Biochemical and genetic mechanisms in Pieris rapae (Lepidoptera: Pieridae) resistance under emamectin benzoate stress.

Pieris rapae (Lepidoptera: Pieridae) poses a significant threat to Brassicaceae crops, leading to substantial losses annually. Repeated insecticide applications are widely used to protect crops and increase the resistance of P. rapae. Exploring the biochemical and molecular basis of insecticide tolerance in P. rapae is crucial for achieving effective insect suppuration and implementing resistance control strategies. In our research, emamectin benzoate (EBZ) resistance was developed in P. rapae strain through selective pressure over 15 generations. Moreover, the biochemical mechanisms underlying resistance to EBZ and its potential cross-resistance to other insecticides were studied. Additionally, the expression levels of cytochrome P450 (CYP450) and glutathione-s-transferase (GST) genes in P. rapae were quantitatively assessed upon exposure to EBZ using real-time PCR. Our data exhibited that the LC50 value of susceptible strain (Sus) and EBZ resistance strain (EBZ-R) were 0.009 and 8.09 mg/L, with a resistance ratio (RR) reaching 898.8-fold. The EBZ-R stain displayed notably low cross-resistance to lambda-cyhalothrin, spinetoram, and cypermethrin. However, it demonstrated a moderate level of cross-resistance to deltamethrin. Conversely, no cross-resistance was noted to chlorantraniliprole and indoxacarb. Notably, enzyme inhibitors of detoxification enzymes revealed that piperonyl butoxide (PBO) and diethyl maleate (DEM) enhanced the EBZ toxicity to the resistant strain, indicating the potential involvement of CYP450 and GST in avermectin resistance. A remarkable enhancement in CYP450 and GST activity was observed in the EBZ-R stain. CYP450 and GST genes are upregulated in the EBZ-R stain compared to the Sus strain, which serves as a basis for comprehending the mechanism behind P. rapae resistance to EBZ. The molecular docking analysis demonstrated that EBZ has a high binding affinity with CYP6AE120 and PrGSTS1 with docking energy values of -20.19 and -22.57 kcal/mol, respectively. Our findings offer valuable insights into crafting efficient strategies to monitor and manage resistance in P. rapae populations in Egypt.

Cinnamon nanoemulsion mitigates acetamiprid-induced hepatic and renal toxicity in rats: biochemical, histopathological, immunohistochemical, and molecular docking analysis.

Acetamiprid (ACDP) is a widely used neonicotinoid insecticide that is popular for its efficacy in controlling fleas in domestic settings and for pets. Our study aims to offer a comprehensive examination of the toxicological impacts of ACDP and the prophylactic effects of cinnamon nanoemulsions (CMNEs) on the pathological, immunohistochemical, and hematological analyses induced by taking ACDP twice a week for 28 days. Forty healthy rats were divided into four groups (n = 10) at random; the first group served as control rats; the second received CMNEs (2 mg/Kg body weight); the third group received acetamiprid (ACDP group; 21.7 mg/Kg body weight), and the fourth group was given both ACDP and CMNEs by oral gavage. Following the study period, tissue and blood samples were extracted and prepared for analysis. According to a GC-MS analysis, CMNEs had several bioactive ingredients that protected the liver from oxidative stress by upregulating antioxidant and anti-inflammatory agents. Our findings demonstrated that whereas ACDP treatment considerably boosted white blood cells (WBCs) and lymphocytes, it significantly lowered body weight gain (BWG), red blood cells (RBCs), hemoglobin (Hb), hematocrit (HCT), and platelets (PLT). ACDP notably reduced antioxidant enzyme activities: superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) and elevated hydrogen peroxide and malondialdehyde levels compared with other groups. ACDP remarkably raised alanine aminotransferase (ALT), aspartate amino transaminase (AST), and alkaline phosphatase (ALP) levels.Moreover, the histopathological and immunohistochemistry assays discovered a severe toxic effect on the liver and kidney following ACDP delivery. Furthermore, cyclooxygenase 2 (COX-2) + immunoexpression was enhanced after treatment with CMNEs. All of the parameters above were returned to nearly normal levels by the coadministration of CMNEs. The molecular docking of cinnamaldehyde with COX-2 also confirmed the protective potential of CMNEs against ACDP toxicity. Our findings highlighted that the coadministration of CMNEs along with ACDP diminished its toxicity by cutting down oxidative stress and enhancing antioxidant capacity, demonstrating the effectiveness of CMNEs in lessening ACDP toxicity.

Identification and Characterization of Glutathione S-transferase Genes in Spodoptera frugiperda (Lepidoptera: Noctuidae) under Insecticides Stress.

