of antioxidative and antimicrobial activities between the dandelions in Uiryeong and the dandelions in Seoul. Antioxidative activity, however, was higher in the flower of the dandelion, irrespective of habitat. Further research with other physiological factors (besides antioxidative and antimicrobial activities) is necessary to shed light on dandelion physiological function and to enhance the utilization of dandelion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.1087-1090
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• 2009

This study was carried out to research antimicrobial agents from medicinal plants, Glycyrrhiza uralensis, Dryopteris crassirhizoma, Dictamnus albus, Paeonia lactiflora, Angelica dahurica, Spirodela polyrhiza, Cimicifuga heracleifolia, Bupleurum falcatum, Magnolia kobus, Artemisia princeps, Arctium lappa, Aster tataricus, Hovenia dulcis, Citrus unshiu, Asparagus cochinchinensis, Gardenia jasminoides, Smilax china, Hovenia dulcis, Prunus sargentii, Scutellaria baicalensis. The ethanol extracts of 20 medicinal plants were tested for the antimicrobial activity against Agrobacterium tumefaciens. The extracts of Glycyrrhiza uralensis, Dryopteris crassirhizoma, Cimicifuga heracleifolia, Bupleurum falcatum showed antimicrobial activities against Agrobacterium tumefaciens.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1814-1822
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• 2018

Most people use cosmetics to protect their skin. Preservatives are often used to prevent their contamination upon use. There has been a great demand for natural preservatives due to recent reports on the side effects of parabens. Therefore, we evaluated the antimicrobial activities of Lonicera japonica and Magnolia obovata extracts and determined their potential as natural preservatives. We found that the 50% ethanol extract from L. japonica had antibacterial activity only against S. aureus and P. aeruginosa, while the ethyl acetate fraction showed antimicrobial activity against all six microbial strains tested. On the other hand, the 70% ethanol extract and the ethyl acetate fraction from M. obovata showed antimicrobial activity against all six strains. A synergistic effect against S. aureus, B. subtilis, and C. albicans was confirmed when two ethyl acetate fractions having antimicrobial activity against all six strains were used in combination. Synergistic activity against B. subtilis was also confirmed through kill-time analysis. High-performance liquid chromatography was performed to identify the components of each extract. Based on the minimum inhibitory concentration and the results of a disc diffusion assay, we confirmed that caffeic acid and luteolin influenced the antimicrobial activity of L. japonica and that the antimicrobial activity of M. obovata was influenced by the interaction of magnolol and honokiol with other components. Therefore, this study suggests that the combination of L. japonica and M. obovata extracts may be used as a plant-derived natural preservative.

• Journal of Environmental Science International
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• v.28 no.2
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• pp.225-233
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• 2019

In this study, we investigated the in vitro anti-biofilm activities of plant extracts of chives (Allium tuberosum), garlic (Allium sativum), and radish (Raphanus sativus L.) against environment harmful bacteria (gram-positive Staphylococcus aureus and, gram-negative Salmonella typhimurium and Escherichia coli O157:H7). In the paper disc assay, garlic extracts exhibited the highest anti-biofilm activity. The Minimal Inhibitory Concentration (MIC) of all plant extracts was generally higher for gram-negative bacteria than it was for gram-positive bacteria. Gram-negative bacteria were more resistant to plant extracts. The tetrazolium dye (XTT) assay revealed that, each plant extract exhibited a different anti-biofilm activity at the MIC value depending on the pathogen involved. Among the plant extracts tested, garlic extracts (fresh juice and powder) effectively reduced the metabolic activity of the cells of food-poisoning bacteria in biofilms. These anti-biofilm activities were consistent with the results obtained through light microscopic observation. Though the garlic extract reduced biofilm formation for all pathogens tested, to elucidate whether this reduction was due to antimicrobial effects or anti-biofilm effects, we counted the colony forming units of pathogens in the presence of the garlic extract and a control antimicrobial drug. The garlic extract inhibited the E. coli O157:H7 biofilm effectively compared to the control antimicrobial drug ciprofloxacin; however, it did not inhibit S. aureus biofilm significantly compared to ciprofloxacin. In conclusion, garlic extracts could be used as natural food preservatives to prevent the growth of foodborne pathogens and elongater the shelf life of processed foods.

• Food Science and Preservation
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• v.23 no.3
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• pp.432-437
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• 2016

The objective of this research was to investigate the antioxidant and antimicrobial activities of Jeok Hasuo (Polygonum multiflorum Thunb., PM) and Baek Hasuo (Cynanchi wilfordii Radix, CW) root extracts. Total phenolic contents of PM and CW root extracts were determined and the antioxidant activities of the root extracts were determined by scavenging activity of diphenylpicrylhydrazyl (DPPH) radicals. The antimicrobial activities against Staphylococcus aureus and Propionibacterium acnes were determined and expressed as the minimum inhibitory concentration (MIC). The disc diffusion method was also used to determine the zone of inhibition. The butanol extracts of PM and CW roots exhibited greater total phenolic contents (1,212.6 and 1,454.5 mg/g GAE, respectively) than those of ethanol and water extracts. The ethanol (89.0%) and butanol extracts (88.9%) of PM exhibited significantly greater DPPH radical scavenging activities than that of water extracts (73.1%) (p<0.05). Only ethanol extract exhibited an MIC of 0.8 mg/mL against both bacteria. Zones of inhibition started to form when the concentration of extract was greater than 5 mg/disc. The diameters of the zone of inhibition of PM and CW were measured to be 8.9 and 9.2 mm against S. aureus and P. acnes, respectively, exhibiting the greatest antimicrobial activities among the extracts. This research demonstrated that the PM and CW root extracts possessed not only antioxidant activity but also strong antimicrobial activity against skin-related bacteria.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.376-380
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• 2011

We investigated the total phenolic and flavonoid contents and the antimicrobial activity of ethanol extracts obtained from Saussurea lappa C.B. Clarke. The ethanol extracts of S. lappa C.B. Clarke were fractionated with various solvents (n-hexane, chloroform, and n-butanol). The antimicrobial activity of S. lappa C.B. Clarke was examined by disc-diffusion and micro-dilution susceptibility assays with six food-borne pathogens, and compared to that of the synthetic antibiotics. It is found that the S. lappa C.B. Clarke ethanol extract and n-hexane fraction have strong activity against B. cereus and V. parahaemolyticus strains compared to ampicillin. The inhibitory concentration ($IC_{50}$) values of hexane fraction against L. monocytogenes, B. cereus, and B. subtilis were 62.5, 250 and 500 ppm, respectively. Therefore, these data suggest that S. lappa C.B. Clarke may be useful as antimicrobial agents against food-borne pathogens.