• 제목/요약/키워드: biological assays

검색결과 479건 처리시간 0.027초

Characterization of a Phenazine and Hexanoyl Homoserine Lactone Producing Pseudomonas aurantiaca Strain PB-St2, Isolated from Sugarcane Stem

  • Mehnaz, Samina;Baig, Deeba Noreen;Jamil, Farrukh;Weselowski, Brian;Lazarovits, George
    • Journal of Microbiology and Biotechnology
    • /
    • 제19권12호
    • /
    • pp.1688-1694
    • /
    • 2009
  • A novel strain of fluorescent pseudomonad (PB-St2) was isolated from surface-sterilized stems of sugarcane grown in Pakistan. The bacterium was identified as Pseudomonas aurantiaca on the basis of 16S rRNA gene sequence analysis and results from physiological and biochemical characteristics carried out with API50 CH and QTS 24 bacterial identification kits. Assays using substrate-specific media for enzymes revealed lipase and protease activities but cellulase, chitinase, or pectinase were not detected. The bacterium was unable to solubilize phosphate or produce indole acetic acid. However, it did produce HCN, siderophores, and homoserine lactones. In dual culture assays on agar, the bacterium showed antifungal activity against an important pathogen of sugarcane in Pakistan, namely Colletotrichum falcatum, as well as for pathogenic isolates of Fusarium oxysporium and F. lateritium but not against F. solani. The antifungal metabolites were identified using thin-layer chromatography, UV spectra, and MALDI-TOFF spectra and shown to be phenazine-1-carboxylic acid (PCA), 2-hydroxyphenazine (2-OH-PHZ), and N-hexanoyl homoserine lactone (HHL) (assessed using only TLC data). The capacity of this bacterium to produce HCN and 2-OH-PHZ, as well as to inhibit the growth of C. falcatum, has not been previously reported.

Apoptosis-inducing effect and structural basis of Polygonatum cyrtonema lectin and chemical modification properties on its mannose-binding sites

  • Liu, Bo;Xu, Xiao-Chao;Cheng, Yan;Huang, Jian;Liu, Yan-Hong;Liu, Zhen;Min, Ming-Wei;Bian, He-Jiao;Che, Jing;Bao, Jin-Ku
    • BMB Reports
    • /
    • 제41권5호
    • /
    • pp.369-375
    • /
    • 2008
  • Polygonatum cyrtonema Lectin (PCL), which is classified as a monocot mannose-binding lectin, has received great regards for its uniquely biological activities and potentially medical applications in cancer cells. This paper was initially aimed to study apoptosis of PCL on Hela cells. Thus, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) method was carried out. Through observation of cell morphologic changes and Lactate dehydrogenase (LDH) activity-based cytotoxicity assays, PCL induced HeLa cell apoptosis in a dose-dependent manner. To further gain structural basis, multiple alignments, homology modeling and docking experiments were performed to analyze the correlation between its biological activities and mannose-binding sites. Eventually, considering docking data, chemical modification properties on the three mannose-binding sites were analyzed by a series of biological experiments (e.g., hemagglutinating and mitogenic activity assays, fluorescence and Circular Dichrosim (CD) spectroscopy) to profoundly identify the role of some key amino acids in the structure-function relationship of PCL.

Biological activities of extracts from Tongue fern (Pyrrosia lingua)

  • Akhmadjon, Sultanov;Hong, Shin Hyub;Lee, Eun-Ho;Park, Hye-Jin;Cho, Young-Je
    • Journal of Applied Biological Chemistry
    • /
    • 제63권3호
    • /
    • pp.181-188
    • /
    • 2020
  • In this study, Tongue fern (Pyrrosia lingua) plants that have been used traditionally as medicines. Their traditional medicinal uses, regions where indigenous people use the plants, parts of the plants used as medicines. This study was designed to assess the antioxidant and inhibition activities of extracts from P. lingua. In the P. lingua extracts was measured ethanol activity, 80.0% ethanol was high activity. The antioxidant activity was measured in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), assays. DPPH and ABTS radical in this experiment, solid and phenolic of extract were tested, but only an average concentration of 100 ㎍/mL was used. However, the phenolic extract is shown phenolic activity reached a peak. Also, phenolic extracts ware reached peak water and ethanol extracts. As a result, using the phenolic extracts did other antioxidant assays such as DPPH, ABTS, protection factor, and thiobarbituric acid reactive substances at 50-200 ㎍/mL concentrations. The activity of elastase and collagenase, inhibiting their activities may retard skin aging. α-Glucosidase and α-amylase, inhibitors need to be explored for the benefit of postprandial hyperglycemia in diabetic patients. Activities of tyrosinase, hyaluronidase and xanthine oxidase inhibitors of these enzymes are increasingly important ingredients in cosmetics and medications to protect the skin against hyperpigmentation and skin aging. Inhibition effects were investigated using the P. lingua extracts at 50-200 ㎍/mL concentrations. The expression levels of enzyme inhibitions activities were decrease in dependent-concentrations manner when P. lingua extracts were treated.