Insect glutathione S-transferases (GSTs) serve critical roles in insecticides and other forms of xenobiotic chemical detoxification. The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a major agricultural pest in several countries, especially Egypt. This is the first study to identify and characterize GST genes in S. frugiperda under insecticidal stress. The present work evaluated the toxicity of emamectin benzoate (EBZ) and chlorantraniliprole (CHP) against the third-instar larvae of S. frugiperda using the leaf disk method. The LC50 values of EBZ and CHP were 0.029 and 1.250 mg/L after 24 h of exposure. Moreover, we identified 31 GST genes, including 28 cytosolic and 3 microsomal SfGSTs from a transcriptome analysis and the genome data of S. frugiperda. Depending on the phylogenetic analysis, sfGSTs were divided into six classes (delta, epsilon, omega, sigma, theta, and microsomal). Furthermore, we investigated the mRNA levels of 28 GST genes using qRT-PCR under EBZ and CHP stress in the third-instar larvae of S. frugiperda. Interestingly, SfGSTe10 and SfGSTe13 stood out with the highest expression after the EBZ and CHP treatments. Finally, a molecular docking model was constructed between EBZ and CHP using the most upregulated genes (SfGSTe10 and SfGSTe13) and the least upregulated genes (SfGSTs1 and SfGSTe2) of S. frugiperda larvae. The molecular docking study showed EBZ and CHP have a high binding affinity with SfGSTe10, with docking energy values of -24.41 and -26.72 kcal/mol, respectively, and sfGSTe13, with docking energy values of -26.85 and -26.78 kcal/mol, respectively. Our findings are important for understanding the role of GSTs in S. frugiperda regarding detoxification processes for EBZ and CHP.

Cloning and expression of the mitochondrial cytochrome c oxidase subunit II gene in Sitophilus zeamais and interaction mechanism with allyl isothiocyanate.

In the United States, allyl isothiocyanate (AITC) has been registered as an insecticide, bactericide, and nematicide. And it has been confirmed that AITC has significant insecticidal activities against four stored product pests including Sitophilus zeamais Mostchulky (Coleoptera: Curculionidae). This study aimed to verify the mechanism of action of AITC on cytochrome c oxidase core subunits II in S. zeamais. Enzyme - catalyzed reactions and Fourier transform infrared spectrometer (FTIR) analysis revealed that the expressed COX II proteins could competitively bind and inhibit the activity of COX II. Furthermore, molecular docking results showed that a sulfur atom of AITC could form a 2.9 Å hydrogen bond with Ile-30, having a binding energy of -2.46 kcal/mol.

High-temperature shock consequences on the red flour beetle (Tribolium castaneum) and the rice weevil (Sitophilus oryzae).

Temperature shocks have profound effects on biological and physiological functions at all levels of organization. However, the recovery periods from these shocks and their subsequent impacts remain unknown. Herein, our study investigated the effect of short temperature stress on survival, dormancy recovery time, nutritional indices, life traits and development rate for T. castaneum (larvae and adults) and S. oryzae adults. The results showed significant effects on survival rates of T. castaneum (larvae and adults) and S. oryzae adults. When both insects had been exposed to high-temperature shock, survival rates decreased with higher temperatures and longer periods of exposure. Furthermore, recovery times varied between and within the insect species, as prolonged exposure to thermal shocks increased recovery periods. Moreover, dormancy time resulting from the high-temperature shocks significantly affected food deterrence and food intake, regardless of the stage of development, species, exposure periods and temperature-exposure conditions. Subsequently, differences in body growth rates and food consumption rates are an appropriate indicator of differences in food conversion rates under high-temperature shocks, regardless of the species and developmental stages. On the other hand, our results indicated that as high-temperature shocks increased, the total development period increased of T. castaneum. Likewise, the pupal stage increased with increasing high-temperature shocks, and the larval stage decreased with increasing thermal shocks and increasing the periods of exposure. In summary, our study showed the importance of dormancy recovery time and its subsequent effects for improving disinfestation effectiveness of heat treatment, and understanding insect response to high temperatures.

Low temperature shock and chill-coma consequences for the red flour beetle (Tribolium castaneum) and the rice weevil (Sitophilus oryzae).

Insects face several (environmental) abiotic stressors, including low temperature, which cause the failure of neuromuscular function. Such exposure leads insects toa reversible comatose state termed chill-coma, but the consequences of this state for the organism biology were little explored. Here, the consequences of the chill-coma phase were investigated in two of the main stored product pest species - the red flour beetle Tribolium castaneum (larvae and adults) and the rice weevil Sitophilus oryzae (adults). For this purpose, a series of low-temperature shocks were used to estimate the chill-coma recovery time (CCRT), survival, nutrition and weight gain/growth of T. castaneum (larvae and adults) and S. oryzae, as well as the development of T. castaneum life stages. The relatively long CCRT was characteristic of beetle larvae, at different low-temperature shocks, and CCRT increased with decreasing temperatures and increasing exposure intervals for both pest species. The survival was little affected by the low-temperature shocks applied, but such shocks affected insect feeding and growth. Tribolium castaneum larvae was more sensitive than adults of both insect species. Moreover, the relative consumption and weight gain of S. oryzae adults were lower than those of T. castaneum adults and mainly larvae, while feeding deterrence was not affected by low temperature shocks, unlike food conversion efficiency. Low-temperature shocks, even under short duration at some temperatures, significantly delayed development. The lower the temperature and the higher the exposure period, the more delayed the development. Thus, the physiological costs of chill-coma are translated into life-history consequences, with potential implications for the management of this insect pest species in stored products and even more so on red flour beetles and rice weevils.

