Susceptibility status of Aedes aegypti (Diptera: Culicidae) to public health insecticides in Southern Afar Region, Ethiopia.

Mosquito-borne viral diseases such as dengue fever, chikungunya, and yellow fever have been documented in Ethiopia since the 1960s. However, the efficacy of public health insecticides against Aedes aegypti that transmits these viruses remains poorly understood in the country, particularly in the Afar Region. Thus, the aim of the study was to assess the susceptibility status of Ae. aegypti to deltamethrin, permethrin, alpha-cypermethrin, pirimiphos-methyl, bendiocarb, and propoxur insecticides. Larvae and pupae of Aedes species were collected from Awash Arba, Awash Sebat, and Werer towns of the Afar Region of Ethiopia during July-October 2022, brought to the Aklilu Lemma Institute of Pathobiology, insectary and reared to adults. Non-blood-fed, 3-5 days-old females Ae. aegypti were exposed to pyrethroid, carbamate, and organophosphate insecticide impregnated papers in tube test following the standard guidelines. Knockdown rates were noted at 10 minutes interval until one hour. The mortality in mosquitoes was recorded 24 hours after 60 minutes of exposure. The mortality rates of Ae. aegypti exposed to propoxur were 87% in all the study towns. Similarly, 88% mortality in Ae. aegypti was recorded when tested with bendiocarb in Awash Sebat and Awash Arba towns. Suspected resistance of Ae. aegypti (95% mortality) to alpha-cypermethrin was observed in Awash Arba town. However, Ae. aegypti collected from all the three sites was observed to be susceptible to deltamethrin, permethrin, and pirimiphos-methyl. Ae. aegypti was resistant to 0.1% bendiocarb and 0.1% propoxur and possibly resistant to 0.05% alpha-cypermethrin. On the other hand, it was susceptible to 0.05% deltamethrin, 0.75% permethrin, and 0.25% pirimiphos-methyl. Thus, vector control products with deltamethrin, permethrin, and pirimiphos-methyl can be used in the control of adult Ae. aegypti in the Afar Region of Ethiopia. However, further studies should be carried out to evaluate the susceptibility status of Ae. aegypti to alpha-cypermethrin in the Awash Arba area.

Zafirlukast induces DNA condensation and has bactericidal effect on replicating Mycobacterium abscessus.

Mycobacterium abscessus infections are emerging in cystic fibrosis patients, and treatment success rate in these patients is only 33% due to extreme antibiotic resistance. Thus, new treatment options are essential. An interesting target could be Lsr2, a nucleoid-associated protein involved in mycobacterial virulence. Zafirlukast is a Food and Drug Administration (FDA)-approved drug against asthma that was shown to bind Lsr2. In this study, zafirlukast treatment is shown to reduce M. abscessus growth, with a minimal inhibitory concentration of 16 µM and a bactericidal concentration of 64 µM in replicating bacteria only. As an initial response, DNA condensation, a known stress response of mycobacteria, occurs after 1 h of treatment with zafirlukast. During continued zafirlukast treatment, the morphology of the bacteria alters and the structural integrity of the bacteria is lost. After 4 days of treatment, reduced viability is measured in different culture media, and growth of M. abscessus is reduced in a dose-dependent manner. Using transmission electron microscopy, we demonstrated that the hydrophobic multilayered cell wall and periplasm are disorganized and ribosomes are reduced in size and relocalized. In summary, our data demonstrate that zafirlukast alters the morphology of M. abscessus and is bactericidal at 64 µM. The bactericidal concentration of zafirlukast is relatively high, and it is only effective on replicating bacteria but as zafirlukast is an FDA-approved drug, and currently used as an anti-asthma treatment, it could be an interesting drug to further study in in vivo experiments to determine whether it could be used as an antibiotic for M. abscessus infections.

Long-lasting residual efficacy of Actellic®300CS and Icon®10CS on different surfaces against Anopheles stephensi, an invasive malaria vector.

