Application of a tissue culture microtiter test for the detection of cytotoxic agents from natural products.

Mirabelli, Christopher K.; Bartus, H F; Bartus, J O; Johnson, Randall K.; Mong, Shau Ming; Sung, Cheng Po; Crooke, Stanley T.

doi:10.7164/antibiotics.38.758

Cited by 45 publications

(22 citation statements)

References 4 publications

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“…For determination of the cytotoxic activities of the drugs, BALB/c 3T3 H-ras cells (1.5 x 105 cells per well) were preincubated for 24 h at 37°C in 96-well plastic plates and were then treated with different dilutions of drug for 3 days. After washing the monolayer cells with phosphate-buffered saline, the concentrations of drugs required for 50% inhibition of cell growth were determined by a Giemsa stain method described previously (26). RESULTS Topoisomerase 11-mediated DNA cleavage by naphthoquinones.…”

Section: Methodsmentioning

confidence: 99%

Induction of topoisomerase II-mediated DNA cleavage by the plant naphthoquinones plumbagin and shikonin

Fujii

Yamashita

Arima

et al. 1992

Antimicrob Agents Chemother

131

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Plumbagin and shikonin, plant metabolites which have naphthoquinone structures, induced mammalian topoisomerase II-mediated DNA cleavage in vitro. Treatment of a reaction mixture containing these naphthoquinones and topoisomerase II at an elevated temperature (65°C) resulted in a great reduction in DNA cleavage, suggesting that the mechanism of the topoisomerase II-mediated DNA cleavage induced by these naphthoquinones is through formation of a cleavable complex, as seen with antitumor agents such as 4'-(9-acridinylamino)methanesulfon-m-anisidide and demethylepipodophyllotoxin ethylidene-13-glucoside.Lawson and lapacol, which are structurally related plant metabolites with naphthoquinone moieties, could not induce topoisomerase U-mediated DNA cleavage. Plumbagin and shikonin induced a similar DNA cleavage pattern with topoisomerase II which was different from the cleavage patterns induced with other known topoisomerase II-active drugs. A DNA-unwinding assay with T4 DNA ligase showed that shikonin, lawson, and lapacol did not intercalate into DNA, while plumbagin and 2-methyl-1,4-naphthoquinone intercalate into DNA, but to a lower degree than 4'-(9-acridinylamino)methanesulfon-m-anisidide does.DNA topoisomerases are a class of enzymes that alter DNA conformation through a concerted breaking and rejoining of the DNA molecule, thereby controlling the topological state of DNA. They are reported to be involved in many important processes of DNA metabolism including replication, transcription, recombination, and chromosome segregation (38). In addition, topoisomerases have been potential targets for chemotherapy. Bacterial topoisomerase II (DNA gyrase) is well known as the primary target of quinolone antibacterial agents. Mammalian topoisomerase II has also been identified as the primary cellular target for a number of clinically important antitumor agents which include intercalating agents [e.g., 4'-(9-acridinylamino)methanesulfon-manisidide {m-AMSA}, adriamycin, and ellipticine] as well as nonintercalating agents (e.g., VP16 and VM26 [epipodophyllotoxin]) (6,29,34,35). All of these drugs trap topoisomerase II in an intermediary conformation with DNA, termed the "cleavable complex," which can be detected as DNA double-strand breaks upon treatment of the complex with protein denaturants. Structure-activity studies of a large number of acridine derivatives, epipodophyllotoxin congeners, and antitumor quinolones have shown a strong correlation between antitumor activity and the ability to induce the cleavable complex (23,31,39). In addition, there is now good evidence that mammalian topoisomerase I is the cellular target of camptothecin, an alkaloid with antitumor activity which was isolated from the Chinese tree Camptotheca acuminata. Camptothecin derivatives have shown promising activities in clinical studies (12,16 purified mammalian topoisomerases. We found that the plant naphthoquinones plumbagin and shikonin are potent inducers of the cleavable complex formation with topoisomerase II in vitro.In this report, we de...