Pimpinella anisum Essential Oil Nanoemulsion Toxicity against Tribolium castaneum? Shedding Light on Its Interactions with Aspartate Aminotransferase and Alanine Aminotransferase by Molecular Docking.

The insecticidal activity is the result of a series of complex interactions between toxic substances as ligands and insect's enzymes as targets. Actually, synthetic insecticides used in pest control programs are harmful to the environment and may affect non-target organisms; thus, the use of natural products as pest control agents can be very attractive. In the present work, the toxic effect of aniseed (Pimpinella anisum L.) essential oil (EO) and its nanoemulsion (NE) against the red flour beetle Tribolium castaneum, has been evaluated. To assess the EO mode of action, the impact of sub-lethal concentrations of aniseed EO and NE was evaluated on enzymatic and macromolecular parameters of the beetles, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, total lipids and glucose. Finally, a molecular docking study was conducted to predict the mode of action of the major EO and NE components namely E-anethole, Limonene, alpha-himalachalene, trans-Verbenol and Linalool at binding site of the enzymes AST and ALT. Herein, the binding location of the main compounds in both proteins are discussed suggesting the possible interactions between the considered enzymes and ligands. The obtained results open new horizons to understand the evolution and response of insect-plant compounds interactions and their effect predicted at the molecular levels and side effects of both animal and human.

Topical hyaluronic acid in the management of oral lichen planus: A comparative study.

AIM: Oral lichen planus (OLP) is a chronic mucocutaneous disorder seen in clinical dental practice. Despite the progress in research and advances in knowledge, the successful management of OLP is still difficult to achieve. The aim of the present study was to compare the therapeutic effects of triamcinolone (TA) preparation (0.1%) with hyaluronic acid (HA) preparation (0.2%) in the management of OLP. METHODS: In total, 40 patients of any age or sex who had symptomatic OLP were selected and randomly divided into two groups. Group I received topical 0.1% TA, and group II received topical 0.2% HA preparation three times per day for a period of 4 weeks. Basement data were recorded for each patient. Patients were evaluated on days 14 and 21, and after completing the course of treatment. The visual analog scale (VAS) was used for evaluating pain and burning sensation, along with an evaluation of the degree of erythema and mean area of the lesion. Data were analyzed by SPSS 17.0 software using Mann-Whitney and t test. P ≤ 0.05 was considered statistically significant. RESULTS: Our results showed considerable improvement in all of the parameters evaluated. Baseline characteristics, including pain score, size, and clinical characteristics of the lesions, were not different between the two treatment groups. Both TA and HA were found to reduce the VAS score, the degree of erythema, and size of the lesions after treatment. CONCLUSION: The application of HA is suggested, and is an effective substitute for TA in the treatment of OLP.

Pimpinella anisum essential oil nanoemulsions against Tribolium castaneum-insecticidal activity and mode of action.

The red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), is an economically important pest of stored products. As possible alternative to conventional insecticides for its management, plant essential oils have gained interest owing to their effectiveness and eco-friendly features. However, they also show some drawbacks, such as low stability, poor water solubility and diffusion, and limited persistence in the environment. A good strategy to overcome these disadvantages is represented by green nanotechnologies. Herein, we developed a nanoemulsion based on the essential oil from Pimpinella anisum L. (Apiaceae) containing 81.2% of (E)-anethole and evaluated its toxicity on T. castaneum adults and F1 progeny, as well as its morphological and histological impact. The aniseed oil nanoemulsion was characterized by the formation of a semi-solid interphase between oil and water; mean drop size was 198.9 nm, PDI was 0.303, zeta potential was - 25.4 ± 4.47 mV, and conductivity was 0.029 mS/cm. The nanoemulsion showed toxicity on T. castaneum (LC50 = 9.3% v/v), with a significant impact on its progeny. Morphological and histological damages triggered by feeding and exposure to the aniseed nanoemulsion were analyzed by scanning electron microscopy (SEM) and light microscopy. Overall, our findings showed that the development of nanoemulsions allows to improve the stability of P. anisum essential oil enhancing its efficacy against stored grain pests and contributing to reduce the use of harmful synthetic insecticides.