BACKGROUND: Anopheles stephensi, a malaria-transmitting mosquito species, has developed resistance to various insecticides such as DDT, Dieldrin, Malathion, and synthetic pyrethroids. To combat this issue, the World Health Organization (WHO) suggests using Actellic®300CS and Icon®10CS for Indoor Residual Spraying to tackle pyrethroid-resistant mosquitoes. The aim of this research project was to evaluate the susceptibility of An. stephensi to certain insecticides at the diagnostic concentration + intensity 5x diagnostic concentration (5XDC) assays in Iran and to study the lasting effectiveness of Actellic®300CS and Icon®10CS against this particular malaria vector. METHODS: This study assessed the susceptibility of An. stephensi populations in southern Iran to various insecticides, including deltamethrin 0.05%, DDT 4%, malathion 5%, bendiocarb 0.1%, a synergist assay with PBO 4% combined with deltamethrin 0.05%, and an intensity assay using 5x the diagnostic concentration of deltamethrin (0.25%) and bendiocarb 0.5%. Laboratory cone bioassay tests were conducted to determine the residual effectiveness of Actellic®300 and Icon®10CS insecticides on different surfaces commonly found in households, such as cement, mud, plaster, and wood. The tests were carried out following the WHO test kits and standard testing protocols. RESULTS: The An. stephensi populations in Bandar Abbas were found to be susceptible to malathion 5% and deltamethrin 0.25% (5XDC), but exhibited resistance to DDT, standard concentration of deltamethrin, and both standard and intensity concentrations of bendiocarb. In laboratory cone bioassay tests, An. stephensi mortality rates when exposed to Actellic®300CS and Icon®10CS on different surfaces remained consistently more than 80%. Actellic®300CS achieved more than 80% mortality on all substrates for the entire 300-day post-spraying period. Conversely, Icon®10CS maintained mortality rates more than 80% on plaster and wood surfaces for 165 days and on mud and cement surfaces for 270 days post-spraying. Both Actellic®300CS and Icon®10CS demonstrated 100% mortality within 72 h of each test on all surfaces throughout the entire 300-day post-spraying period. CONCLUSION: The study shows the varying levels of resistance of An. stephensi Bandar Abbas population to different insecticides and demonstrates the consistent performance of Actellic®300CS in controlling these mosquitoes on various surfaces. The findings suggest that long-lasting CS formulations may be more effective for malaria vector control compared to the current options. Further research is needed to validate these findings in field settings and assess the impact of these insecticides on malaria transmission.

Differential effects of montelukast and zafirlukast on MDA­MB­231 triple­negative breast cancer cells: Cell cycle regulation, apoptosis, autophagy, DNA damage and endoplasmic reticulum stress.

Montelukast and zafirlukast, cysteinyl leukotriene receptor antagonists (LTRAs), trigger apoptosis and inhibit cell proliferation of triple­negative breast cancer MDA­MB­231 cells. By contrast, only zafirlukast induces G0/G1 cell cycle arrest. The present study compared the effects of these drugs on proteins regulating cell proliferation, apoptosis, autophagy, and endoplasmic reticulum (ER) and oxidative stress using reverse transcription­quantitative PCR, western blotting and flow cytometry. The expression of proliferating markers, Ki­67 and proliferating cell nuclear antigen, was decreased by both drugs. Zafirlukast, but not montelukast, decreased the expression of cyclin D1 and CDK4, disrupting progression from G1 to S phase. Zafirlukast also increased the expression of p27, a cell cycle inhibitor. Both drugs decreased the expression of anti­apoptotic protein Bcl­2 and ERK1/2 phosphorylation, and increased levels of the autophagy marker LC3­II and DNA damage markers, including cleaved PARP­1, phosphorylated (p)­ATM and p­histone H2AX. The number of caspase 3/7­positive cells was greater in montelukast­treated cells compared with zafirlukast­treated cells. Montelukast induced higher levels of the ER stress marker CHOP compared with zafirlukast. Montelukast activated PERK, activating transcription factor 6 (ATF6) and inositol­requiring enzyme type 1 (IRE1) pathways, while zafirlukast only stimulated ATF6 and IRE1 pathways. GSK2606414, a PERK inhibitor, decreased apoptosis mediated by montelukast, but did not affect zafirlukast­induced cell death. The knockdown of CHOP by small interfering RNA reduced apoptosis triggered by montelukast and zafirlukast. In conclusion, the effects on cell cycle regulator proteins may contribute to cell cycle arrest caused by zafirlukast. The greater apoptotic effects of montelukast may be caused by the higher levels of activated caspase enzymes and the activation of three pathways of ER stress: PERK, ATF6, and IRE1.

