Syntaxin5 is essential for survival by ensuring midgut epithelial homeostsis and regulating feeding in Locusta migratoria.

Syntaxin5 (Syx5) belongs to SNAREs family, which play important roles in fusion of vesicles to target membranes. Most of what we know about functions of Syx5 originates from studies in fungal or vertebrate cells, how Syx5 operates during the development of insects is poorly understood. In this study, we investigated the role of LmSyx5 in the gut development of the hemimetabolous insect Locusta migratoria. LmSyx5 was expressed in many tissues, with higher levels in the gut. Knockdown of LmSyx5 by RNA interference (RNAi) considerably suppressed feeding in both nymphs and adults. The dsLmSyx5-injected locusts lost body weight and finally died at a mortality of 100%. Furthermore, hematoxylin-eosin staining indicated that the midgut is deformed in dsLmSyx5-treated nymphs and the brush border in midgut epithelial cells is severely damaged, suggesting that LmSyx5 is involved in morphogenesis of the midgut. TEM further showed that the endoplasmic reticulum of midgut cells have a bloated appearance. Taken together, these results suggest that LmSyx5 is essential for midgut epithelial homeostsis that affects growth and development of L. migratoria. Thus, Syx5 is a promising RNAi target for controlling L. migratoria, and even other pests.

Extra-corporeal detoxification in insects.

Upon uptake of toxins, insects launch a detoxification program. This program is deployed in multiple organs and cells to raise their tolerance against the toxin. The molecular mechanisms of this program inside the insect body have been studied and understood in detail. Here, we report on a yet unexplored extra-corporeal detoxification of insecticides in Drosophila melanogaster. Wild-type D. melanogaster incubated with DDT, a contact insecticide, in a closed environment died as expected. However, incubation of a second cohort in the same environment after removal of the dead flies was not lethal. The effect was significantly lower if the flies of the two cohorts were unrelated. Incubation assays with Chlorpyrifos, another contact insecticide, yielded identical results, while incubation assays with Chlorantraniliprole, again a contact insecticide, was toxic for the second cohort of flies. A cohort of flies incubated in a DDT environment after an initial incubation of a honeybee survived treatment. Together, our data suggest that insects including Apis mellifera and D. melanogaster have the capacity to modify their proximate environment. Consequently, in their ecological niche, following individuals might be saved from intoxication thereby facilitating colonisation of an attractive site.

Nanoparticles-mediated entomotoxicology: lessons from biologica.

Nanotechnology has grown in importance in medicine, manufacturing, and consumer products. Nanoparticles (NPs) are also widely used in the field of insect pest management, where they show a variety of toxicological effects on insects. As a result, the primary goal of this review is to compile and evaluate available information on effects of NPs on insects, by use of a timely, bibliometric analysis. We also discussed the manufacturing capacity of NPs from insect tissues and the toxic effects of NPs on insects. To do so, we searched the Web of Science database for literature from 1995 to 2023 and ran bibliometric analyses with CiteSpace© and Bibliometrix©. The analyses covered 614 journals and identified 1763 relevant documents. We found that accumulation of NPs was one of the top trending topics. China, India, and USA had the most published papers. The most overall reported models of insects were those of Aedes aegypti (yellow fever mosquito), Culex quinquefasciatus (southern house mosquito), Bombyx mori (silk moth), and Anopheles stephensi (Asian malaria mosquito). The application and methods of fabrication of NPs using insect tissues, as well as the mechanism of toxicity of NPs on insects, were also reported. A uniform legal framework is required to allow nanotechnology to fully realize its potential while minimizing harm to living organisms and reducing the release of toxic metalloid nanoparticles into the environment.

RNA interference-mediated silencing of coat protein II (COPII) genes affects the gut homeostasis and cuticle development in Locusta migratoria.

