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Silkworm (Bombyx mori) larvae are expected to be useful as an ingredient in entomophagy. They are full of nutrients, including indigestible proteins; however, there have been few studies on the effects of the consumption of the entire body of silkworms on the intestinal microflora. We prepared a customized diet containing silkworm larval powder (SLP), and investigated the effects of ad libitum feeding of the SLP diet on the intestinal microbiota and the amount of short-chain fatty acids (SCFAs) in mice. We found that the diversity of the cecal and fecal microbiota increased in the mice fed the SLP diet (SLP group), and that the composition of their intestinal microbiota differed from that of the control mice. Furthermore, a genus-level microbiota analysis showed that in the SLP group, the proportions of Alistipes, Lachnospiraceae A2, and RF39, which are associated with the prevention of obesity, were significantly increased, while the proportions of Helicobacter and Anaerotruncus, which are associated with obesity, were significantly decreased. Additionally, the level of butyrate was increased in the SLP group, and Clostridia UCG 014 and Lachnospiraceae FCS020 were found to be associated with the level of butyrate, one of the major SCFAs. These findings indicated that silkworm powder may be useful as an insect food that might also improve obesity. [ABSTRACT FROM AUTHOR]

In this study, silkworm larvae were used for expression of porcine rotavirus A (KS14 strain) inner capsid protein, VP6, and outer capsid protein, VP7. Initially, VP6 was fused with Strep-tag II and FLAG-tag (T-VP6), and T-VP6 was fused further with the signal peptide of Bombyx mori 30k6G protein (30k-T-VP6). T-VP6 and 30 k-T-VP6 were then expressed in the fat body and hemolymph of silkworm larvae, respectively, with respective amounts of 330 μg and 50 μg per larva of purified protein. Unlike T-VP6, 30k-T-VP6 was N-glycosylated due to attached signal peptide. Also, VP7 was fused with PA-tag (VP7-PA). Additionally, VP7 was fused with Strep-tag II, FLAG-tag, and the signal peptide of Bombyx mori 30k6G protein (30k-T-ΔVP7). Both VP7-PA and 30k-T-ΔVP7 were expressed in the hemolymph of silkworm larvae, with respective amounts of 26 μg and 49 μg per larva of purified protein, respectively. The results from our study demonstrated that T-VP6 formed nanoparticles of greater diameter compared with the ones formed by 30k-T-VP6. Also, higher amount of VP6 expressed in silkworm larvae reveal that VP6 holds the potential for its use in vaccine development against porcine rotavirus with silkworm larvae as a promising host for the production of such multi-subunit vaccines. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the single and joint toxicities of insecticide imidacloprid (commercial formulation and technical grade) and heavy metal lead (Pb) against 2nd, 3rd, 4th and 5th instars of silkworm. For treatment, leaf-dipping method was used and toxicity calculated after 48h exposure to the treatment. Both chemicals showed high toxicity against all instars of silkworm. However, results indicated that imidacloprid was more toxic for silkworm larvae compared to lead. The acute toxicity of imidacloprid formulation (IMF), imidacloprid technical grade (IMT) and Pb showed positive correlation with the concentration and negative with the age of larvae. From second to fifth instars, LC50 values of IMF ranges from 0.72 to 2.96, IMT from 0.86 to 2.75 and Pb from 1.93 to 6.88 mg/L. The toxicity of binary mixture of IMF + Pb showed synergism against all instars of silkworm. While, binary mixture of IMT + Pb displayed synergism, additive, and antagonism and antagonism activity in silkworm larvae in silkworm larvae. The results of our study provide useful data for the assessment of ecological risk of the tested compounds (single or mixture) against different silkworm instars. [ABSTRACT FROM AUTHOR]