Gossypol Induces Apoptosis of Human Pancreatic Cancer Cells via CHOP/Endoplasmic Reticulum Stress Signaling Pathway

  • Lee, Soon;Hong, Eunmi;Jo, Eunbi;Kim, Z-Hun;Yim, Kyung June;Woo, Sung Hwan;Choi, Yong-Soo;Jang, Hyun-Jin
    • Journal of Microbiology and Biotechnology
    • /
    • 제32권5호
    • /
    • pp.645-656
    • /
    • 2022
  • Gossypol, a natural phenolic aldehyde present in cotton plants, was originally used as a means of contraception, but is currently being studied for its anti-proliferative and anti-metastatic effects on various cancers. However, the intracellular mechanism of action regarding the effects of gossypol on pancreatic cancer cells remains unclear. Here, we investigated the anti-cancer effects of gossypol on human pancreatic cancer cells (BxPC-3 and MIA PaCa-2). Cell counting kit-8 assays, annexin V/propidium iodide staining assays, and transmission electron microscopy showed that gossypol induced apoptotic cell death and apoptotic body formation in both cell lines. RNA sequencing analysis also showed that gossypol increased the mRNA levels of CCAAT/enhancer-binding protein homologous protein (CHOP) and activating transcription factor 3 (ATF3) in pancreatic cancer cell lines. In addition, gossypol facilitated the cleavage of caspase-3 via protein kinase RNA-like ER kinase (PERK), CHOP, and Bax/Bcl-2 upregulation in both cells, whereas the upregulation of ATF was limited to BxPC-3 cells. Finally, a three-dimensional culture experiment confirmed the successful suppression of cancer cell spheroids via gossypol treatment. Taken together, our data suggest that gossypol may trigger apoptosis in pancreatic cancer cells via the PERK-CHOP signaling pathway. These findings propose a promising therapeutic approach to pancreatic cancer treatment using gossypol.

Discovery of Chitin Deacetylase Inhibitors through Structure-Based Virtual Screening and Biological Assays

  • Liu, Yaodong;Ahmed, Sibtain;Fang, Yaowei;Chen, Meng;An, Jia;Yang, Guang;Hou, Xiaoyue;Lu, Jing;Ye, Qinwen;Zhu, Rongjun;Liu, Qitong;Liu, Shu
    • Journal of Microbiology and Biotechnology
    • /
    • 제32권4호
    • /
    • pp.504-513
    • /
    • 2022
  • Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 µM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 ㎍/ml and minimum fungicidal concentration (MFC) at 520 ㎍/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

High fat diet-induced brain damaging effects through autophagy-mediated senescence, inflammation and apoptosis mitigated by ginsenoside F1-enhanced mixture

  • Hou, Jingang;Jeon, Byeongmin;Baek, Jongin;Yun, Yeejin;Kim, Daeun;Chang, Boyoon;Kim, Sungyeon;Kim, Sunchang
    • Journal of Ginseng Research
    • /
    • 제46권1호
    • /
    • pp.79-90
    • /
    • 2022
  • Background: Herbal medicines are popular approaches to capably prevent and treat obesity and its related diseases. Excessive exposure to dietary lipids causes oxidative stress and inflammation, which possibly induces cellular senescence and contribute the damaging effects in brain. The potential roles of selective enhanced ginsenoside in regulating high fat diet (HFD)-induced brain damage remain unknown. Methods: The protection function of Ginsenoside F1-enhanced mixture (SGB121) was evaluated by in vivo and in vitro experiments. Human primary astrocytes and SH-SY5Y cells were treated with palmitic acid conjugated Bovine Serum Albumin, and the effects of SGB121 were determined by MTT and lipid uptake assays. For in vivo tests, C57BL/6J mice were fed with high fat diet for 3 months with or without SGB121 administration. Thereafter, immunohistochemistry, western blot, PCR and ELISA assays were conducted with brain tissues. Results and conclusion: SGB121 selectively suppressed HFD-induced oxidative stress and cellular senescence in brain, and reduced subsequent inflammation responses manifested by abrogated secretion of IL-6, IL-1β and TNFα via NF-κB signaling pathway. Interestingly, SGB121 protects against HFD-induced damage by improving mitophagy and endoplasmic reticulum-stress associated autophagy flux and inhibiting apoptosis. In addition, SGB121 regulates lipid uptake and accumulation by FATP4 and PPARα. SGB121 significantly abates excessively phosphorylated tau protein in the cortex and GFAP activation in corpus callosum. Together, our results suggest that SGB121 is able to favor the resistance of brain to HFD-induced damage, therefore provide explicit evidence of the potential to be a functional food.

