In this study, the sensitivity of Aedes aegypti mosquitoe larvae to four types of pesticides two ... more In this study, the sensitivity of Aedes aegypti mosquitoe larvae to four types of pesticides two phosphorous-based and two pyrethroid insecticides was investigated. The larvae revealed approximately 1.126-fold more susceptibility to Safrotin (LC50 = 0.127 ppm) than Fendure (LC50 = 0.143) in the case of phosphorous-based pesticides and approximately 1.265-fold more susceptibility to AlphaQuest (LC50 = 0.0347 ppm) than Klash (LC50 = 0.0439) in the case of pyrothroid insecticides. Comparison between groups revealed that AlphaQuest was more effective than Klash, Safrotin and Fendure by approximately 1.3, 3.6 and 4.1-fold, respectively. The presence of enzyme activities relevant to insecticide resistance was often evaluated using enzyme assays to detect the underlying resistance mechanisms that may not be detected using bioassays. In this study, the results revealed significant decrease in the activity of esterase, glutathione- S- transferase and acetylcholine esterase enzymes to varying degrees. There were significant increases in catalase and total glutathione activity in all treatments compared to the control. The study concluded that this variation in enzyme activities is due to the type and purity of the additive compound and the source and purity of the active ingredient. The study recommends using the catalase enzyme and total glutathione as a biomarker indication for pesticide synergistic intoxication in aquatic animals.
Natural products are considered a good choice in the biological control of mosquitoes because the... more Natural products are considered a good choice in the biological control of mosquitoes because they are an effective way to eliminate larvae and prevent an increase in mosquito numbers, while simultaneously not polluting the environment or damaging health. This investigation was designed to study the potential toxicity of three species of algae, Caulerpa racemosa (Weber‐van Bosse, 1909), Padina boryana (Thivy, 1966), and Turbinaria ornata (Turner J. Agardh, 1848), on the larvae of Aedes aegypti mosquito, the vector of dengue and Zika viruses. Among the studied species, Caulerpa racemosa showed the greatest effectiveness in eradicating A. aegypti larvae with an LC50 = 43.5 ppm, followed by Padina boryana with an LC50 = 51.93 ppm. Both species proved to be excellent candidates as a source of larvicidal agents and could be used commercially in mosquito control programs as eco‐friendly biopesticides. The combined activity of different mixtures against mosquito larvae was expressed as the coeffective factor (C.F.). C.F. values showed that the joint activity of insect growth regulator Dudim in combination with Caulerpa racemosa and Padina boryana extracts produced degrees of potentiation effects and degrees of additive effects were obtained with Dudim in combination with Turbinaria ornata extract.
Dengue fever (DF) was originally discovered and registered in the Kingdom of Saudi Arabia within ... more Dengue fever (DF) was originally discovered and registered in the Kingdom of Saudi Arabia within the premises of the Jeddah governate (province) during 1994. Currently there is no vaccine against this type of dengue virus, however, the most practical methods of suppression and control of this fatal disease are confined to the control of its vector. This study aimed to investigate the effectiveness of six types of conventional pesticides of the pyrethroid (Icon 2.5% and Residex C‐10EC), organophosphorous (Rizfin 50% EC and Keen 600EC) and biocide (Bacilod and VectoMax) groups against the Aedes aegypti mosquito, as well as four pesticides in the insect growth regulators (IGR) groups (In 2 Mix and Starycide) and the plant oils group (lemon oil and peppermint oil). Taking the LC50 values (the concentration required for killing 50% of the individuals) into consideration, larvae of Ae. aegypti mosquitoes exhibited more susceptibility to Icon 2.5% (0.023 ppm) than Rizfin (0.032 ppm), Residex C‐10EC (0.05 ppm), Keen (0.052 ppm), VectoMax FG (0.115 ppm) and Bacilod (0.174 ppm) by approximately 1.39, 2.18, 2.26, 5.1 and 7.6 fold, respectively. Based on the IC50 values (the concentration that prevents the emergence of 50% of adults), the IGR In 2 Mix (IC50 = 0.0023 ppm) revealed more larvicidal activity against Ae. aegypti than did Starycide 480 SC (0.0047 ppm), lemon oil (11.842 ppm) and peppermint oil (17.213 ppm) by approximately 2.04, 5.15 and 7.5 fold, respectively. The differences in susceptibility levels can be attributed to the mode of action and the nature of the active ingredients of each pesticide. Generally, these bioassay tests are of great importance to provide reference for mosquito control managers and make informed decisions on the best usage of insecticides.
