Papers by Aly A H M E D Abd-Ella
Egyptian Academic Journal of Biological Sciences, F. Toxicology & Pest Control
Assiut Journal of Agricultural Sciences
Honeybees exposed to pesticides direct or indirect ways through their food research trips. Herein... more Honeybees exposed to pesticides direct or indirect ways through their food research trips. Herein, this study examined the toxicity effects on laboratory of seven tested pesticides insecticides from different pesticide groups. emamectin benzoate, imidacloprid, chlorpyrifos, indoxacarb, lambada cyhalothrine, glyphosate and thiophanate-methyl on honeybee workers, Apis mellifera L. through different exposure periods of time at 24, 48, and 72 hours. The selected pesticides were ranked based on their toxicity from the most to least one as following: emamectin benzoate, imidacloprid, chlorpyrifos, indoxacarb, and lambda cyhalothrine. Further, thiophanate-methyl and glyphosate were the lowest toxicity among selected pesticides. The highest toxic pesticide during the exposure period 24, 48 and 72 hrs was emamectin benzoate with LC 50 values (0.247, 0.047 and 0.020 ppm) and with LC90 values (5.752, 0.302 and 0.072 ppm) respectively, and the least one was glyphosate with LC50 values of (6861.151, 3366.968 and 2477.267 ppm) and LC90 values of (28243.795, 9033.695 and 6203.485 ppm) after 24, 48 and 72hr of exposure respectively. However, chlorpyrifos ranked the third toxic pesticide at 24 and 48 hrs of treatment with LC50 values of 10.226 and 2.731 ppm and with LC90 values of (101.224 and 7.496 ppm for 24 and 48 hrs, respectively). Whereas, after 72 hrs chlorpyrifos recorded the fourth toxic pesticide with LC502.086 ppm and LC90 5.179ppm. Based on the toxicity index, results showed that, the most to least toxic pesticides were arranged as followed: emamectin benzoate>imidacloprid >chlorpyrifos >indoxacarb >lambada cyhalothrine> thiophanate-methyl > glyphosate. These results demonstrated that pesticides are very toxic to honeybee workers and must avoid applying them during the times when bees are most active such as during flowering periods.
Journal of Pure and Applied Microbiology
This study aims to evaluate the toxicity and genetic improvement of Bacillus thuringiensis isolat... more This study aims to evaluate the toxicity and genetic improvement of Bacillus thuringiensis isolates. Isolates were obtained from soil, insect and water samples from different regions of Assiut, Egypt for biological control of mosquito larvae. B. thuringiensis colonies were identified based on morphological and then by PCR which detect the Cry toxic genes in the isolates. Bioassays were performed to evaluate the toxicity of different strains of B. thuringiensis against mosquito larvae such as (Culex spp). In general, 36 B. thuringiensis isolates were obtained (31 from soil, 4 from insects, and 1 from water). And they were all toxic to mosquito larvae with different mortality percentages from 7 to 97% after 48 hours. Isolate Am2 recorded the highest mortality percentage 97% and Mn3 lowest mortality percentage 7%. PCR revealed that Am2 isolate which caused the highest mortality encodes three different types of Cry toxins, Cyt1AA, Cry1Ac and Cry2Aa. This isolate Am2 was examined by scan...
