• Toxicological Research
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• 제22권4호
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• pp.391-395
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• 2006

Flavonoids are polyphenolic compounds that are ubiquitous in plants. They have been shown to possess a variety of biological activities, such as antioxidant and anticancer. Reactive oxygen species (ROS) lead to damages of cellular molecules and it is the one of various factors to induce cancer. The one of flavonoids, Luteolin, was found to scavenge 1,1-diphenyl-2-piculhydrazyl (DPPH) radical and intracellular reactive oxygen species (ROS). Moreover luteolin showed protection on hamster lung fibroblast cells (V79-4 cell) damage induced by $H_2O_2$. And then it was investigated whether it may show cytotoxicity effect against various cancer cells by MTT, Luteolin at $10{\mu}g/ml$ showed the cell viability of 63.2%, 34.7%, 18.4% and 71.4% against NCl-H460, HeLa, U937 and MCF-7, respectively. As a result, luteolin shows more sensitive to U937 cells among the tested cancer cell lines. In summary, luteolin has antioxidant and cytotoxicity effect or various cancer cell lines.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 1999년도 The 6th International Symposium on the Development of Anti-Cancer Resource from Plants
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• pp.1-45
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• 1999

To date many kinds of compounds have been obtained from plants kingdom as antineoplastic and anti-cancerous agents. However, there is no special type of compounds for ncancer therapy. Various types of substances are effective for various types of cancers and tumors: for instance, alkaloids, lignans, terpenes and steroids etc. Curcumol obtained from Curcuma aromatica was tested and noticed to be effective against cancer of the uterine cervix clinically Oridonin isolated from Rabdosia ssp.is now investigated for clinical trials in China. Moreover, camptothecine isolated from Camptotheca acuminata is also antineoplastic alkaloid, but is very toxic. Chemical modification has been tried to decrease its toxicity. This compound is now using as clinical agent. Harringtonin was investigated as an anticancerous drug in China. Taxol, a compound with a taxane ring isolated from the bark of Taxus brevifolia, has been demonstrated to have substantial anticancer activity in patients with solid tumors refractory standard chemotherapy. Supply of this drug has severely limited full exploration of its antineoplastic potential. Some efforts are continued in National Cancer Institute NCI) Washington for surveying various Taxus species for optimal taxol content, improvement in semi-synthesis from baccatin III, improvement in method of extraction, and development of alternative renewable resources. Further, there are many compounds which have been reported as antineoplastic agents. On the other hand, we have screened on higher plants collected in Japan, China, Korea, Southeast Asia and South America for antineoplastic activity, which has been done using Sarcoma 180 ascites in mice, P388 Iymphocytic leukemia in mice, Chinese hamster lung V-79 cells, P388 cells and nasopharynx carcinoma (KB) cells in our laboratory, as primary screening. In this meeting, I will present on antitumor and cytotoxic substances of the higher plants (Rubia cordifolia, Ailanfhus Vilmoriniana, Aster tataricus, Taxus cuspidata var. nana, Cephalotaxus harringtonia var drupacea, etc.) selected from above screening tests.

• Plant Resources
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• 제3권1호
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• pp.1-45
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• 2000

To date many kinds of compounds have been obtained from plants kingdom as antineoplastic and anti-cancerous agents. However, there is no special type of compounds for cancer therapy. Various types of substances are effective for various types of cancers and tumors: for instance, alkaloids. lignans, terpenes and steroids etc. Curcumol obtained from Curcuma aromatica was tested and noticed to be effective against cancer of the uterine cervix clinically. Oridonin isolated from Rabdosia ssp. is now investigate for clinical trials in China. Moreover camptothecine isolated from Camptotheca acuminata is also antineoplastic alkaloid, but is very toxic. Chemical modification has been tried to decrease its toxicity This compound is now using as clinical agent. Harringtonin was investigated as an anticancerous drug in China. Taxol, a compound with a taxane ring isolated from the bark of Taxus brevifotia. has been demonstrated to have substantial anticancer activity in patients with solid tumors refractory standard chemotherapy. Supply of this drug has severely limited full exploration of its antineoplastic potential Some efforts are continued in National Cancer Institute(NCI) Washington for surveying various Taxus species for optimal taxol content, improvement in semi-synthesis from baccatin 111, improvement in method of extraction, and development of alternative renewable resources. Further, there are many compounds which have been reported as antineoplastic agents. On the other hand, we have screened on higher plants collected In Japan, China, Korea. Southeast Asia and South America for antineoplastic activity, which has been done using Sarcoma 180 ascites in mice, P388 Iymphocytic leukemia In mice, Chinese hamster lung V-79 cells, P388 cells and nasopharynx carcinoma(KB) cells in our laboratory, as primary screening. In this meeting, 1 will present on antitumor and cytotoxic substances of the higher plants(Rubis cordifolia, Ailanthus vilmoriniana, Aster tataricus, Taxus cuspidata var. nana, Cephalotaxus harringtonia var. drupacea, etc.) selected from above screening tests.

