• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2294-2298
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• 2009

In present work an attempt was made to synthesize various analogues of levofloxacin by introducing new functionality at carboxylic group position via nucleophilic substitution reaction. For this purpose the carboxylic group at C-6 was esterified and later subjected to nucleophilic attack at the carbonyl carbon by various aromatic amines. Structure of the analogues was confirmed by different techniques i.e. IR, $^1H$ NMR and mass spectrometry. The antibacterial activity of the derivatives was also assessed and compared with the parent against a series of Gram-positive and Gramnegative bacteria. A synergistic as well as antagonistic behavior was observed in these derivatives. Additionally unlike levofloxacin, the derivatives were also found to modulate oxidative burst response of phagocytes exhibiting moderate to significant inhibitory activity.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5903-5908
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• 2012

Objective: The purpose of this study is to investigate the combined effects of exemestane and aspirin on MCF-7 human breast cancer cells. Methods: Antiproliferative effects of exemestane and aspirin, alone and in combination, on growth of MCF-7 human breast cancer cells were assessed using the MTT assay. Synergistic interaction between the two drugs was evaluated in vitro using the combination index (CI) method. The cell cycle distribution was analyzed by flow cytometry and Western blotting was used to investigate the expression of cyclooxygenase-1, cyclooxygenase-2 and Bcl-2. Results: MTT assays indicated that combination treatment obviously decreased the viability of MCF-7 human breast cancer cells compared to individual drug treatment (CI<1). In addition, the combination of exemestane and aspirin exhibited a synergistic inhibition of cell proliferation, significantly arrested the cell cycle in the $G_0/G_1$ phase and produced a stronger inhibitory effect on COX-1 and Bcl-2 expression than control or individual drug treatment. Conclusion: These results indicate that the combination of exemestane and aspirin might become a useful method to the treatment of hormone-dependent breast cancer. The combination of the two inhibitors significantly increased the response as compared to single agent treatment, suggesting that combination treatment could become a highly effective approach for breast cancer.

• The Plant Pathology Journal
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• 제36권6호
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.

• 대한본초학회지
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• 제25권4호
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• pp.11-16
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• 2010

Objective : Oriental medicines have been combined oriental medical theory which based on the seven modes of emotions. Notopterygium incisum (N. incisum) and Clematis manshurica (C. manshurica) have been used as an anti-rheumatic and analgesic medicine for the treatment of rheumatism, headache, cold, etc. In this study, we evaluate the synergistic anti-inflammatory effect of N. incisum and C. manshurica. Method : To evaluate the synergistic anti-inflammatory effect of a herbal mixture N. incisum and C. manshurica, we examined the changed ear thickness in 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear edema model after topical application of herbal mixture. In addition, the levels of markers for inflammation, such as tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$, prostaglandin $G_2$ ($PGE_2$), and nitric oxide (NO) were measured by ELISA assay and Griess reagent in lipopolysaccharide-stimulated Raw 264.7 cells. Results : Our results showed that aqueous extracts of N. incisum and C. manshurica combination significantly inhibited the mouse ear edema induced by TPA. Moreover, the aqueous extracts of N. incisum and C. manshurica combination exhibited synergistic effects in down-regulating TNF-${\alpha}$, IL-$1{\beta}$, $PGE_2$ level, but not NO. Conclusions : This study suggested that combined treatment of N. incisum and C. manshurica, based on seven methods in prescription compatibility, has a synergistic effect in down-regulating inflammatory response both in vitro and in vivo models.