The effect of single and repeated doses of rivastigmine on gastric myoelectric activity in experimental pigs.

BACKGROUND: Rivastigmine is a pseudo-irreversible cholinesterase inhibitor used for therapy of Alzheimer's disease and non-Alzheimer dementia syndromes. In humans, rivastigmine can cause significant gastrointestinal side effects that can limit its clinical use. The aim of this study was to assess the impact of rivastigmine on gastric motor function by means of electrogastrography (EGG) in experimental pigs. METHODS: Six experimental adult female pigs (Sus scrofa f. domestica, hybrids of Czech White and Landrace breeds; 3-month-old; mean weight 30.7 ± 1.2 kg) were enrolled into the study twice and created two experimental groups. In group A, a single intragastric dose of 6 mg rivastigmine hydrogen tartate was administered in the morning to fasting pigs before EGG recording. In group B, rivastigmine was administered to overnight fasting animals in a dietary bolus in the morning for 7 days (6 mg per day). On day 8, an intragastric dose of 12 mg rivastigmine was given in the morning to fasting pigs before EGG. EGG recording was accomplished by means of an EGG standalone system. Recordings from both groups were evaluated in dominant frequency and EGG power (areas of amplitudes). RESULTS: In total, 1,980 one-minute EGG intervals were evaluated. In group A, basal EGG power (median 1290.5; interquartile range 736.5-2330 µV2) was significantly higher in comparison with the power of intervals T6 (882; 577-1375; p = 0.001) and T10 (992.5; 385-2859; p = 0.032). In group B, the dominant frequency increased significantly from basal values (1.97 ± 1.57 cycles per minute) to intervals T9 (3.26 ± 2.16; p < 0.001) and T10 (2.14 ± 1.16; p = 0.012), respectively. In group B, basal EGG power (median 1030.5; interquartile range 549-5093) was significantly higher in comparison with the power of intervals T7 (692.5; 434-1476; p = 0.002) and T8 (799; 435-1463 µV2; p = 0.004). CONCLUSIONS: Both single as well as repeated intragastric administration of rivastigmine hydrogen tartrate caused a significant decrease of EGG power (areas of amplitudes) in experimental pigs. EGG power may serve as an indirect indicator of gastric motor competence. These findings might provide a possible explanation of rivastigmine-associated dyspepsia in humans.

Fenoxycarb exposure affects antiviral immunity and HaNPV infection in the cotton bollworm, Helicoverpa armigera.

BACKGROUND: Application of insect growth regulators (IGR) is a good option for insect pest management because of their fewer adverse effects on humans and domestic animals. These compounds are capable of interfering with normal growth and development by mimicking the actions of hormones such as juvenile hormone (JH) or ecdysone. The effect of JH and its analogs on some aspects of insect immunity has been determined, yet their possible effects on antiviral immunity response has not been investigated yet. Considering the importance of antiviral response in viral replication, in this study the effects of the JH analog (JHA), fenoxycarb on the antiviral immunity pathway core genes [i.e. micro (mi)RNA, small interfering (si)RNA and apoptosis] of Helicoverpa armigera (Hubner) larvae were investigated. The effect of fenoxycarb on the susceptibility of the larvae to H. armigera nuclear polyhedrosis virus (HaNPV) also was assessed. RESULTS: The results showed that the transcription level of miRNA (Dicer1, Ago1), siRNA (Dicer2, Ago2) and apoptosis (Caspase1, Caspase5) core genes in H. armigera larvae were decreased significantly after 24, 48 and 96 h feeding on a diet containing lethal and sublethal doses of fenoxycarb. Moreover, the mortality rate to HaNPV in the larvae treated with fenoxycarb increased compared to the control, leading to an increased replication of HaNPV. CONCLUSION: Together, our results suggest that the antiviral immune system could be modulated by JHA and facilitate HaNPV replication in the larvae, increasing the mortality rate of the insect larvae. Understanding the effect of JHA on antiviral immunity is an important step toward the process of exploiting JHAs and viral pathogens to control insect pests. © 2022 Society of Chemical Industry.

Analysis of treatment pattern of anti-dementia medications in newly diagnosed Alzheimer's dementia using OMOP CDM.