<p>A) Bath application of 10nM DEET increases intracellular free calcium concentration ([Ca... more <p>A) Bath application of 10nM DEET increases intracellular free calcium concentration ([Ca<sup>2+</sup>]<sub>i</sub>) in Fura-2 loaded DUM neurons (<i>inset</i> 2). Note that, under control condition, calcium spark-like events are detected (<i>inset</i> 1). B) Pretreatment with 1μM atropine, a specific antagonist of muscarinic receptors (mAChRs), completely blocks the enhancement of [Ca<sup>2+</sup>]<sub>i</sub> produced by 10nM DEET, indicating the involvement of mAChRs. C) Bar graph summarizing the inhibitory effect of M1 and M3 mAChR antagonists pirenzepine (PZP) and 4-DAMP, respectively, on the synergism between DEET and propoxur. D) Bar graph illustrating that TMB-8 (100μM) also completely blocks the synergism between DEET and propoxur. E,F) Characterization of the intracellular calcium-dependent molecular events involved in the synergistic action of DEET on the propoxur-induced anticholinesterase effect. Intracellular application of 0.5mM W7, the calmodulin inhibitor and 50nM calmodulin (CaM) inhibit the positive potentiating effect of DEET on the toxic activity of propoxur. By contrast, KN-62 (10μM), which binds to CaM kinase II and blocks its activation by calmodulin, does not produce any effect (E). If pretreatment with 10μM of U73122, an inhibitor of PI-PLC known to regulate AChE activity, partially counteracts the effect of 0.5mM W7, application of the PI-PLC activator, <i>m</i>-3M3FBS (10μM) produces similar inhibition of the synergism between DEET and propoxur to that of observed with W7 tested alone (F). G) Modulation of the maximum amplitude of muscarine-elicited currents <i>versus</i> the concentration of DEET applied. The limited window of DEET concentration within which a maximum response potentiating effect is observed, is around 10nM (G). For higher DEET concentrations, the sensitizing effect is counteracted and eventually outweighed by an inhibitory action of DEET. Inset illustrates the semi-logarithmic dose-response curve for the muscarine-induced current applied by pressure ejection. Arrow indicates that the maximum current amplitude is obtained for pressure ejection duration of 500ms. H) DEET induces a transient concentration-dependent [Ca<sup>2+</sup>]i rise in Fura-2-loaded DUM neuron cell bodies. The changes in [Ca<sup>2+</sup>]<sub>i</sub> response amplitudes and the window of concentrations for DEET action were very similar with those illustrated in 2G. <b>(I)</b> Bath application of MT-7 (30nM), which is known to bind on M1 mAChR allosteric site, partially reversed the inhibitory effect observed for high concentration of DEET. Number of experiments varies from 8 to 13 cells. Data are means ± S.E.M. *, ** and ***, values significantly different, <i>p</i> < 0.05, <i>p</i> < 0.01 and <i>p</i> < 0.001, respectively. ns, not significant (<i>p</i> > 0.05). Scale bar: 20μm.</p
African Journal of Microbiology Research, 2012
<p>A) Dorsal view <i>camera lucida</i> drawing of typical DUM neuron morphology... more <p>A) Dorsal view <i>camera lucida</i> drawing of typical DUM neuron morphology revealed by anterograde cobalt staining performed on a soma located along the midline of the cockroach terminal abdominal ganglion (TAG) of the nerve cord. A, anterior; P, posterior; scale bar 120μm. B) Light micrograph of the whole cell patch-clamp technique adapted on the isolated DUM neuron cell body obtained after enzymatic digestion and mechanical dissociation of the TAG. C) Anticholinesterase effects of the carbamate, propoxur, the anticholinesterase compound BW284c51 and the repellent DEET on the duration of the ACh-induced inward currents (measured at 50% of the maximum current amplitudes) obtained in whole-cell voltage-clamp at a steady-state holding potential of -50 mV. D) Comparative bar graph summarizing the anticholinesterase effect of the specific inhibitor BW284c51 (100nM) and the carbamate, propoxur (prop) (100nM) measured on the duration of the ACh-induced inward currents (measured at 50% of the maximum current amplitudes) obtained in whole-cell voltage-clamp at a steady-state holding potential of -50 mV. E) Concentration-dependent inhibition of the residual AChE activity determined spectrophotometrically induced by propoxur and expressed as percentage of initial activity (i. e., without propoxur). The curve represents the best fit to the data points according to the Hill equation yielding the corresponding IC<sub>50</sub> (i.e., the concentration of propoxur that produces 50% inhibition of the AChE enzymatic activity) as illustrated in the comparative bar graph shown <i>in inset</i>. This indicates that isolated DUM neurons express functional AChE. F) Bar graph summarizing the unexpected concentration-dependent effect of DEET on the ACh-induced inward current duration. At low concentration (10nM), DEET produces a more important anticholinesterase effect than those observed with higher concentrations (i.e., 100nM and 1μM). By contrast, DEET (1μM) do not produce any effect on the carbachol(CCh)-induced current. G) Comparative bar graph illustrating the anticholinesterase effects of DEET (10nM) and propoxur (100nM) tested alone and in combination (DEET/propoxur). Pretreatment of DUM neuron with low concentration of DEET (10nM), for 15 minutes, strongly potentiates the propoxur-induced anticholinesterase effect. H) Comparative bar graph showing that synergistic effect between DEET and propoxur is only observed at low concentration of DEET (i. e., 10nM) and not with higher concentration (i. e., 1μM). I) Semi-logarithmic concentration-response curves for the anticholinesterase effect induced by propoxur applied alone and in the presence of 10nM DEET. The sigmoid curves represent the best fit to the mean data points according to the Hill equation yielding the corresponding IC<sub>50</sub> of 2.10<sup>-8</sup>M and 6.10<sup>-8</sup>M estimated for DEET and propoxur applied in combination and for propoxur applied alone, respectively. Number of experiments varies from 10 to 16 cells. Data are means ± S.E.M. ** and ***, values significantly different, <i>p</i> < 0.01 and <i>p</i><0.001, respectively; ns, not significant (<i>p</i> > 0.05).