• 한국잡초학회지
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• 제3권1호
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• pp.69-74
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• 1983

이앙답(移秧畓)에 사용(使用)되는 제초제(除草劑)들의 상호작용(相互作用) 관계(關係)를 해명(解明)하고 최소(最少) 혼합비율(混合比率)을 구명(究明)하여 효과적(效果的)인 제초제(除草劑) 사용(使用) 체계(體系) 수립(樹立)과 신제초제(新除草劑) 개발(開發)을 위한 기초(基礎) 자료(資料)를 얻기 위해 현재(現在) 시중(市中) 판매중(販賣中)에 있거나 시험연구중(試驗硏究中)에 있는 우량제초제(優良除草劑), butachlor, chlormethoxynil, Sw751, S47, SL 49, naproanilide 등(等) 14 종(種)을 91개(個)의 혼합조합(混合組合)으로 조성(組成)한 다음 이들을 피 (63%)-물달개비(16%)-울챙고랭이(10%)-너도방동산이(5%)-마디꽃(4%)의 상태(狀態)로 되어 있는 잡초군락형(雜草群落型)에 처리(處理)하였던 결과(結果)를 요약(要約)하면 다음과 같다. 1. 91개(個)의 혼합조합중(混合組合中) 길항적(拮抗的) 반응(反應)(Antagonism)을 보였던 혼합조합수(混合組合數)는 38 조합(組合)이였는데, 이 중 길항적(拮抗的) 반응(反應)이 5% 미만(未滿)인 것은 chlormethoxynil과 perfluidon 외(外) 10조합(組合), 길항적(拮抗的) 반응(反應)이 6~10%였던 것은 butachlor+SL 49 외(外) 11 조합(組合), 길항적(拮抗的) 반응(反應)이 11% 이상(以上)이였던 것은 butachlor+ nitrofen 외(外) 14 조합(組合)이였다. 2. 상가적(相加的) 반응(反應)(Additive)(혼합효과(混合效果) ${\pm}$ 2%) 을 보인 혼합조합(混合組合)은 butachlor와 bifenox, Sw 751, thiobencarb, naproanilide/thiobencarb, piperphos/dimethametryne, CG 113/napranilide 혼합(混合) 등(等) 40 조합(組合)이였다. 3. 공력적(共力的) 반응(反應)(synergism)을 보인 것은 13혼합조합(混合組合)이였는데 이 중 공력적(公力的) 효과(効果)가 5% 미만(未滿)인 혼합조합(混合組合)은 ACN/MCPB/nitrofen과 napronilide, naproanilide/thiobencarb, chlormethoxynil 혼합(混合), thiobencarb와 chlormethoxynil, nitrofen 혼합(混合), butachlor와 S47/bifenox 조합(組合)이였고 공력적(公力的) 효과(効果)가 6~10%였던 조합(組合)은 nitrofen과 chlormethoxynilide 혼합(混合), butachlor와 naproanilide, ACN/MCPB/nitrofen 혼합조합(混合組合)이였으며, 공력적(公力的) 효과(効科)가 11% 이상(以上)이였던 것은 chlormethoxynil과 butachlor, bifenox 혼합(混合), nitrofen과 ACN/MCPB/nitrofe 혼합조합(混合組合)이였다. 4. diphenylether 계(系) 제초제(除草劑)인 oxyfluorfen과 carbamate계(系) 제초제(除草劑)인 thiobencarb의 상호작용성(相互作用性)은 공력적(共力的) 효과(効果)가 인정(認定)되었으며 최대(最大) 상호작용지수(相互作用指數)는 약(約) 2에 해당하였고, 살초율(殺草率)이 90% 기대(期待)되는 최소약량(最少藥量) 혼합비율(混合比率)은 oxyfluorfen의 경우 0.012kg ai/ha 였고 thiobencarb의 경우는 0.45 kg ai/ha였다.

• 환경생물
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• 제20권2호
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• pp.165-172
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• 2002

