Comparative activity of three inhibitors of the angiotensin converting enzyme on growth, development and ecdysteroid contents of the mediterranean flour moth, Ephestia kuehniella Zeller

Three angiotensin converting enzyme (ACE) inhibitors, enalapril, lisinopril and captopril were tested in vivo by topical application on growth, development and whole body ecdysteroids in Ephestia kuehniella Zeller (Lepidoptera:Pyralidae), an important pest in stored products worldwide. The compounds were diluted in acetone and applied topically (10 μg/2 μl) on newly molted pupae. Results show that treatments delayed the pupal development and caused a large decrease in successful adult formation. Treatments had no significant effect on the pupal body weight at 1 and 3 days. Only enalapril at day 5 increases significantly the weight. The enzyme-immunoassay measurements of ecdysteroids in whole body extracts revealed that only lisinopril reduced significantly the hormonal contents at day 3.Keywords: Ephestia kuehniella, development, growth, ecdysteroids, angiotensin converting enzyme, captopril, enalapril, lisinopri

Atriplex halimus L. and Centaurium erythraea Rafn. Essential Oils: The Phytochemical Profile, Antimicrobial and Antioxidant Properties

This study was conducted to determine in vitro the antioxidant and antimicrobial potency of essential oils from two medicinal plants known in the Algerian northwest (Mascara city): Atriplex halimus L. and Centaurium erythraea Rafn. The analysis of essential oils (EOs) chemical compounds was performed by GC/MS. In total, 72 and 35 chemical components were identified for C. erythraea and A. halimus, which represents respectively 91.89% and 89.17% of the essential oil content. In fact, EO of A. halimus abundantly contained viridiflorol (40.23%), phytol (18.24%), germacrene D (6.94%), whereas β-copaen-4α-ol (38.41%), manool (8.2%) and carvacrol (6.43%) were found in OE of C. erythraea. Both essential oils were tested for antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis (Gram-positive bacteria), Escherichia coli, Pseudomonas aeruginosa (Gram-negative bacteria) and one yeast strain Candida albicans using the agar-disc diffusion assay and the microdilution method (Minimum Inhibitory Concentration, MIC). A. halimus EO is active against Escherichia coli, whereas the essential oil of C. erythraea is active against Staphylococcus aureus, Escherichia coli and Candida albicans. The antioxidant properties were evaluated using free radical scavenging and ferric reducing power (FRAP) assay. The results obtained showed the existence of an antioxidant activity of the studied essential oils but less effective compared to the standards used (ascorbic acid and catechin)

Atriplex halimus L. and Centaurium erythraea Rafn. Essential Oils: The Phytochemical Profile, Antimicrobial and Antioxidant Properties

This study was conducted to determine in vitro the antioxidant and antimicrobial potency of essential oils from two medicinal plants known in the Algerian northwest (Mascara city): Atriplex halimus L. and Centaurium erythraea Rafn. The analysis of essential oils (EOs) chemical compounds was performed by GC/MS. In total, 72 and 35 chemical components were identified for C. erythraea and A. halimus, which represents respectively 91.89% and 89.17% of the essential oil content. In fact, EO of A. halimus abundantly contained viridiflorol (40.23%), phytol (18.24%), germacrene D (6.94%), whereas β-copaen-4α-ol (38.41%), manool (8.2%) and carvacrol (6.43%) were found in OE of C. erythraea. Both essential oils were tested for antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis (Gram-positive bacteria), Escherichia coli, Pseudomonas aeruginosa (Gram-negative bacteria) and one yeast strain Candida albicans using the agar-disc diffusion assay and the microdilution method (Minimum Inhibitory Concentration, MIC). A. halimus EO is active against Escherichia coli, whereas the essential oil of C. erythraea is active against Staphylococcus aureus, Escherichia coli and Candida albicans. The antioxidant properties were evaluated using free radical scavenging and ferric reducing power (FRAP) assay. The results obtained showed the existence of an antioxidant activity of the studied essential oils but less effective compared to the standards used (ascorbic acid and catechin)

Differenciation des sexues neoteniques chez Kalotermes flavicollis Fabr. (Isoptera, Kalotermitidae) : evolution ultrastructurale des organes genitaux femelles

SIGLET 55929 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Analyse des hydrocarbures cuticulaires chez Blattella germanica : effets de divers groupes de pesticides

Analyse des hydrocarbures cuticulaires chez [i]Blattella germanica[/i] : effets de divers groupes de pesticides. Actes de la CIFE VI. Série Zoologi