Anti-dementia medications are widely prescribed to patients with Alzheimer's dementia (AD) in South Korea. This study investigated the pattern of medical management in newly diagnosed patients with AD using a standardized data format-the Observational Medical Outcome Partnership Common Data Model from five hospitals. We examined the anti-dementia treatment patterns from datasets that comprise > 5 million patients during 2009-2019. The medication utility information was analyzed with respect to treatment trends and persistence across 11 years. Among the 8653 patients with newly diagnosed AD, donepezil was the most commonly prescribed anti-dementia medication (4218; 48.75%), followed by memantine (1565; 18.09%), rivastigmine (1777; 8.98%), and galantamine (494; 5.71%). The rising prescription trend during observation period was found only with donepezil. The treatment pathways for the three cholinesterase inhibitors combined with N-methyl-D-aspartate receptor antagonist were different according to the drugs (19.6%; donepezil; 28.1%; rivastigmine, and 17.2%; galantamine). A 12-month persistence analysis showed values of approximately 50% for donepezil and memantine and approximately 40% for rivastigmine and galantamine. There were differences in the prescribing pattern and persistence among anti-dementia medications from database using the Observational Medical Outcome Partnership Common Data Model on the Federated E-health Big Data for Evidence Renovation Network platform in Korea.

Residual efficacy of Fludora Fusion against Anopheles arabiensis in simple huts in Ethiopia.

Emergence and spread of malaria vectors resistant to the available insecticides required a new and efficacious insecticide. Residual efficacy of Fludora® Fusion was evaluated against insecticide susceptible Anopheles arabiensis in ten circular huts similar to the residential huts. Fludora® Fusion WP-SB 56.25, FICAM WP80 and Clothianidin WG70 were sprayed, by experienced technician, on interior wall surfaces: paint, dung, smooth mud, and rough mud. WHO cone bioassays were carried out a month after spraying and thereafter on monthly intervals for 12 months. Knockdown was recorded at 60 minutes and mortality at 24 hours, 48 hours and 72 hours holding time post-exposure. Fludora Fusion induced 100% An. arabiensis mortality during the first four months post-treated on all surface types at 24 hours holding time post-exposure. Its activity remained over 80% from the fifth to the twelfth month post-treated on the surfaces with the exception of two assessment points, at seventh month and eleventh month, on paint and smooth mud surfaces. FICAM induced 100% mortality rate during the first 4 months and 92% mortality during the fifth month post-treatment on painted surfaces. Its activity was over 96% mortality 1-month post-treatment on smooth mud and rough mud surfaces and 92% mortality 2-month post-treatment on dung surfaces. Clothianidin caused 89% and 86% mortality 1-month post-treatment on smooth mud and rough mud surfaces. Fludora Fusion can be used as alternative indoor residual insecticide spraying against An. arabiensis in Ethiopia.

Zafirlukast inhibits the growth of lung adenocarcinoma via inhibiting TMEM16A channel activity.

Lung cancer has the highest mortality among cancers worldwide due to its high incidence and lack of the effective cures. We have previously demonstrated that the membrane ion channel TMEM16A is a potential drug target for the treatment of lung adenocarcinoma and have identified a pocket of inhibitor binding that provides the basis for screening promising new inhibitors. However, conventional drug discovery strategies are lengthy and costly, and the unpredictable side effects lead to a high failure rate in drug development. Therefore, finding new therapeutic directions for already marketed drugs may be a feasible strategy to obtain safe and effective therapeutic drugs. Here, we screened a library of over 1400 Food and Drug Administration-approved drugs through virtual screening and activity testing. We identified a drug candidate, Zafirlukast (ZAF), clinically approved for the treatment of asthma, that could inhibit the TMEM16A channel in a concentration-dependent manner. Molecular dynamics simulations and site-directed mutagenesis experiments showed that ZAF can bind to S387/N533/R535 in the nonselective inhibitor binding pocket, thereby blocking the channel pore. Furthermore, we demonstrate ZAF can target TMEM16A channel to inhibit the proliferation and migration of lung adenocarcinoma LA795 cells. In vivo experiments showed that ZAF can significantly inhibit lung adenocarcinoma tumor growth in mice. Taken together, we identified ZAF as a novel TMEM16A channel inhibitor with excellent anticancer activity, and as such, it represents a promising candidate for future preclinical and clinical studies.

In Silico Drug Repurposing Approach: Investigation of Mycobacterium tuberculosis FadD32 Targeted by FDA-Approved Drugs.