두 가지 유해인자가 동시에 작용할 때 생물체에 나타나는 영향은 길항작용에서 상승작용에 이르기까지 폭넓게 나타난다. 상승작용의 생물학적 중요성에도 불구하고 유해인자간의 복합작용을 설명할 수 있는 구체적 연구결과들은 별로 없는 실정이다. 본 연구는 고온과 기타 환경 유해인자의 복합작용에 의해 생물체에 나타내는 반응에 있어서의 규칙성을 도출해 내기 위하여 수행되었다. 고온과 이온화방사선, 자외선, 초음파 등의 동시작용에 관한 효모세포 실험결과를 분석하였으며 다른 연구자들에 의하여 수행된 바이러스, 세균포자, 동식물세포 및 포유류 배양세포에 관한 실험결과를 이용하여 도출된 규칙성을 검증하였다. 본 연구를 통하여 검증된 상승 작용에 관한 규칙성은 다음과 같이 요약될 수 있다. 방사선량률이 일정할 경우 특정 온도범위 내에서만 상승작용을 관찰할 수 있다. 방사선량률을 증가시키면 최대 상승작용을 나타내는 온도 값도 증가하게 되며, 선량률을 낮추면 온도값도 따라서 낮아지게 된다. 방사선 조사시의 온도가 일정할 경우 특정범위의 선량률에서만 상승작용이 관찰되는데, 이 범위 내에 최대상승작용 유발선량률 값이 존재한다. 방사선 조사시의 온도를 낮추면 선량률의 값 또한 낮아지며 그 역도 마찬가지이다. 본 연구에서 밝혀진 규칙성은 상승작용의 신개념 적립에 실마리를 제공할 것이며 특히 생물체에 대한 유해 환경 요인의 복합영향 해석과 환경재해 예방을 위한 영향평가 및 위해 평가에 유용하게 활용될 수 있을 것이다

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.722-729
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• 2004

Leptin is an adipocyte-secreted hormone and its plasma levels correlate with total body fat mass, however, it also plays a regulatory role in immunity, inflammation, and hematopoiesis. Chemokine is known as a chemoattractant cytokine in inflammatory reaction, but its role in leptin reaction has not been well studied. In this study, the direct effect of leptin on the expression of chemokine mRNAs and lipopolysaccharide (LPS)-induced chemokine KC mRNA in mouse peritoneal macrophages was investigated. Leptin did not induce the expression of lymphotactin, RANTES, eotaxin, MIP-1$\beta$, MIP-1$\alpha$, MIP-2, MCP-1, IP-10, TCA-3, and KC mRNA in mouse peritoneal macrophages, and had no direct effect on the expression of these LPS-induced chemokine mRNAs except KC mRNA. The synergistic effect of leptin on the expression of LPS-induced KC mRNA occurred late in the time course of response to LPS. The increased expressions of Ob-Rb mRNA and leptin receptor protein were detected during the LPS treatment. Leptin produced a substantial increase in the stability of the LPS-induced KC mRNA, and the synergistic effect of leptin on LPS-induced KC mRNA expression was further augmented by cycloheximide (CHX). Pyrrolidine dithiocarbamate (PDTC) did not block the synergistic effect of leptin on LPS-induced KC mRNA expression in mouse peritoneal macrophages. These data suggest that although leptin has no direct effect on the expression of lymphotactin, RANTES, eotaxin, MIP-1$\beta$, MIP-1$\alpha$, MIP-2, MCP-1, IP-10, TCA-3, and KC mRNA in mouse peritoneal macrophages, the synergistic effect of leptin on the expression of LPS-induced KC mRNA has the possibility that LPS might induce the expression of the Ob-Rb receptor or an unknown gene(s) that sensitizes macrophages to the synergistic function of leptin. Therefore, further studies are necessary to examine leptin as a regulatory factor of chemokine production.

• 환경생물
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• 제23권1호
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• pp.64-70
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• 2005