The coat protein II (COPII) complex consists of five primary soluble proteins, namely the small GTP-binding protein Sar1, the inner coat Sec23/Sec24 heterodimers, and the outer coat Sec13/Sec31 heterotetramers. COPII is essential for cellular protein and lipid trafficking through cargo sorting and vesicle formation at the endoplasmic reticulum. However, the roles of COPII assembly genes remain unknown in insects. In present study, we identified five COPII assembly genes (LmSar1, LmSec23, LmSec24, LmSec13 and LmSec31) in Locusta migratoria. RT-qPCR results revealed that these genes showed different expression patterns in multiple tissues and developmental days of fifth-instar nymphs. Injection of double-stranded RNA against each LmCOPII gene induced a high RNAi efficiency, and considerably suppressed feeding, and increased mortality to 100 %. Results from the micro-sectioning and hematoxylin-eosin staining of midguts showed that the brush border was severely damaged and the number of columnar cells was significantly reduced in dsLmCOPII-injected nymphs, as compared with the control. The dilated endoplasmic reticulum phenotype of columnar cells was observed by transmission electron microscopy. RT-qPCR results further indicated that silencing any of the five genes responsible for COPII complex assembly repressed the expression of genes involved in insulin/mTOR-associated nutritional pathway. Therefore, COPII assembly genes could be promising RNAi targets for insect pest management by disrupting gut and cuticle development.

Reversal Effects of Royal Jelly and Propolis Against Cadmium-Induced Hepatorenal Toxicity in Rats.

Heavy metal toxicity is an exponentially growing health problem. In this study, we aimed to assess the protective properties of propolis and royal jelly against cadmium adverse effects. Thirty-two adult male rats were included in our study; kidney and liver functions, histopathological changes, and the level of oxidative stress were evaluated in rats exposed to a daily dose of 4.5 mg cadmium per kilogram of body weight for 1 month and those cotreated simultaneously with either propolis (50 mg/kg/day) or royal jelly (200 mg/kg/day) with cadmium compared to control animals. Cadmium-mediated hepatorenal toxicity was manifested as per the increased oxidative stress, function deterioration, and characteristic histopathological aberrations. The supplementation of royal jelly or propolis restores most of the affected parameters to a level similar to the control group. However, the parameters describing the grade of DNA damage and the interleukin-1ß expression in the liver, as well as the levels of malondialdehyde and metallothionein, were slightly elevated compared to controls, despite the regular use of royal jelly or propolis. It is worth noting that better results were found in the case of royal jelly compared to propolis administration. Most likely, the ability of both products to chelate cadmium and contribute in reducing oxidative stress is of great importance. However, further investigations are needed to complement the knowledge about the expected nutritional and medicinal values.

Assessment of breast cytoarchitecture and its associated axillary lymph node status under normal and pathological conditions in Egyptian women.

OBJECTIVE: Herein, we compare the features of neoplastic cancer cells in invasive ductal carcinoma (IDC) grade II and III patients to their corresponding normal cells both in breast and axillary lymph node (ALN) tissues. METHODS: A retrospective cohort of 70 female breast cancer patients enrolled between 2018 and 2020 at Medical Research Institute, Alexandria University, Egypt, was analyzed for clinicopathological features presentation. Fresh tiny pieces of breast tissue and its associated ALN tissues were then processed to investigate the morphological appearance by scanning electron microscopy. Moreover, the histological architecture of tissue sections stained with hematoxylin and eosin was studied by light microscope, while the characterization of the ultrastructure features of breast and ALN tissues was analyzed by transmission electron microscopy. RESULTS: Clinicopathological presentation of patients revealed that the Egyptian female breast cancer population adhered to the global trends of breast cancer disease with elevated incidence rate among postmenopausal women (61.3%), high frequency of IDC (95.7%), and increased ALN metastasis (65.7%). The percentage of estrogen receptor alpha (ERα) and human epidermal growth factor receptor 2 (HER2) expression, as key indicators for carcinogenesis and disease progression was 87.1% and 55.8%, respectively. The present study points to the observed discrepancies among the investigated variables in the diagnostic separation between IDC grade II and grade III. Ductal epithelial cells organization, nuclei size and irregularity, chromatin amount and uniformity, mitochondrial abundance and dysfunction were differentially manifested in IDC grades. Moreover, aberrations in the cellular organelles like lysosomes, endoplasmic reticulum, and lipid droplets vary according to the grade of IDC and the aggressiveness of the invasive breast cancer. CONCLUSIONS: To sum up, this study emphasizes the importance of accurate specimen evaluation for treatment choice and decision.

Eco-friendly postharvest irradiation strategy with 131I isotope for environmental management of populations of migratory locust, Locusta migratoria.

