Alzheimer’s disease (AD) is the most common type of presenile and senile dementia. Human β-amyloid precursor cleavage enzyme (BACE-1) is a key enzyme responsible for amyloid plaque production. We assessed anti-BACE-1 and behavioral activities of curcuminoids from Curcuma longa, curcumin (CCN), demethoxycurcumin (DMCCN), and bisdemethoxycurcumin (BDMCCN) against AD fly models. Neuro-protective ability of curcuminoids was assessed using fly model system overexpressing BACE-1 and its substrate APP in compound eyes and entire neurons. BDMCCN has the strongest inhibitory activity toward BACE-1 with 17 μM IC50, which was 20 and 13 times lower than those of CCN and DMCCN respectively. Expression of APP/BACE-1 resulted in the progressive and measurable defects in morphology of eyes and locomotion. Supplementing diet with either 1 mM BDMCCN or CCN rescued APP/BACE1 expressing flies and kept them from developing both morphological and behavioral defects. Structural characteristics and hydrophobicity appear to play a role in determining inhibitory potency of curcuminoids on BACE-1.

An assessment was made of beta-site amyloid precursor protein (APP) cleaving enzyme (BACE1) inhibitory, feeding, climbing activities and lifespan of the diarylalkyls curcumin (CCN), demethoxycurcumin (DCCN) and bisdemethoxycurcumin (BDCCN) identified in the rhizomes of Curcuma longa. Based on IC50 values, BDCCN (0.024 mM) was the most inhibitory constituent, followed by DCCN (0.31 mM) and CCN (0.59 mM). Overall the three curcuminoids were significantly less inhibitory than BACE1 inhibitor IV isophthalamide (8.5 × 10-5 mM). The expression of human APP and BACE1 in compound eye of Drosophila melangaster presented rough abnormal ommatidial lattice. Co-expression of APP and BACE1 within the developing nervous system of drosophila showed climbing defects. These transgenic flies kept on media containing 1 mM of CCN and BDCCN were observed to ameliorate eye degeneration, significantly suppress locomotive dysfunctions, and increase media life time, as well as isophthalamide. CCN and BDCCN as human BACE1 inhibitory constituents may be used as potential therapeutics or lead molecules to develop Alzheimer's disease treatment drugs.

The application to genome study has been particularly developed with the introduction of the next-generation DNA sequencer (NGS) Roche/454 and Illumina/Solexa systems, along with bioinformation analysis technologies of whole-genome de novoassembly, expression profiling, DNA variation discovery, and genotyping. One of the advantages of the NGS systems is the cost-effectiveness to obtain the result of high-throughput DNA sequencing for genome, RNAnome, and miRNAnome studies. Both massive whole-genome shotgun paired-end sequencing and mate paired-end sequencing data are important steps for constructing de novo assembly of novel genome sequencing data and for resequencing the samples with a reference genome DNA sequence. To construct high-quality contig consensus sequences, each DNA fragment read length is important to obtain de novo assembly with long reading sequences of the Roche/454 system. It is necessary to have DNA sequence information from a multiplatform NGS with at least 2× and 30×depth sequence of genome coverage using Roche/454 and Illumina/Solexa, respectively, for effective an way of de novo assembly, as hybrid assembly for novel genome sequencing would be cost-effective. In some cases, Illumina/Solexa data are used to construct scaffolds through de novo assembly with high coverage depth and large diverse fragment mate paired-end information,even though they are already participating in assembly and have made many contigs. Massive short-length reading data from the Illumina/Solexa system is enough to discover DNA variation, resulting in reducing the cost of DNA sequencing. MAQ and CLC software are useful to both single nucleotide polymorphism discovery and genotyping through a comparison of resequencing data to a reference genome. Whole-genome expression profile data are useful to approach genome system biology with quantification of expressed RNAs from a whole-genome transcriptome, depending on the tissue samples, such as control and exposed tissue. The hybrid mRNA sequences from Rohce/454 and Illumina/Solexa are more powerful to find novel genes through de novo assembly in any whole-genome sequenced species. The 20× and 50× coverage of the estimated transcriptome sequences using Roche/454 and Illumina/Solexa, respectively,is effective to create novel expressed reference sequences. However, only an average 30× coverage of a transcriptome with short read sequences of Illumina/Solexa is enough to check expression quantification, compared to the reference expressed sequence tag sequence. In an in silicomethod, conserved miRNA and novel miRNA discovery is available on massive miRNAnome data in any species. Particularly, the discovered target genes of miRNA could be robust to approach genome biology study.

