Prevention of pesticide-induced neuronal dysfunction and mortality with nucleophilic poly-Oxime topical gel

Direct detection of acetylcholinesterase by Fe(HCOO)2.6(OH)0.3. H2O nanosheets with oxidase-like activity on a smartphone platform

Monitoring acetylcholinesterase (AChE) is crucial in clinical diagnosis and drug screening. Traditional methods for detecting AChE usually require the addition of intermediates like acetylthiocholine, which complicates the detection process and introduces interference risks. Herein, we develop a direct colorimetric assay based on alkaline iron formate nanosheets (Fe(HCOO)2.6(OH)0.3·H2O NSs, Fef NSs) for the detection of AChE without any intermediates. The as-prepared Fef NSs exhibit oxidase-like activity, catalyzing the generation of O2·-, 1O2 and ·OH, which leads to a color change from colorless to blue when exposed to 3,3',5,5'-tetramethylbenzidine. AChE directly inhibits the oxidase-like activity of Fef NSs, resulting in a hindered color reaction, enabling the detection of AChE. The biosensor has a linear detection range of 0.1-30 mU/mL, with a minimum detection limit of 0.0083 mU/mL (S/N = 3), representing a 100-fold improvement in detection sensitivity over the traditional Ellman's method. Satisfactory results were obtained when analyzing real AChE samples. Attractively, a method for the quantitative detection of AChE by a smartphone is established based on the Fef NSs. This method enables instant acquisition of AChE concentrations, achieving real-time visualized detection.

Mitigation of pesticide-mediated ocular toxicity via nanotechnology-based contact lenses: a review

The xenobiotic stress exerted by pesticides leads to the deterioration of human and animal health including ocular health. Acute or prolonged exposure to these agricultural toxicants has been implicated in a number of pathological conditions of the eye such as irritation, epiphora or hyper-lacrimation, abrasions on the ocular surface, and decreased visual acuity. The issue is compounded by the fact that tissues of the eye absorb pesticides faster than other organs of the body and are more susceptible to damage as well. However, there is a lacuna in our knowledge regarding the ways by which pesticide exposure-mediated ocular insult might be counteracted. Topical instillation of drugs known to combat the pesticide induced toxicity has been explored to mitigate the detrimental impact of pesticide exposure. However, topical eye drop solutions exhibit very low bioavailability and limited drug residence duration in the tear film decreasing their efficacy. Contact lenses have been explored in this respect to increase bioavailability of ocular drugs, while nanoparticles have lately been utilized to increase drug bioavailability and increase drug residence duration in different tissues. The current review focuses on drug delivery and futuristic aspects of corneal protection from ocular toxicity using contact lenses.

"On-On-Off" Recyclable Fluorescence Battery for Direct and Selective Detection of Glyphosate and Cu2

Residues of environmental organophosphorus pesticides (OPs) will seriously endanger human health. Most reported OP sensors utilized the restrictions capacity of OPs on the catalytic capacity of acetylcholinesterase (AChE) to acetylthiocholine chloride (ATCh), which suffers from high costs, weak stability, long reaction time, and unrecyclable. Herein, a recyclable strategy was proposed for selective and sensitive detection of glyphosate (Gly). The weak fluorescence of UIO-66-NH2 at 450 nm was enhanced almost 10-fold after reacting with Gly because of the rotation-restricted emission enhancement mechanism. Moreover, inspired by the process of charging and discharging the batteries, we introduced Cu2+ to chelate with Gly. Because of the strong chelation between Cu2+ and Gly, the Gly was removed from UIO-66-NH2, which resulted in the quenching of fluorescence intensity and making UIO-66-NH2 recycle. This method proposed is fast, recyclable, easily conducted, and with a low 0.33 μM LOD in dd H2O based on 3σ/S. The recovery rates of Gly in tap water ranged from 93.07 to 104.35% within a satisfied 7.75% RSD. The Cu2+ LOD is 0.01 mM based on 3σ/S and 94.37-118.34% recovery rates within 6.48% RSD in tap water. We believe that the findings in this work provide a meaningful and promising strategy to detect Gly and Cu2+ in real samples. This sensor first successfully achieves the recycling use of the material in OP fluorescence detection, which greatly decreases the cost of the designed sensor and reduces the possibility of secondary pollution to the environment, broadens a new circulation dimension of fluorescence detection methods in detecting OPs, and has the potential to remove glyphosate from water. It also provides a method to utilize functionalized metal-organic frameworks to establish various sensors.