PURPOSE: Irradiation of food is promising for control of pests to minimize postharvest losses of yields and thus improvement of food safety, shelf life of produce. It is a method of choice that induces a series of lethal biochemical and molecular changes culminating into the engagement of a downstream cascade to cause abnormalities in irradiated pests. In this study, the effects of iodine-131 (131I) isotope radiation on the male gonad development of the migratory locust, Locusta migratoria, were evaluated. MATERIALS AND METHODS: Newly emerged adult male locusts, less than one-day-old, were divided into two groups, control and irradiated. Locusts in the control group (n = 20 insects) didn't drink irradiated water and were reared under normal environmental conditions for one week. Locusts in the irradiated group (n = 20 insects) were exposed to irradiated water at a dose of 30 mCi and they were subsequently observed until they drank the whole quantity. RESULTS: At the end of the experiment, scanning and electron microscopic examination of testes obtained from irradiated locusts revealed several major abnormalities, including malformed nuclei of spermatozoa, irregular plasma membranes, shrinkage of testicular follicles, vacuolated cytoplasm, disintegrated nebenkern and agglutinations of spermatids. Flow cytometry analysis revealed that 131I radiation induced both early and late apoptosis, but not necrosis, in testicular tissues. Testes of irradiated insects also exhibited a burst in reactive oxygen species (ROS), as indicated by significant elevation in amounts of malondialdehyde (MDA), a marker for peroxidation of lipids. In contrast, irradiation coincided with significant reductions in activities of enzymatic antioxidant biomarkers. Relative to controls, a three-fold upregulation of expression of mRNA of heat shock protein, Hsp90, was observed in testicular tissue of irradiated locusts. 131I-irradiated insects exhibited genotoxicity, as indicated by significant increases in various indicators of DNA damage by the comet assay, including tail length (7.80 ± 0.80 µm; p < .01), olive tail moment (40.37 ± 8.08; p < .01) and tail DNA intensity % (5.1 ± 0.51; p < .01), in testicular cells compared to the controls. CONCLUSION: This is the first report on elucidation of I131-irradiation-mediated histopathological, biochemical and molecular mechanisms in gonads of male L. migratoria. Herein, the findings underscore the utility of 131I radiation as an eco-friendly postharvest strategy for management of insect pests and in particular for control of populations of L. migratoria.

RNAi-mediated silencing of SlitPer disrupts sex pheromone communication behavior in Spodoptera litura.

BACKGROUND: The 24-h circadian rhythm is considered crucial for insect sexual communication. However, its molecular mechanisms and signaling pathways, particularly the roles of the clock gene period (Per), remain largely unclear. The sex pheromone communication behavior of Spodoptera litura displays typical circadian rhythm characteristics. Thus, it represents an excellent model for functional analyses of the clock gene Per. RESULTS: In this study, we investigated the potential roles of SlitPer in regulating sex pheromone communication in S. litura using RNA interference, quantitative real-time polymerase chain reactions (qPCR), gas chromatography, and behavioral assays. The qPCR results showed that the expression levels of SlitPer and two desaturase genes (SlitDes5 and SlitDes11) in the siPer group differed significantly at most time points from those in the siNC group. Dynamic variation in the three major sex pheromone titers and calling behavior of S. litura females in the siPer group was disordered. In addition, the mating rates of siPer S. litura females decreased significantly by 33.33%. Oviposition by mated siPer females was substantially reduced by 84.84%. CONCLUSION: These findings provide a fundamental basis for elucidating the molecular mechanism by which Per regulates sex pheromone communication behavior in lepidopteran species. © 2023 Society of Chemical Industry.

Switchable hepatic organelles aberrations in DEN-induced mice under the influence of chemically characterized silk sericin.

OBJECTIVE: Assessing the beneficial effects of silk sericin against hepatic injury induced by diethylnitrosamine (DEN). METHODS: Aiming at promoting sericin as a natural product able to counteract the hazards of toxic elements, HPLC profile was conducted on the extracted sericin sample versus the standard one to qualitatively identify it. Following sericin treatment on human HepG2 liver cancer cells, many parameters were analyzed in vitro including cell viability, cell cycle, and cell apoptosis. Hepatic pro-inflammatory cytokines as well as histopathological and ultrastructure changes were evaluated in vivo in the different experimental groups. RESULTS: Sericin exhibited a dose-dependent cytotoxic effect on HepG2 cells with an IC50 of 14.12 + 0.75 µg/mL. The hepatotoxicity of DEN was manifested in mice by increased pro-inflammatory markers (IL-2, IL-6, and TNF-α), decreased IL-10, liver structure deterioration, and characteristic histopathological and ultrastructure changes. Sericin administration reversed most of the observed alterations inflected by DEN. CONCLUSIONS: Our results substantiate the sericin's powerful apoptotic impact in vitro. In experimental mice, combination treatment using sericin together with melatonin appears to be more potent in mitigating the adverse effects of DEN. However, further investigations are needed to identify the underlying mechanism of action and complement the knowledge about the expected medicinal values of sericin.

