Influences of chlorpyrifos on antioxidant enzyme activities of Nilaparvata lugens

Mechanisms and Efficacy of Chinese Herbal Medicines in Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is one of the most common diseases in elderly men, the incidence of which gradually increases with age and leads to lower urinary tract symptoms (LUTS), which seriously affects the quality of life of patients. Chinese herbal medicines (CHMs) are widely used for the treatment of BPH in China and some other countries. To explore the molecular mechanisms of CHMs for BPH, we conducted a review based on peer-reviewed English-language publications in PubMed and Web of Science databases from inception to December 31, 2023. This article primarily reviewed 32 papers on the use of CHMs and its active compounds in the treatment of BPH, covering animal and cell experiments, and identified relevant mechanisms of action. The results suggest that the mechanisms of action of CHMs in treating BPH may involve the regulation of sex hormones, downregulation of cell growth factors, anti-inflammatory and antioxidative effects, inhibition of cell proliferation, and promotion of apoptosis. CHMs also exhibit α-blocker-like effects, with the potential to relax urethral smooth muscle and alleviate LUTS. Additionally, we also reviewed 4 clinical trials and meta-analyses of CHMs for the treatment of BPH patients, which provided initial evidence of the safety and effectiveness of CHMs treatment. CHMs treatment for BPH shows advantages as a multi-component, multi-target, and multi-pathway therapy, which can mitigate the severity of the disease, improve LUTS, and may become a reliable treatment option in the future.

Dynamics and regulatory role of circRNAs in Asian honey bee larvae following fungal infection

Non-coding RNA (ncRNA) plays a vital part in the regulation of immune responses, growth, and development in plants and animals. Here, the identification, characteristic analysis, and molecular verification of circRNAs in Apis cerana cerana worker larval guts were conducted, followed by in-depth investigation of the expression pattern of larval circRNAs during Ascosphaera apis infection and exploration of the potential regulatory part of differentially expressed circRNAs (DEcircRNAs) in host immune responses. A total of 3178 circRNAs in the larval guts of A. c. cerana were identified, with a length distribution ranging from 15 to 96,007 nt. Additionally, 155, 95, and 86 DEcircRNAs were identified in the in the 4-, 5-, and 6-day-old larval guts following A. apis infection. These DEcircRNAs were predicted to target 29, 25, and 18 parental genes relevant to 12, 20, and 17 GO terms as well as 144, 114, and 61 KEGG pathways, including 5 cellular and 4 humoral immune pathways. Complex competing endogenous RNA (ceRNA) regulatory networks were detected as being formed among DEcircRNAs, DEmiRNAs, and DEmRNAs. The target DEmRNAs were engaged in 36, 47, and 47 GO terms as well as 331, 332, and 331 pathways, including 6 cellular and 6 humoral immune pathways. Further, 19 DEcircRNAs, 5 DEmiRNAs, and 3 mRNAs were included in the sub-networks relative to 3 antioxidant enzymes. Finally, back-splicing sites within 15 circRNAs and the difference in the 15 DEcircRNAs' expression between uninoculated and A. apis-inoculated larval guts were confirmed based on molecular methods. These findings not only enrich our understanding of bee host-fungal pathogen interactions but also lay a foundation for illuminating the mechanism underlying the DEcircRNA-mediated immune defense of A. c. cerana larvae against A. apis invasion. KEY POINTS: • The expression pattern of circRNAs was altered in the A. cerana worker larval guts following A. apis infection. • Back-splicing sites within 15 A. cerana circRNAs were verified using molecular approaches. DEcircRNAs potentially modulated immune responses and antioxidant enzymes in A. apis-challenged host guts.

