• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.694-700
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• 2017

Clostridium difficile, which causes pseudomembranous colitis, releases toxin A and toxin B. These toxins are considered to be the main causative agents for the disease pathogenesis, and their expression is associated with a marked increase of apoptosis in mucosal epithelial cells. Colonic epithelial cells are believed to form a physical barrier between the lumen and the submucosa, and abnormally increased mucosal epithelial cell apoptosis is considered to be an initial step in gut inflammation responses. Therefore, one approach to treating pseudomembranous colitis would be to develop agents that block the mucosal epithelial cell apoptosis caused by toxin A, thus restoring barrier function and curing inflammatory responses in the gut. We recently isolated an antimicrobial peptide, Periplanetasin-2 (Peri-2, YPCKLNLKLGKVPFH) from the American cockroach, whose extracts have shown great potential for clinical use. Here, we assessed whether Peri-2 could inhibit the cell toxicity and inflammation caused by C. difficile toxin A. Indeed, in human colonocyte HT29 cells, Peri-2 inhibited the toxin A-induced decrease in cell proliferation and ameliorated the cell apoptosis induced by this toxin. Moreover, in the toxin A-induced mouse enteritis model, Peri-2 blocked the mucosal disruption and inflammatory response caused by toxin A. These results suggest that the American cockroach peptide Peri-2 could be a possible drug candidate for addressing the pseudomembranous colitis caused by C. difficile toxin A.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.11a
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• pp.104-104
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• 2001

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.179.2-179
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• 2001

No Abstract, See Full Text

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.2
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• pp.67-72
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• 2015

In this study, growth characteristics of insects for mass production was investigated. For Hermetia illucens, the biomass was increased by the supply of the mixture of FWDF with hop cake and typical feed at the early growth stage, however, no difference was shown between 100% of FWDF and the mixture at the late stage. The growth of Housefly larvae was retarded with the 100% of FWDF, resulting in abnormal paputation, hence the amount of FWDF shoud be lowered to 20% to 30% for the efficient growth. Super mealworm larvae was found to grow with little influence by the kind of feed, and none of them was died or inhibited by the supply of FWDF as a feeding source.

• Applied Biological Chemistry
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• v.50 no.2
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• pp.127-131
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• 2007

The molecular design and holographic (H) quantitative structure-activity relationships (HQSARs) on the binding affinity constants between new 3-benzylidenemyosmine analogues and nicotin acetylcholine receptors (nAChRs) of American cockroach (Periplaneta. americana L.) were studied quantitatively. The optimized HQSAR model (IV-2) for the binding affinity constants was derived from fragment distinction of hydrogene atoms in fragment size, 5${\sim}$8 bin. The statistical results of the HQSAR model (IVI-2) exhibited the best predictability and fitness for the binding affinity constants based on the cross-validated value (q$^2$=0.507) and non cross-validated value (r$^2_{nev.}$=0.944). From the graphical analyses of atomic contribution maps, it was revealed that the binding affinity constants depends upon the anabaseine ring in molecule and the most active compounds were designed by optimized HQSAR model (VI-2).

• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.210-219
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• 2004

Susceptibility of Periplaneta americana male adults to 61 commercial insecticides was evaluated by diet dipping method. Among them eight insecticides of dichlorvos, benfuracarb, cypermethrin, deltamethrin, fenpropathrin, $\zeta$-cypermethrin, $\lambda$-cyhalothrin and fipronil showed 100% mortality. The insect was more susceptible to dichlorvos and fenpropathrin in filter paper contact method than in diet dipping one, but benfuracarb was vice versa. Toxicities of the seven chemicals were evaluated by application parts of the such as head, thorax, abdomen, and legs. Dichlorvos, benfuracarb and $\lambda$-cyhalothrin were more toxic when applied to head, and deltamethrin, fenpropathrin and cypermethrin were abdomen. $LT_{50}$ values by diet dipping method showed that dichlorvos, benfuracarb and $\lambda$-cyhalothrin acted more rapidly than boric acid and hydramethylnon. The values of the former three were 0.10, 0.29 and 0.12 days, and those of the latter two were 6.2 and 4.8 days, respectively.