• Advances in Traditional Medicine
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• 제10권3호
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• pp.208-213
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• 2010

The aerial parts of methanol extract of Oxystelma esculentum (MEOE) (Asclepiadaceae) was evaluated for in vitro lipid peroxidation and antimicrobial activity. Lipid peroxidation was assayed by the change in optical density of the various concentrations (20 - 320 ${\mu}g$/ml) and the percentage inhibition was estimated. Ascorbate/FeSO4-induced peroxidation was inhibited by MEOE and standard antioxidants such as BHA, BHT and the percentage inhibition of the methanol extract was increased with dose dependent manner. The $IC_{50}$ value of the MEOE, BHA and BHT for lipid peroxidation was found to be 135.24 ${\mu}g$/ml, 25.62 ${\mu}g$/ml and 17.13 ${\mu}g$/ml, respectively. The antimicrobial activity of MEOE was determined by disc diffusion method with three grampositive, five gram-negative and two fungal microorganisms. MEOE exhibited the antimicrobial activity against the tested microorganisms except Salmonella typhimurium (MTCC 98). In present study, it is concluded that MEOE has significant effect in the inhibition of lipid peroxidation and possesses good antimicrobial activity.

• Food Science and Biotechnology
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• 제15권4호
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• pp.582-588
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• 2006

The antioxidant and antimicrobial activity of the fermentation extract (PFE) and the 50 and 80% ethanol extracts (PE 50, PE 80) of Pinus densiflora pine needles were evaluated. Electron donating ability, superoxide dismutase (SOD) ability, and antimicrobial activity were observed in PFE; those abilities differed in PE 80 and PE 50, depending on the ethanol concentration used for the extraction. PFE had the highest electron donating ability with a value of 92.20%, while PE 80 and PE 50 had values of 74.66 and 53.47%, respectively. For SOD activity, PE 80 exhibited a slightly higher value of 31.11% compared to that of PFE and PE 50, which were 29.65 and 25.43%, respectively. PFE, PE 50, and PE 80 were all found to inhibit bacteria, and the effectiveness of this inhibition was strongly related to the type of extracts used. PFE showed good antimicrobial effects for all of the tested Gram-positive strains and for most of the tested Gram-negative strains. These results suggest that PFE has superior functionality compared to the ethanol extracts (PE 80, PE 50), in terms of antioxidant and antimicrobial activity. On the basis of these results, pine needle fermentation extracts can be used for industrial applications as a functional material.

• 대한한방내과학회지
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• 제31권2호
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• pp.290-297
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• 2010

Objectives : This study evaluated the effect of Dioscoreae Rhizoma on antioxidant and antimicrobial activity in vitro. Methods : In vitro experiments were made on antioxidant by DPPH radical scavenging activity, enzyme activity of SOD, protective effect about $H_2O_2$ and DNA fragmentation in RAW264.7 cells, as well as antimicrobial by Cox-2 expression in LPS-induced RAW264.7 cells. Results : 1. Dioscoreae Rhizoma's antioxidant ability was improved by DPPH radical scavenging activity. 2. Antioxidant ability of Dioscoreae Rhizoma produced good results at more than 0.025 mg/$m{\ell}$. 3. On protective effect of Dioscoreae Rhizoma about $H_2O_2$ on RAW264.7 cells, with addition of Dioscoreae Rhizoma extract the cells' survival increased compared to adding $H_2O_2$ only. 4. About revelation-control of Cox-2 at RAW264.7 cells which induce by LPS, when Dioscoreae Rhizoma's concentration was higher from 0.0125 mg/$m{\ell}$ to 1 mg/$m{\ell}$, its control activity was stronger. Thus we found Dioscoreae Rhizoma has antimicrobial activity. 5. The power of DNA fragmentation control of Dioscoreae Rhizoma was time-independent. Conclusions : From this study we conclude that Dioscoreae Rhizoma has effects on antioxidant and antimicrobial activity. However, considerable work still needs to be done studying antioxidants by concentration, as well as a variety of experiments about antimicrobial activity.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.1052-1061
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• 2019