Background: Despite the enormous efforts made towards combating tuberculosis (TB), the disease remains a major global threat. Hence, new drugs with novel mechanisms against TB are urgently needed. Fatty acid degradation protein D32 (FadD32) has been identified as a promising drug target against TB, the protein is required for the biosynthesis of mycolic acids, hence, essential for the growth and multiplication of the mycobacterium. However, the FadD32 mechanism upon the binding of FDA-approved drugs is not well established. Herein, we applied virtual screening (VS), molecular docking, and molecular dynamic (MD) simulation to identify potential FDA-approved drugs against FadD32. Methodology/Results: VS technique was found promising to identify four FDA-approved drugs (accolate, sorafenib, mefloquine, and loperamide) with higher molecular docking scores, ranging from -8.0 to -10.0 kcal/mol. Post-MD analysis showed that the accolate hit displayed the highest total binding energy of -45.13 kcal/mol. Results also showed that the accolate hit formed more interactions with FadD32 active site residues and all active site residues displayed an increase in total binding contribution. RMSD, RMSF, Rg, and DCCM analysis further supported that the presence of accolate exhibited more structural stability, lower bimolecular flexibility, and more compactness into the FadD32 protein. Conclusions: Our study revealed accolate as the best potential drug against FadD32, hence a prospective anti-TB drug in TB therapy. In addition, we believe that the approach presented in the current study will serve as a cornerstone to identifying new potential inhibitors against a wide range of biological targets.

Chronobiological activity of cysteinyl leukotriene receptor 1 during basal and induced autophagy in the ARPE-19 retinal pigment epithelial cell line.

Autophagy is an important cellular mechanism for maintaining cellular homeostasis, and its impairment correlates highly with age and age-related diseases. Retinal pigment epithelial (RPE) cells of the eye represent a crucial model for studying autophagy, as RPE functions and integrity are highly dependent on an efficient autophagic process. Cysteinyl leukotriene receptor 1 (CysLTR1) acts in immunoregulation and cellular stress responses and is a potential regulator of basal and adaptive autophagy. As basal autophagy is a dynamic process, the aim of this study was to define the role of CysLTR1 in autophagy regulation in a chronobiologic context using the ARPE-19 human RPE cell line. Effects of CysLTR1 inhibition on basal autophagic activity were analyzed at inactive/low and high lysosomal degradation activity with the antagonists zafirlukast (ZTK) and montelukast (MTK) at a dosage of 100 nM for 3 hours. Abundances of the autophagy markers LC3-II and SQSTM1 and LC3B particles were analyzed in the absence and presence of lysosomal inhibitors using western blot analysis and immunofluorescence microscopy. CysLTR1 antagonization revealed a biphasic effect of CysLTR1 on autophagosome formation and lysosomal degradation that depended on the autophagic activity of cells at treatment initiation. ZTK and MTK affected lysosomal degradation, but only ZTK regulated autophagosome formation. In addition, dexamethasone treatment and serum shock induced autophagy, which was repressed by CysLTR1 antagonization. As a newly identified autophagy modulator, CysLTR1 appears to be a key player in the chronobiological regulation of basal autophagy and adaptive autophagy in RPE cells.

Discovery of Zafirlukast as a novel SARS-CoV-2 helicase inhibitor using in silico modelling and a FRET-based assay.

The coronavirus helicase is an essential enzyme required for viral replication/transcription pathways. Structural studies revealed a sulphate moiety that interacts with key residues within the nucleotide-binding site of the helicase. Compounds with a sulphoxide or a sulphone moiety could interfere with these interactions and consequently inhibit the enzyme. The molecular operating environment (MOE) was used to dock 189 sulphoxide and sulphone-containing FDA-approved compounds to the nucleotide-binding site. Zafirlukast, a leukotriene receptor antagonist used to treat chronic asthma, achieved the lowest docking score at -8.75 kcals/mol. The inhibitory effect of the compounds on the SARS-CoV-2 helicase dsDNA unwinding activity was tested by a FRET-based assay. Zafirlukast was the only compound to inhibit the enzyme (IC50 = 16.3 µM). The treatment of Vero E6 cells with 25 µM zafirlukast prior to SARS-CoV-2 infection decreased the cytopathic effects of SARS-CoV-2 significantly. These results suggest that zafirlukast alleviates SARS-CoV-2 pathogenicity by inhibiting the viral helicase and impairing the viral replication/transcription pathway. Zafirlukast could be clinically developed as a new antiviral treatment for SARS-CoV-2 and other coronavirus diseases. This discovery is based on molecular modelling, in vitro inhibition of the SARS-CoV helicase activity and cell-based SARS-CoV-2 viral replication.

