• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4753-4758
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• 2014

In recent times, a number of studies have provided evidence that biotoxins present great potential as antitumor agents, such as snake venom, bee venom, some bacteria toxins and plant toxins, and thus could be used as chemotherapeutic agents against tumors. The biodiversity of venoms and toxins make them a unique source from which novel anticancer agent may be developed. Biotoxins, also known as natural toxins, include toxic substances produced by plants, animals and microorganisms. Here, we systematically list representative biological toxins that have antitumor properties, involving animal toxins, plant toxins, mycotoxins as well as bacterial toxins. In this review, we summarize the current knowledge involving biotoxins and the active compounds that have anti-cancer activity to induce cytotoxic, antitumor, immunomodulatory, and apoptotic effects in different tumor cells in vivo or in vitro. We also show insights into the molecular and functional evolution of biotoxins.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.2
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• pp.147-153
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• 2013

To prevent paralytic shellfish poisoning (PSP) due to the consumption of shellfish contaminated with PSP toxins, the quantitative analysis of these toxins is very crucial. The AOAC International mouse bioassay (MBA) has been used widely for the routine monitoring of PSP toxins for more than 50 years. However, this method has low sensitivity and high limit of quantification (LOQ) and interferences from other components in the extract, and it cannot determine toxic profiles. Ethical problems also exist with the continued use of this live mouse assay. To establish an alternative method to the MBA used for PSP toxins analysis, we attempted to optimize the analysis conditions of a precolumn high-performance liquid chromatography (HPLC) oxidation method and succeeded in validating its accuracy and precision in quantifying PSP toxins. A clear peak and the isolation of PSP toxins were obtained by injecting the working standards of Certified Reference Materials using HPLC. The LOQ of the precolumn HPLC oxidation method for PSP toxins was about $0.1002{\mu}g/g$, which represented an approximately fourfold improvement in detection capability versus the AOAC MBA. The intra-accuracy and precision for PSP toxins in oysters were 77.0-103.3% and 2.0-5.7%, respectively, while the respective inter-accuracy and precision were 77.3-100.7% and 2.4-6.0%. The mean recoveries of PSP toxins from oysters were 75.2-112.1%. The results of a comparison study showed good correlation between the results of the precolumn HPLC oxidation method and those of MBA, with a correlation factor of 0.9291 for mussels. The precolumn HPLC oxidation method may be used as an alternative to, or supplementary method with, MBA to monitor the occurrence of PSP toxins and to analyze the profiles of these toxins in shellfish.

• BMB Reports
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• v.41 no.1
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• pp.79-85
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• 2008

The source of nitric oxide (NO) in plants is unclear and it has been reported NO can be produced by nitric oxide synthase (NOS) like enzymes and by nitrate reductase (NR). Here we used wild-type, Atnos1 mutant and nia1, nia2 NR-deficient mutant plants of Arabidopsis thaliana to investigate the potential source of NO production in response to Verticillium dahliae toxins (VD-toxins). The results revealed that NO production is much higher in wild-type and Atnos1 mutant than in nia1, nia2 NR-deficient mutants. The NR inhibitor had a significant effect on VD-toxins-induced NO production; whereas NOS inhibitor had a slight effect. NR activity was significantly implicated in NO production. The results indicated that as NO was induced in response to VD-toxins in Arabidopsis, the major source was the NR pathway. The production of NOS-system appeared to be secondary.

• Journal of Environmental Health Sciences
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• v.31 no.3
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• pp.192-198
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• 2005

The occurrence of toxic cyanobacterial blooms has been reported worldwide and poses a threat to human health through drinking water exposure. The toxins they produce are highly water soluble and can leach into the water body. To eliminate any risk of drinking water exposure, removal of these toxins is essential before the water is consumed. Conventional water treatment techniques such as chlorination, if managed well, can be effectively used to remove some of these toxins, however, saxitoxin and its derivatives pose a problem. Little toxicological data are available to evaluate the real threat of these toxins.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.11-44
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• 2005

The occurrence of toxic cyanobacterial blooms has been reported worldwide and pose a threat to human health through drinking water exposure. The toxins they produced are highly water soluble and can leach into the water body. To eliminate any risk of drinking water exposure, removal of these toxins is essential before the water is consumed. Conventional water treatment techniques such as chlorination, if managed well, can be effectively used to remove some of these toxins, however, saxitoxin and derivatives pose a problem. Little toxicological data are available to evaluate the real threat of these toxins.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.247-255
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• 1992

A laboratory bioassay that incorporates Bacillus thuringiensis (Bt) purified crystal protein toxins into an artificial diet has identified three toxins, CryIA(b), CryIA(c), and CryIIA, to by effective against the yellow stemborer, Scirpophaga incertulas(Walker). Research is aimed at engineering rice that incorporates genes of one of or more of these toxins so as to mimic the insecticidal action of the insect to Bt. The paper discusses potential strategies for slowing the rate of adaptation that include the use of multiple Bt toxins, promoters that express the toxins only in specific plant tissues at specific times, and mixing transgenic and non-transgenic plants.