벼의 유묘 생육과 광합성 효율에 대한 저선량 방사선과 생장조절물질 간의 상승작용 효과를 확인하기 위해 4년 된 종자로 기내실험과 온실실험을 수행하였다. 기내실험에서 관찰한 종자 발아의 경우 방사선을 조사한 IBA 0.001 ppm 처리구에서 가장 높은 값을 보였다. 또한, 파종 6일 후 측정한 유묘 생육은 방사선 무 조사구보다 방사선을 조사한 GA₃와 IBA 처리구에서 대체로 높은 값을 보였으며, 그 중 IBA 0.001 ppm 처리에서 저선량 방사선과 생장조절물질간의 유의성 있는 상승작용 효과를 확인 할 수 있었다. 저선량 방사선을 조사 한 후 IBA 0.001 ppm을 처리하여 관찰한 온실 실험에서도 유묘 생육에서의 상승작용 효과를 확인할 수 있었다. 광합성 효율을 확인하기 위해 측정한 엽록소 형광은 생장조절물질에 의해서만 차이를 보여, IBA 처리에 의해 광계 2의 양자 수율을 나타내주는 Ф/sub PSⅡ/와 광화학적 소멸을 나타내는 qP는 증가하였고 비광화학적 소멸을 나타내는 형광지표인 qN은 감소하였다. 이러한 결과를 통해 저선량 방사선을 조사한 후 생장조절물질을 처리하였을 때 벼의 종자 발아와 더불어 생육이 두 요인간의 상승작용 효과로 촉진됨을 확인할 수 있었다.

• Ocean and Polar Research
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• 제28권1호
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• pp.45-56
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• 2006

This study investigated primarily the toxic effects of bis(tributyltin)oxide (TBT) and DDT (Dichlorodiphenyltrichloroethane) on the mortality of adult Acartia omorii and barnacle nauplii as well as the hatching rate of A. omorii. Subsequently, compound effects of TBT and DDT on the mortality of immature copepods were tested in order to assess whether or not synergistic influence existed in the mixture of sublethal concentration of two pollutants. Mortality of adult A. omorii increased as exposure concentration of DDT increased in the range of from 0.0001 to 1ppm. Egg hatching rate of the copepod showed no distinctive difference in the range between 0.1 and 10ppm, while barnacle nauplii showed abnormal motility of their appendages in the range of 0.0001 to 1 ppm. Mortality of adult A. omorii increased as TBT concentration increased within the range of 1 and 10 ppb, whereas egg hatching rate of the copepod showed no linear response to the same exposure range. Moreover, copepod nauplii were almost motionless even though copepod eggs hatched under the exposure condition of TBT $(0{\sim}10 ppb)$ and DDT $(0{\sim}10 ppm)$, respectively, suggesting that the nauplii are hard to develop into adult stage. On the basis of the sublethal concentration less than the 24-h $LC_{50}$, 0.001 ppm (DDT) and 2 ppb (TBT) were selected to confirm the compound effects of two pollutants on the mortality of immature copepods. Mortality of immature copepods under the condition of mixture of the two pollutants was higher than that in the single exposure condition. This result seems to indicate that synergistic effects of sublethal toxicants can make a more hazardous effect on the survival of immature copepods even though the concentration of single toxicant is not lethal to copepods in the marine environment.

• 환경생물
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• 제19권1호
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• pp.19-24
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• 2001

병해충을 막기 위해 농업용 살충제가 광범위하게 사용되고 있다. 농약사용에 따른 생물학적 위해가 우려되며 농약이 또 다른 환경유해요인과 인체에 상승적으로 작용할 경우 농업재해로 이어질 가능성이 있다. 다양한 인자에 의한 DNA손상을 감지하는데 유용한 단세포 겔 전기영동법을 이용하여 살충제와 방사선에 의한 사람 림프구 DNA손상을 평가하였다. 각기 다른 농도로 살충제를 10분간 전처리한 림프구와 정상 림프구에 0-2.0 Gy의 방사선으로 조사한 다음 DNA 손상도를 평가하였다. DNA가닥 절단에 대한 표식인 tail moment의 증가는 감마선에 대해서 뚜렷한 선량-반응 관계를 나타내었다. 단세포 겔 전기영동법을 통한 평가결과 권장 사용농도 이상의 살충제는 림프구에 대한 유전독성을 나타내었을 뿐 아니라 방사선과 함께 상승작용을 일으켜 림프구 DNA손상을 더욱 증가시키는 것이 확인되었다. 이와 같은 결과는 환경재해의 방재 및 예방 조치에 필요한 생물정보를 사전에 제공하는 의미를 가진다.