Olfaction as an important sensory modality in insects is essential for identification of hosts, mates, oviposition sites, and food resources in nature. In the cockroach, both olfactory sensitivity in the antennae and the formation of shortand long-term olfactory memories exhibit daily fluctuations that are regulated by the circadian system. An important problem is to characterize the signalling systems and molecules that are involved in this regulation of olfactory reception and olfactory behaviour. Recent results suggest that insect olfactory systems are modulated by both biogenic amines and neuropeptides. However, it remains elusive how these molecules modulate olfactory system in the peripheral systems. In the present study, our aim was to characterize the structure and organization of these signalling systems in the peripheral olfactory system of the American cockroach, Periplaneta americana. This work illuminated that tachykinin and its receptors regulate olfactory sensitivity in the antennae of the cockroach. Injections of tachykinin peptides caused decreases in the amplitude of the electroantennoogram (EAG), cells that produce tachykinin were localized in the antennae, and olfactory receptor neurons expressed tachykinin receptors. Interestingly, the tachykinin expressing cells also express receptors for the biogenic amine, octopamine and injections of octopamine also cause reductions in EAG amplitude. These results suggest that both octopaminergic and tachykinin peptide signalling pathways are important regulators of olfactory reception in the cockroach. We propose the hypothesis that octopamine regulates the release of tachykinin from cells in the antennae that, in turn, modulate the sensitivity of olfactory receptor neurons.

Origanum essential oil [Origanum acutidens (Hand.-Mazz.)] showing insecticidal activity and repellency against red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae) adults was analysed by GC-MS. All constituents of the oil were identified, and the main components were carvacrol (67.2%), p-cymene (16.2%), γ-terpinene (5.5%), thymol (4.9%),and linalool(2.1%). In vapor phase fumigant assay, the origanum oil was more effective in closed condition (LD50 = 0.555 mg/cm3) than in open one (LD50 = 0.353 mg/cm3).This result suggests that the toxicity of the oil to red flour beetle is exerted largely by vapor phase. Based on 24-h LD50 values, the toxicity of caryophyllene oxide (0.00018 mg/cm3) was comparable with that of dichlorvos (0.00007mg/cm3) as a positive insecticide. In addition, thymol, camphene, α-pinene, p-cymene, and γ-terpinene gave good insecticidal activity (LD50 = 0.012 - 0.195 mg/cm3). In repellent test using 9 constituents of origanum oil, caryophyllene oxide showed 100% repellent activity at 0.0158 and 0.0032 mg/cm2. These results indicate that the origanum oil and its some components could be potential candidates as a fumigant and repellent for managing T. castaneum adults. Potential molecular target of repellents will be discussed.

An olfactory system is one of the complicatedly-equipped sensory facilities in the insect sensory systems, which is most essential for insect olfactory-driven behaviors relevant to survival such as finding hosts, mates, oviposition sites, and food resources. These behaviors are mostly controlled by circadian rhythm. The american cockroach, Periplaneta americana, has been an ideal model to extensively study olfactory system associated with complex behavioral repertoires and circadian controls of certain behaviors, respectively. Even though it is known that olfactory-related physiology in peripheral and central olfactory systems seems to be highly variable by circadian rhythms, little is known about how these are controlled at the neuronal and molecular levels. It has been reported that the plasticity in the olfactory system is modulated by a set of neuropeptides. However, it remains still elusive how these neuropeptides and neuroendocrine system interact in the peripheral systems to change olfactory responses in cockroaches. Here, current study focuses on the localization of neuropeptides and their receptors by using in situ hybridization and immunostaining methods. Also, expression level of these genes are evaulated by qRT-PCR methods. Circadian fluctuation of these genes seem to be important neurotransmission machineries in the periphery. Our current study suggests that microcircuits of neuronal systems in the peripheral olfactory organ play an important in olfactory modulation by circadian rhythm

Olfactory sense is an essential modality for insects to locate hosts, mates, oviposition sites, and food resources in nature. Based on many studies so far, insect olfactory systems in periphery as well as central nervous systems seem to be highly plastic with behavioral and physiological changes associated with learning and memory, sensory processes, and other developmental processes. Eventually, it is also evident that these plasticity and processes in olfactory systems are modulated by a various ensemble or sets of neuropeptides. The olfactory reception in the peripheral systems of the cockroach, Periplaneta americana, associated with learning behaviors, is fluctuated by the circadian rhythm, which is subsequently thought to control the titer of hormones and various neuropeptides concomitantly. However, it remains still elusive how neuropeptides and neuroendocrine systems modulate olfactory system in the peripheral systems in cockroaches as well as any other insects. Here, our aims to characterize the ultrastructure of these neuro-endocrine systems in the peripheral olfactory systems in American cockroach, Periplaneta americana. Using in situ hybridization methods, we found out that tachykinin and its receptors seem to be important neurotransmission machineries in the periphery to convey the arousal signals from the insect brain. Our findings also indicate complicated endocrine systems connected with central nervous systems may modulate the olfactory reception in the periphery.