Zafirlukast ameliorates Docetaxel-induced activation of NOD-like receptor protein 3 (NLRP3) inflammasome, mediated by sirtuin1 (SIRT1) in hepatocytes.

Docetaxel-associated liver injury has become a serious public health problem, resulting in therapy discontinuation, liver failure, and death. Zafirlukast is a typical leukotriene receptor antagonist used for prophylaxis and chronic treatment of asthma. In this study, we investigate whether treatment with Zafirlukast could alleviate Docetaxel-induced cytotoxicity in hepatocytes. Our results indicate that Zafirlukast mitigated Docetaxel-induced toxicity in LO-2 hepatocytes. Firstly, Zafirlukast reduced the production of 8-hydroxy-2p-deoxyguanosine (8-OHdG) and increased the levels of reduced glutathione (GSH) against Docetaxel. Secondly, Zafirlukast elevated the levels of mitochondrial membrane potential (ΔΨm) and adenosine triphosphate (ATP). Thirdly, Zafirlukast prevented Docetaxel-induced release of lactate dehydrogenase (LDH) and increased cell viability of LO-2 hepatocytes against Docetaxel. We also found that Zafirlukast ameliorated Docetaxel-induced apoptosis by reducing Caspase-3 and Caspase-9 activity. Mechanistically, our results demonstrate that Zafirlukast inhibited the activation of NOD-like receptor protein 3 (NLRP3), mediated by SIRT1. Based on these findings, we conclude that the administration of Zafirlukast might have a protective effect against Docetaxel-induced cytotoxicity in hepatocytes.

Preliminary Report of the Insecticide Susceptibility Status of Aedes albopictus in Bangladesh.

Aedes albopictus is a highly invasive mosquito species and a vector of human arboviral diseases including dengue, chikungunya, and Zika. There are no effective drugs or vaccines for the treatment or prevention of most of these diseases, so the primary option for disease prevention and control is to target mosquitoes, often using insecticides. Despite vector control efforts, cases of arboviral diseases are increasing in Bangladesh and it is important to understand if this escalation is associated with the presence of insecticide resistance in Aedes populations, including Ae. albopictus. The CDC bottle bioassays performed on Ae. albopictus from two districts in Bangladesh detected resistance to permethrin but susceptibility to deltamethrin, malathion, and bendiocarb. The detection of permethrin resistance is worrisome, since arbovirus vector control strategies in Bangladesh currently include the use of permethrin. Routine monitoring of the susceptibility status of key vector populations in Bangladesh will allow a better understanding of resistance trends, enabling the strengthening of control strategies.

Characterization of resistance profile (intensity and mechanisms) of Anopheles gambiae in three communes of northern Benin, West Africa.

BACKGROUND: The selection and the spread of insecticide resistance in malaria vectors to the main classes of insecticides used in vector control tools are a major and ongoing challenge to malaria vector control programmes. This study aimed to determine the intensity of vector resistance to insecticides in three regions of Benin with different agro-ecological characteristics. METHODS: Larvae of Anopheles gambiae sensu lato (s.l.) were collected from September to November 2017 in different larval sites in three northern Benin communes: Parakou, Kandi and Malanville. Two to five-day-old, non-blood-fed, female mosquitoes were exposed to papers impregnated with deltamethrin, permethrin and bendiocarb at dosages of 1 × the diagnostic dose, 5 × and 10 × to determine the intensity of resistance in these vectors. Molecular frequencies of the kdr L1014F and ace-1R G119S insecticide resistance mutations and levels of detoxification enzymes were determined for mosquitoes sampled at each study site. RESULTS: Resistance to pyrethroids (permethrin and deltamethrin) was recorded in all three communes with mortality rates below 60% using the diagnostic dose (1x). The results obtained after exposure of An. gambiae to permethrin 10 × were 99% in Kandi, 98% in Malanville and 99% in Parakou. With deltamethrin 10x, mortality rates were 100% in Kandi, 96% in Malanville and 73% in Parakou. For the diagnostic dose of bendiocarb, suspected resistance was recorded in the communes of Malanville (97%) and Kandi (94%) while sensitivity was observed in Parakou (98%).Using the 10 × dose, mortality was 98% in Kandi, 100% in Malanville and 99% in Parakou. The frequencies of the kdr L1014F allele varied between 59 and 83% depending on the sites and species of the An. gambiae complex, while the frequency of the ace-1R G119S gene varied between 0 and 5%. Biochemical tests showed high levels of oxidase and esterase activity compared to the susceptible colony strain of An. gambiae sensu stricto (Kisumu strain). CONCLUSION: Anopheles gambiae showed a generalized loss of susceptibility to permethrin and deltamethrin but also showed moderate to high intensity of resistance in different regions of Benin. This high intensity of resistance is a potential threat to the effectiveness of vector control.