Background The Aedes aegypti mosquito is the primary vector for dengue, chikungunya, yellow fever... more Background The Aedes aegypti mosquito is the primary vector for dengue, chikungunya, yellow fever and Zika viruses worldwide. The first record of Ae. aegypti in southwestern Saudi Arabia was in 1956. However, the first outbreak and cases of dengue fever were reported in 1994, and cases have increased in recent years. Vector control for Ae. aegypti mainly uses pyrethroid insecticides in outdoor and indoor space spraying. The constant use of pyrethroids has exerted intense selection pressure for developing target-site mutations in the voltage-gated sodium channel (vgsc) gene in Ae. Aegypti against pyrethroids—mutations that have led to knockdown resistance (kdr). Methods Aedes aegypti field populations from five regions (Jazan, Sahil, Makkah, Jeddah and Madinah) of southwestern Saudi Arabia were genotyped for known kdr mutations in domains IIS6 and IIIS6 of the vgsc gene using polymerase chain reaction (PCR) amplification and sequencing. We estimated the frequency of kdr mutations and...
In this study, three pyrethroid insecticides 'Deltamethrin, Cypermethrin and Cyfluthrin' ... more In this study, three pyrethroid insecticides 'Deltamethrin, Cypermethrin and Cyfluthrin' were evaluated against field and laboratory strains of the adult females of the housefly, Musca domestica L. using topical application bioassay technique under laboratory conditions. Different concentrations were used, which were ranged between 0.001-0.5 ppm against laboratory strain, while were ranged between 0.01-1.0 ppm against field strain. The mortality% of Deltamethrin ranged between 18-99%, while ranged between 16-98% for Cypermethrin and ranged between 15-99% in case of Cyfluthrin against laboratory strain. On the other hand, the mortality% ranged between 25-92%, 25-91 and 25-89% for Deltamethrin, Cypermethrin and Cyfluthrin against field strain, respectively. The results indicated that Cyfluthrin was the most effective insecticide (LD 50 0.0133 ppm) against the adult females as well as, Deltamethrin (LD 50 0.0185 ppm), while Cypermethrin gave (LD 50 0.0223 ppm) against laborator...
Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in f... more Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in food, cosmetic and pharmaceutical industries. In this research the fatty acid moieties derived from polyunsaturated fatty acid containing single cell oils (SCOs), i.e. those produced from Cunninghamella echinulata, Umbelopsis isabellina and Nannochloropsis gaditana as well as from olive oil and an eicosapentaenoic acid (EPA) concentrate were converted into GEs by enzymatic synthesis, using lipases as biocatalysts. The GE synthesis was monitored using thin-layer chromatography, FT-IR and in situ NMR. It was found that GE synthesis carried out using immobilized Candida antarctica B lipase was very effective reaching high yields, near to 100%. It was shown that EPA-GEs were very effective against several pathogenic bacteria and their activity can be attributed to their high EPA content. Furthermore, C. echinulata-GEs were more effective against pathogens comparing to U. isabellina-GEs, proba...
Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in f... more Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in food, cosmetic and pharmaceutical industries. In this research, the fatty acid moieties derived from polyunsaturated fatty acids containing single-cell oils (SCOs) (i.e., those produced from Cunninghamella echinulata, Umbelopsis isabellina and Nannochloropsis gaditana, as well as from olive oil and an eicosapentaenoic acid (EPA) concentrate) were converted into GEs by enzymatic synthesis, using lipases as biocatalysts. The GE synthesis was monitored using thin-layer chromatography, FTIR and in situ NMR. It was found that GE synthesis carried out using immobilized Candida antarctica B lipase was very effective, reaching total conversion of reactants. It was shown that EPA-GEs were very effective against several pathogenic bacteria and their activity can be attributed to their high EPA content. Furthermore, C. echinulata-GEs were more effective against pathogens compared with U. isabellina-...