Entomotherapeutic Role of Periplaneta americana Extract in Alleviating Aluminum Oxide Nanoparticles-Induced Testicular Oxidative Impairment in Migratory Locusts (Locusta migratoria) as an Ecotoxicological Model.

In this study, we shed light for the first time on the usage of migratory locusts (Locusta migratoria) as an insect model to investigate the nanotoxicological influence of aluminum oxide (Al2O3) nanoparticles at low doses on testes, and evaluate the capacity of a whole-body extract of American cockroaches (Periplaneta americana) (PAE) to attenuate Al2O3 NPs-induced toxicity. Energy dispersive X-ray microanalyzer (EDX) analysis verified the bioaccumulation of Al in testicular tissues due to its liberation from Al2O3 NPs, implying their penetration into the blood-testis barrier. Remarkably, toxicity with Al engendered disorders of antioxidant and stress biomarkers associated with substantial DNA damage and cell apoptosis. Furthermore, histopathological and ultrastructural analyses manifested significant aberrations in the testicular tissues from the group exposed to Al2O3 NPs, indicating the overproduction of reactive oxygen species (ROS). Molecular docking analysis emphasized the antioxidant capacity of some compounds derived from PAE. Thus, pretreatment with PAE counteracted the detrimental effects of Al in the testes, revealing antioxidant properties and thwarting DNA impairment and cell apoptosis. Moreover, histological and ultrastructural examinations revealed no anomalies in the testes. Overall, these findings substantiate the potential applications of PAE in preventing the testicular impairment of L. migratoria and the conceivable utilization of locusts for nanotoxicology studies.

Chitinase 6 is required for procuticle thickening and organ shape in Drosophila wing.

The polysaccharide chitin is a major scaffolding molecule in the insect cuticle. In order to be functional, both chitin amounts and chitin organization have been shown to be important parameters. Despite great advances in the past decade, the molecular mechanisms of chitin synthesis and organization are not fully understood. Here, we have characterized the function of the Chitinase 6 (Cht6) in the formation of the wing, which is a simple flat cuticle organ, in the fruit fly Drosophila melanogaster. Reduction of Cht6 function by RNA interference during wing development does not affect chitin organization, but entails a thinner cuticle suggesting reduced chitin amounts. This phenotype is opposed to the one reported recently to be caused by reduction of Cht10 expression. Probably as a consequence, cuticle permeability to xenobiotics is enhanced in Cht6-less wings. We also observed massive deformation of these wings. In addition, the shape of the abdomen is markedly changed upon abdominal suppression of Cht6. Finally, we found that suppression of Cht6 transcript levels influences the expression of genes coding for enzymes of the chitin biosynthesis pathway. This finding indicates that wing epidermal cells respond to activity changes of Cht6 probably trying to adjust chitin amounts. Together, in a working model, we propose that Cht6-introduced modifications of chitin are needed for chitin synthesis to proceed correctly. Cuticle thickness, according to our hypothesis, is in turn required for correct organ or body part shape. The molecular mechanisms of this processes shall be characterized in the future.

Hepatoprotective effects of a chemically-characterized extract from artichoke (Cynara scolymus L.) against AFB1-induced toxicity in rats.

This study was conducted to investigate the protective potential of a pharmaceutically formulated capsule of artichoke leaf powder (ArLP) against aflatoxin B1 (AFB1)-induced hepatotoxicity in male albino rats. In the 42-day experiment, rats were divided into five equal groups: (i) control, treated with sterile water, (ii) treated with 4% DMSO as AFB1 vehicle, (iii) ArLP of 100 mg kg-1 bw, (iv) AFB1 of 72 µg kg-1 bw, and (v) AFB1 plus ArLP. Exposure of rats to AFB1 resulted in hepatotoxicity as manifested by the intensification of oxidative stress, production of free radicals and significant increase in the activity levels of liver function enzymes relative to the control. Significant reductions in both the enzymatic and non-enzymatic antioxidant markers as well as histopathological abnormalities in liver tissues were also observed. Notably, the combined administration of ArLP with AFB1 clearly reduced AFB1-mediated adverse effects leading to the normalization of most of these parameters back to control levels. These findings clearly highlight the potential benefits of artichoke dietary supplements as a safe and natural solution in counteracting the adverse hepatotoxic effects conferred by AFB1 exposure. Further research is warranted to fully dissect the biochemical and molecular mechanism of action of the observed artichoke-mediated hepatoprotection.

