Chemical composition and bio-efficacy of agro-waste plant extracts and their potential as bioinsecticides against Culex pipiens mosquitoes.

Mosquitoes are considered one of the most lethal creatures on the planet and are responsible for millions of fatalities annually through the transmission of several diseases to humans. Green trash is commonly employed in agricultural fertilizer manufacturing and microbial bioprocesses for energy production. However, there is limited information available on the conversion of green waste into biocides. This study investigates the viability of utilizing green waste as a new biopesticide against Culex pipiens mosquito larvae. The current study found that plant extracts from Punica granatum (98.4 % mortality), Citrus sinensis (92 % mortality), Brassica oleracea (88 % mortality), Oryza sativa (81.6 % mortality), and Colocasia esculenta (53.6 % mortality) were very good at killing Cx. pipiens larvae 24 h post-treatment. The LC50 values were 314.43, 370.72, 465.59, 666.67, and 1798.03 ppm for P. granatum, C. sinensis, B. oleracea, O. sativa, and C. esculenta, respectively. All plant extracts, particularly P. granatum extract (14.93 and 41.87 U/g), showed a significant reduction in acid and alkaline phosphate activity. Additionally, pomegranate extract showed a significant decrease (90 %) in field larval density, with a stability of up to five days post-treatment. GC-MS results showed more chemical classes, such as terpenes, esters, fatty acids, alkanes, and phenolic compounds. HPLC analysis revealed that the analyzed extracts had a high concentration of phenolic and flavonoid components. Moreover, there are many variations among these plants in the amount of each compound. The docking interaction showed a simulation of the atomic-level interaction between a protein and a small molecule through the binding site of target proteins, explaining the most critical elements influencing the enzyme's activity or inhibitions. The study's findings showed that the various phytochemicals found in agro-waste plants had high larvicidal activity and provide a safe and efficient substitute to conventional pesticides for pest management, as well as a potential future in biotechnology.

Evaluating larvicidal, ovicidal and growth inhibiting activity of five medicinal plant extracts on Culex pipiens (Diptera: Culicidae), the West Nile virus vector.

Mosquitoes, one of the deadliest animals on the planet, cause millions of fatalities each year by transmitting several human illnesses. Synthetic pesticides were previously used to prevent the spread of diseases by mosquitoes, which was effective in protecting humans but caused serious human health problems, environmental damage, and developed mosquito pesticide resistance. This research focuses on exploring new, more effective, safer, and environmentally friendly compounds to improve mosquito vector management. Phytochemicals are possible biological agents for controlling pests and many are target-specific, rapidly biodegradable, and eco-friendly. The potential of extracts of Lantana camara, Melia azedarach, Nerium oleander, Ricinus communis, and Withania somnifera against 3rd instar Culex pipiens (Common house mosquito) larvae was evaluated. Methanol extracts had more toxic effects against Cx. pipiens larvae (95-100%, 24 h post-treatment) than aqueous extracts (63-91%, 24 h post-treatment). The methanol extracts of Nerium oleander (LC50 = 158.92 ppm) and Ricinus communis (LC50 = 175.04 ppm) were very effective at killing mosquito larvae, 24 h after treatment. N. oleander (LC50 = 373.29 ppm) showed high efficacy in aqueous plant extracts. Among the different extracts of the five plants screened, the methanol extract of R. communis recorded the highest ovicidal activity of 5% at 800 ppm concentration. Total developmental duration and growth index were highly affected by R. communis and M. azedarach methanol extracts. In field tests it was clear that plant extracts decreased mosquito larval density, especially when mixed with mosquito Bti briquette, with stability up to seven days for N. oleander. GC-MS results showed that the methanol extract had a higher number of chemical compounds, particularly with more terpene compounds. A high-performance liquid chromatography (HPLC) technique was used to detect the existence of non-volatile polyphenols and flavonoids. All five methanol extracts showed high concentrations of active ingredients such as gallic acid, chlorogenic acid (more than 100 µg/ml) and the rosmarinic acid was also found in all the five extracts in addition to 17 active polyphenols and flavonoids presented at moderate to low concentrations. Molecular modeling of 18 active ingredients detected by the HPLC were performed to the vicinity of one of the fatty acid binding proteins of lm-FABP (PDB code: 2FLJ). Rutin, Caffeic acid, coumaric acid and rosmarinic acid which presented densely in R. communis and N. oleander showed multiple and stable intermolecular hydrogen bonding and π-π stacking interactions. The inhibition ability of the fatty acid binding protein, FABP4, was evaluated with remarkable receptor inhibition evident, especially with R. communis and N. oleander having inhibitory concentrations of IC50 = 0.425 and 0.599 µg/mL, respectively. The active phytochemical compounds in the plants suggest promising larvicidal and ovicidal activity, and have potential as a safe and effective alternative to synthetic insecticides.