Oxime-functionalized anti-insecticide fabric reduces insecticide exposure through dermal and nasal routes, and prevents insecticide-induced neuromuscular-dysfunction and mortality

Farmers from South Asian countries spray insecticides without protective gear, which leads to insecticide exposure through dermal and nasal routes. Acetylcholinesterase plays a crucial role in controlling neuromuscular function. Organophosphate and carbamate insecticides inhibit acetylcholinesterase, which leads to severe neuronal/cognitive dysfunction, breathing disorders, loss of endurance, and death. To address this issue, an Oxime-fabric is developed by covalently attaching silyl-pralidoxime to the cellulose of the fabric. The Oxime-fabric, when stitched as a bodysuit and facemask, efficiently deactivates insecticides (organophosphates and carbamates) upon contact, preventing exposure. The Oxime-fabric prevents insecticide-induced neuronal damage, neuro-muscular dysfunction, and loss of endurance. Furthermore, we observe a 100% survival rate in rats when repeatedly exposed to organophosphate-insecticide through the Oxime-fabric, while no survival is seen when organophosphate-insecticide applied directly or through normal fabric. The Oxime-fabric is washable and reusable for at least 50 cycles, providing an affordable solution to prevent insecticide-induced toxicity and lethality among farmers.

Metal co-factors to enhance catalytic activity of short prion-derived peptide sequences

Development of biomolecular enzyme mimics to efficiently catalyse biochemical reactions are of prime relevance for the bulk scale production of industrially relevant biocatalyst. In this regard, amyloidogenic peptides act as suitable self-assembling scaffolds, providing stable nanostructures with high surface area facilitating biocatalysis. Herein, we rationally design two positional amyloidogenic peptide isomers, "Fmoc-VYYAHH (1)" and "Fmoc-VHHAYY (2)" considering catalytic and metal binding affinity of histidine and tyrosine when placed in periphery vs. inner core of the peptide sequence. With an ultimate objective of designing metalloenzyme mimic, we choose Co2+ and Cu2+ as divalent transition metal cations for peptide complexation to aid in catalysis. After optimizing self-assembly of innate peptides, we investigate metal-peptide binding ratio and co-ordination, finally selecting 1:1 peptide metal complex suitable for biocatalysis. Metallopeptides act as better catalysts than the innate peptides as acyl esterase when tyrosines were present at the periphery. Kinetic parameters for assessing hydrolysis rate were calculated by fitting data into Michaelis-Menten and Lineweaver Burk plots. Catalytic activity is altered depending on the stability of peptide metal complexes. 2-Cu acting as the best biocatalyst with a kcat/KM = 0.08 M/s. The protocols mentioned in this chapter meticulously cover the design, synthesis, self-assembly and enzyme kinetics.

Investigating the therapeutic potential of Allium cepa extract in combating pesticide exposure induced ocular damage

The ocular surface is subject to a range of potentially hazardous environmental factors and substances, owing to its anatomical location, sensitivity, and physiological makeup. Xenobiotic stress exerted by chronic pesticide exposure on the cornea is primarily responsible for ocular irritation, excessive tear production (hyper-lacrimation), corneal abrasions and decreased visual acuity. Traditional medicine hails the humble onion (Allium cepa) for its multi-faceted properties including but not limited to anti-microbial, antioxidant, anti-inflammatory and wound healing. However, there is a lacuna regarding its impact on the ocular surface. Thereby, the current study investigated whether topical application of crude extract of Allium cepa aided in mitigating pesticide-induced damage to the ocular surface. The deleterious effects of pesticide exposure and their mitigation through the topical application of herbal extract of Allium cepa were analysed initially through in vitro evaluation on cell lines and then on the ocular surface via various in-vivo and ex-vivo techniques. Pathophysiological alterations to the ocular surface that impacted vision were explored through detailed neurophysiological screening with special emphasis on visual acuity wherein it was observed that the murine group treated with topical application of Allium cepa extract had comparable visual capacity to the non-pesticide exposed group. Additionally, SOD2 was utilized as an oxidative stress marker along with the expression of cellular apoptotic markers such as Bcl-xL to analyse the impact of pesticide exposure and subsequent herbal intervention on oxidative stress-induced corneal damage. The impact on the corneal epithelial progenitor cell population (ABCG2 and TERT positive cells) was also flowcytometrically analysed. Therefore, from our observations, it can be postulated that the topical application of Allium cepa extract might serve as an effective strategy to alleviate pesticide exposure related ocular damage.