• BMB Reports
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• v.53 no.12
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• pp.611-621
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• 2020

Bacterial endoribonuclease toxins belong to a protein family that inhibits bacterial growth by degrading mRNA or rRNA sequences. The toxin genes are organized in pairs with its cognate antitoxins in the chromosome and thus the activities of the toxins are antagonized by antitoxin proteins or RNAs during active translation. In response to a variety of cellular stresses, the endoribonuclease toxins appear to be released from antitoxin molecules via proteolytic cleavage of antitoxin proteins or preferential degradation of antitoxin RNAs and cleave a diverse range of mRNA or rRNA sequences in a sequence-specific or codon-specific manner, resulting in various biological phenomena such as antibiotic tolerance and persister cell formation. Given that substrate specificity of each endoribonuclease toxin is determined by its structure and the composition of active site residues, we summarize the biology, structure, and substrate specificity of the updated bacterial endoribonuclease toxins.

• Korean Journal of Veterinary Research
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• v.60 no.4
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• pp.225-228
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• 2020

Apx toxins are a virulent factor of Actinobacillus pleuropneumoniae (App). At least four genes, apxC, apxA, apxB, and apxD, are involved in the release of Apx toxins from App. apxA encodes Apx toxins, whereas apxB and apxD encode exporters. Some serotypes of App such as serotype 2 retain apxIBD, apxIICA, and apxIIICABD. Although the specificity of the ApxIB/ApxID exporter to ApxII has been established in those serotypes, that to ApxIII is under-studied. We constructed an apxIB- and apxID-lacking mutant strain of the App serotype 2 to study whether the ApxIB/ApxID exporter is capable of secreting both ApxII and ApxIII toxins.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1037-1043
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• 2020

Actinobacillus pleuropneumoniae (APP) is a causative agent of porcine pleuropneumonia. Therefore, the development of an effective vaccine for APP is necessary. Here, we optimized the culture medium and conditions to enhance the production yields of Apx toxins in APP serotype 1, 2, and 5 cultures. The use of Mycoplasma Broth Base (PPLO) medium improved both the quantity and quality of the harvested Apx toxins compared with Columbia Broth medium. Calcium chloride (CaCl₂) was first demonstrated as a stimulation factor for the production of Apx toxins in APP serotype 2 cultures. Cultivation of APP serotype 2 in PPLO medium supplemented with 10 ㎍/ml of nicotinamide adenine dinucleotide (NAD) and 20 mM CaCl₂ yielded the highest levels of Apx toxins. These findings suggest that the optimization of the culture medium and conditions increases the concentration of Apx toxins in the supernatants of APP serotype 1, 2, and 5 cultures and may be applied for the development of vaccines against APP infection.

• Journal of Microbiology
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• v.43 no.3
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• pp.266-271
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• 2005

In eukaryotic cells, various proteins are anchored to the plasma membrane through glycosylphosphatidylinositol (GPI). To study the biosynthetic pathways and modifications of GPI, various mutant cells have been isolated from the cells of Chinese hamster ovaries (CHO) supplemented with several exogenous genes involved in GPI biosynthesis using aerolysin, a toxin secreted from gram-negative bacterium Aeromonas hydrophila. Alpha toxin from Gram-positive bacterium Clostridium septicum is homologous to large lobes (LL) of aerolysin, binds GPI-anchored proteins and possesses a cell-destroying mechanism similar to aerolysin. Here, to determine whether alpha toxins can be used as an isolation tool of GPI-mutants, like aerolysin, CHO cells stably transfected with several exogenous genes involved in GPI biosynthesis were chemically mutagenized and cultured in a medium containing alpha toxins. We isolated six mutants highly resistant to alpha toxins and deficient in GPI biosynthesis. By genetic complementation, we determined that one mutant cell was defective of the second subunit of dolichol phosphate mannose synthase (DPM2) and other five cells were of a putative catalytic subunit of inositol acyltransferase (PIG-W). Therefore, C. septicum alpha toxins are a useful screening probe for the isolation of various GPI-mutant cells.