Biological effects of Bougainvillea glabra, Delonix regia, Lantana camara, and Platycladus orientalis extracts and their possible metabolomics therapeutics against the West Nile virus vector, Culex pipiens (Diptera: Culicidae).

Plants are a treasure trove of biological materials containing a wide range of potential phytochemicals that are target-specific, rapidly biodegradable, and environmentally friendly, with multiple medicinal effects. Unfortunately, the development of resistance to synthetic pesticides and antibiotics led to the discovery of new antibiotics, antioxidants, and biopesticides. This has also led to the creation of new medications that work very well. The current study aimed to prove that ornamental plants contain specialized active substances that are used in several biological processes. Mosquitoes, one of the deadliest animals on the planet, cause millions of fatalities each year by transmitting several human illnesses. Phytochemicals are possible biological agents for controlling pests that are harmful. The potential of leaf extracts of Bougainvillea glabra, Delonix regia, Lantana camara, and Platycladus orientalis against Culex pipiens and microbial agents was evaluated. Acetone extracts had more toxic effects against Cx. pipiens larvae (99.0-100 %, 72 h post-treatment), and the LC50 values were 142.8, 189.5, 95.4, and 71.1 ppm for B. glabra, D. regia, L. camara, and P. orientalis, respectively. Plant extracts tested in this study showed high insecticidal, antimicrobial, and antioxidant potential. GC-MS and HPLC analyses showed a higher number of terpenes, flavonoids, and phenolic compounds. The ADME analysis of element, caryophyllene oxide, caryophyllene, and copaene showed that they were similar to drugs and that they were better absorbed by the body and able to pass through the blood-brain barrier. Our results confirm the ability of ornamental plants to have promising larvicidal and antimicrobial activity and biotechnology.

The potential biological activities of Aspergillus luchuensis-aided green synthesis of silver nanoparticles.

Biosynthetic metals have attracted global attention because of their safety, affordability, and environmental friendliness. As a consequence, the cell-free filtrate (CFF) of Dill leaf-derived endophytic fungus Aspergillus luchuensis was employed for the extracellularly synthesis silver nanoparticles (AgNPs). A reddish-brown color shift confirmed that AgNPs were successfully produced. The obtained AgNPs were characterized by UV-Vis (ultraviolet-visible spectroscopy), Transmission electron microscopy (TEM), FTIR, EDX, and zeta potential. Results demonstrated the creation of crystalline AgNPs with a spherical shape at 427.81 nm in the UV-Vis spectrum, and size ranged from 16 to 18 nm as observed by TEM. Additionally, the biogenic AgNPs had a promising antibacterial activity versus multidrug-resistant bacteria, notably, S. aureus, E. coli, and S. typhi. The highest growth reduction was recorded in the case of E. coli. Furthermore, the biosynthesized AgNPs demonstrated potent antifungal potential versus a variety of harmful fungi. The maximum growth inhibition was evaluated from A. brasinsilles, followed by C. albicans as compared to cell-free extract and AgNO3. In addition, data revealed that AgNPs possess powerful antioxidant activity, and their ability to scavenge radicals increased from 33.0 to 85.1% with an increment in their concentration from 3.9 to 1,000 µg/mL. Furthermore, data showed that AgNPs displayed high catalytic activity of safranin under light irradiation. The maximum decolorization percentage (100%) was observed after 6 h. Besides, the biosynthesized AgNPs showed high insecticidal potential against 3rd larval instar of Culex pipiens. Taken together, data suggested that endophytic fungus, A. luchuensis, is an attractive candidate as an environmentally sustainable and friendly fungal nanofactory.

Integrated metabolomic analysis and molecular docking: Unveiling the potential of Nephrolepis exaltata (L.) Schott phytocompounds for mosquito control via glutathione-S-transferase targeting.