Effect of a novel juvenoid fenoxycarb on the pupal-adult transformation in the blowfly, Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae).

Chrysomya megacephala (Fabricius, 1794) (Diptera, Calliphoridae) acts as a vector of many disease-causing pathogens. It causes myiasis in human beings and other living vertebrates. In the present study, the effect of a juvenile hormone analog (JHA), fenoxycarb, was evaluated on pupal-adult transformation by exposing pupae (0 and 1-day-old) of blowfly. Pupae were topically treated with different concentrations of the compound, viz., 20, 40, and 80 µg/µl applied on the posterior dorsum with the help of a micropipette. The effects comprised various developmental aberrations, such as delayed pupal-adult ecdysis duration, pupal mortality, formation of pupal-adult intermediates, eclosion failure, reduced adult emergence, and formation of abnormal adults. The freshly molted pupae (0 day) were more susceptible as compared to 1-day-old pupae. Pupal mortality was highest at 80 µg. Normal adult emergence was completely inhibited at day 0 pupae treated with 80 µg of the fenoxycarb. These results demonstrate that fenoxycarb was capable of successfully inhibiting the pupal-adult transformation, and thus, it can be used to control this myiasis-causing agent.

Zafirlukast promotes mitochondrial respiration by stimulating mitochondrial biogenesis in human bronchial epithelial cells.

Lung diseases, including asthma, pose a serious global health issue. Loss of mitochondrial function and decreased mitochondrial biogenesis play pivotal roles in the initiation and progression of chronic lung diseases. Thus, maintaining mitochondrial function and homeostasis is an important treatment goal. Zafirlukast is a CysLTR1 antagonist that is widely used as an adjuvant treatment for asthma. In the present study, we investigated the effects of zafirlukast in vitro using human bronchial epithelial cells (BECs). We performed measurements of oxygen consumption and bioenergetics and found that zafirlukast increased mitochondrial respiration and biogenesis in human BECs as evidenced by increased mitochondrial mass and mtDNA/nDNA. Through real-time PCR and western blot analysis, we found that zafirlukast significantly increased the expression of PGC-1α, NRF1, and TFAM at both the mRNA and protein levels. Finally, we determined that these effects are mediated through CREB signaling and that inhibition of CREB with its specific inhibitor H89 abolished the effects of zafirlukast described above. Thus, zafirlukast might have potential in enhancing mitochondrial function by promoting mitochondrial biogenesis in human bronchial epithelial cells through upregulating the expression of PGC-1α and activating the CREB pathway.

Sub-lethal aquatic doses of pyriproxyfen may increase pyrethroid resistance in malaria mosquitoes.