</p
<p>In all panels, the M1 and M3 mAChRs orthosteric and allosteric binding sites are shown w... more <p>In all panels, the M1 and M3 mAChRs orthosteric and allosteric binding sites are shown with the ligand DEET in green. Residues observed in vicinity of DEET in M1 mAChR orthosteric site (A) and allosteric region (B) and in M3 mAChR orthosteric site (C) and allosteric site (D) are shown in licorice representations. The following colour coding for transmembrane helices used: TM1—orange, TM2—green, TM3—dark blue, TM4—yellow, TM5—red, TM6—magenta, TM7—light blue.</p
Egyptian Academic Journal of Biological Sciences, F. Toxicology & Pest Control
Olive, Olea europaea L. is one of the most economical horticultural crops in Egypt. Olive fruits ... more Olive, Olea europaea L. is one of the most economical horticultural crops in Egypt. Olive fruits are a valuable commodity worldwide; they are eaten whole, filled and sliced as table olives and olive oil produced from fruit milling and must be prepared under safe
Assiut Journal of Agricultural Sciences
Assiut Journal of Agricultural Sciences
<p>The functional properties of DEET are investigated using CHO cells expressing human M1 (... more <p>The functional properties of DEET are investigated using CHO cells expressing human M1 (hM1) and M3 (hM3) mAChR subtypes. A) Dose-dependent inhibition of [<sup>3</sup>H]-NMS binding to M1 and M3 human muscarinic ACh receptor (mAChR) subtypes by DEET. The results are expressed as the ratio of the specific [<sup>3</sup>H]-NMS binding measured with (B) or without DEET (Bo). B-C) Signals acquired for calcium fluorescence after the addition at 20 sec of carbamylcholine (CCh) (300nM) and DEET (1mM) on CHO-hM1 cells (n = 3). DEET inhibition of the Ca<sup>2+</sup> mobilization after pretreatment of the cells with increasing concentrations of DEET (3nM to 3 mM), followed by a sub-maximal concentration of CCh (100 nM) (C). D-E) <i>in silico</i> Docking of DEET into human M1 and rat M3 mAChRs. The two binding regions (allosteric and orthosteric sites) of DEET molecules (green) in human M1 mAChR are represented (D). In red are shown residues of a M1 mAChR monomer interacting with MT-7 loops previously indentified. Analogous interaction residues from the second M1 mAChR monomer are indicated in blue (D) close to the hypothetical M1 mAChR allosteric site occupied by DEET. The <i>in silico</i> docking results to rat M3 mAChR crystal structure 4DAJ (E) also show that DEET binds on two distinct sites (allosteric and orthosteric sites). Ten DEET poses from each group located in both sites are shown in green. The following colour coding for transmembrane helices used: TM1—orange, TM2—green, TM3—dark blue, TM4—yellow, TM5—red, TM6—magenta, TM7—light blue. ECL, extracellular loop.</p
Assiut University Journal of Multidisciplinary Scientific Research, 2020
Four 3,5-pyrazolidinedione derivatives namely, 4-(4`-chlorobenzylidene)-1-phenylpyrazolidine-3,5-... more Four 3,5-pyrazolidinedione derivatives namely, 4-(4`-chlorobenzylidene)-1-phenylpyrazolidine-3,5-dione (1), 4-(4`-nitrobenzylidene)-1-phenylpyrazolidine-3,5-dione (2), 2'-(4-chlorophenyl)-1phenyl-3,5-dioxo-1,2,3,5 tetrahydrospiropyrazole-4,3' oxirane (3) and 2'-(4-nitrophenyl)-1phenyl-3,5-dioxo-1,2,3,5 tetrahydrospiropyrazole-4,3' oxirane (4) were prepared in pure state and bioassayed against 2 nd and 4 th instars larvae of cotton leaf worm, Spodoptera littoralis (Boised) (Lepidoptera: Noctuidae) using feeding and dipping bioassay. The results of bioassays indicated that title compounds exhibit satisfactory insecticidal activities. Among those, compound (1) exhibit the highest insecticidal activities against 2 nd instar larvae, with LC 50s 3.23 and 0.619 mgL-1 for feeding, and 36.04 and 28.69 mgL-1 for dipping, after 48 and 72 h treatment. According to the toxicity index the compound (1) showed the highest larvicidal activity against 4 th instar larvae with LC 50s 141.33 and 76.12 mgL-1 for feeding larvae, and 26.94 and 12.29 mgL-1 for dipping larvae after 48 and 72 h treatment. These results showed that, the 2 nd larvae was more susceptible than 4 th instars larvae to these compounds. In addition, the insecticidal activity of these compounds was Aly A. Abd-Ella et al. 2 more effective on cotton leaf worm larvae in feeding bioassay as compared with the dipping treatment. The rest of the tested compounds possessed moderate to strong larvicidal activities against cotton leaf worm. In general, the results indicate the possible use of 3,5-pyrazolidinedione derivatives as components in integrated pest management program against S. littoralis.