The mulberry leaves are considered as the traditional food for the silkworm larvae due to the presence of the constituent Morin and the silkworms are completely dependent on them. Sericulture has been benefitting the human beings through the silkworm in several ways. At present, research has been probed for the need for an alternative nutritive source in the sericulture and this has lead to the development of a number of supplement nutrients for the rearing of the silkworm. There are several foods which are used as an ingredient for the artificial diet of silkworm. This type of diet encourages the small landless farmers to indulge in sericulture and also helps in reducing the labor cost for the mulberry cultivation. In this study, the silkworms were fed with Honey, Glucose, Lemon, B- complex and Calciferol and their impact on the levels of the hydrolytic enzymes, detoxification enzyme and macromolecular content in the hemolymph, silk gland and gut were studied. There were significant improvements in the levels indicating their candidature in their application as artificial dietary source for the silkworms thereby enabling a more beneficial strategy for the rearing of silkworms. [ABSTRACT FROM AUTHOR]

High blood cholesterol levels and oxidized cholesterol are risk factors for cardiovascular disease, which displays high annual incidence. Although studies on sericulture products, including pupae, silk protein, and blood lymph, as hypocholesterolemic substances have been reported, insufficient research in this field has been focused on silkworm larvae. Six larval extracts (Low temperature distilled water, LW; hot temperature distilled water, HW; and 30- 100% ethanol, E30-E100) were prepared, and their effects on cholesterol metabolism were examined. LW most potently reduced the risk of cholesterol-related disorders. Polyphenols were highly represented in LW, corresponding with its increased antioxidant potency. The cholesterol biosynthesis enzyme, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) was strongly inhibited by LW. Hepatocytes over-expressed LDL receptor (LDLR) after LW stimulation, promoting cholesterol elimination from plasma. LW also increased ATP binding cassette transporter 1 (ABCA1) gene expression, upregulating HDL biogenesis. In conclusion, LW exhibited strong antioxidant activity, suppressed cholesterol biosynthesis, improved LDL uptake from plasma, and upregulated HDL biosynthesis. In aggregate, these activities could reduce blood cholesterol levels and prevent cardiovascular disease. [ABSTRACT FROM AUTHOR]

Objective: Porphyromonas gulae, a major periodontal pathogen in animals, possesses fimbriae that have been classified into three genotypes (A, B, C) based on the diversity of fimA genes encoding fimbrillin protein (FimA). P. gulae strains with type C fimbriae were previously shown to be more virulent than other types. In this study, we further examined the host toxicity mediated by P. gulae fimbriae by constructing recombinant FimA (rFimA) expression vectors for each genotype and raised antibodies to the purified proteins. Methods and Results: All larvae died within 204 h following infection with P. gulae type C at the low-dose infection, whereas type A and B did not. Among fimA types, the survival rates of the larvae injected with rFimA type C were remarkably decreased, while the survival rates of the larvae injected with rFimA type A and type B were greater than 50%. Clindamycin treatment inhibited the growth of type C strains in a dose-dependent manner, resulting in an increased rate of silkworm survival. Finally, type C rFimA-specific antiserum prolonged the survival of silkworm larvae stimulated by infection with P. gulae type C strain or injection of rFimA type C protein. Conclusion: These results suggested that type C fimbriae have high potential for enhancement of bacterial pathogenesis, and that both clindamycin and anti-type C rFimA-specific antibodies are potent inhibitors of type C fimbriae-induced toxicity. This is the first report to establish a silkworm infection model using P. gulae for toxicity assessment. [ABSTRACT FROM AUTHOR]