BACKGROUND: Pyriproxyfen (PPF), an insect growth hormone mimic is widely used as a larvicide and in some second-generation bed nets, where it is combined with pyrethroids to improve impact. It has also been evaluated as a candidate for auto-dissemination by adult mosquitoes to control Aedes and Anopheles species. We examined whether PPF added to larval habitats of pyrethroid-resistant malaria vectors can modulate levels of resistance among emergent adult mosquitoes. METHODOLOGY: Third-instar larvae of pyrethroid-resistant Anopheles arabiensis (both laboratory-reared and field-collected) were reared in different PPF concentrations, between 1×10-9 milligrams active ingredient per litre of water (mgAI/L) and 1×10-4 mgAI/L, or no PPF at all. Emergent adults escaping these sub-lethal exposures were tested using WHO-standard susceptibility assays on pyrethroids (0.75% permethrin and 0.05% deltamethrin), carbamates (0.1% bendiocarb) and organochlorides (4% DDT). Biochemical basis of pyrethroid resistance was investigated by pre-exposure to 4% PBO. Bio-efficacies of long-lasting insecticide-treated nets, Olyset® and PermaNet 2.0 were also examined against adult mosquitoes with or without previous aquatic exposure to PPF. RESULTS: Addition of sub-lethal doses of PPF to larval habitats of pyrethroid-resistant An. arabiensis, consistently resulted in significantly reduced mortalities of emergent adults when exposed to pyrethroids, but not to bendiocarb or DDT. Mortality rates after exposure to Olyset® nets, but not PermaNet 2.0 were also reduced following aquatic exposures to PPF. Pre-exposure to PBO followed by permethrin or deltamethrin resulted in significant increases in mortality, compared to either insecticide alone. CONCLUSIONS: Partially-resistant mosquitoes exposed to sub-lethal aquatic concentrations of PPF may become more resistant to pyrethroids than they already are without such pre-exposures. Studies should be conducted to examine whether field applications of PPF, either by larviciding or other means actually exacerbates pyrethroid-resistance in areas where signs of such resistance already exist in wild the vector populations. The studies should also investigate mechanisms underlying such magnification of resistance, and how this may impact the potential of PPF-based interventions in areas with pyrethroid resistance.

Apoptotic and autophagic characteristics of perivisceral fat body remodeling of the greater wax moth Galleria mellonella and effects of juvenile hormone analog, fenoxycarb, on these processes.

In holometabolous insects, many tissues and organs such as the fat body and midgut undergo a remodeling process during metamorphosis. Larval fat body cells are eliminated by programmed cell death (PCD), while tissue cells that adapt to adult life are formed by stem cells. In this study, we analyzed the features of the remodeling period of Galleria mellonella fat body in terms of PCD types, apoptotic and autophagic cell death characteristics. Besides, the effects of juvenile hormone (JH) on these processes were evaluated under the modified hormonal conditions via applications of JH analog, fenoxycarb. Several hallmarks of apoptotic and autophagic cell death were analyzed by morphological, biochemical, and molecular methods. The results of the present study have ascertained that the degeneration process of larval cells occurs via autophagic cell death accompanied by caspase-3 activity during the pupal period and it is regulated by 20-hydroxyecdysone (20HE) mediated by ecdysone receptor B1 (EcR-B1). Increased activity of the acid phosphatase and upregulation of ATG6 and ATG8 in parallel with the formation of autophagosomes in the fat body of Galleria during the pupal period strongly indicated that autophagy was the key player in the remodeling processes.

Short Persistence and Vector Susceptibility to Ficam 80WP (bendiocarb active ingredient) During Pilot Application of Indoor Residual Spraying in Burkina Faso, West Africa.

Indoor residual spraying (IRS) was applied in addition to the use of long-lasting insecticidal nets in the South West in Burkina Faso, where Anopheles gambiae s.l. the major malaria vector was resistant to pyrethroids. This study was designed to evaluate the efficacy and residual life of bendiocarb (active ingredient) used for spraying on different wall surfaces (mud and cement). Cone bioassays were done monthly with the susceptible An. gambiae 'Kisumu' strain and the local wild populations to determine the duration for which insecticide was effective in killing mosquitoes. Cone bioassay data showed low efficacy and short persistence of bendiocarb applied on mud and cement walls, lasting 2 mo with the susceptible insectary strain and less than 1 mo with An. gambiae wild populations. In addition, WHO tube assays confirmed resistance of An. gambiae wild populations to 0.1% bendiocarb with mortality rates less than 80% in both study sites (sprayed and unsprayed sites). The pilot study of IRS with bendiocarb showed that the residual efficacy of bendiocarb was very short, and resistance to bendiocarb was confirmed in wild populations of An. gambiae s.l. Therefore, Ficam 80 WP was not suitable for IRS in this area due to the short residual duration related mainly to vectors resistance to bendiocarb. While waiting for innovative malaria control tool, alternative insecticide (organophosphate or neonicotinoid classes) or combinations of insecticides have to be used for insecticide resistance management in Burkina Faso.