Magnetic Bead-Based Immunoassay on a Microfluidic Lab-on-a-Chip

  • Park, Jin-Woo;Chong H. Ahn
    • 전자공학회지
    • /
    • 제29권3호
    • /
    • pp.41-48
    • /
    • 2002
  • This paper presents a basic concept of lab-on-a-chip systems and their advantages in chemical and biological analyses. In addition, magnetic bead-based immunoassay on a microfluidic system is also presented as a typical example of lab-on-chip systems. Rapid and low volume immunoassays have been successfully achieved on the demonstrated lab-on-a-chip using magnetic beads, which are used as both immobilization surfaces and bio-molecule carriers. Total time required for an immunoassay was less than 20 minutes including sample incubation time, and sample volume wasted was less than $50{\mu}l$ during five repeated assays. Lab-on-a-chip is becoming a revolutionary tool for many different applications in chemical and biological analysis due to its fascinating advantages (fast and low cost) over conventional chemical or biological laboratories. Furthermore, simplicity of lab-on-a-chip systems will enable self-testing capability for patients or health consumers overcoming space limitation.

  • PDF

Recent advances in microfluidic technologies for biochemistry and molecular biology

  • Cho, Soong-Won;Kang, Dong-Ku;Choo, Jae-Bum;Demllo, Andrew J.;Chang, Soo-Ik
    • BMB Reports
    • /
    • 제44권11호
    • /
    • pp.705-712
    • /
    • 2011
  • Advances in the fields of proteomics and genomics have necessitated the development of high-throughput screening methods (HTS) for the systematic transformation of large amounts of biological/chemical data into an organized database of knowledge. Microfluidic systems are ideally suited for high-throughput biochemical experimentation since they offer high analytical throughput, consume minute quantities of expensive biological reagents, exhibit superior sensitivity and functionality compared to traditional micro-array techniques and can be integrated within complex experimental work flows. A range of basic biochemical and molecular biological operations have been transferred to chip-based microfluidic formats over the last decade, including gene sequencing, emulsion PCR, immunoassays, electrophoresis, cell-based assays, expression cloning and macromolecule blotting. In this review, we highlight some of the recent advances in the application of microfluidics to biochemistry and molecular biology.

클로렐라 가수분해물의 생리활성 분석 (Biological Efficacy Assay of Chlorella hydrolysate)

  • 강민숙;채희정
    • 한국산학기술학회논문지
    • /
    • 제4권4호
    • /
    • pp.366-371
    • /
    • 2003
  • 클로렐라 추출물을 trypsin으로 가수분해하여 얻은 가수분해물을 이용하여 항균, 미백과 항암 활성을 분석하였다. Tyrosinase inhibition assay를 이용하여 미백활성을 측정한 결과 클로렐라 가수분해물의 효소활성에 대한 IC/sub 50/(50% inhibitory concentration)은 12%로 나타났다. In vitro에서 인체 폐암세포인 A-549에 대한 클로렐라 가수분해물의 항암 활성을 분석한 결과 클로렐라 가수분해물 0.15%에서 88.2%의 높은 암세포 억제율을 보였다.

  • PDF

Thresholds of Genotoxic and Non-Genotoxic Carcinogens

  • Nohmi, Takehiko
    • Toxicological Research
    • /
    • 제34권4호
    • /
    • pp.281-290
    • /
    • 2018
  • Exposure to chemical agents is an inevitable consequence of modern society; some of these agents are hazardous to human health. The effects of chemical carcinogens are of great concern in many countries, and international organizations, such as the World Health Organization, have established guidelines for the regulation of these chemicals. Carcinogens are currently categorized into two classes, genotoxic and non-genotoxic carcinogens, which are subject to different regulatory policies. Genotoxic carcinogens are chemicals that exert carcinogenicity via the induction of mutations. Owing to their DNA interaction properties, there is thought to be no safe exposure threshold or dose. Genotoxic carcinogens are regulated under the assumption that they pose a cancer risk for humans, even at very low doses. In contrast, non-genotoxic carcinogens, which induce cancer through mechanisms other than mutations, such as hormonal effects, cytotoxicity, cell proliferation, or epigenetic changes, are thought to have a safe exposure threshold or dose; thus, their use in society is permitted unless the exposure or intake level would exceed the threshold. Genotoxicity assays are an important method to distinguish the two classes of carcinogens. However, some carcinogens have negative results in in vitro bacterial mutation assays, but yield positive results in the in vivo transgenic rodent gene mutation assay. Non-DNA damage, such as spindle poison or topoisomerase inhibition, often leads to positive results in cytogenetic genotoxicity assays such as the chromosome aberration assay or the micronucleus assay. Therefore, mechanistic considerations of tumor induction, based on the results of the genotoxicity assays, are necessary to distinguish genotoxic and non-genotoxic carcinogens. In this review, the concept of threshold of toxicological concern is introduced and the potential risk from multiple exposures to low doses of genotoxic carcinogens is also discussed.