Silk sericin alleviates aberrant photoperiod-induced alterations in testicular and adrenal steroidogenesis in adult mice.

BACKGROUND: Steroidogenesis is a complex process of sequential enzymatic reactions affected by climate change. Animals respond to altered day length, the so-called photoperiod, with changes in physiology. The study aimed to an evaluation of sericin effect in alleviating steroidogenesis disorders induced by disturbed photoperiod in mice. METHODS: The animals were randomly divided into three groups according to the lighting cycle: a control group with a standard 12Light:12Dark cycle, a short-term photoperiod group with a 6Light:18Dark cycle, and a long-term photoperiod group with an 18Light:6Dark cycle. Both short and long-term groups were subdivided into two equal subgroups: The placebo and the sericin-treated subgroups received, for five weeks from prepubertal throughout adulthood, one intraperitoneal injection per week of the solvent and 1 g sericin/kg body weight, respectively. RESULTS: Selected oxidative stress parameters and testicular and adrenal steroidogenic capacities of adult mice were measured. After five weeks, the placebo group with impaired photoperiod showed a decrease in the quality and quantity of sperm and a reduction in testosterone, corticosterone, aldosterone, total antioxidant capacity, xanthine oxidase, and melatonin. At the same time, in these groups, there was an increase in the level of aromatase, malondialdehyde, cholesterol, and steroidogenic factor-1 (SF-1) expression in the adrenal cortex and an enhancement in histological lesions. Mice receiving sericin had parameters similar to the control group. CONCLUSION: Our findings reveal that silk sericin can reduce the stress caused by photoperiod disorders regarding testicular function, sex hormone levels, and sperm quantity and quality. Thus, sericin is a biocompatible protein with a promising potential for its use in the case of organisms living under an abnormal photoperiod.

Insights into the Role of Natural Products in the Control of the Honey Bee Gut Parasite (Nosema spp.).

The honey bee is an important economic insect due to its role in pollinating many agricultural plants. Unfortunately, bees are susceptible to many pathogens, including pests, parasites, bacteria, and viruses, most of which exert a destructive impact on thousands of colonies. The occurrence of resistance to the therapeutic substances used against these organisms is rising, and the residue from these chemicals may accumulate in honey bee products, subsequently affecting the human health. There is current advice to avoid the use of antibiotics, antifungals, antivirals, and other drugs in bees, and therefore, it is necessary to develop alternative strategies for the treatment of bee diseases. In this context, the impact of nosema diseases (nosemosis) on bee health and the negative insults of existing drugs are discussed. Moreover, attempts to combat nosema through the use of alternative compounds, including essential oils, plant extracts, and microbes in vitro and in vivo, are documented.

Carboxymethyl cellulose/sericin-based hydrogels with intrinsic antibacterial, antioxidant, and anti-inflammatory properties promote re-epithelization of diabetic wounds in rats.

Diabetic wound healing encounters significant challenges due to the extreme oxidative stress resulting from excessive inflammation and microbial infections, disrupting the typical cascade of wound healing and thwarting the re-epithelialization of skin tissues. Benefiting from the biological activities of carboxymethyl cellulose (CMC) and sericin, we thus fabricated multifunctional hydrogels of CMC-Sericin. The hydrogel revealed high swelling performance alongside its porous structure. The incorporation of sericin bestowed the CMC-Sericin hydrogels with a prominent capacity to scavenge free radicals and antibacterial activity. In vivo investigations using diabetic full-thickness excision wounds demonstrated the capability of CMC-Sericin dressing to enhance diabetic wounds in rats treated or untreated with insulin concurrently. Furthermore, histopathological examinations manifested the skin tissue regeneration evidenced by the development of skin appendages like hair follicles and collagen deposition after treatment with CMC-Sericin hydrogel. Moreover, the levels of antioxidant parameters, including GSH and SOD, were substantially augmented and associated with a significant diminution in lipid peroxidation, implying a decrease in oxidative stress in the tissues. Beyond that, CMC-Sericin dressing downregulated the pro-inflammatory markers and upregulated the heat shock proteins, indicating the restoration of physiological features in cells. Strikingly, CMC-Sericin dressing remarkably promoted the healing of diabetic wounds without insulin treatment.