Objective: This study was conducted to identify duck liver-expressed antimicrobial peptide 2 (LEAP-2) and demonstrate its antimicrobial activity against various pathogens. Methods: Tissue samples were collected from 6 to 8-week-old Pekin ducks (Anas platyrhynchos domesticus), total RNA was extracted, and cDNA was synthesized. To confirm the duck LEAP-2 transcript expression levels, quantitative real-time polymerase chain reaction was conducted. Two kinds of peptides (a linear peptide and a disulfide-type peptide) were synthesized to compare the antimicrobial activity. Then, antimicrobial activity assay and fluorescence microscopic analysis were conducted to demonstrate duck LEAP-2 bactericidal activity. Results: The duck LEAP-2 peptide sequence showed high identity with those of other avian species (>85%), as well as more than 55% of identity with mammalian sequences. LEAP-2 mRNA was highly expressed in the liver with duodenum next, and then followed by lung, spleen, bursa and jejunum and was the lowest in the muscle. Both of LEAP-2 peptides efficiently killed bacteria, although the disulfide-type LEAP-2 showed more powerful bactericidal activity. Also, gram-positive bacteria was more susceptible to duck LEAP-2 than gram-negative bacteria. Using microscopy, we confirmed that LEAP-2 peptides could kill bacteria by disrupting the bacterial cell envelope. Conclusion: Duck LEAP-2 showed its antimicrobial activity against both gram-positive and gram-negative bacteria. Disulfide bonds were important for the powerful killing effect by disrupting the bacterial cell envelope. Therefore, duck LEAP-2 can be used for effective antibiotics alternatives.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4227-4232
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• 2011

A number of new 2,5-disubstituted 1,3,4-thiadiazole and their S- or N-substituted derivatives as well as the corresponding sugar hydrazone derivatives were synthesized and tested for their antimicrobial activity against Bacillus subtilis (Gram-positive), Pseudomonas aeruginosa (Gram-negative), and Streptomyces species (Actinomycetes). The synthesized compounds displayed different degrees of antimicrobial activities or inhibitory actions.

• 한국안광학회지
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• 제14권3호
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• pp.95-102
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• 2009

목적: 본 연구는 마늘 allyl 유도체의 안질환 세균에 대한 항균활성을 조사하고, 이를 다목적용액(MPS)에 응용함으로써 천연물유래 마늘성분을 이용하여 MPS 개발에 대한 기초자료를 얻고자 실시하였다. 방법: 녹농균(Pseudomonas aeruginosa)과 황색포도상구균(Staphyloccus aereus)에서 마늘유래 allyl 유도체인 diallyl sulfide(DAS)의 항균활성을 측정하였으며, 항균활성이 없는 MPS에 DAS를 함께 처리하여 세균의 생육억제 효과를 측정하였다. 결과: 50%의 생육저해($IC_{50}$)를 나타내는 DAS농도는 녹농균과 황색포도상구균 각각 0.25%와 0.64% 였다. MPS의 항균활성 실험에서 A사의 제품은 효과가 없었으며 B사의 제품은 두 균 모두에서 항균활성을 보였다. B사 MPS의 항균활성은 그람음성과 그람양성 세균에 대해 모두 유의한 차이를 나타내지 않았다. 따라서 DAS의 항균활성을 이용한 보존제의 개발을 위해 처리된 농도에서 항균활성을 나타내지 않은 A사의 MPS를 사용하여 A사의 MPS에 DAS를 첨가하여 항균활성을 조사한 바 DAS의 항균활성 효과가 나타났으며, 콘택트렌즈 살균제에 대한 적용가능성이 확인되었다. 결론: 마늘의 allyl 유도체는 황색포도상구균과 녹농균에 대한 항균작용을 나타내었으며, 녹농균에서 더큰 항균활성을 가지는 것으로 나타났다. 따라서 마늘성분과 같은 천연물유래 항균활성물질이 MPS의 보존제로 개발 가능성이 있음을 시사한다.

• International Journal of Oral Biology
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• 제39권4호
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• pp.169-176
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• 2014

A positional scanning synthetic peptide combinatorial library (PS-SCL) was screened in order to identify antimicrobial peptides against the cariogenic oral bacteria, Streptococcus mutans. Activity against Streptococcus gordonii and Aggregatibacter actinomycetemcomitans was also examined. The library was comprised of six sub-libraries with the format $O_{(1-6)}XXXXX-NH_2$, where O represents one of 19 amino acids (excluding cysteine) and X represents equimolar mixture of these. Each sub-library was tested for antimicrobial activity against S. mutans and evaluated for antimicrobial activity against S. gordonii and A. actinomycetemcomitans. The effect of peptides was observed using transmission electron microscopy (TEM). Two semi-mixture peptides, RXXXXN-$NH_2$ (pep-1) and WXXXXN-$NH_2$ (pep-2), and one positioned peptide, RRRWRN-$NH_2$ (pep-3), were identified. Pep-1 and pep-2 showed significant antimicrobial activity against Gram positive bacteria (S. mutans and S. gordonii), but not against Gram negative bacteria (A. actinomycetemcomitans). However, pep-3 showed very low antimicrobial activity against all three bacteria. Pep-3 did not form an amphiphilic ${\alpha}$-helix, which is a required structure for most antimicrobial peptides. Pep-1 and pep-2 were able to disrupt the membrane of S. mutans. Small libraries of biochemically-constrained peptides can be used to generate antimicrobial peptides against S. mutans and other oral microbes. Peptides derived from such libraries may be candidate antimicrobial agents for the treatment of oral microorganisms.