Plants contain a wide range of potential phytochemicals that are target-specific, and less toxic to human health. The present study aims to investigate the metabolomic profile of Nephrolepis exaltata (L.) Schott and its potential for mosquito control by targeting Glutathione-S-Transferase, focusing on the larvicidal activity against Culex pipiens. Crude extracts (CEs) were prepared using ethanol, ethyl acetate and n-hexane. CEs have been used for assessment of mosquitocidal bioassay. The metabolomic analyses for CEs were characterized for each CE by gas chromatography-mass spectrometry (GC-MS). The most efficient CE with the highest larval mortality and the least LC50 was the hexane CE. Then, alkaline phosphatase (ALP) activity, and glutathione-S-transferase (GST) activity were assessed in larvae treated with the hexane CE. The results demonstrated a decline in protein content, induction of ALP activity, and reduction in GST activity. Finally, molecular docking and dynamic simulation techniques were employed to evaluate the interaction between the hexane phytochemicals and the GST protein. D-(+)-Glucuronic acid, 3TMS derivative and Sebacic acid, 2TMS derivative showed best binding affinities to GST protein pointing to their interference with the enzyme detoxification functions, potentially leading to reduced ability to metabolize insecticides.

Acaricidal Efficacy of Thirty-Five Egyptian Plants Against the Camel Tick, Hyalomma Dromedarii.

PURPOSE: Alternative and affordable tick control strategies are crucial to control and prevent tick bites and tick-borne diseases. METHODS: In this study, we evaluated the acaricidal efficacy of 35 aqueous plant extracts (17%) against the camel tick, Hyalomma dromedarii. RESULTS: The phytochemical profile indicated the presence of various secondary substances. Plants were classified into three groups according to their mortality percentage 15 days post-treatment with 17%. This highly effective group (91%-95%) comprised Ocimum basilicum, Mespilus germanica, and Viola alpine followed by Carum carvi, Cucurbita pepo (peel), and Peganum harmala. A moderately effective group (80%-90%) included Acacia nilotica, Apium graveolens, Capsicum annuum, Ceratonia siliqua, Cucurbita pepo (seeds), Equisetum arvense, Eruca sativa, Ginkgo biloba, Plantago psyllium, Phyllanthus emblica, Punica granatum, and Ziziphus spinachristi. The 20 remaining plants were assigned to the less effective group (< 80%). Viscum album (58.3%), which was the least effective reference plant. The high potency of six plant extracts as acaricides may be attributed to the high content of active principles, e.g., phenols, flavonoids, and tannins. CONCLUSION: All of these highly effective plants are recommended for use as an acaricide, in case of facing acaricidal resistance or limited options for tick control.

Larvicidal activity of Acacia nilotica extracts against Culex pipiens and their suggested mode of action by molecular simulation docking.

Mosquitoes are one of the deadliest and most hazardous animals on Earth, where they transmit several diseases that kill millions of people annually. There is an ongoing search almost everywhere in the world for more effective and contemporary ways to control mosquitoes other than pesticides. Phytochemicals are affordable, biodegradable biological agents that specialize in eliminating pests that represent a risk to public health. The effectiveness of Acacia nilotica methanol and aqueous leaf extracts against 4th instar larvae was evaluated. The results revealed that the methanol extract of A. nilotica had a noticeable influence on the mortality rate of mosquito larvae, especially at high concentrations. Not only did the mortality rate rise significantly, but the hatching of the mosquito eggs was potentially suppressed.Terpenes, fatty acids, esters, glycosides, pyrrolidine alkane, piperazine, and phenols were the most prevalent components in the methanol extract, while the aqueous extract of A. nilotica exclusively showed the presence of fatty acids. The insecticidal susceptibility tests of both aqueous and alcoholic extract of A. nilotica confirmed that the Acacia plant could serves as a secure and efficient substitute for chemical pesticides because of its promising effect on killing larvae and egg hatching delaying addition to their safety as one of the natural pesticides. Molecular docking study was performed using one of the crucial and life-controlling protein targets, fatty acid binding protein (FABP) and the most active ingredients as testing ligands to describe their binding ability. Most of the structurally related compounds to the co-crystallized ligand, OLA, like hexadecanoic acid furnished high binding affinity to the target protein with very strong and stable intermolecular hydrogen bonding and this is quite similar to OLA itself. Some other structural non-related compounds revealed extraordinarily strong binding abilities like Methoxy phenyl piperazine. Most of the binding reactivities of the majortested structures are due to high structure similarity between the positive control, OLA, and tested compounds. Such structure similarity reinforced with the binding abilities of some detected compounds in the A. nilotica extract could present a reasonable interpretation for its insecticidal activity via deactivating the FABP protein. The FABP4 enzyme inhibition activity was assessed for of both methanolic and aqueous of acacia plant extract and the inhibition results of methanol extract depicted noticeable potency if compared to orlistat, with half-maximal inhibitory concentration (IC50) of 0.681, and 0.535 µg/ml, respectively.

