The escalating challenge of resistance to insecticides among agricultural and public health pests poses a significant threat to global food security and vector-borne disease control. This review synthesizes current understanding of the molecular mechanisms underpinning resistance, including well-characterized pathways such as target-site mutations affecting nicotinic acetylcholine receptors (nAChRs), acetylcholinesterase (AChE), voltage-gated sodium channels (VGSCs), and γ-aminobutyric acid (GABA) receptors, and metabolic detoxification mediated by cytochrome P450 monooxygenases (CYPs), esterases, and glutathione S-transferases (GSTs). Emerging resistance mechanisms are also explored, including protein sequestration by odorant-binding proteins and post-transcriptional regulation via non-coding RNAs, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Focused case studies on Aedes aegypti and Spodoptera frugiperda illustrate the complex interplay of genetic and biochemical adaptations driving resistance. In Ae. aegypti, voltage-gated sodium channel (VGSCs) mutations (V410L, V1016I, F1534C) combined with metabolic enzyme amplification confer resistance to pyrethroids, accompanied by notable fitness costs and ecological impacts on vector populations. In S. frugiperda, multiple resistance mechanisms, including overexpression of cytochrome P450 genes (e.g., CYP6AE43, CYP321A8), target-site mutations in ryanodine receptors (e.g., I4790K), and behavioral avoidance, have rapidly evolved across global populations, undermining the efficacy of diamide, organophosphate, and pyrethroid insecticides. The review further evaluates integrated pest management (IPM) strategies, emphasizing the role of biopesticides, biological control agents, including entomopathogenic fungi and parasitoids, and molecular diagnostics for resistance management. Taken together, this analysis underscores the urgent need for continuous molecular surveillance, the development of resistance-breaking technologies, and the implementation of sustainable, multifaceted interventions to safeguard the long-term efficacy of insecticides in both agricultural and public health contexts.

Background/Objective: Antimicrobial resistance (AMR) and therapy-resistant cancer cells represent major clinical challenges, necessitating the development of novel therapeutic strategies. This study explores the use of selenium nanoparticles (SeNPs) and colistin-conjugated selenium nanoparticles (Col-SeNPs) as a dual-function nanotherapeutic against multidrug-resistant Pseudomonas aeruginosa, antifungal-drug-resistant Candida spp., and human breast carcinoma (MCF-7) cells. Methods: SeNPs were synthesized and characterized using UV-Vis spectroscopy, atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR), confirming their nanoscale morphology, purity, and stability. Results: The antimicrobial activity of SeNPs and Col-SeNPs was assessed based on the minimum inhibitory concentration (MIC) and bacterial viability assays. Col-SeNPs exhibited enhanced antibacterial effects against P. aeruginosa, along with significant downregulation of the mexY efflux pump gene, which is associated with colistin resistance. Additionally, Col-SeNPs demonstrated superior antifungal activity against Candida albicans, C. glabrata, and C. krusei compared to SeNPs alone. The anticancer potential of Col-SeNPs was evaluated in MCF-7 cells using the MTT assay, revealing dose-dependent cytotoxicity through apoptosis and oxidative stress pathways. Although MCF-7 is not inherently drug-resistant, this model was used to explore the potential of Col-SeNPs in overcoming resistance mechanisms commonly encountered in cancer therapy. Conclusions: these findings support the promise of Col-SeNPs as a novel approach for addressing both antimicrobial resistance and cancer treatment challenges. Further in vivo studies, including pharmacokinetics and combination therapies, are warranted to advance clinical translation.

The paper represents a comprehensive study of the optimum subcellular fractions were prepared from the haemolymph of the seventh instar of the red palm weevil (RPW), Rhynchophorus ferrugineus Oliv. (Coleopter Curculionidae) to study some physicochemical characteristics of haemolymph esterases. The results showed that there were differences in characters between haemolymph α-esterases (hydrolyze alpha naphthyl acetate) and β-esterases (hydrolyze beta naphthyl acetate). The optimal pH and temperature were 8 and 50°C for α-esterases, respectively, and they were 7 and 35°C for β-esterases, respectively. Km (Michaelis constant) determined with alpha naphthyl acetate was 4X10-7 M, and it was 13.3X10-6 M for that determined with beta naphthyl acetate. Vmax (maximum velocity) was 5.55 mg α-naphthol/min/mg protein and 1.66 mg β-naphthol/min/mg protein for α- and β-esterases, respectively. The effect of organic solvents on substrate hydrolysis was also discussed. The study provided biochemical optimized conditions for esterases activity, and with these ongoing studies, our further aim will be to develop new strategies for the red palm weevil control using disruptors of esterases as important detoxifying enzymes.

Phenoloxidases (EC.1.14.18.1) are implicated in the immunity of insects toward microorganisms, so oxidative enzymes such as phenoloxidases (PO) from the 7th instar larvae of the red palm weevil; Rhynchophorus ferrugineus (Oliv.) was partially isolated to characterize its activity using catechol as a substrate. The mitochondrial fraction of larval homogenate was used as enzyme source for partial kinetic studies.Enzyme catalysis was directly proportional to enzyme crude protein conc. up to 200 ug contained in 1 ml of the reaction mixture. Michaelis-Menten kinetics of PO activity was evaluated by constructing Lineweaver Burk double reciprocal plot. Michaelis constant (Km) was, 3.45 X10-4 M and maximum velocity (V max) of PO reaction was 344.8 O.D.min-1 mg protein-1. Effect of pH, temperature and substrate concentration on enzyme reaction was tested. Generally, each variable was chosen while other conditions were at optimum found primarily. Reaction rate was optimal at 10-1 N catechol, neutral medium (pH 7) and 40 C. PO kept its most activity when incubated at 60 C for 15 min before reaction initiation. Phenoloxidases efficiently catalyze catechol. Results in the present study may probably offer a fundamental anchor for future alternative strategies in controlling R. ferrugineus via obstructing its innate defence mechanisms.

Approximately 50% of total harvested cereal grains are lost during the post-harvest handling and storage, and insects are the main cause for both quantity (reductions in weight) and quality. In the present study the effect of microwave radiation was studied on one of the stored product pest, the flour beetle Tribolium castaneum (Hersbt). Adult insects were obtained from infested flour products at stores specialized in selling cereal and stored products from Sakaka. Insects with its food media inside sac were exposed to microwave radiation for 15, 30, 45 and 60 sec for each radiation power. Tribolium castaneum beetles were exposed to microwave for 15, 30 and 45 sec. This result revealed that the mortality of immature and adults reached 100% in 15 and 45 sec, respectively.