Silver nanoparticles instigate physiological, genotoxicity, and ultrastructural anomalies in midgut tissues of beetles.

Silver nanoparticles (AgNPs) have long been materials of great interest in numerous fields; however, there is escalating alarm over their toxicity to public health since exposure to these particles is inevitable. This study sheds light on the deleterious impacts of AgNPs on the midgut tissues of beetles (Blaps polychresta) collected from Egypt as a biological model. The investigations were conducted on the beetles administered with a sublethal dose of AgNPs (0.03 mg/g body weight) after 30 days. Oxidative stress parameters and antioxidant enzyme activities were assessed, which exposed critical disruption in the antioxidant defense system of treated beetles. Remarkably, metallothionein (MT) gene expression was significantly increased, while reduced glutathione (GSH) level was notably decreased in midgut tissues subjected to AgNPs. These findings manifestly imply the presence of overproduction in terms of reactive oxygen species (ROS) inside the cells. Additionally, DNA impairment and apoptosis of midgut cells were appraised employing comet and flow cytometry analyses, respectively. The comet results revealed a significant increase in comet cells for the AgNPs treated beetles compared with the control group. Furthermore, the apoptosis results demonstrated a substantial diminution in viable cells with significant growth in apoptotic cells in midgut cells exposed to AgNPs, manifesting their striking correlation with comet and biochemical findings. Noticeably, the histopathological and ultrastructural inspections revealed substantial aberrations in the midgut tissues in the AgNPs treated group, substantiating the previous results. As far as we know, no research has been found that surveyed how the AgNPs at low doses affect the midgut tissues of beetles. Overall, these findings evince the aberrant influences of AgNPs on living organisms.

Insights into Ag-NPs-mediated pathophysiology and ultrastructural aberrations in ovarian tissues of darkling beetles.

With the evolution of nanostructure materials, silver nanoparticles (Ag-NPs) emerged as the predominantly exploited nanomaterial in multifarious sectors due to their versatile properties. Along with the heightening applications of Ag-NPs, however, there is increasing concern over their indubitable toxicity towards the ecosystem, which indeed affects surrounding organisms and human health. In this study, we evaluated the detrimental effects of Ag-NPs in relation to Egyptian wild female beetles, Blaps polychresta, after injection with a single dose of Ag-NPs at different doses and monitoring for 30 days to determine the sublethal dose. Accordingly, the sublethal dose revealed the lowest negative influence was found at 0.03 mg/g body weight. The adverse impacts of Ag-NPs on the ovaries of female beetles were investigated by estimating the enzyme activities, DNA damage using a comet assay, and apoptosis by means of flow cytometry. Besides, the ultrastructural abnormalities were surveyed adopting transmission electron microscopy (TEM). The results manifested comet cells of 7.67 ± 0.88% and 22.33 ± 0.51 for Ag-NPs treated and control groups, respectively. Similarly, the data from flow cytometry demonstrated a substantial reduction in viable cells associated with a significant rise in apoptotic cells for the Ag-NPs treated group in comparison with the control group. Moreover, significant disturbances in enzyme activities for the treated group were perceived correlated with evident diminutions in antioxidant enzymes. Remarkably, the ultrastructural investigation emphasized these findings, exposing considerable deformities of the ovaries in the Ag-NPs treated group compared with the control group. To the best of our knowledge, this is the first report discussing the influence of Ag-NPs at the lowest dose on ovaries of B. polychresta. Collectively, our findings would significantly contribute to considering the critical effects of Ag-NPs at low levels, in addition to the potential use of B. polychresta as a good bio-indicator in ecotoxicological analyses.

Memory Impairment, Pro-Inflammatory Host Response and Brain Histopathologic Severity in Rats Infected with K. pneumoniae or P. aeruginosa Meningitis.