Synthesis of eco-friendly layered double hydroxide and nanoemulsion for jasmine and peppermint oils and their larvicidal activities against Culex pipiens Linnaeus.

Mosquito-borne diseases represent a growing health challenge over time. Numerous potential phytochemicals are target-specific, biodegradable, and eco-friendly. The larvicidal activity of essential oils, a jasmine blend consisting of Jasmine oil and Azores jasmine (AJ) (Jasminum sambac and Jasminum azoricum) and peppermint (PP) Mentha arvensis and their nanoformulations against 2nd and 4th instar larvae of Culex pipiens, was evaluated after subjecting to different concentrations (62.5, 125, 250, 500, 1000, and 2000 ppm). Two forms of phase-different nanodelivery systems of layered double hydroxide LDH and oil/water nanoemulsions were formulated. The synthesized nanoemulsions showed particle sizes of 199 and 333 nm for AJ-NE and PP-NE, with a polydispersity index of 0.249 and 0.198, respectively. Chemical and physiochemical analysis of TEM, SEM, XRD, zeta potential, drug loading capacity, and drug release measurements were done to confirm the synthesis and loading efficiencies of essential oils' active ingredients. At high concentrations of AJ and PP nanoemulsions (2000 ppm), O/W nanoemulsions showed higher larval mortality than both LDH conjugates and crude oils. The mortality rate reached 100% for 2nd and 4th instar larvae. The relative toxicities revealed that PP nanoemulsion (MA-NE) was the most effective larvicide, followed by AJ nanoemulsion (AJ-NE). There was a significant increase in defensive enzymes, phenoloxidase, and α and ß-esterase enzymes in the treated groups. After treatment of L4 with AJ, AJ-NE, PP, and PP-NE, the levels of phenoloxidase were 545.67, 731.00, 700.00, and 799.67 u/mg, respectively, compared with control 669.67 u/mg. The activity levels of α-esterase were 9.71, 10.32, 8.91, and 10.55 mg α-naphthol/min/mg protein, respectively. It could be concluded that the AJ-NE and PP-NE nanoformulations have promising larvicidal activity and could act as safe and effective alternatives to chemical insecticides.

Efficacy of alumina nanoparticles as a controllable tool for mortality and biochemical parameters of Culex pipiens.

Mosquitoes still pose a clear risk to human and animal health. Recently, nanomaterials have been considered one of the cost-effective solutions to this problem. Therefore, alumina nanoparticles (Al) were synthesized using an auto-combustion method, followed by calcination at 600 and 800 °C. Glucose (G) and sucrose (Su) were used as fuels and the combustion was performed at pH 2, 7, and 10. The as-synthesized Al2O3 nanoparticles were characterized by XRD, FTIR, SEM, and TEM. Alumina nanoparticles prepared using G and Su fuels at pH 7 and 800 °C (Al-G7-800 and Al-Su7-800) have crystallite sizes of 3.9 and 4.05 nm, respectively. While the samples (Al-G7-600 and Al-Su7-600) synthesized at pH 7 and 600 °C were amorphous. The prepared alumina nanoparticles were applied to the larval and pupal stages of Culex pipiens. The results showed that alumina nanoparticles cause higher mortality in the 1st larval instar than in all other larval instars and pupal stages of Culex pipiens after treatment at a high concentration of 200 ppm. Additionally, the larval duration after treatment with LC50 concentrations of alumina (Al-G7-800 and Al-Su7-800) was 31.7 and 23.6 days, respectively, compared to the control (13.3 days). The recorded data found that the content of glutathione-S-transferase, alkaline/acid phosphatase, ß/α-esterase, and total protein were altered upon treatment with the LC50 concentration of alumina (Al-G7-800) nanoparticles. Based on these findings, alumina nanoparticles are a promising candidate as a potential weapon to control pests and mosquitoes.

Sustainable Pest Management Using Novel Nanoemulsions of Honeysuckle and Patchouli Essential Oils against the West Nile Virus Vector, Culex pipiens, under Laboratory and Field Conditions.