• Biomolecules & Therapeutics
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• 제30권1호
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• pp.72-79
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• 2022

Licochalcone H (LCH) is a phenolic compound synthetically derived from licochalcone C (LCC) that exerts anticancer activity. In this study, we investigated the anticancer activity of LCH in human skin cancer A375 and A431 cells. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay was used to evaluate the antiproliferative activity of LCH. Cell cycle distribution and the induction of apoptosis were analyzed by flow cytometry. Western blotting assays were performed to detect the levels of proteins involved in cell cycle progression, apoptosis, and the JAK2/STAT3 signaling pathway. LCH inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay revealed that LCH induced apoptosis, and the LCH-induced apoptosis was accompanied by cell cycle arrest in the G1 phase. Western blot analysis showed that the phosphorylation of JAK2 and STAT3 was decreased by treatment with LCH. The inhibition of the JAK2/STAT3 signaling pathway by pharmacological inhibitors against JAK2/STAT3 (cryptotanshinone (CTS) and S3I-201) simulated the antiproliferative effect of LCH suggesting that LCH induced apoptosis by modulating JAK2/STAT3 signaling.

• Current Photovoltaic Research
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• 제4권2호
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• pp.68-79
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• 2016

The power conversion efficiency of perovskite solar cells has remarkably increased from 3.81% to 22.1% in the past 6 years. Perovskite solar cells, which are based on the perovskite crystal structure, are fabricated using organic-inorganic hybrid materials. The advantages of these solar cells are their low cost and simple fabrication procedure. Also, they have a band gap of about 1.6 eV and effectively absorb light in the visible region. For the commercialization of perovskite solar cells in the field of photovoltaics, the issue of their long term stability cannot be overlooked. Although the development of perovskite solar cells is unprecedented, their main drawback is the degradation of the perovskite structure by moisture. This degradation is accelerated by exposure to UV light, temperature, and external bias. This paper reviews the aforesaid reasons for perovskite solar cell degradation. We also discuss the research directions that can lead to the development of perovskite solar cells with high stability.

• 한국안광학회지
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• 제12권2호
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• pp.79-86
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• 2007

본 연구는 mycoplasma가 오염된 배양 각막 상피세포에 anti-FAS and anti-FAS ligand antibody를 노출시킨 후 세포고사 메커니즘을 조사하기 위해 시행하였다. 배양각막 상피세포에 anti-FAS antibody 와 anti-FAS ligand antibody를 2일과 4일 동안 처리하여 주어진 기간 동안 배양하였다. 배양 중인 각막상피세포가 mycoplasma sp.에 의해 오염된 것이 밝혀졌다. mycoplasma removal agent(MRA)가 세포주로부터 세균을 제거하기 위해 이용되었다. MRA를 세포주에 첨가하여 1주일 동안 배양하였다. 그 후 각막상피 세포주는 MRA가 포함되지 않는 배양액에서 수세대 동안 배양되어 커버글라스에 계대배양하여 50-80% 채워졌을 때 MRA 제거여부를 확인하기 위한 검사 키트에 제공된 Hoechst staining을 이용하여 염색하였다. 세포고사 실험은 MRA 제거 전과 제거 후에 시행되었다. mycoplasma가 오염된 배양 각막상피세포에 대한 anti-FAS and anti-FAS ligand antibody의 영향을 알아보기 위해 Hoechst 33342 staining과 Annexin V-FITC and Propidium Iodide Staining을 이용하여 세포고사 유도를 확인하였다. 본 연구는 anti-FAS antibody가 배양각막 상피세포에서 시간과 농도에 비례하는 메커니즘으로 세포고사를 유도한다. mycoplasma가 오염된 세포주는 FAS 유도 세포고사의 민감성을 증가시키는 것으로 나타났다.

• 환경생물
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• 제17권4호
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• pp.529-541
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• 1999