Synthesis, characterization and larvicidal studies of ethyl 3-benzoyl-7-(piperidin-1-yl)indolizine-1-carboxylate analogues against Anopheles arabiensis and cheminformatics approaches

According to WHO, in 2021, there was an estimation of 247 million malaria cases from 84 malaria-endemic countries. Globally an estimated count of 2 billion malaria cases and 11.7 million deaths due to malaria were recorded in the past two decades. Further, the emergence of drug-resistant mosquitos threatens mankind. Therefore, the development of newer larvicidal agents is the need of the hour. This research identifies a new series of variably substituted indolizines for their effectiveness in controlling Anopheles arabiensis larvae through larvicidal activity. The series of Ethyl 3-benzoyl-7-(piperidin-1-yl)indolizine-1-carboxylate analogues (4a-j) were synthesized by reacting 4-(piperidin-1-yl)pyridine, phenacyl bromides with ethyl propiolate via 1, 3-dipolar cycloaddition and the green metrics of the process are reported. All the newly synthesized compounds were characterized by spectroscopic techniques such as 1H NMR,13C NMR, FT-IR, and HRMS. The larvicidal effectiveness of the newly synthesized compounds was assessed against Anopheles arabiensis. Among the compounds studied, namely 4c, 4d, 4e, and 4f, displayed the most notable larval mortality rates within the series, reaching 73%, 81%, 76%, and 71% respectively, in contrast with the negative control acetone. In comparison, the standard Temephos exhibited a mortality rate of 99% at the same concentration. Furthermore, computational approaches including molecular docking and molecular dynamics simulations identified the potential targets of the series compounds as the larval Acetylcholinesterase (AChE) enzyme and the Sterol Carrier Protein-2 (SCP-2) protein. However, it is essential for these computational predictions to undergo experimental validation.Communicated by Ramaswamy H. Sarma.

The potential impacts of micro-and-nano plastics on various organ systems in humans

Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully understood. This review aims to provide an overview of the potential impacts of MNPs on various organ systems and identify knowledge gaps in current research. The summarized results suggest that exposure to MNPs can lead to health effects through oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity. There is limited human data on the health effects of MNPs, despite evidence from animal and cellular studies. Most of the published research has focused on specific types of MNPs to assess their toxicity, while other types of plastic particles commonly found in the environment remain unstudied. Future studies should investigate MNPs exposure by considering realistic concentrations, dose-dependent effects, individual susceptibility, and confounding factors.

TPB-DMTP@S-CDs/MnO2 Fluorescence Composite on a Dual-Emission-Capture Sensor Module for Fingerprint Recognition of Organophosphorus Pesticides

Residues of organophosphorus pesticides (OPs) raise considerable concern, while identifying OPs from unknown sources is still a challenge to onsite fluorescence techniques. Herein, a dual-emission-capture sensor module, based on a TPB-DMTP@S-CDs/MnO₂ fluorescence composite, is developed for OP fingerprint recognition. TPB-DMTP@S-CDs/MnO₂, synthesized by a hydrothermal method and self-assembly, is spectrographically validated as a dual-wavelength fluorescence source. OP-sensitive catalysis (acetylcholinesterase on acetylthiocholine chloride) is designed to regulate fluorescence by decomposing quenchable MnO₂. A flexibly fabricated sensor module supports the optimal dual-wavelength fluorescence excitations and captures and converts fluorescence emissions into equivalent photocurrents for feasible access. The most prominent finding is that dual-fluorescence emissions alternatively respond to levels, species, and multi-pH pretreatments of OPs due to varied MnO₂ sizes and distributions. Therefore, OP fingerprint recognition is conducted by refining the multidimensional information from fluorescence-triggered photocurrents and preset hydrolyzation using principal component analysis and the rule of maximum covariance. The recommended method provides a wide dynamic range (1 × 10^-6 ∼ 12 μg mL^-1), a good limit of detection (7.9 × 10^-7 μg mL^-1), 15-day stability, and good selectivity to guarantee fingerprint recognition. For laboratory and natural samples, this method credibly identifies a single kind of OPs from multiple species at trace levels (10^-5 μg mL^-1) and performs well in two-component and multicomponent analyses.