Silkworm ( Bombyx mori ) larvae are expected to be useful as an ingredient in entomophagy. They are full of nutrients, including indigestible proteins; however, there have been few studies on the effects of the consumption of the entire body of silkworms on the intestinal microflora. We prepared a customized diet containing silkworm larval powder (SLP), and investigated the effects of ad libitum feeding of the SLP diet on the intestinal microbiota and the amount of short-chain fatty acids (SCFAs) in mice. We found that the diversity of the cecal and fecal microbiota increased in the mice fed the SLP diet (SLP group), and that the composition of their intestinal microbiota differed from that of the control mice. Furthermore, a genus-level microbiota analysis showed that in the SLP group, the proportions of Alistipes , Lachnospiraceae A2, and RF39, which are associated with the prevention of obesity, were significantly increased, while the proportions of Helicobacter and Anaerotruncus , which are associated with obesity, were significantly decreased. Additionally, the level of butyrate was increased in the SLP group, and Clostridia UCG 014 and Lachnospiraceae FCS020 were found to be associated with the level of butyrate, one of the major SCFAs. These findings indicated that silkworm powder may be useful as an insect food that might also improve obesity., Competing Interests: HU is an employee of Morus Inc. The other authors declare that they have no commercial or financial relationships that could be construed to be a potential conflict of interest., (Copyright © 2024 Murakami, Yamaguchi, Namai, Sato, Yamazaki, Uehara, Fujii, Tochio, Shiomi and Shimosato.)

Abstract Background Mulberry silkworm larvae (Bombyx mori) are known as the oldest resource of food and traditional medicine. Although silkworm larvae have been reported to treat various chronic diseases, the effect of fermentation by microorganisms improving the biological activities of silkworm larvae was not reported. In the present study, fermented silkworm larvae was developed via solid-state fermentation with Aspergillus kawachii and investigated its anti-cancer activity in human hepatocellular carcinoma cells. Methods We investigated the anti-cancer effects of unfermented (SEE) and fermented silkworm larva ethanol extract (FSEE) on HepG2 human hepatocellular carcinoma cells as well as compared changes in free amino acid, fatty acid, and mineral contents. Anti-cancer activities were evaluated by SRB staining, cell cycle analysis, Annexin V staining, Hoechst staining, DNA fragmentation analysis and western blot analysis. Fatty acid, free amino acid and mineral contents of SEE and FSEE were determined by gas chromatography, amino acid analyzer and flame atomic absorption spectrophotometer, respectively. Results Compared with SEE, treatment with FSEE resulted in apoptotic cell death in HepG2 cells characterized by G0/G1 phase cell cycle arrest, DNA fragmentation, and formation of apoptotic bodies. Furthermore, FSEE significantly up-regulated pro-apoptotic as well as down-regulated anti-apoptotic proteins in HepG2 cells. However, an equivalent concentration of SEE did not induce cell cycle arrest or apoptosis in HepG2 cells. Moreover, fermentation process by Aspergillus kawachii resulted in enhancement of fatty acid contents in silkworm larvae, whereas amino acid and mineral contents were decreased. Conclusion Collectively, this study demonstrates that silkworm larvae solid state-fermented by Aspergillus kawachii strongly potentiates caspase-dependent and -independent apoptosis pathways in human hepatocellular carcinoma cells by regulating secondary metabolites.

Ionic liquids (ILs) have been reported to be a potential water and soil pollutant, whose toxicity has gained much attention in recent years. In this work, silkworm larvae were used as a novel in vivo model to assess the biotoxicity of ILs, which were performed by three steps. The first step was to determine the susceptibility of different silkworm strains to ILs. Data showed that Jingsong×haoyue was the most susceptible one among three silkworm strains (Jingsong×haoyue, P50, and Yi16) for evaluating the biological effects of ILs. The second step was to compare the toxicity of ILs with different structures using the larvae of Jingsong×haoyue. It was found that three representative ILs, 1-octyl-3-methylimidazole chloride ([C8mim]Cl), N-octyl-3-methylpyridine chloride ([C8mpy]Cl), and 1-octyl-3-methylimidazole tetrafluoroborate ([C8mim]BF4), had significant toxic effects on the growth and development of the larvae with 24 h median lethal concentration (24 h-LC50) values of 112.3, 156.3, and 68.9 μg g−1, respectively, indicating that the types of anions and cations had impacts on the toxicity of ILs. The last step was targeted at investigating responses of the larvae to the exposure of ILs. It was observed that remarkable physiological and biochemical responses occurred in different tissues of the larvae. For example, activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in different tissues increased significantly to form an active protective mechanism for alleviating the toxic effects of ILs. Additionally, an increase of malondialdehyde (MDA) contents was found in the larvae. The data suggested that ILs could induce lipid peroxidation and cellular damage, which may be the main reason for toxicity of ILs to the larvae. Therefore, silkworm larvae could be used as a susceptible and reliable in vivo model to evaluate the toxicity of ILs, and the results are helpful to reveal their toxic mechanism to insects.

