• Korean Journal of Pharmacognosy
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• v.53 no.2
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• pp.87-95
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• 2022

Methicillin resistance Staphylococcus aureus (MRSA) is a gram-positive bacterium, the most commonly isolated bacterial human pathogen. JiYu-san is one of the natural products used to treat diseases in the folk recipe. In this study, we investigated the antimicrobial activity of EtOH 70% extracts of JiYu-san (JYS) against MRSA. The antibacterial activity of JYS against MRSA strain was evaluated using minimum inhibitory concentration (MIC), checkerboard dilution test, and time-kill assay. The effect of JYS on the immune mechanism of MRSA was confirmed through cell membrane permeability tests and energy metabolism tests, and the antibacterial activity mechanism was performed using qRT-PCR and western blot. As a result, in the antibacterial test of JYS, the MIC was measured to be 1.9~1000 ㎍/mL, and synergistic or showed a partial synergistic effect. In addition, JYS showed antibacterial activity in a combination test with DCCD or TX-100. In a study on the mechanism of action of antibacterial activity, it was found that JYS suppressed MRSA resistance genes and proteins. These results suggest that JYS has antibacterial activity and provides great potential as a natural antibiotic by modulating the immune mechanism against MRSA.

• Journal of Pharmacopuncture
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• v.26 no.3
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• pp.265-275
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• 2023

Objectives: The aim of this study was to evaluate the effect of fruit juices on Multi-Drug Resistant (MDR) bacterial pathogens involved in Urinary Tract Infections (UTIs) and Sexually Transmitted Infections (STIs) among tribal women in the district Anuppur, Madhya Pradesh, India. Methods: Fresh juices of lemon (Citrus limon), amla/Indian gooseberry (Phyllanthus emblica), pineapple (Ananas comosus), mosambi/sweet lime (Citrus limetta), orange (Citrus sinensis), kiwi (Actinidia deliciosa), and pomegranate (Punica granatum) fruits were evaluated for in vitro antibacterial activity against bacterial pathogens involved in UITs and STIs among tribal women. Physico-chemical analysis of fresh fruits was also carried out by measuring the pH, moisture, protein, fat, crude fibre, carbohydrate, and ascorbic acid content. Results: Lemon and amla juice showed better antibacterial activity against the pathogens as compared to other juices. MIC results fruit juices against UTIs and STIs pathogens vary depending on the specific pathogen and juice chemical constituents. The physico-chemical analysis showed that the moisture content was highest in mosambi (90%), followed by orange (87%). Ascorbic acid content was found highest in amla (540 mg/100 g), followed by kiwi (90.3 mg/100 g). Pomegranate showed highest concentration of carbohydrate (15.28 g/100 g), fat (1.28 g/100 g), and protein (1.65 g/100 g). Lemon juice had lowest pH of 2.20, followed by amla 2.67. Conclusion: The lemon juice showed highest antibacterial activity against MDR bacterial pathogens involved in UTIs and STIs among tribal women in district Anuppur, Madhya Pradesh, India. The low pH of lemon may be responsible for its high antibacterial activity as compared to other juices.

• The Plant Pathology Journal
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• v.39 no.3
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• pp.290-302
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• 2023

Abamectin offers great protection against Bursaphelenchus xylophilus, a well-known devastating pathogen of pine tree stands. Trunk injection of nematicides is currently the most preferred method of control. This study aimed to evaluate the potency of the commonly used formulations of abamectin against B. xylophilus. Twenty-one formulations of abamectin were evaluated by comparing their sublethal toxicities and reproduction inhibition potentials against B. xylophilus. Nematodes were treated with diluted formulation concentrations in multi-well culture plates. And, populations preexposed to pre-determined concentrations of the formulations were inoculated onto Botrytis cinerea culture, and in pine twig cuttings. Potency was contrastingly different among formulations, with LC₉₅ of 0.00285 and 0.39462 mg/ml for the most, and the least potent formulation, respectively. Paralysis generally occurred at an application dose of 0.06 ㎍/ml or higher, and formulations with high sublethal toxicities caused significant paralysis levels at the tested doses, albeit the variations. Nematode reproduction was evident at lower doses of 0.00053-0.0006 ㎍/ml both on Botrytis cinerea and pine twigs, with significant variations among formulations. Thus, the study highlighted the inconsistencies in the potency of similar product formulations with the same active ingredient concentration against the target organism, and the need to analyze the potential antagonistic effects of the additives used in formulations.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.75-87
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• 2023