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International audienceParticle tracking Microrheology (PTM) is an attractive experimental technique to measure the viscoelastic properties of complex fluids in a tiny volume. In the case of anisotropic materials such as liquid crystals, it should be however used cautiously. Here, we examined the case of the lyotropic chromonic liquid crystal disodium chromoglycate (DSCG). The unusual Brownian motions of microspheres in this system has attracted recent attention [1,2] suggesting a complex coupling between the fluctuations of the director and of the beads. Although it has been claimed that PTM could be used to extract the viscosities of the nematic phase [3], this effect may give rise to inconsistent microrheological measurements.In order to explore these issues, we have experimentally studied the Brownian motion of particles in aligned samples (see figure 1.A), varying both the concentration of DSCG and the size of the probes. Effective viscoelastic properties have been extracted from these measurements and compared to the ones obtained by active microrheology based on optical tweezers. Our results explain why various viscoelastic behaviors have been previously reported for DSCG

Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transferase activity

0048-3575 doi: DOI: 10.1016/j.pestbp.2005.05.002Oral toxicity of boric acid, an inorganic insecticide, was evaluated on German cockroach, Blattella germanica L. (Dictyoptera, Blattellidae). Newly emerged adults were exposed to various concentrations of boric acid incorporated into the diet. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. Histological study of midgut revealed alterations in the epithelial cells and a signiWcant increase in the epithelium thickness. In a second series of experiments, the compound was investigated on the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs). Data showed that the compound induced GSTs and reduced the activity of AChE. From this experiment, it may be concluded that ingested boric acid caused death of insects perhaps ultimately by starvation via alterations of the midgut. Additionally, the compound seemed to present a neurotoxic action as evidenced by the symptoms of poisoning and the reduction in AchE activity

Toxicity of boric acid to Blattella germanica (Dictyoptera: Blattellidae) and analysis of residues in several organs

1373-7503 (Print) Journal ArticlePestiferous cockroach species are associated closely with humans and are important from medical and public health points of view. Conventional insecticides have been used widely to control cockroaches which have developed resistance to these compounds. Thus, interest has again centered on lesser-used compounds such as boric acid. Boric acid has been used as an insecticide for many years, especially against cockroach. Its mode of action on insects has not been satisfactorily established. In Algeria, Blattella germanica (Dictyoptera: Blattellidae) is a serious pest in the urban environment and their infestation were controlled for many years by organophosphate, carbamate or pyrethroid insecticides. In order to obtain more information on the mode of action of boric acid, we first evaluated the oral toxicity of boric acid on B. germanica adults. Then, the compound was determined in several organs by an colorimetric method. This insecticide was incorporated into the diet and orally administered at different concentrations ranging from 1 to 40% (w/w) to newly emerged adults. Mortality was recorded at different times during treatment (24, 48, 72 and 144 h). Treatment resulted in a dose-dependent mortality since the LD50 (%) recorded are 85 at 24 h, 67 at 48 h, 39 at 72 h and 8 at 144 h, respectively. Then the quantity of boric acid accumulated in several organs (hemolymph, gut, ovaries, testicles and fat body) was determined as function the duration of treatment (1 to 5 days) for two doses (LD50 and LD90). Results revealed that bioaccumulation of residues in these organs increased as function the duration of treatment. In addition, relatively important amounts of residues, are detected in fat body

Cuticular hydrocarbon profiles in Blattella germanica: effects of halofenozide, boric acid and benfuracarb

1379-1176 (Print) Journal ArticleIn order to complete previous studies conducted on Blattella germanica, three insecticides from different groups were evaluated: boric acid, an inorganic compound, benfuracarb, a carbamate, and halofenozide, a non-steroidal ecdysone agonist. Boric acid (8.20%, LD50) and benfuracarb (2%, LD50) were incorporated into the diet and orally administrated to newly emerged adults of both sexes, while halofenozide (0.33%, LD50) was applied topically. Hydrocarbons extracts was made on bidistilled pentane from control and treated series sampled 6 days following treatment. Extracts was analyzed by gas chromatography. Data showed that cuticular profiles of control and treated series were qualitatively similar with thirteen major compounds; however, significant quantitative differences were noted. Boric acid seemed to feminize the cuticular profile in males with a significant reduction of the two first cuticular compounds detected. Halofenozide and benfuracarb reduced cuticular compounds in both sexes