Objective: Porphyromonas gulae, a major periodontal pathogen in animals, possesses fimbriae that have been classified into three genotypes (A, B, C) based on the diversity of fimA genes encoding fimbrillin protein (FimA). P. gulae strains with type C fimbriae were previously shown to be more virulent than other types. In this study, we further examined the host toxicity mediated by P. gulae fimbriae by constructing recombinant FimA (rFimA) expression vectors for each genotype and raised antibodies to the purified proteins. Methods and Results: All larvae died within 204 h following infection with P. gulae type C at the low-dose infection, whereas type A and B did not. Among fimA types, the survival rates of the larvae injected with rFimA type C were remarkably decreased, while the survival rates of the larvae injected with rFimA type A and type B were greater than 50%. Clindamycin treatment inhibited the growth of type C strains in a dose-dependent manner, resulting in an increased rate of silkworm survival. Finally, type C rFimA-specific antiserum prolonged the survival of silkworm larvae stimulated by infection with P. gulae type C strain or injection of rFimA type C protein. Conclusion: These results suggested that type C fimbriae have high potential for enhancement of bacterial pathogenesis, and that both clindamycin and anti-type C rFimA-specific antibodies are potent inhibitors of type C fimbriae-induced toxicity. This is the first report to establish a silkworm infection model using P. gulae for toxicity assessment.

Cordyceps militaris produces cordycepin, a secondary metabolite that exhibits numerous bioactive properties. However, cordycepin pharmacology in vivo is not yet understood. In this study, the roles of cordycepin in C. militaris during its infection were investigated. After the injection of conidia, C. militaris NBRC100741 killed silkworm larvae more rapidly than NBRC103752. At 96 and 120 h, Cmcns genes (Cmcns1–4), which are part of the cordycepin biosynthesis gene cluster, were expressed in fat bodies and cuticles. Thus, cordycepin may be produced in the infection of silkworm larvae. Further, cordycepin enhanced pathogenicity toward silkworm larvae of Metarhizium anisopliae and Beauveria bassiana, that are also entomopathogenic fungi and do not produce cordycepin. In addition, by RNA-seq analysis, the increased expression of the gene encoding a lipoprotein 30K-8 (Bmlp20, KWMTBOMO11934) and decreased expression of genes encoding cuticular proteins (KWMTBOMO13140, KWMTBOMO13167) and a serine protease inhibitor (serpin29, KWMTBOMO08927) were observed when cordycepin was injected into silkworm larvae. This result suggests that cordycepin may aid the in vivo growth of C. militaris in silkworm larvae by the influence of the expression of some genes in silkworm larvae.

During the growth of silkworm larvae study, also was done a research which aimed to determine the chemical composition of mulberry leaves from a Romanian Selected Hybrid. The results showed that advancing in the vegetation stage at the same time with different periods of the silkworm larvae's growth, the mulberry leaves experience an aging process being noticed through its quality decreasing from chemical composition point of view. So, for example, the CP which was in average 20.78±0.627% (from DM), decreased during the study with 2.87%; while the CF had an average of 18.10±0.271%, (from DM) increased with 1.47%. [ABSTRACT FROM AUTHOR]