The pine wood nematode (PWN), Bursaphelenchus xylophilus is a well-known devastating pathogen of economic importance in the Republic of Korea and other countries. In the Republic of Korea, trunk injection of nematicides is the preferred method of control. In this study, the efficacy of 16 locally produced formulations of emamectin benzoate against the PWN are compared through determining their sublethal toxicities and reproduction inhibition potentials. Nematodes were treated with varying concentrations of the tested chemicals in multi-well culture plates, and rates of paralysis and mortality were determined after 24 h. Reproduction inhibition potential was tested by inoculating pre-treated nematodes onto Botrytis cinerea, and in pine twig cuttings. Despite the uniformity in the concentration of the active ingredient, efficacy was contrastingly different among formulations. The formulations evidently conformed to three distinct groups based on similarities in sublethal activity (group 1: LC₉₅ of 0.00768-0.01443 mg/ ml; group 2: LC₉₅ of 0.03202-0.07236 mg/ml, and group 3: LC₉₅ of as high as 0.30643-0.40811 mg/ml). Nematode paralysis generally occurred at the application dose of 0.0134-0.1075 ㎍/ml, and there were significant differences in nematode paralysis rates among the products. Nematode reproduction was only evident at lower doses both on B. cinerea and pine twigs, albeit the variations among formulations. Group 1 formulations significantly reduced nematode reproduction even at a lower dose of 0.001075 ㎍/ml. The variations in efficacy might be attributed to differences in inert ingredients. Therefore, there is need to analyze the potential antagonistic effects of the large number of additives used in formulations.

• Korean Journal of Pharmacognosy
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• v.54 no.1
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• pp.27-37
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• 2023

This research was conducted to investigate the comprehensive effects of methanol extract of Coptidis rhizoma (MECR) against oral pathogen. We studied the antibacterial, anti-biofilm, anti-gingipain and anti-inflammatory activity of MECR. The minimum bactericidal concentration (MBC) of MECR was 100 ㎍/mL against several oral pathogens. The formation of biofilm of Streptococcus mutans was reduced to 8.93~24.12% in the presence of 25 ㎍/mL of MECR. The gingipain activity of Porphyromonas gingivalis were reduced to 3.91~6.23% in case of Kgp and 5.73~7.78% in case of Rgp in the presence of 10 mg/mL of MECR. The expression of fadA mRNA, virulence factor of Fusobacterium nucleatum (F. nucleatum) was 3 folds decreased in the presence of 25 ㎍/mL of MECR. In case of YD-38 cells challenged with F. nucleatum, RQ values of IL-8 and IL-6 were reduced about 12 folds and 5.45 folds in the presence of 2 ㎍/mL of MECR. In case of RAW 264.7 murine cell challenged with F. nucleatum, RQ values of IL-1β and IL-6 were 2.52 folds and 2.55 folds reduced in the presences of 2 ㎍/mL of MECR. Conclusively, MECR showed potent antibacterial and anti-inflammatory effects against oral pathogenic bacteria.

• Research in Plant Disease
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• v.16 no.3
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• pp.279-284
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• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.

• Research in Plant Disease
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• v.20 no.4
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• pp.259-263
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• 2014

For application of sodium hypochlorite as a seed disinfectant to the control of bakanae disease caused by Gibberella fujikuroi in rice, we investigated the effects of sodium hypochlorite for antifungal activity, eliminating fungus from seeds and reducing disease occurrence in vitro and greenhouse. The viability of the pathogen was significantly reduced at $80{\mu}l/l$ concentration of sodium hypochlorite, and the pathogens did not grow at over $100{\mu}l/l$ concentration of sodium hypochlorite. The effect of eliminating fungus was 90% at treatment of 0.3% sodium hypochlorite solution to infected rice seeds for eight hours. When the rice seeds were soaked into 0.5% and 0.3% sodium hypochlorite solutions for twelve hours, the disease incidences of rice seedling were remarkably reduced to 4.3% and 4.7%, respectively, compared to 97.3% of non-treatment control. The rates of seedling stand were 29.1% and 26.9% higher with the sodium hypochlorite treatment than that of non-treatment control. When prochloraz and sodium hypochlorite was treated to naturally severely infested rice seeds with bakanae disease, the disinfection effect was higher than that of prochloraz alone treatment. When the seeds were soaked in sodium hypochlorite before or after prochloraz, the rate of seed contamination was low as 4.0% or 6.3%, respectively, compared to prochloraz alone as 13.7%. The disease incidence was low as 3.7% or 8.3%, respectively, compared to prochloraz alone as 14.3%. The disinfection effect of treatment with prochloraz after sodium hypochlorite was higher than that of treatment with prochloraz before sodium hypochlorite.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.233-238
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• 2008