Essential oils are natural plant products that are very interesting, as they are important sources of biologically active compounds. They comprise eco-friendly alternatives to mosquito vector management, particularly essential oil nanoemulsion. Therefore, the aim of this study is to evaluate the effectiveness of 16 selected essential oils (1500 ppm) in controlling mosquitoes by investigating their larvicidal effects against the larvae and adults of the West Nile virus vector Culex pipiens L. (Diptera: Culicidae); the best oils were turned into nanoemulsions and evaluated under laboratory and field conditions. The results show that honeysuckle (Lonicera caprifolium) and patchouli (Pogostemon cablin) essential oils were more effective in killing larvae than the other oils (100% mortality) at 24 h post-treatment. The nanoemulsions of honeysuckle (LC50 = 88.30 ppm) and patchouli (LC50 = 93.05 ppm) showed significantly higher larvicidal activity compared with bulk honeysuckle (LC50 = 247.72 ppm) and patchouli (LC50 = 276.29 ppm) oils. L. caprifolium and P. cablin (100% mortality), followed by Narcissus tazetta (97.78%), Rosmarinus officinalis (95.56%), and Lavandula angustifolia (95.55%), were highly effective oils in killing female mosquitoes, and their relative efficacy at LT50 was 5.5, 5.3, 5.8, 4.1, and 3.2 times greater, respectively, than Aloe vera. The results of the field study show that the honeysuckle and patchouli oils and their nanoemulsions reduced densities to 89.4, 86.5, 98.6, and 97.0% at 24 h post-treatment, respectively, with persistence for eight days post-treatment in pools. Nano-honeysuckle (100% mortality) was more effective than honeysuckle oils (98.0%). Our results show that honeysuckle and patchouli oils exhibited promising larvicidal and adulticidal activity of C. pipiens.

Novel acaricidal and growth-regulating activity of Aloe vera and Rheum rhabarbarum extracts and their oil/water nanoemulsions against the camel tick, Hyalomma dromedarii.

Hyalomma dromedarii is an important tick species infesting livestock. This work evaluated the novel adulticidal, insect growth-regulating, and enzymatic efficacy of ethanol plant extracts of Aloe vera and Rheum rhabarbarum and their nanoemulsions against males and engorged females of the camel tick, H. dromedarii. The physicochemical properties of nanoemulsions were evaluated. The High-Performance Liquid Chromatography (HPLC) analyses indicated that the extracts contained polyphenols and flavonoids, which could enhance their acaricidal effect. Dynamic light scattering (DLS) of the nanoemulsions of A. vera and R. rhabarbarum were 196.7 and 291 nm, whereas their zeta potentials were - 29.1 and - 53.1 mV, respectively. Transmission electron microscope (TEM) indicated that nanoemulsions showed a regular spherical shape (less than 100 nm). Fifteen days post-treatment (PT) with 25%, the mortality% of A. vera and R. rhabarbarum were 88.5 and 96.2%, respectively. Five days PT, the median lethal concentration values of A. vera, R. rhabarbarum, and their nanoemulsions were 7.8, 7.1, 2.8, and 1.02%, respectively, and their toxicity indices were 91.02, 100, 36.4, and 100%, respectively. Their median lethal time values PT with 3.5% were 6.09, 5.09, 1.75, and 1.34 days, respectively. Nanoemulsions enhanced the efficacy of the crude extract 1-7 folds, 5 days PT, and accelerated their speed of killing ticks 2-4 times. The total protein and carbohydrates, Acetylcholinesterase, Alpha esterase, and Amylase were affected PT. The reproductive potential of engorged females was adversely impacted. In conclusion, the novel A. vera and R. rhabarbarum extracts were promising acaricides, and their nanoformulations enhanced their efficacies.

Efficacy of Acacia nilotica, Eucalyptus camaldulensis, and Salix safsafs on the mortality and development of two vector-borne mosquito species, Culex pipiens and Aedes aegypti, in the laboratory and field.

Mosquitoes are one of the most lethal animals in the world and transmit many dangerous human pathogens, causing millions of deaths each year. The search for modern and better mosquito control is an endless effort almost all over the world. Phytochemicals are promising biological agents for getting rid of pests that are harmful to human and animal health and crops, they are inexpensive, biodegradable, and have diverse modes of action. The efficacy of acetone and hexane leaf extracts of Acacia nilotica, Eucalyptus camaldulensis, and Salix safsafs was investigated against the 2nd and 4th larvae and pupae of two vectors, Culex pipiens and Aedes aegypti. The results showed the obvious effect of A. nilotica extract on the mortality of mosquito larvae, the reduction of female eggs, and a higher mortality rate in sunlight than in shadow (fluorescein). Data from field trials revealed that A. nilotica extracts had the greatest effect on larval reduction, reaching 89.8% in 24 h and having a 12-day stability. Polyethylene glycol, sesquiterpenes, and fatty acids were the most common compounds found in A. nilotica, E. camaldulensis, and S. safsafs, respectively. The acacia plant had promising larvicidal activity, safe and effective alternative to chemical insecticides.

Role of adiponectin, resistin and monocyte chemo-attractant protein-1 in overweight/obese asthma phenotype in children.