In this study, we report the expression of human thyroid peroxidase (TPO) in silkworm larvae and Pichia pastoris GS115. Recombinant TPO is sequentially purified from the hemolymph of infected silkworm larvae and yeast using a Ni-NTA resin kit. The concentration of yield of recombinant TPO is 4.87 mg per thousand larvae and 40.83 mg per liter yeast culture. However, the recombinant TPO produced in silkworm show similar binding ability with the specific anti-TPO serum to standard human TPO purified from insect cells. The lower antigen activity indicates the TPO expressed in yeast is not suitable to be used as the coating antigen in enzyme linked immunosorbent assay (ELISA). The cost of TPO expressed in B. mori is about 1/4 that of in insect cells, and the cost of TPO purified from silkworm for ELISA is only 1/8 that of TPO produced from Sf9 cells. It indicates the BmNPV-silkworm expression system is a cost-effective platform for producing TPO with high antigen activity. [ABSTRACT FROM AUTHOR]

Abstract: Transmembrane domains of some receptors have been found to be very important in the process of constitutive oligomerization, and in the stability and functioning of the receptor. In this study, full-length of human (pro)renin receptor (hPRR) and hPRR lacking cytoplasmic domain (hPRR-ΔCD) were expressed in fat body of silkworm larvae, and the extracellular domain of hPRR (hPRR-ΔTMΔCD) in hemolymph. Three forms of hPRR were used for investigation of the interaction between receptor and ligand using surface plasmon resonance (SPR). As a result, the cytoplasmic domain was not an essential requirement for binding affinity, but the transmembrane domain of hPRR was indispensable in the formation of functional hPRR. The dissociation equilibrium constants (K D) of purified hPRR and hPRR-ΔCD were estimated to be 46 nM and 330 nM, respectively. No evidence of binding by the extracellular domain of hPRR located in hemolymph was found. However, the solubilized microsomal fraction of the extracellular domain of hPRR expressed in the fat body showed specific affinity, but lost its binding affinity after purification. Its binding affinity was recovered by mixing microsomal fraction of mock-injected fat body to the purified extracellular domain. It is probable that an artificial transmembrane domain stabilizes the extracellular domain of hPRR and native conformation may be structurally recovered. To our knowledge, these are the first findings describing the interaction of transmembrane and extracellular domains of hPRR with ligand and this may help towards the understanding of binding affinity of hPRR to ligand. [Copyright &y& Elsevier]

Abstract: N-Glycosylation of human β1,3N-acetylglucosaminyltransferase 2 (β3GnT2) is essential for its biological function. β3GnT2 fused to GFPuv (GFPuv–β3GnT2) was produced by non-virus expression systems in stably transformed insect cells and silkworm larvae using a recombinant BmNPV bacmid, and purified for analysis of N-glycosylation. The N-glycan structure of β3GnT2 was identified by glycoamidase A digestion, labeling with 2-aminopyridine (PA), and HPLC mapping. The paucimannosidic N-glycan structure (73.2%) was predominant in stably transformed Trichoplusia ni cells. In contrast, N-glycan with Gal (21.3%) and GlcNAc (16.2%) terminal residues linked to Manα(1,3) branch were detected on β3GnT2 expressed in silkworm larvae. The presence of terminal Gal and bisecting GlcNAc residues such as Galβ1, 4GlcNAcβ1, 2Manα1,3(GlcNAcβ1,4)(Manα1,6)Manβ1, 4GlcNAc is not typical structure for lepidopteran insect N-glycosylation. Although allergenic α1,3-fucose residues have been found in T. ni cells, only α1,6-fucose residues were attached to the β3GnT2 glycan in silkworm larvae. Therefore, silkworm larvae might be a useful host for producing human glycoproteins. [Copyright &y& Elsevier]

