• Journal of Life Science
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• v.31 no.10
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• pp.898-904
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• 2021

Locusta migratoria is a widespread locust species in many parts of the world and is considered an alternative source for the production of protein for value-added ingredients. We previously identified putative antimicrobial peptides derived from L. migratoria through an in silico analysis of its transcriptome. However, its anti-inflammatory effect has not been studied. In this study, we investigated the anti-inflammatory activities of the antimicrobial peptide locustacin (KTHILSFFPSFLPLFLKK-NH₂) derived from L. migratoria on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Locustacin (50, 100, and 200 ㎍/ml) significantly reduced the production of nitric oxide (NO) in LPS-stimulated macrophages without any cytotoxicity. Locustacin also inhibited the mRNA and protein expression of pro-inflammatory mediators, such as inducible NO synthase and cyclooxygenase-2, in contrast to the presence of LPS alone. Locustacin decreased the release of LPS-induced pro-inflammatory cytokines, including interleukin (IL)-6 and IL-1β, and their gene expression in a dose-dependent manner. Furthermore, locustacin (100 and/or 200 ㎍/ml) inhibited phosphorylation levels of extracellular signal regulated kinase, p38, and c-Jun N-terminal kinase. Locustacin also suppressed the degradation of inhibitory kappa B alpha, which was considered to be an inhibitor of nuclear factor kappa B (NF-κB). Collectively, these results demonstrate that locustacin can exert anti-inflammatory effects through the inhibition of mitogen-activated protein kinase (MAPK) phosphorylation, activation of NF-κB, and downstream inflammatory mediators in LPS-stimulated macrophage cells.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.