대청호의 중.하류 주요지점에서 수질특성을 파악하기 위하여 환경요인과 식물플랑크톤의 변동을 98년 6월부터 99년 6월까지 매월 조사하였다. 환경요인 중 수온, DO및 pH는 각각 5.3~27.7$^{\circ}C$, 6.2~13.8 mgO$_2$/1 및 6.4~9.5 범위로서 계절적 영향이 컸다. 무기영양염 중 NH$_4$, NO$_3$, SRP 및 SRSi 농도는 각각 18~104 $\mu$g N/1, 79~1,111 $\mu$g N/1, 0~16 $\mu$g P/1 및 0~3.0 mg Si/l 범위였다. 무기질소 중 NH$_4$ 는 NO$_3$의 5.5~7.2%수준이었다. NO$_3$는 하계에만 다소 낮았고 다른 시기에는 거의 일정하였다. SRP와 SRSi농도는 남조류가 우점하는 하계에 증가하였고 수온이 감소된 10월 이후에 규조류의 증가와 함께 SRP와 SRSi농도가 감소하였다. 따라서 SRSi는 SRP와 더불어 조류 생장에 밀접한 관련성이 있는 영양염으로 평가되었다. Chl-$\alpha$ 평균농도는 8~12 $\mu$g/1 범위로서 하류(댐)에서 가장 낮았다. 또한 하절기에 TN/TP비가 감소할수록 chi-$\alpha$ 농도는 증가하였고 TN/TP비의 평균값은 110으로서 조류의 생장에 대해 P 제한성이 강하였다. 식물플랑크톤의 변동은 계절에 따라 소수종이 우점하는 특성이 관찰되었다. 하계에는 남조류 Anabaena, Microcystis 및 Oscillatoria속 조류가 주로 초여름부터 늦가을까지 발생하여 번무하였다. 이 중에서 A. spiroides v. crassa는 0.3~2.0$\times$$10^4$cells/ml, M. aeruginosa는 6.4$\times$$10^2$~1.0$\times$$10^4$cells/m1 및 O. limosu는 4.6$\times$$10^3$~1.6$\times$$10^4$ cells/ml 범위로서 변화 폭이 가장 컸다. 반면 동계에는 규조류 Stephanodiscus속 조류가 11월~4월에 평균 4.9$\times$$10^2$cells/m1수준이었고 1월에 평균 세포수가 1.3$\times$$10^3$ cells/ml로 많아 중요종으로 볼 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.79-85
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• 1996

By using a T7 expression system, a large amount of Bacillus stearothermophilus endo-xylanase A (XynA) could be produced in Escherichia coli cells. The overproduced enzyme formed inclusion bodies, and so the protein could be more easily purified to homogeneity. The molecular weight of the purified enzyme was estimated to be 22 kDa by SDS-polyacrylamide gel electrophoresis and 43 kDa by Sephacryl S-200 gel filtration, suggesting that the native enzyme was a homodimer. The pI value was determined to be 8.4. The Michaelis constants for birchwood xylan and oat spelts xylan were calculated to be 3.83 mg/ml and 5.03 mg/ml, respectively, and the $V_{max}$ max/ values for both xylans were 2.86 $\mu mole$/min. The purified enzyme was most active at $55^{\circ}C$ and pH 8.0, and stable up to $60^{\circ}C$ and in the near neutral pH range. From the zymogram, Bacillus stearothermophilus was found to have at least three xylanases and the purified one was the smallest among them.

• 대한한의학회지
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• 제25권4호
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• pp.79-89
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• 2004

Saussurea lappa and Taraxacum mongolicum have been used for herbal medicinal treatments against cancers in East Asia. We performed this study to understand the molecular basis underlying the anti-tumor effects of two herbs and analyzed the effects of these medicinal herbs on proliferation and on expression of cell growth/apoptosis related molecules by using an AGS gastric cancer cell line. The treatments of Saussurea lappa dramatically reduced cell viabilities in a dose and time-dependent manner, but Taraxacum mongolicum did not. FACS analysis and Annexin V staining assay also showed that Saussurea lappa induces apoptotic cell death of AGS. Expression analyses via RT-PCR and Western blots revealed that Saussurea lappa increased expression of the p53 and its downstream effector p21/sup Waf1/, and that the both increased expression of apoptosis related Bax and cleavage of active caspase-3 protein. We also confirmed the translocation of Bax to mitochondria Collectively, our data demonstrate that Saussurea lappa induces growth inhibition and apoptosis of human gastric cancer cells, and these effects are correlated with down- and up-regulation of growth-regulating apoptotic and tumor suppressor genes, respectively.

• Environmental Analysis Health and Toxicology
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• 제15권4호
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• pp.147-155
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• 2000

In order to evaluate anti -oxidant activities and protective effect against oxidatve damage, DPPH radical scavenging activity and lipid peroxidation inhibitory activity were measured among methanol extracts prepared from natural medicinal plants. Fourteen natural medicinal plants which were reported to have anti -oxidative or anti-inflammatory effects were selected based on our previous report. In addition to the total methanol extracts, n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions were prepared from each total extract. DPPH radical scavenging assay was performed against 14 total extracts and all samples showed dose-dependent activities in various extent. Among those, 6 samples, methanol extracts of Euryale ferox, paeonia suffruticosa, Areca catechu var. dulcissima, Cinnamomun cassia, Alpinia katsumadai and Betula platyphlla var. japonica showed IC$\sub$50/ value lower than 6.0 $\mu\textrm{g}$/ml. The highest DPPH radical scavenging activity was found in ethylacetate fraction of paeonia suffruticosa with IC$\sub$50/ value of 1.1 $\mu\textrm{g}$/ml. Analysis of lipid peroxidation inhibitory activity on hydrogen peroxide-induced oxidative damage in Chinese hamster lung fibroblast (V79-4) cells revealed that the highest inhibitory effect was observed in methanol extract of Betula platyhpylla var. japonica. Lipid peroxidation inhibitory activity was observed as a dose-dependent manner in all samples used in this study. Among fraction samples, ethylacetate fraction of Alpinia katsumadai had the strongest inhibitory activity with IC$\sub$50/ value of 0.9 $\mu\textrm{g}$/ml.