Current Chemistry Letters, 2022
Oxo derivatives of pyrazolines and pyrazolidines are important heterocyclic compounds due to thei... more Oxo derivatives of pyrazolines and pyrazolidines are important heterocyclic compounds due to their unique biological activities and have been widely applied in pharmaceutical and agromedical fields. In this review, we provide an account of some recent advances in the field of pyrazolone chemistry, specifically on the reported synthesis methods of pyrazolinone (3-oxo-1,2-dihydropyrazole) and 3,5-pyrzolidinediones (3,5-dioxotetrahydropyrazoles) derivatives.
In this paper, 2-((3-Cyano-4,6-distyrylpyridin-2-yl)thio)acetamide (2) and its cyclized form, 3-a... more In this paper, 2-((3-Cyano-4,6-distyrylpyridin-2-yl)thio)acetamide (2) and its cyclized form, 3-amino-4,6-distyrylthieno[2,3-b]pyridine-2-carboxamide (3), were prepared and their structure characterizations were performed by the means of elemental and spectroscopic analyses. Their biological activity as insecticides against cowpea aphid Aphis craccivora Koch using acetamiprid insecticide as a reference was studied. The bioassay results for compounds (2) and (3) against nymphs of cowpea aphid showed that the LC50 values were 0.192 and 0.841 ppm, respectively, after 24 h of treatment but the LC50 values were 0.041 and 0.095 ppm, respectively, after 48 h of treatment. Furthermore, the bioassay results for compounds (2) and (3) showed that the LC50 values were 1.233 and 2.949 ppm, respectively, after 24 h of treatment and the LC50 values were 0.142 and 0.270 ppm, respectively, after 48 h of treatment against adults of cowpea aphid. Given these observations, it has been found that there ...
Journal of Saudi Chemical Society, 2017
Laboratoire Récepteurs et Canaux Ioniques Membranaires (RCIM), UPRES EA 2647/ USC INRA 2023, IFR ... more Laboratoire Récepteurs et Canaux Ioniques Membranaires (RCIM), UPRES EA 2647/ USC INRA 2023, IFR 149 QUASAV UFR Sciences, Université d'Angers, 49045 Angers cedex, France ED (N°) 495
Acetylcholinesterase (AChE) is a key enzyme of the insect cholinergic system because it regulates... more Acetylcholinesterase (AChE) is a key enzyme of the insect cholinergic system because it regulates the level of acetylcholine within the synaptic cleft by catalyzing the hydrolysis of acetylcholine. Because its inhibition causes insect death, insecticides such as organophosphates and carbamates used as irreversible inhibitors, have been developed. These compounds have similar properties to acetylcholine but are hemisubstrates because they phosphorylate or carbamoylate the active-site serine leading to irreversible inhibition of the enzyme. This inhibition leads to an accumulation of acetylcholine in the synapses which in turn leaves the acetylcholine receptors permanently activated, resulting in the death of the insect. Very recently, previous report have also suggested that the most commonly used repellent DEET (N, N-diéthyl-m-toluamide) could display an unusual insecticidal effect in the insect central nervous system, through an inhibition of acetylcholinesterase activity. Conseque...
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Papers by Aly A H M E D Abd-Ella