BACKGROUND: Asthma is a chronic inflammatory disorder of the airways with diverse overlapping pathologies and phenotypes contributing to a significant heterogeneity in clinical manifestations. Obesity may modify asthma risk, phenotype, and prognosis. A suggested mechanism linking obesity and asthma is through systemic inflammation. Adipokines secreted by adipose tissue were suggested to provide a link between obesity and asthma. OBJECTIVE: To have an understanding for the contribution of adiponectin, resistin and MCP-1 to development of distinct asthma phenotype in overweight/obese children through assessment of their serum level and correlation to pulmonary function tests. SUBJECTS AND METHODS: The study included 29 normal weight asthmatics, 23 overweight/obese asthmatic children and 30 controls. All cases were subjected to detailed history taking, thorough examination and pulmonary function tests. Serum adiponectin, resistin, MCP-1 and IgE were assessed to all recruited subjects. RESULTS: Adiponectin level was significantly higher in overweight/obese asthmatics (24900 ± 1600 ng/ml) compared to normal weight asthmatics (21700 ± 1700 ng/ml) and control (23000 ± 3200 ng/ml), (p < 0.001 & 0.051 respectively). Normal weight asthmatics had significantly lower adiponectin level than control, (p = 0.039). A significant low level of MCP-1 in overweight/obese asthmatics (149.5 (20-545) ng/L) compared to control (175 (28 -1123.5) ng/L), p = 0.037. No significant difference was found regarding resistin. Normal weight asthmatics had significantly lower FEV1% and FVC% compared to overweight/obese asthmatics (p = 0.036, 0.016 respectively). A significant positive correlation was found between (FEV1%, FVC) and BMI in normal weight asthmatics (P = 0.01, < 0.01 respectively) and a significant negative correlation between PEF and BMI (-0.42, p = 0.05) in obese/overweight asthmatics. Resistin/adiponectin ratio was not affected by sex, degree of asthma severity or level of asthma control in either normal weight or overweight/obese asthmatic. CONCLUSION: This work could suggest that adiponectin may play a role in overweight/obese asthma phenotype where it is possible to have a dual action (pro & anti- inflammatory). It seems that resistin had no role in asthma pathogenesis.

Prevalence and Risk Factors of Asthma in Children and Adolescents in Rabigh, Western Saudi Arabia.

The worldwide prevalence of asthma in children is variable. The different epidemiological definitions of asthma, the use of various methods of measurement, and the environmental variations between countries are responsible for such different prevalence rates. This study has been performed to identify the prevalence/risk factors of asthma in Saudi children/adolescents in Rabigh. A cross-sectional epidemiological survey has been conducted using the validated Arabic version of the "International Study of Asthma and Allergies in Childhood questionnaire". Data on the sociodemographic characteristics of participants and risk factors of asthma have also been collected. Three hundred and forty-nine Children/adolescents with an age range of 5-18 years have been randomly selected for an interview from public places and houses in different regions of Rabigh City. The prevalence rates of physician-diagnosed asthma, any wheezing, and wheezing in the last 12 months among children/adolescents (mean age: 12.22 ± 4.14 years) have remarkably increased in association with the rapidly developing industrialization of Rabigh from previously recorded rates of 4.9%, 7.4%, and 6.4% in the only study that has previously been conducted in Rabigh in 1998 to 31.5%, 23.5%, and 14.9%, respectively. The univariate analysis has detected some significant risk factors for asthma. However, in younger aged children (5-9 years), allergic rhinitis, associated chronic illnesses, and viral respiratory infection-induced wheezing have remained significant risk factors of any wheezing. Drug allergy, exposure to dust, and viral respiratory infection-induced wheezing have persisted as significant risk factors for wheezing in the last 12 months. Eczema in the family, exposure to perfumes/incense, and viral respiratory infection-induced wheezing have remained as significant risk factors of physician-diagnosed asthma. The results of this survey should be useful in future targeted preventive plans/measures with special attention to improving air quality to limit the progressive increase in asthma prevalence in Rabigh, as well as in other similar industrial communities.

Acaricide resistance and novel photosensitizing approach as alternative acaricides against the camel tick, Hyalomma dromedarii.