Molecular biomarkers as tool for early warning by chlorpyrifos exposure on Alpine chironomids

Pesticides used in agriculture can be transported at a medium-high distance due to the drift effect, reaching even remote areas as mountain regions, glaciers, and snow cover. With the melting process, pesticides enter freshwater glacier ecosystems, becoming a threat to wildlife fauna, mainly dominated by Diptera Chironomidae. Chlorpyrifos (CPF), as one of the most commonly used pesticides in alpine vineyards and apple orchards, is frequently detected in icemelt waters. We selected as target species, larvae of the cold stenothermal chironomid Diamesa zernyi, collected in two glacier-fed streams (Presena and Amola) in the Italian Alps. Firstly, a de novo transcriptome was obtained, and secondly, a gene array was designed to study the molecular response of a wild population of D. zernyi exposed to three sub-lethal CPF concentrations corresponding to 1/100 LC10 (0.011 μg/L), 1/10 LC10 (0.11 μg/L), and LC10 (1.1 μg/L), for 24 h. The sub-organismal response was evaluated by Real-Time Polymerase Chain Reaction (RT-PCR), employing 40 genes related to essential metabolic routes as future candidates for biomarkers in wildlife chironomids. After 24 h, the endocrine system (E75, E93, EcR, and Met), detoxification response (GSTO3, GSTS1), and stress response (hsp75, hsp83, HYOU1) were altered. CPF seems to act as an endocrine disruptor and could lead to defective larval development, disrupted cellular homeostasis through heat shock proteins (HSPs) alteration (defective protein folding and mitochondrial functions), as well as oxidative damage (confirmed by increased GST expression). For the first time, molecular studies detected early alarm signals in wildlife in glacier environments. Our findings confirm the high environmental risk of CPF affecting aquatic insect metabolism and raise the level of concern about this pesticide in high altitude water bodies, generally considered pristine. Furthermore, this study emphasizes the incipient need to use non-model organisms for the evaluation of natural ecosystems. We also highlight the demand for research into new molecular biomarkers, and the importance of including molecular approaches in toxicology evaluations to detect the early adverse effects of pollutants.

Croton campestris A. St.-Hill Methanolic Fraction in a Chlorpyrifos-Induced Toxicity Model in Drosophila melanogaster: Protective Role of Gallic Acid

Croton campestris A. St-Hill popularly known as "velame do campo" is a native species of the savannah from northeastern Brazil, being used in folk medicine due to its beneficial effects in the treatment of many diseases, inflammation, detoxification, gastritis, and syphilis; however, its potential use as an antidote against organophosphorus compound poisoning has not yet been shown. Here, the protective effect of the methanolic fraction of C. campestris A. St.-Hill (MFCC) in Drosophila melanogaster exposed to chlorpyrifos (CP) was investigated. Flies were exposed to CP and MFCC during 48 h through the diet. Following the treatments, parameters such as mortality, locomotor behavior, and oxidative stress markers were evaluated. Exposure of flies to CP induced significant impairments in survival and locomotor performance. In parallel, increased reactive oxygen species and lipoperoxidation occurred. In addition, the activity of acetylcholinesterase was inhibited by CP, and superoxide dismutase and glutathione S-transferase activity was induced. Treatment with MFCC resulted in a blockage of all CP-induced effects, with the exception of glutathione S-transferase. Among the major compounds found in MFCC, only gallic acid (GA) showed a protective role against CP while quercetin and caffeic acid alone were ineffective. When in combination, these compounds avoided the toxicity of CP at the same level as GA. As far as we know, this is the first study reporting the protective effect of MFCC against organophosphate toxicity in vivo and highlights the biotechnological potential of this fraction attributing a major role in mediating the observed effects to GA. Therefore, MFCC may be considered a promising source for the development of new therapeutic agents for the treatment of organophosphate intoxications.

Metarhizium anisopliae CQMa128 regulates antioxidant/detoxification enzymes and exerts acaricidal activity against Psoroptes ovis var. cuniculi in rabbits: A preliminary study

The entomopathogenic fungi Metarhizium anisopliae is highly pathogenic toward arthropods. Here, we evaluated the efficacy of a commercial formulation of M. anisopliae against P. ovis var. cuniculi in vivo and in vitro and explored the acaricidal mechanism of M. anisopliae by determining the antioxidant/detoxification-related enzymes activities including glutathione S-transferase (GST), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in mites. The results showed that M. anisopliae had high acaricidal activity against P. ovis var. cuniculi in vitro, in a time- and dose-dependent manner, with 83.33 % mortality at day 9 and a median lethal time (LT₅₀) of 6.10 days after applying 6.14 × 10⁹ conidia/ml of M. anisopliae. In vivo experiments, M. anisopliae achieved 100 % therapeutic effect after 3 days, compared with only 62.21 % for ivermectin. Enzyme assays showed that M. anisopliae significantly upregulated activities of GST, SOD and CAT in Psoroptes mites. The results indicate that M. anisopliae may be an effective biological agent for control of P. ovis var. cuniculi infestations in rabbits and the acaricidal activity may be associated with the changes of enzyme activities of the detoxification and antioxidant system in Psoroptes mites.