Baculovirus expression vector systems (BEVSs) are broadly used for producing foreign proteins in lepidopteran cells. Most commercial BEVSs are engineered to insert foreign genes into the polyhedrin ( polh) locus. They lack the polh gene. These viruses cannot produce occlusion bodies and are inconvenient for per os inoculation of larvae. To avoid this, expression cassettes can be inserted in other parts of the virus genome. The preS2-S gene, coding for the recombinant middle surface antigen of the human hepatitis B virus (M-HBsAg), was expressed from the baculovirus construct rBmNPV-Δv-cath-M-HBsAg, inserting the foreign gene into the v-cath locus of Bombyx mori nucleopolyhedrovirus (BmNPV) so that v-cath was deleted and native polh was retained. Silkworm larvae were infected per os and M-HBsAg was observed to be abundantly produced till very late stages of infection. Infection of larvae with a mixture of the recombinant and wild-type baculoviruses was followed by degradation of the bulk of the produced M-HBsAg as early as 96 h after inoculation. [ABSTRACT FROM AUTHOR]

Osteoprotegerin (OPG) regulates the formation of osteoclasts and is involved in the regulation of bone resorption and remodeling. To investigate the feasibility of using silkworm ( Bombyx mori) larvae to produce recombinant osteoprotegerin as a oral administration drug, the rh-OPG was expressed in the larvae of silkworm through the silkworm baculovirus expression system, and was orally administered to mice. Compared with the control, oral administration of rh-OPG was effective to decrease serum calcium concentration in normal mice, and block the bone loss induced by the loss of estrogen in ovariectomized mice. These results indicated that oral administration of rh-OPG expressed in silkworm larvae had the proper bioactivity. [ABSTRACT FROM AUTHOR]

The silkworm has become an ideal multicellular eukaryotic model system for basic research. The major advantages of expressing foreign genes in silkworm larvae are the low cost of feeding, the extremely high levels of expression achievable compared with expression in cell lines and increased safety because the baculovirus is noninfectious to vertebrates. In this study, we used a recently developed Bombyx mori Nucleopolyhedrovirus (BmNPV) bacmid to express the spider flagelliform silk gene in silkworm larvae. The recombinant bacmid baculoviruses (rBacmid/BmNPV/Flag) were introduced into the first-day larvae of the fifth instar by subcutaneous injection. The worms presented symptoms typical of NPV infection from 72 h after injection compared with control. The haemolymph was collected from the infected larvae 120 h post-infection and the recombinant 6× His-tagged Flag protein was purified by the Ni-NTA spin kit under denaturing conditions with 8 m urea. A 37.0-kDa protein was visualized both in rBacmid/BmNPV/Flag-infected haemolymph and eluting fraction. The results showed that the Bac-to-Bac/BmNPV baculovirus expression system is an efficient tool to express the target gene in silkworm larvae, which takes only 7–10 days for generating recombinant baculovirus, compared with the traditional homologous recombination method, which needs at least 40 days for multiple rounds of purification and amplification of viruses. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, recombinant human lactoferrin (rhLf) was expressed very well using Bombyx mori nuclear polyhedrosis baculovirus expression system. Infection of silkworm larvae with recombinant virus, vBm-hLf, the rhLf was efficiently secreted into larvae hemolymph and the concentration of product purified was about 65μg/ml. The isolated rhLf molecular mass was ∼78kDa, lower than that of the human lactoferrin (hLf) standards, which may be due to incomplete glycosylation or protein degradation. Furthermore, the rhLf was characterized and its biological activities were evaluated by in vivo bioassay using dextran sodium sulfate (DSS)-induced colitis mouse model that mimics some characteristics of colitis disease in human. We conclude that silkworm expression system can be used successfully to express functional human lactoferrin. [Copyright &y& Elsevier]

Human hepatitis B virus middle surface antigen (M-HBsAg) is an envelope protein used as a basis for constructing vaccines and test systems detecting the virus. The M-HBsAg cDNA was inserted in transfer vector pBK273 under the transcriptional control of the polyhedrin gene promoter to obtain recombinant pBHep-2. Cotransfection with pBHep-2 and the wild-type Bombix mori NPV DNA yielded a recombinant baculovirus, rBmNPVHep, with the M-HBsAg cDNA controlled by the polyhedrin gene promoter. Infection of B. mori larvae with rBmNPVHep led to expression of the foreign gene; recombinant M-HBsAg accumulated predominantly (to more than 90% its total content) in the fat body of larvae. [ABSTRACT FROM AUTHOR]