The development of natural insecticide from plant products may have a beneficial effect as a prom... more The development of natural insecticide from plant products may have a beneficial effect as a promising candidate for practical strategies for controlling vector‐borne diseases without current treatment. The present study was carried out to characterize green synthesized metallic nanomaterials for silver (Ag‐NPs) and gold (Au‐NPs) from extract leaf of Nerium oleander L., assess in vivo toxicity, and evaluate the larvicidal activity against Aedes aegypti. The prepared nanomaterials (Ag‐NPs and Au‐NPs) were characterized by Ultraviolet–Visible Spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). In addition, the subacute in vivo toxicity method was used to assess the extract and the nanomaterials (Ag‐NPs and Au‐NPs); in evaluating larvicidal activities using the World Health Organization (WHO) method. The Ag‐NPs and Au‐NPs were confirmed by shifting the absorption band in UV–Vis, FTIR spectrums toward higher wavelengths. TEM and XRD analysis were revealed that the average particle size of Au‐NPs and Ag‐NPs showed 15.30 and 11.48 nm, respectively. In the toxicity experiment, no mortality or signs of toxicity were reported in all groups of treated animals; in larvicidal activity, the Au‐NPs and Ag‐NPs with LC50 36.0716 and 46.645 ppm respectively showed more effectiveness than leaf extract alone 108.1665 ppm. Collectively, extract leaf of N. oleander L. can be efficiently used to synthesize metallic nanomaterials with silver and gold, which can be adopted as a natural source of insecticide against Ae. aegypti.
Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were fabricated using Plumeria alba l... more Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were fabricated using Plumeria alba leaf extracts to control the mosquito Aedes aegypti. Synthesized AgNPs and AuNPs were characterized by ultraviolet-visible spectroscopy, Fourier-Transform Infrared Radiation (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscope (TEM) analysis. Susceptibility levels of Ae. aegypti mosquito larvae to the plant extract P. alba and its silver nanoparticles (AgNPs) and gold nanoparticles were determined. The AgNPs and AuNPs spectra displayed their maximum absorption at 300 nm and 500 nm, respectively. The larval mortality of AgNPs and AuNPs were highly effective LC50 were 69.9592 ppm and 88.2635 ppm compared to the aqueous leaf extract of P. alba LC50 was 178.4713 ppm. Furthermore, no significant effects of nanoparticle preparations of P. alba extract 10,000 ppm dose up to one week revealed neither toxic signs nor death within seven days of administration. However, there were no apparent signs of delayed toxicity when the rats were observed for an additional seven days. Current studies revealed that the P. alba leaf extract, AgNPs and AuNPs are biologically safe on animals and eco-friendly for control of Aedes aegypti mosquito.
In this study, the sensitivity of Aedes aegypti mosquitoe larvae to four types of pesticides two ... more In this study, the sensitivity of Aedes aegypti mosquitoe larvae to four types of pesticides two phosphorous-based and two pyrethroid insecticides was investigated. The larvae revealed approximately 1.126-fold more susceptibility to Safrotin (LC50 = 0.127 ppm) than Fendure (LC50 = 0.143) in the case of phosphorous-based pesticides and approximately 1.265-fold more susceptibility to AlphaQuest (LC50 = 0.0347 ppm) than Klash (LC50 = 0.0439) in the case of pyrothroid insecticides. Comparison between groups revealed that AlphaQuest was more effective than Klash, Safrotin and Fendure by approximately 1.3, 3.6 and 4.1-fold, respectively. The presence of enzyme activities relevant to insecticide resistance was often evaluated using enzyme assays to detect the underlying resistance mechanisms that may not be detected using bioassays. In this study, the results revealed significant decrease in the activity of esterase, glutathione- S- transferase and acetylcholine esterase enzymes to varying degrees. There were significant increases in catalase and total glutathione activity in all treatments compared to the control. The study concluded that this variation in enzyme activities is due to the type and purity of the additive compound and the source and purity of the active ingredient. The study recommends using the catalase enzyme and total glutathione as a biomarker indication for pesticide synergistic intoxication in aquatic animals.
Natural products are considered a good choice in the biological control of mosquitoes because the... more Natural products are considered a good choice in the biological control of mosquitoes because they are an effective way to eliminate larvae and prevent an increase in mosquito numbers, while simultaneously not polluting the environment or damaging health. This investigation was designed to study the potential toxicity of three species of algae, Caulerpa racemosa (Weber‐van Bosse, 1909), Padina boryana (Thivy, 1966), and Turbinaria ornata (Turner J. Agardh, 1848), on the larvae of Aedes aegypti mosquito, the vector of dengue and Zika viruses. Among the studied species, Caulerpa racemosa showed the greatest effectiveness in eradicating A. aegypti larvae with an LC50 = 43.5 ppm, followed by Padina boryana with an LC50 = 51.93 ppm. Both species proved to be excellent candidates as a source of larvicidal agents and could be used commercially in mosquito control programs as eco‐friendly biopesticides. The combined activity of different mixtures against mosquito larvae was expressed as the coeffective factor (C.F.). C.F. values showed that the joint activity of insect growth regulator Dudim in combination with Caulerpa racemosa and Padina boryana extracts produced degrees of potentiation effects and degrees of additive effects were obtained with Dudim in combination with Turbinaria ornata extract.