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Section: Methodsmentioning

confidence: 99%

Induction of topoisomerase II-mediated DNA cleavage by the plant naphthoquinones plumbagin and shikonin

Fujii

Yamashita

Arima

et al. 1992

Antimicrob Agents Chemother

131

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“…Marine microorganisms (actinobacteria) are sources of novel compounds with often unique structures and potential therapeutic applications. The Actinomycetes are widely distributed in natural and manmade environments and are also well known as a rich source of antibiotics and bioactive molecules, which are of considerable importance in chemotherapy [2,3].…”

Section: Introductionmentioning

confidence: 99%

“…According to physical and chemical analysis data, the strain was found to produce chrysophanol 8-methyl ether (1) [7], asphodelin; 4,7Ј-bichrysophanol (2) [8] identified as two known anthraquinone metabolites; justicidin B (3) as arylnaphthalene lignanolide [9], reported here to be isolated for the first time from microorganisms; and a novel bioactive water soluble compound, ayamycin, 1,1-dichloro-4-ethyl-5-(4-nitro-phenyl)-hexan-2-one (4). The absolute stereochemistry of a novel compound 4 has been assigned through X-ray crystallographic analysis.…”

Section: Introductionmentioning

confidence: 99%

Novel Bioactive Metabolites from a Marine Derived Bacterium Nocardia sp. ALAA 2000

2008

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Extracts of the Egyptian marine actinomycete, Nocardia sp. ALAA 2000, were found to be highly bioactive. It was isolated from the marine red alga Laurenica spectabilis collected off the Ras-Gharib coast of the Red Sea, Egypt. According to detailed identification studies, the strain was classified as a member of the genus Nocardia. The cultivation and chemical analysis of this species yielded four structurally related compounds namely, chrysophanol 8-methyl ether (1), asphodelin; 4,7Ј-bichrysophanol (2) and justicidin B (3), in addition to a novel bioactive compound ayamycin; 1,1-dichloro-4-ethyl-5-(4-nitro-phenyl)-hexan-2-one (4) which is unique in contain both chlorination and a rarely observed nitro group. The compounds were isolated by a series of chromatographic steps and their structures of 1ϳ3 secured by detailed spectroscopic analysis of the MS and NMR data whereas that of 4 was elucidated by single crystal X-ray diffraction studies. These compounds displayed different potent antimicrobial activity against both Gram-positive and Gram-negative bacteria as well as fungi with MIC ranging from 0.1 to 10 mg/ml.

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“…The cytotoxicity of (S)-curvularin against C28/I2 cells was determined in a Giemsa staining assay according to Mirabelli et al (1985). Absorbances were read by a Lambda Spectral 340 Microplate reader (MWG Biotech, Ebersberg, Germany) at a wavelength of 600 nm and a reference wavelength of 405 nm.…”

Section: Methodsmentioning

confidence: 99%

The Anti-Inflammatory Fungal Compound (S)-Curvularin Reduces Proinflammatory Gene Expression in an In Vivo Model of Rheumatoid Arthritis

Schmidt

Art

Forsch

et al. 2012

J Pharmacol Exp Ther

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In previous studies, we identified the fungal macrocyclic lactone (S)-curvularin (SC) as an anti-inflammatory agent using a screening system detecting inhibitors of the Janus kinase/signal transducer and activator of transcription pathway. The objective of the present study was to investigate whether SC is able to decrease proinflammatory gene expression in an in vivo model of a chronic inflammatory disease. Therefore, the effects of SC and dexamethasone were compared in the model of collagen-induced arthritis (CIA) in mice. Total genomic microarray analyses were performed to identify SC target genes. In addition, in human C28/I2 chondrocytes and MonoMac6 monocytes, the effect of SC on proinflammatory gene expression was tested at the mRNA and protein level. In the CIA model, SC markedly reduced the expression of a number of proinflammatory cytokines and chemokines involved in the pathogenesis of CIA as well as human rheumatoid arthritis (RA). In almost all cases, the effects of SC were comparable with those of dexamethasone. In microarray analyses, we identified additional new therapeutic targets of SC. Some of them, such as S100A8, myeloperoxidase, or cathelicidin, an antimicrobial peptide, are known to be implicated in pathophysiological processes in RA. Similar anti-inflammatory effects of SC were also observed in human C28/I2 chondrocyte cells, which are resistant to glucocorticoid treatment. These data indicate that SC and glucocorticoid effects are mediated via independent signal transduction pathways. In summary, we demonstrate that SC is a new effective anti-inflammatory compound that may serve as a lead compound for the development of new drugs for the therapy of chronic inflammatory diseases.

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Application of a tissue culture microtiter test for the detection of cytotoxic agents from natural products.

Cited by 45 publications

References 4 publications

Induction of topoisomerase II-mediated DNA cleavage by the plant naphthoquinones plumbagin and shikonin

Induction of topoisomerase II-mediated DNA cleavage by the plant naphthoquinones plumbagin and shikonin

Novel Bioactive Metabolites from a Marine Derived Bacterium Nocardia sp. ALAA 2000

The Anti-Inflammatory Fungal Compound (S)-Curvularin Reduces Proinflammatory Gene Expression in an In Vivo Model of Rheumatoid Arthritis

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