The control of the camel tick, Hyalomma dromedarii is very crucial. This study evaluated the novel toxicity of photosensitizers and Phoxim insecticide against H. dromedarii males using the adult immersion tests. Ticks were subjected to sunlight for 10 min post-treatment (PT). The optical characters of the applied materials were determined by UV-Vis spectroscopy (250-900 nm wavelengths). The intensity of spectra decreased as dye concentration decreased. The optical bandgap energies of the dyes at different concentrations were not changed as the concentration changed and decreased as the absorption peak of individual dyes red-shifted. The mortalities 72 h PT reached 42.2%, 44.4%, 51.1%, 71.1%, 46.7%, 48.9%, 44.4%, and 55.6% for chlorophyllin, echinochrome, field stain, methylene blue, phthalocyanine, rhodamine 6G, riboflavin, and safranin, respectively. Methylene blue recorded the highest median lethal concentration (LC50 = 127 ppm) followed by safranin, field stain, rhodamine 6G, phthalocyanine, echinochrome riboflavin, and chlorophyllin (LC50 = 209, 251, 271, 303, 324, 332, and 362 ppm, respectively, 72 h PT). Their median lethal time, LT50, values PT with 240 ppm were 45, 87, 96, 72, 129, 115, 131, and 137 h, respectively. The relative toxicities of the LC50 values 72 h PT showed that chlorophyllin, echinochrome, field stain, methylene blue, phthalocyanine, rhodamine 6G, riboflavin, and safranin were 3.2, 3.6, 4.6, 9.1, 3.8, 4.3, 3.5, and 5.6 times, respectively, more effective than Phoxim. Methylene blue, safranin, and field stain showed a broad absorbance area indicating a large photoactivity and better phototoxicity and could be used as alternative agents to synthetic acaricides.

Evaluation of the virtual learning environment by school students and their parents in Saudi Arabia during the COVID-19 pandemic after school closure.

BACKGROUND: Very few previous studies have involved school students or their parents in the evaluation of virtual learning environment (VLE). Thus, this survey was performed to evaluate the satisfaction of both school students and their parents with the VLE in the Kingdom of Saudi Arabia during the COVID-19 pandemic. METHODS: A cross-sectional questionnaire-based survey was distributed online for VLE evaluation. The questionnaire was based on previous studies and expert opinions from validated instruments for assessing distance education, integrative and literature reviews of VLE environment. A median value >3 indicated participant satisfaction in each of the 5 domains of the questionnaire as well as overall VLE satisfaction. The used questionnaire was checked after its implementation by all possible statistical means and it was found to be of acceptable validity and reliability. RESULTS: Six hundred and ninety-three participants including 571 Saudi citizens and 122 non-Saudi residents participated in this survey. The number of school students who agreed or strongly agreed were significantly lower than the number of students who disagreed or strongly disagreed with preferring the VLE over traditional education (p<0.001). The participants evaluated the VLE experience as unsatisfactory with a median value ≤3 for 4 out of 5 questionnaire domains with an overall satisfaction value of 2.8. Among the 117 participants who gave further written opinions/comments, 42(35.9%) participants supported the VLE as an alternative to traditional classrooms, if equipment and internet are made available and for the safety of their children. CONCLUSIONS: This is one of few available adequate population-based studies for exploring the VLE satisfaction of both Saudi citizens and non-Saudi residents school students and their parents. This study showed the participants' unsatisfactory VLE experience. The VLE is accepted as an alternative to traditional classrooms to keep up with learning and to maintain the safety of children and it can be a supplementary learning method but many measures are still needed to develop the VLE.

Ovicidal Aroma Shields for Prevention of Blow Fly Strikes Caused by Lucilia sericata (Meigen), Diptera: Calliphoridae.

The blow fly, Lucilia sericata (Meigen) (Diptera: Culicidae) is a primary facultative ectoparasite controlled by insecticides that have environmental and safety concerns; therefore, its natural and safe control is crucial. L. sericata eggs were subjected to 400 µL of 5% of 24 materials of plant-borne origin. The number of hatched and unhatched eggs were counted 24 h postexposure. Stopmyasis® expressed the highest ovicidal effect, followed by cedarwood, orange, and tea tree oils. The mean ovicidal results were 46.09-95.24% grouped as Class A, which provided the lowest hatchability rates. Even though benzoin, vanillin, citronella, and camphor oils grouped as Class B provided moderate ovicidal effects (33.69-43.92%), their efficacy differed significantly from those of the treatments in Classes A and C containing the control group and vetiver, eucalyptus, Olbas®, neem, sunflower, oil blends, patchouli, frankincense, p-menthane-3,8 diol (PMD), lavender, peppermint, cinnamon, calry sag, myrtle, and silicone oil. According to our knowledge, most (19 out of 24) applied materials were used as ovicides against L. serricata for the first time, except orange, eucalyptus, patchouli, cinnamon oils, and six of them were applied as ovicides against pests for the first time. Stopmyasis containing Géraniol and PMD is the drug of choice as an ecofriendly product to prevent blow fly strikes through correct diagnosis and prompt treatment preventing a disastrous and destructive course of the disease and improving quality of life.