General Method for Pesticide Recognition Using Albumin-Based Host-Guest Ensembles

The massive use of pesticides nowadays has led to serious consequences for the environment and public health. Fluorescence analytical methods for pesticides are particularly advantageous with respect to simplicity and portability; however, currently available fluorescence methods (enzyme-based assays and indicator displacement assays) with poor universality are only able to detect few specific pesticides (e.g., organophosphorus). Making use of the multiple flexible and asymmetrical binding sites in albumin, we herein report a set of multicolor albumin-based host-guest ensembles. These ensembles exhibit a universal but distinctive fluorescent response to most of the common pesticides and allow array-based identification of pesticides with high accuracy. Furthermore, the simplicity, portability, and visualization of this method enable on-site determination of pesticides in a practical setting. This albumin host strategy largely expands the toolbox of traditional indicator displacement assays (synthetic macrocycles as hosts), and we expect it to inspire a series of sensor designs for pesticide detection.

Photothermally switchable peptide nanostructures towards modulating catalytic hydrolase activity

Enzymes are the most efficient catalysts in nature that possess an impressive range of catalytic activities, albeit limited by stability in adverse conditions. Functional peptides have emerged as alternative robust biocatalysts to mimic complex enzymes. Here, a rational design of minimalistic amyloid-inspired peptides 1-2 is demonstrated, which leads to pathway-driven self-assembly triggered by heat, light and chemical cues to render 1D and 2D nanostructures by the interplay of hydrogen bonding, host-guest interaction and reversible photodimerization. Such in situ transformable peptide nanostructures by means of external cues are envisaged as a catalytic amyloid for the first time to mimic the hydrolase enzyme activity. Michaelis Menten's enzyme kinetic parameters for the hydrolysis rate correlate the external cue-mediated structure-function augmentation with the twisted bundles, 1_TB being the most efficient biocatalyst among all the dimensionally diverse nanostructures. Unlike the natural enzyme, the peptide nanostructures exhibited the robust nature of the hydrolase activity over a broad range of temperature and pH. Finally, the peptide nanostructures are explored as efficient heterogeneous flow catalysts to improve the turnover number for the hydrolase activity.

Chronic pesticide exposure induced aberrant Notch signalling along the visual pathway in a murine model

Pesticides aid in crop-protection against pests and increase yield. However, the xenobiotic stress exerted by pesticides leads to the deterioration of human and animal health. There is a lacuna in our knowledge about their impact on the ocular surface The present work sheds light on this gap by analysing the deterioration of visual acuity as a consequence of pesticide induced xenobiotic stress and Notch pathway dysregulation. Alteration in the expression of vital components of the notch signalling was analyzed along the visual pathway with special focus on its two terminals-the cornea and the visual cortex, by mimicking the on-field scenario regarding chronic pesticide exposure in experimental murine model (Swiss albino mice; Mus musculus). Various aspects were taken into consideration through visual acuity tests, histological evaluations, culture analyses, wound healing assays, flowcytometric evaluation, fluorescence microscopic studies etc. Complete dysregulation of key players of the Notch signalling pathway was observed in both: cells of the ocular surface as well as those in the murine visual cortex post pesticide exposure, indicating activities relating to cell proliferation, differentiation and wound healing in the pesticide exposed samples. Ultra-microscopic analyses corroborated our findings by revealing the loss of fine neural processes in the visual cortex of the pesticide exposed murine samples, thereby hinting at delayed perception to visual stimuli. In vivo evaluations of the functional capacity of the neuroanatomical structures along the visual pathway also confirmed that pesticide exposure leads to severe damage along the various parts of the visual pathway, right from the ocular surface to the visual cortex.

Role of Zr6 Metal Nodes in Zr-Based Metal-Organic Frameworks for Catalytic Detoxification of Pesticides

Pesticides are chemicals widely used for agricultural industry, despite their negative impact on health and environment. Although various methods have been developed for pesticide degradation to remedy such adverse effects, conventional materials often take hours to days for complete decomposition and are difficult to recycle. Here, we demonstrate the rapid degradation of organophosphate pesticides with a Zr-based metal-organic framework (MOF), showing complete degradation within 15 min. MOFs with different active site structures (Zr node connectivity and geometry) were compared, and a porphyrin-based MOF with six-connected Zr nodes showed remarkable degradation efficiency with half-lives of a few minutes. Such a high efficiency was further confirmed in a simple flow system for several cycles. This study reveals that MOFs can be highly potent heterogeneous catalysts for organophosphate pesticide degradation, suggesting that coordination geometry of the Zr node significantly influences the catalytic activity.