• 통합자연과학논문집
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• 제1권1호
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• pp.47-53
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• 2008

In a previous study, we showed that Cecropin A (1-8)-Magainin 2 (1-12) hybrid peptide (CA-MA)'s analogue, Anal P5, exhibit broad-spectrum antimicrobial activity. Anal P5, designed by flexible region (positions 9, 10)-substitution, Lys- (positions 4, 8, 14, 15) and Leu- (positions 5, 6, 12, 13, 16, 17, 20) substitutions, showed an enhanced antimicrobial and antitumor activity without hemolysis. The primary objective of the present study was to gain insight into the relevant mechanisms of antimicrobial activities of Anal P5 by using flow cytometric analysis. Anal P5 exhibits strong antifungal activity in a salt concentration independent manner. In addition, Anal P5 causes significant morphological alterations of the bacterial surfaces as shown by scanning electron microscopy, supporting its antibacterial activity. Its potent antibiotic activity suggests that Anal P5 is an excellent candidate as a lead compound for the development of novel antibiotic agents.

• 한국식품위생안전성학회지
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• 제27권2호
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• pp.109-116
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• 2012

본 연구에서는 에탄올추출과 초임계추출(SFE) 조건에 따른 생강 oleresin(GO) 추출물의 Gram 양성균(Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes)과 Gram 음성균(Pseudomonas aeruginosa, Escherichia coli)에 대한 항균활성을 살펴보았다. GO 에탄올추출은 추출물의 농도가 증가할수록 clear zone이 비례적으로 증가하였다. 이의 항균성은 Gram 양성균이 Gram 음성균보다 크게 나타났으며, 특히 Listeria monocytogenes에서 항균활성이 크게 나타났다. 생강분말과 에탄올의 추출비율이 1:6인 E-III 처리구가 항균활성이 높았다. GO 에탄올추출물의 항균성은$80^{\circ}C$ 조건에서 처리하는 것이 효과적이었고, 추출시간 (1시간~7시간)은 처리구 간에 큰 차이가 없었다. 초임계추출물에 대한 항균성은 Listeria monocytogenes에서 가장 크게 나타났다. 초임계추출물에서는 100 bar $35^{\circ}C$, 250 bar $35^{\circ}C$, 250 bar $65^{\circ}C$ 조건에서 강한 항균력을 보였다. 그리고 용매추출물의 경우 추출조건에 따라서 항균활성에 큰 차이를 나타내지 않았으나, 초임계추출물의 경우 추출압력 100 bar, 500 bar 처리구와 추출온도 $35^{\circ}C$, $65^{\circ}C$ 처리구에서 항균활성이 크게 나타났다.

• 디지털융복합연구
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• 제16권6호
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• pp.353-361
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• 2018

천연 항균제 및 항산화제 개발의 일환으로 선택한 피마자 열매의 열수 추출물(RFW)과 에탄올 추출물(RFE)은 각각 15.8%와 18.4%의 수율을 나타냈다. Paper-disc method을 통한 항균활성 측정 결과, 피마자 열매를 에탄올로 추출한 추출물에서 항균활성이 나타났다. 특히 녹농균 및 황색포도상구균에서 활성이 우수하였으며, 캔디다균에서도 배양 16시간까지 1.5mm 정도의 항균활성이 나타났으나 24시간 이후에는 캔디다균의 증식이 다시 관찰되었다. 피마자 열매 에탄올추출물(RFE)의 MIC실험 결과 S. aureus와 P. aeruginosa에서 각각 96%와 93%의 항균력이 나타났다. 피마자 잎 열수추출물(RLW)과 피마자 잎 에탄올추출물(RLE)의 DPPH radical 소거능 측정을 통한 항산화 효능 결과는 $1000({\mu}g/m{\ell})$에서 각각 $1.8{\pm}0.6%$, $2.1{\pm}0.7%$의 free radical 소거율을 나타냈다. 본 연구가 향후 천연물을 이용한 항균제 및 항산화제 개발을 위한 기초 자료로 제공되리라 사료된다.