Dengue fever (DF) was originally discovered and registered in the Kingdom of Saudi Arabia within ... more Dengue fever (DF) was originally discovered and registered in the Kingdom of Saudi Arabia within the premises of the Jeddah governate (province) during 1994. Currently there is no vaccine against this type of dengue virus, however, the most practical methods of suppression and control of this fatal disease are confined to the control of its vector. This study aimed to investigate the effectiveness of six types of conventional pesticides of the pyrethroid (Icon 2.5% and Residex C‐10EC), organophosphorous (Rizfin 50% EC and Keen 600EC) and biocide (Bacilod and VectoMax) groups against the Aedes aegypti mosquito, as well as four pesticides in the insect growth regulators (IGR) groups (In 2 Mix and Starycide) and the plant oils group (lemon oil and peppermint oil). Taking the LC50 values (the concentration required for killing 50% of the individuals) into consideration, larvae of Ae. aegypti mosquitoes exhibited more susceptibility to Icon 2.5% (0.023 ppm) than Rizfin (0.032 ppm), Residex C‐10EC (0.05 ppm), Keen (0.052 ppm), VectoMax FG (0.115 ppm) and Bacilod (0.174 ppm) by approximately 1.39, 2.18, 2.26, 5.1 and 7.6 fold, respectively. Based on the IC50 values (the concentration that prevents the emergence of 50% of adults), the IGR In 2 Mix (IC50 = 0.0023 ppm) revealed more larvicidal activity against Ae. aegypti than did Starycide 480 SC (0.0047 ppm), lemon oil (11.842 ppm) and peppermint oil (17.213 ppm) by approximately 2.04, 5.15 and 7.5 fold, respectively. The differences in susceptibility levels can be attributed to the mode of action and the nature of the active ingredients of each pesticide. Generally, these bioassay tests are of great importance to provide reference for mosquito control managers and make informed decisions on the best usage of insecticides.
Background The Aedes aegypti mosquito is the primary vector for dengue, chikungunya, yellow fever... more Background The Aedes aegypti mosquito is the primary vector for dengue, chikungunya, yellow fever and Zika viruses worldwide. The first record of Ae. aegypti in southwestern Saudi Arabia was in 1956. However, the first outbreak and cases of dengue fever were reported in 1994, and cases have increased in recent years. Vector control for Ae. aegypti mainly uses pyrethroid insecticides in outdoor and indoor space spraying. The constant use of pyrethroids has exerted intense selection pressure for developing target-site mutations in the voltage-gated sodium channel (vgsc) gene in Ae. Aegypti against pyrethroids—mutations that have led to knockdown resistance (kdr). Methods Aedes aegypti field populations from five regions (Jazan, Sahil, Makkah, Jeddah and Madinah) of southwestern Saudi Arabia were genotyped for known kdr mutations in domains IIS6 and IIIS6 of the vgsc gene using polymerase chain reaction (PCR) amplification and sequencing. We estimated the frequency of kdr mutations and...
In this study, three pyrethroid insecticides 'Deltamethrin, Cypermethrin and Cyfluthrin' ... more In this study, three pyrethroid insecticides 'Deltamethrin, Cypermethrin and Cyfluthrin' were evaluated against field and laboratory strains of the adult females of the housefly, Musca domestica L. using topical application bioassay technique under laboratory conditions. Different concentrations were used, which were ranged between 0.001-0.5 ppm against laboratory strain, while were ranged between 0.01-1.0 ppm against field strain. The mortality% of Deltamethrin ranged between 18-99%, while ranged between 16-98% for Cypermethrin and ranged between 15-99% in case of Cyfluthrin against laboratory strain. On the other hand, the mortality% ranged between 25-92%, 25-91 and 25-89% for Deltamethrin, Cypermethrin and Cyfluthrin against field strain, respectively. The results indicated that Cyfluthrin was the most effective insecticide (LD 50 0.0133 ppm) against the adult females as well as, Deltamethrin (LD 50 0.0185 ppm), while Cypermethrin gave (LD 50 0.0223 ppm) against laborator...
Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in f... more Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in food, cosmetic and pharmaceutical industries. In this research the fatty acid moieties derived from polyunsaturated fatty acid containing single cell oils (SCOs), i.e. those produced from Cunninghamella echinulata, Umbelopsis isabellina and Nannochloropsis gaditana as well as from olive oil and an eicosapentaenoic acid (EPA) concentrate were converted into GEs by enzymatic synthesis, using lipases as biocatalysts. The GE synthesis was monitored using thin-layer chromatography, FT-IR and in situ NMR. It was found that GE synthesis carried out using immobilized Candida antarctica B lipase was very effective reaching high yields, near to 100%. It was shown that EPA-GEs were very effective against several pathogenic bacteria and their activity can be attributed to their high EPA content. Furthermore, C. echinulata-GEs were more effective against pathogens comparing to U. isabellina-GEs, proba...
Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in f... more Sugar fatty acid esters, especially glucose fatty acid esters (GEs), have broad applications in food, cosmetic and pharmaceutical industries. In this research, the fatty acid moieties derived from polyunsaturated fatty acids containing single-cell oils (SCOs) (i.e., those produced from Cunninghamella echinulata, Umbelopsis isabellina and Nannochloropsis gaditana, as well as from olive oil and an eicosapentaenoic acid (EPA) concentrate) were converted into GEs by enzymatic synthesis, using lipases as biocatalysts. The GE synthesis was monitored using thin-layer chromatography, FTIR and in situ NMR. It was found that GE synthesis carried out using immobilized Candida antarctica B lipase was very effective, reaching total conversion of reactants. It was shown that EPA-GEs were very effective against several pathogenic bacteria and their activity can be attributed to their high EPA content. Furthermore, C. echinulata-GEs were more effective against pathogens compared with U. isabellina-...
The development of natural insecticide from plant products may have a beneficial effect as a prom... more The development of natural insecticide from plant products may have a beneficial effect as a promising candidate for practical strategies for controlling vector‐borne diseases without current treatment. The present study was carried out to characterize green synthesized metallic nanomaterials for silver (Ag‐NPs) and gold (Au‐NPs) from extract leaf of Nerium oleander L., assess in vivo toxicity, and evaluate the larvicidal activity against Aedes aegypti. The prepared nanomaterials (Ag‐NPs and Au‐NPs) were characterized by Ultraviolet–Visible Spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). In addition, the subacute in vivo toxicity method was used to assess the extract and the nanomaterials (Ag‐NPs and Au‐NPs); in evaluating larvicidal activities using the World Health Organization (WHO) method. The Ag‐NPs and Au‐NPs were confirmed by shifting the absorption band in UV–Vis, FTIR spectrums toward higher wavelengths. TEM and XRD analysis were revealed that the average particle size of Au‐NPs and Ag‐NPs showed 15.30 and 11.48 nm, respectively. In the toxicity experiment, no mortality or signs of toxicity were reported in all groups of treated animals; in larvicidal activity, the Au‐NPs and Ag‐NPs with LC50 36.0716 and 46.645 ppm respectively showed more effectiveness than leaf extract alone 108.1665 ppm. Collectively, extract leaf of N. oleander L. can be efficiently used to synthesize metallic nanomaterials with silver and gold, which can be adopted as a natural source of insecticide against Ae. aegypti.
Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were fabricated using Plumeria alba l... more Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were fabricated using Plumeria alba leaf extracts to control the mosquito Aedes aegypti. Synthesized AgNPs and AuNPs were characterized by ultraviolet-visible spectroscopy, Fourier-Transform Infrared Radiation (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscope (TEM) analysis. Susceptibility levels of Ae. aegypti mosquito larvae to the plant extract P. alba and its silver nanoparticles (AgNPs) and gold nanoparticles were determined. The AgNPs and AuNPs spectra displayed their maximum absorption at 300 nm and 500 nm, respectively. The larval mortality of AgNPs and AuNPs were highly effective LC50 were 69.9592 ppm and 88.2635 ppm compared to the aqueous leaf extract of P. alba LC50 was 178.4713 ppm. Furthermore, no significant effects of nanoparticle preparations of P. alba extract 10,000 ppm dose up to one week revealed neither toxic signs nor death within seven days of administration. However, there were no apparent signs of delayed toxicity when the rats were observed for an additional seven days. Current studies revealed that the P. alba leaf extract, AgNPs and AuNPs are biologically safe on animals and eco-friendly for control of Aedes aegypti mosquito.
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Papers by Jazem Mahyoub