Meningitis caused by Klebsiella pneumoniae and Pseudomonas aeruginosa has lately become a prevalent cause of the central nervous system (CNS) infection. Bacterial invasion into the subarachnoid space prompts the releasing mechanism of chemokines and pro-inflammatory cytokines. The present study aimed to compare K. pneumoniae and P. aeruginosa meningitis concerning the memory, pro-inflammatory mediators and brain histopathological changes at different time intervals in adult Albino rats. The animals were sacrificed at three time intervals comprising 5, 10 and 15 days after meningitis induction. Cerebrospinal fluid (CSF) culture, relative brain weights, complete blood analysis, biochemical markers, levels of cytokine, chemokine and brain-derived neurotrophic factor (BDNF), neurotransmitter acetylcholine esterase (AChE) activity, and the brain histopathology of the infected rats in comparison to those in the control group were assessed. There was a significant increase in the levels of pro-inflammatory cytokines and chemokines including TNF-α, IL-1ß, IL-6 and AChE after 5 days of bacterial meningitis infection with both K. pneumoniae and P. aeruginosa. The histopathological analysis of the cerebral cortex in the P. aeruginosa meningitis model at different time intervals revealed abundant numbers of dilated and congested blood vessels with severe hemorrhage, cerebral infarct, intracellular and extracellular vacuoles, and gliosis. Fifteen days post infection, a significant reduction in the brain tissue weight was observed. The meningitis model employing P. aeruginosa exhibited more evident time-dependent severity compared to K. pneumoniae, which may advocate its validity as a simple and effective research model to study meningitis of the CNS. This model may be utilized for further investigation to ascertain the molecular and biological association between bacterial meningitis and the development of the pathophysiological hallmarks underlying Alzheimer's disease in preclinical and clinical setups. Clinical extrapolation based on studies employing animal disease models should be carefully interpreted.

Artichoke Leaf Extract-Mediated Neuroprotection against Effects of Aflatoxin in Male Rats.

Attenuation of adverse effects of aflatoxin (AFB1) in brains of B1 rats by extracts of leaves of artichoke was studied. The active ingredients in extracts of leaves of artichoke, Cynara scolymus L., were determined by HPLC analysis. In the 42-day experiment, rats were exposed to either sterile water, 4% DMSO, 100 mg artichoke leaf extract/kg body mass, 72 µg aflatoxin B1/kg body mass, or AFB1 plus artichoke leaf extract. Neurotoxicity of AFB1 was determined by an increase in profile of lipids, augmentation of plasmatic glucose and concentrations of insulin, oxidative stress, increased activities of cholinergic enzymes, and a decrease in activities of several antioxidant enzymes and pathological changes in brain tissue. Extracts of artichoke leaf significantly reduced adverse effects caused by AFB1, rescuing most of the parameters to values similar to unexposed controls, which demonstrated that adverse, neurotoxic effects caused by aflatoxin B1 could be significantly reduced by simultaneous dietary supplementation with artichoke leaf extract, which itself is not toxic.

Isolation and molecular characterization of lumpy skin disease virus from hard ticks, Rhipicephalus (Boophilus) annulatus in Egypt.

BACKGROUND: Lumpy skin disease (LSD), a disease of cattle and buffaloes, has recently become widely prevalent in Egypt. The aim of this study was to ascertain the potential role of Rhipicephalus (Boophilus) annulatus ticks in the transmission of this disease. Samples collected from suspected lumpy skin disease virus (LSDV) infected cows that had previously been vaccinated with the Romanian sheep pox virus (SPPV) in various Egyptian governorates were obtained between May to November over two consecutive years, namely 2018 and 2019. Ticks were morphologically identified and the partial cytochrome oxidase subunit I gene (COI) were sequenced, revealing that they were closely related to R. (Boophilus) annulatus. The G-protein-coupled chemokine receptor (GPCR) gene of the LSDV was used to test hard ticks. RESULTS: Two positive samples from Kafr El-Sheikh province and one positive sample from Al-Behera province were reported. BLAST analysis revealed that the positive samples were closely related to the Kazakhstani Kubash/KAZ/16 strain (accession number MN642592). Phylogenetic analysis revealed that the GPCR gene of the LSDV recently circulating in Egypt belongs to a global cluster of field LSDV with a nucleotide identity of 98-100%. LSDV isolation was successfully performed four days after inoculation using 9 to 11-day-old embryonated chicken eggs showing characteristic focal white pock lesions dispersed on the choriallantoic membrane after three blind passages. Intracytoplasmic inclusion bodies, cell rupture, vacuoles in cells, and virus particles ovoid in shape were demonstrated by electron microscopy. CONCLUSION: In this study the role of hard ticks in the transmission of the LSDV to susceptible animals in Egypt was revealed and confirmed by various methods.