Insect antimicrobial peptides (AMPs) have been characterized more than 150 peptides since identification of cecropin in the hemolymph of pupae from Hyalophora cecropia in 1980. Therefore, it is considered that insects are good species of AMPs selection. Insect AMPs are small (below 10 kDa), cationic, and amphipathic with variable length, sequence, and structure. They perform a critical role on humoral immunity in the insect innate immune system against invading pathogens such as bacteria, fungi, parasites, and viruses. Most of insect AMPs are induced rapidly in the fat bodies and other specific tissues of insects after septic injury or immune challenge. Then the AMPs subsequently released into the hemolymph to act against microorganisms. These peptides have a broad antimicrobial spectrum against various microorganisms including anticancer activities. Insect AMPs can be divided into four families based on their structures and sequences. That is α-helical peptides, cysteine-rich peptides, proline-rich peptides, and glycine-rich peptides/proteins. For instance, cecropins, insect defensins, proline-rich peptides, and attacins are common insect AMPs, but gloverins and moricins have been identified only in lepidopteran species. In this presentation, we focus on AMPs from insects and discuss current knowledge and recent progresses with potential application of insect AMPs.

In the present study, we investigated the expression patterns of p63, a member of the p53 gene family, in hair follicle cells at different stages of the hair cycle and examined the relation with cell proliferation activity. For this study, immunohistochemistry for p63 and Ki-67, a marker of cell proliferation, was performed in skin obtained from C3H/he mice with depilation. In the anagen stage, p63 was strongly expressed in the cells of bulge areas and epithelial strand, matrix cells of the hair bulbs and outer root sheath cells, but inner root sheath cells and dermal papilla cells were negative for p63. These expression patterns of p63 were similarly noted in hair follicles in the early catagen stage. In the late catagen and telogen stages of hair follicles, outer root sheath cells, seboblasts and duct cells were immunoreactive for p63. On the other hand, Ki-67-positive cells were selectively observed among the p63 positive cell components, although p63 positive cells were not always proliferative. Most of the matrix cells in the hair bulbs were positive for Ki-67. Ki-67-positive cells were also frequently evident in the cells of epithelial strands in the early anagen stage. Outer root sheath cells were often positive for Ki-67 in the anagen and early catagen stages, but very rare in the late catagen and telogen stages. In summary, p63 was expressed in the bulge stem cells, epithelial strand cells, matrix cells and outer root sheath cells of hair follicles at any stage of the cycle, which was associated with the movement of hair progenitor cells for regeneration. Ki-67-positive cells were evident among the p63-expressing cell components. Our results strongly suggest that p63 plays an important role in stem cell regulation, at least associated with cell proliferation, for the regeneration of hair follicles.

The dynastid beetle Allomyrina dichotoma has been used as a herbal medicine. Recently, we performed de novo RNAsequencing of Allomyrina dichotoma and identified several antimicrobial peptide candidates based on in silico analysis.Among them, cationic antimicrobial peptide, Allomyrinasin, was selected and we assessed the anti-inflammatory activitiesof Allomyrinasin against mouse macrophage Raw264.7 cells. The results showed that Allomyrinasin decreased the nitricoxide production of the lipopolysaccharide-induced Raw264.7 cells. In addition, quantitative RT-PCR, ELISA and Westernblot analysis revealed that Allomyrinasin reduced cytokine expression levels in the Raw264.7 cells. Taken together, thesedata indicated that Allomyrinasin had anti-inflammatory activity in the lipopolysaccharide-induced Raw264.7 cells.

We have analyzed the transcriptome of Scolopendra subspinipes mutilans using RNA sequencing and identified severalantimicrobial peptide candidates. Among the peptides, named scolopendrasins, were selected based on the physicochemicalproperties of antimicrobial peptides via an in silico analysis. As a result, we evaluated the antimicrobial activities ofscolopendrasins against Gram positive and negative bacteria including Candida albicans by radial diffusion assay and colonycount assay. We also investigated the cytotoxicity of scolopendrasins through hemolysis assay. We found that the actionof scolopendrasins involved binding to the surface of microorganisms via a specific interaction with lipopolysaccharides,lipoteichoic acid, and peptidoglycans, which are components of the bacterial membrane. These results will provide a basisfor developing therapeutic agents such as peptide antibiotics.

Although the grasshopper Oxya chinensis sinuosa has long been used as a food in Korea, there is little data on itsfunctional effects. Thus we prepared and analyzed total RNA from the whole body of adult Escherichia coli non-immunizedand immunized Oxya chinensis sinuosa strains. Using an Illumina Hiseq sequencer, we generated a total of 66,555 pooledtranscriptome and singletons with and without Escherichia coli immunization, respectively. Then, we performed in silicoanalysis of the Oxya chinensis sinuosa transcriptome, using bioinformatics tools for screening putative antimicrobial peptides(AMPs) and 38 AMPs were finally selected and tested their antimicrobial activity of Gram positive, Gram negative bacteriaand antifungal activity with radial diffusion assay. As a result, 5 out of 38 AMPs showed the highest antimicrobial activityand antifungal activity against microbes and it also evidenced with no hemolytic activity.

The objective of this study was to evaluate the effect of the Allomyrina dichotoma larva (AD) on allergy and inflammation.We examined inhibitory effect of AD on allergic reactions in mast cells (RBL-2H3) activated by Compound 48 / 80and inflammatory response in macrophages (Raw 264.7) activated by LPS. Anti-allergy and anti-inflammatory actions ofAD water extract had no cytotoxicity. At these concentrations AD inhibited ẞ-hexosaminidase, tumor necrosis factor- α(TNF- α), interleukin-4 (IL-4), interleukin-6(IL-6) and cyclooxygenase-2(COX-2). AD also inhibited the expression of inducibleNO synthase (iNOS). AD reduced the release of inflammatory cytokines including IL-4, IL-6, TNF-α, and ẞ-hexosaminidase.These results suggest that AD may be potential anti-allergy and anti-inflammatory therapeutic agent.

The insects have been investigated as novel sources for foods and biomaterials in several recent studies. However,its effects on hair growth have not been sufficiently researched. To develop novel and natural materials for preventingalopecia and promoting hair growth, we investigated the antioxidant activity and hair growth promoting effect of Tenebriomolitor larvae extract (TME). As a result, DPPH radical scavenging activity was 81.17%, and nitrite scavenging activitywas 43.69%, which were similar to blueberry extract. And TME promoted the proliferation of human DPCs and NIH3T3cells, concentration dependently. In addition, the TME prevented not only DHT-induced DPCs cytotoxicity but also actionof TBM as a potassium channel blocker in NIH3T3 cells. These results suggest that TME can be used as a functionalmaterial for alopecia therapeutic reagent by preventing hair loss and promoting hair growth.

We recently reported the in vitro and in vivo antiobesity effects of Tenebrio molitor larvae, a traditional food in manycountries, but it remains unknown how the larvae affect appetite regulation in mice with diet-induced obesity. We hypothesizedthat the extract of T. molitor larvae mediates appetite by regulating neuropeptide expression. We investigated T. molitorlarvae extract's (TME's) effects on anorexigenesis and endoplasmic reticulum (ER) stress–induced orexigenic neuropeptideexpression in the hypothalami of obese mice. Central administration of TME suppressed feeding by down-regulating theexpression of the orexigenic neuropeptides neuropeptide Y and agouti-related protein. T. molitor larvae extract significantlyreduced the expression of ER stress response genes. These results suggest that TME and its bioactive components arepotential therapeutics for obesity and ER stress–driven disease states.