Novel Pesticidal Efficacy of Araucaria heterophylla and Commiphora molmol Extracts against Camel and Cattle Blood-Sucking Ectoparasites.

Botanical insecticides are promising pest control agents. This research investigated the novel pesticidal efficacy of Araucaria heterophylla and Commiphora molmol extracts against four ectoparasites through treated envelopes. Seven days post-treatment (PT) with 25 mg/mL of C. molmol and A. heterophylla, complete mortality of the camel tick, Hyalomma dromedarii and cattle tick, Rhipicephalus (Boophilus) annulatus were reached. Against H. dromedarii, the median lethal concentrations (LC50s) of the methanol extracts were 1.13 and 1.04 mg/mL and those of the hexane extracts were 1.47 and 1.38 mg/mL, respectively. The LC50 values of methanol and hexane extracts against R. annulatus were 1.09 and 1.41 plus 1.55 and 1.08 mg/mL, respectively. Seven days PT with 12.5 mg/mL, extracts completely controlled Haematopinus eurysternus and Hippobosca maculata; LC50 of Ha. eurysternus were 0.56 and 0.62 mg/mL for methanol extracts and 0.55 and 1.00 mg/mL for hexane extracts, respectively, whereas those of Hi. maculata were 0.67 and 0.78 mg/mL for methanol extract and 0.68 and 0.32 mg/mL, respectively, for hexane extracts. C. molmol extracts contained sesquiterpene, fatty acid esters and phenols, whereas those of A. heterophylla possessed monoterpene, sesquiterpene, terpene alcohols, fatty acid, and phenols. Consequently, methanol extracts of C. molmol and A. heterophylla were recommended as ecofriendly pesticides.

Mg-LDH Nanoclays Intercalated Fennel and Green Tea Active Ingredient: Field and Laboratory Evaluation of Insecticidal Activities against Culex pipiens and Their Non-Target Organisms.

(1) Background: Mosquito control with essential oils is a growing demand. This work evaluated the novel larvicidal and adulticidal activity of fennel and green tea oils and their Layered double hydroxides (LDHs) nanohybrid against Culex pipiens (Cx. pipiens) in both laboratory and field conditions and evaluated their effect against non-target organisms; (2) Methods: Two types of nanoclays, MgAl-LDH and NiAl-LDH were synthesized and characterized using PXRD, TEM and SEM, whereas their elemental analysis was accomplished by SEM-EDX; (3) Results: Mg and Ni LDHs were synthesized by the co-precipitation method. The adsorption and desorption of active ingredients were conducted using LC MS/MS, with reference to the SEM-EXD analysis. The desorption process of MgAl-LDH intercalated green tea oil was conducted using ethanol, and reveled significant peaks related to polyphenols and flavonoids like Vanillin, Catechin, Daidzein, Ellagic acid, Naringenin, Myricetin and Syringic acid with concentrations of 0.76, 0.73, 0.67, 0.59, 0.52, 0.44 and 0.42 µg/g, respectively. The larvicidal LC50 values of fennel oil, Mg-LDH-F, and Ni-LDH-F were 843.88, 451.95, 550.12 ppm, respectively, whereas the corresponding values of green tea were 938.93, 530.46, and 769.94 ppm. The larval reduction percentage of fennel oil and Mg-LDH-F reached 90.1 and 96.2%, 24 h PT and their persistence reached five and seven days PT, respectively. The reduction percentage of green tea oil and Mg-LDH-GT reached 88.00 and 92.01%, 24 h PT and their persistence reached five and six days PT, respectively. Against adults, Mg-LDH-GT and Ni-LDH-GT were less effective than green tea oil as their LC95 values were 5.45, 25.90, and 35.39%, respectively. The reduction in adult density PT with fennel oil, Mg-LDH-F, green tea oil, and Mg-LDH-GT reached 83.1, 100, 77.0, and 99.0%, respectively, 24 h PT and were effective for three days. Mg-LDH-GT and Mg-LDH-F increased the predation Cybister tripunctatus (71% and 69%), respectively; (4) Conclusions: For the first time, Mg-LDH-GT and Mg-LDH-F was the best system loaded with relatively good desorption release to its active ingredients and significantly affected Cx. pipiens larvae and adults in both laboratory and field circumstances, and it could be included in mosquito control.