To evaluate biochemical safety of gejang distributed in Korea, 33 samples were collected and analyzed for indicator microorganisms, pathogen, parasite, pH, volatile basic nitrogen(VBN), salinity, 3-MCPD, histamine, and synthetic food colors. Total plate counts of gejang were the range of 3 to 7 log cfu/g and coliform were the range of ND to 4 log cfu/g. Vibrio parahaemolyticus was detected from 4 samples, and Escherichia coli(1 log cfu/g) and copepoda were detected from 1 sample among those. pH and VBN value of samples were the range of 6.69 to 8.10 and 21.99 to 94.55 mg%, respectively. The ranges of salinity concentration for ganjang chamgejang, ganjang ggokgejang, and ganjang dolgejang were $11.6{\sim}32.6%,\;2.8{\sim}20.5%$, and $11.6{\sim}13.3%$, respectively. But, the range of salinity concentration of yangnum gejang was $2.6{\sim}9.4%$, which was lower than ganjang gejang. Besides, 3-MCPD, histamine and synthetic food colors were not detected. From the results, most of gejang was appropriate for Korea national standard for food regulation, but still biological hygiene control for raw materials, processing, and distribution should be improved.

• Journal of Sericultural and Entomological Science
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• v.15 no.1
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• pp.15-25
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• 1973

The author studied the applicability of Furazolidone to the silkworm rearing industry as a useful remedy for certain silkworm diseases, at the silkworm rearing house of the college of agriculture, Seoul national university, during both the spring and the autumn silkworm rearing season of 1972. Discovering the fact that Furazolidone, when put on the mulberry leaves in a powdered form, is eaten along with the leaves by silkworms and thus the systematic administration of Furazolidone to silkworms is possible, the experimenter carried on a series of experiments (1. determining the in vitro antibacterial activity of Furazolidone to four pathogens of silkworm diseases-Bacillus thuringiensis, Aspergillus oryzae, Aspergillus flavus, and Isaria farinosa, 2. observing the prophylactic and therapeutic effect of Furazolidone against the experimental flacherie caused by inoculation of B. thuringiensis, and 3. examining the toxicity of Furazolidone to silkworm larvae). As the results of the experiments the investigator found out the fundamental fact that Furazolidone exerts a good prophylactic and therapeutic effect against flacherie which is the most common and important silkworm disease: Furazolidone, in in vitro test, inhibited completely the growth of B. thuringiensis, the pathogen of bacterial flacherie, at the concentration of 1 ${\mu}$g/mι. with the tube method and at the concentration of 5 ${\mu}$g/mι. with the plate method, and the drug showed an excellent prophylactic effect and a considerably good therapeutic effect, depending on the time of administration, on the 5th instar silkworms inoculated B. thuringiensis, at the tentative dose of 150mg. per 10 silkworms administered once a day for 2 days. For the practical administration of Furazolidone against flacherie, the dose, the time and duration of administration, and the form of preparation, will be investigated more closely.

• Journal of Life Science
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• v.20 no.7
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• pp.1143-1150
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• 2010

The antibacterial activity of methanol extracts from 70 kinds of oriental medicinal herbs on four strains of Staphylococcus aureus and S. epidermidis was investigated. The results showed that C. japonica, C. sappan, R. javanica, R. tanguticum, and S. miltiorrhiza had an antibacterial activity on all the strains used. Among these, C. japonica and R. javanica, which showed excellent antibacterial activity, were extracted with water, ethanol, methanol, and ethyl acetate for further study of antibacterial activities. The results showed that the boiled water extract of C. japonica had the best antibacterial activity. Assuming that the antibacterial activity of C. japonica originated from berberine, which has been reported many times, the berberine content of the boiled water extract of C. japonica was analyzed and the result was 13.88%. To compare the antibacterial activity of berberine with that of other antibiotics, berberine chloride and three other kinds of antibiotics were investigated, which showed that berberine chloride had an antibacterial activity on KCCM 35494 S. epidermidis only when the concentration was higher than 600 mg/l, and it did not show antibacterial activity in the other strains. Based on these results, it was concluded that the antibacterial activity of the boiled water extract of C. japonica on the strains used in this study originated from high concentration of berberine or substances other than berberine. Therefore, identification of the substance will be necessary.