Han J, Zang Y, Lu H, Zhu J, Qin J. A novel recombinant dual human SCF expressed in and purified from silkworm, Bombyx mori, possesses higher bioactivity than recombinant monomeric human SCF. Eur J Haematol 2004: 72: 273–279. © Blackwell Munksgaard 2004. A novel recombinant dual human stem cell factor (rdhSCF) gene was constructed which consisted of a full-length hSCF cDNA plus a truncated hSCF cDNA (1–145 aa), linked by a peptide (GGGGSGGGGSGG) coding region. The rdhSCF gene was cloned into baculovirus transfer vector pAcSecG2T under the polyhedrin promoter control. Silkworm larvae infected with the recombinant virus expressed rdhSCF up to 15 800 units/mL in haemolymph. The specific activity of rdhSCF purified from the haemolymph was up to 3.0 × 106 units/mg, about 8.6 times as high as that of monomer rhSCF from Escherichia coli, and about 9.1 times as high as that of monomer rhSCF from insect cell. The binding affinity of rdhSCF to the cell surface receptor was higher than that of monomer rhSCF. [ABSTRACT FROM AUTHOR]

Seven ergosterol derivatives ( 1~7) were isolated from silkworm larvae infected with Paecilomyces sp. J300. On the basis of spectroscopic means, their structures have been elucidated as 3β,5α-dihydroxy-ergosta-7,22-diene ( 1), 5α,6α-epoxy-(22E,24R)-ergosta-8(14), 22-diene-3β,7α-diol ( 2), 5α,6α-epoxy-(22E,24R)-ergosta-8,22-diene-3β,7β-diol ( 3), ergosta-4,6,8(14),22-tetraene-3-one ( 4), ergosterol ( 5), ergosterol endoperoxide ( 6), 3β,5α-dihydroxy-6β-methoxyer-gosta-7,22-diene ( 7). Compounds 3~7 showed moderate cytotoxicity against five tumor cells. [ABSTRACT FROM AUTHOR]

An experimental study was undertaken to quantify the effects of cetyltriethylammonium bromide (CTAB) on the replication of Bombyx mori nucleopolyhedrovirus (BmNPV) and the transcriptionalactivity of BmNPV ie-1 promoter. The results demonstrated that the budded virus (BV) titer rose about 3.7-fold by adding CTAB to the culture media up to 0.1 μ g ml-1 in infected Bm-N cells with a wild-type BmNPV. The transient expression level of luciferase driven by BmNPV ie-1 promoter was enhanced by more than 3-fold in the presence of 0.1 μ g ml-1 of CTAB in uninfected insect cells via a transient expression system. Contrary to the rise in BV titer, the polyhedra inside the nucleus of infected cells dropped linearly from 4.0 × 106 ml-1 down to 2.1 × 106 ml-1 with in a range of CTAB concentrations from 0 to 0.25 μ g ml-1. The same trend in expression level of β - galactosidase or phytase was given when the Bm-N cells or fifth-instar silkworm larvae infected with a recombinant BmNPV containing the β - galactosidase or phytase reporter gene driven by the polyhedrin promoter. We deduced that CTAB appeared to affect the virus bi-phasic life cycle stages and production pathways, resulting in an enhancement in BV production and a suppression of occluded virus (OV) production and expression of foreign genes controlled by the polyhedrin promoter. [ABSTRACT FROM AUTHOR]

Recombinant peroxidase from Arthromyces ramosu s, fused with domains of antibody-binding proteins, was successfully obtained by a silkworm larvae expression system. The catalytic activity of the fusion peroxidase was increased 6-fold with the injection of 5-aminolevulinic acid into silkworm larvae as a heme precursor. [ABSTRACT FROM AUTHOR]