Effects of polyhydroxyfullerenes on organophosphate-induced toxicity in mice

Two polyhydroxyfullerenes, which decrease organophosphate (OP)-induced acetylcholinesterase (AChE) inhibition in vitro, were administered by the intraperitoneal (ip) route or applied topically at doses of 0.9-24 mg/kg to protect adult male mice from enzyme-inhibiting and behavioral effects indicative of OP toxicity resulting from exposure to 1.7 - 2 mg/kg diphosphorofluoridate (DFP) ip or 2.3 - 2.7 mg paraoxon topical. Dosing paradigms included OP-fullerene simultaneous administration by the ip route, and 20 min post-OP polyhydroxyfullerene treatment topically. Benefits of OP sequestration by the polyhydroxyfullerene were noted and were dependent on the OP compound as well as timing and route of the polyhydroxyfullerene treatment.

Multi-stimuli responsive heterotypic hydrogels based on nucleolipids show selective dye adsorption

Analogous to nucleic acids, the building blocks of nucleic acids and their derivatives are widely used to create supramolecular architectures for application mainly in the field of biomedicine. Here, we describe the construction of a multi-stimuli responsive and toxic dye adsorbing heterotypic hydrogel system formed using simple nucleoside-fatty acid conjugates. The nucleolipids are derived by coupling fatty acid chains of different lengths at the 5' position of ribothymidine and uridine. The nucleolipids in the presence of a strong base (e.g. NaOH) undergo partial hydrolysis, which triggers the self-assembly of the hydrolysed components resulting in the formation of heterotypic hydrogels. Notably, the gels are formed specifically in the presence of Na+ ions as other ions such as Li+ and K+ did not support the hydrogelation process. Systematic analysis by microscopy, NMR, single crystal and powder X-ray diffraction and rheology indicated that the deprotonated nucleolipid and fatty acid salt interdigitate and provide necessary electrostatic interactions supported by Na+ ions to set the path for the hierarchical assembly process. Notably, the hydrogels are highly sensitive to external stimuli, wherein gel-sol transition can be reversibly controlled by using temperature, pH and host-guest interaction. One of the hydrogels made of 5'-O-myristate-conjugated ribothymidine was found to selectively adsorb cationic dyes such as methylene blue and rhodamine 6G in a recyclable fashion. Taken together, the easily scalable assembly, multi-stimuli responsiveness and ability to capture and release dyes highlight the potential of our nucleolipid hydrogel system in material applications and in the treatment of dye industry wastes.

Establishment of resveratrol and its derivatives as neuroprotectant against monocrotophos-induced alteration in NIPBL and POU4F1 protein through molecular docking studies

Monocrotophos (MCP) is a broad spectrum organophosphorus insecticide, which is widely used as foliar spray to the different important crops. MCP may reach the soil and the aquatic environment directly or indirectly during and after the application, which leads to the different environmental issues. MCP is found to be associated with neurotoxicity and its toxic effects have been monitored during different stages of neuronal development. Identification of gene expression in MCP-induced neurotoxicity during neuronal developmental stage is a major area of genomic research interest. In accordance with this identification, screening of potential neuroprotective, natural resources are also required as a preventive aspects by targeting the impaired genes. In this current course of work, microarray experiment has been used to identify genes that were expressed in monocrotophos (MCP)-induced mesenchymal stem cells (MSC) and also the neuroprotectant activity of RV on MCP-exposed MSCs. Microarray experiment data have been deposited in NCBI's Gene Expression Omnibus database and are accessible through GEO Series accession number GSE121261. In this paper, we have discussed two important genes NIPBL (nipped-B-like protein) and POU4F1 (POU domain, class 4, transcription factor 1). These genes were found to be significantly expressed in MCP-exposed MSC and show minimum expression in presence of RV. Homology modelling and docking study was done to identify the interaction and binding affinity of resveratrol and its derivatives with NIPBL and POU4F1 protein. Docking analysis shows that RV and its derivatives have strong interaction with NIPBL and POU4F1 protein hence proves the significance of resveratrol as potential neuroprotectant. This paper highlights the hazardous impact of MCP on neuronal development disorders and repairing potentiality of RV and its derivatives on altered genes involved in neuronal diseases. Graphical Abstract.