Influence of Metarhizium anisopliae (IMI330189) and Mad1 protein on enzymatic activities and Toll-related genes of migratory locust

Efficacy of Metarhizium anisopliae strain (IMI330189) and Mad1 protein alone or in combination by feeding method to overcome immune-related enzymes and Toll-like pathway genes was investigated in migratory locust. M. anisopliae (IMI330189) is a potent and entomopathogenic fungal strain could be effectively used against insect pests. Similarly, Mad1 protein adheres to insect cuticle, causing virulence to insects. We confirmed maximum 55% of mortality when M. anisopliae (IMI330189) and Mad1 was applied in combination. Similarly, increased PO activity was observed in locust with combined dose of Mad1 + IMI330189 whereas PO, POD, and SOD activities reduced using Mad1 independently. Four Toll-like signaling pathway genes (MyD88, Cactus, Pelle, and CaN) were investigated from midgut and body of the migratory locust after 72 h of treatments. Subsequently, the expression of MyD88 in the midgut and body significantly decreased with the application of Mad1 and Mad1 + IMI330189. Performance of these treatments was absolutely non-consistent in both parts of insects. Meanwhile, IMI330189 significantly raised the expression of Cactus in both midgut and body. However, the combined treatment (Mad1 + IMI330189) significantly reduced the Cactus expression in both body parts. Pelle expression was significantly increased in the midgut with the application of independent treatment of Mad1 and IMI330189 whereas the combined treatment (Mad1 + IMI330189) suppressed the Pelle expression in midgut. Its expression level was absolutely higher in body with the application of IMI330189 and Mad1 + IMI330189 only. On the other hand, Mad1 significantly increased the expression of CaN in midgut. However, all three treatments significantly affected and suppressed the expression of CaN gene in body of locust. This shows that the applications of M. anisopliae and Mad1 protein significantly affected Toll signaling pathway genes, which ultimately increased level of susceptibility of locust. However, their effect was significantly different in both parts of locust which recommends that the Toll-related genes are conserved in midgut instead of locust body.

Insecticides induce the co-expression of glutathione S-transferases through ROS/CncC pathway in Spodoptera exigua

Glutathione S-transferases (GSTs) are a family of multifunctional enzymes that are involved in detoxification of electrophilic toxic compounds. Although the co-induced expression of GST genes by insecticides in insects has been documented in recent years, the underlying regulatory mechanisms are not understood. In this study, a total of thirty-one cytosolic S. exigua GSTs (SeGSTs) was cloned and identified. The bioinformatics and gene expression patterns were also analyzed. Out of them, SeGSTe9, SeGSTs6, SeGSTe1, SeGSTe6, SeGSTe8, SeGSTe14, and SeGSTd1 were significantly co-expressed following exposure to three insecticides (lambda-cyhalothrin, chlorpyrifos and chlorantraniliprole). The analysis of upstream sequences revealed that all of these seven SeGSTs harbored CncC/Maf binding site. The luciferase reporter assay showed that the pGL3-SeGST promoter construct exhibited a significant increase in luciferase activities after exposure to insecticides, and mutation of CncC/Maf binding site diminish the induction effect. These data indicate that CncC/Maf pathway regulates the co-expression of GST genes in response to different insecticides in S. exigua. Insecticides significantly enhanced the ROS content and treatment with the ROS inhibitor N-acetylcysteine (NAC) decreased the insecticide-induced luciferase activities of the PGL3-GSTe6 promoter construct, but not the CncC-mutated construct. These results indicate that ROS mediates GST gene expression after exposure to insecticides through CncC/Maf pathway. Overall, these data show that insecticides induce the co-expression of glutathione S-transferases through the ROS/CncC pathway in S. exigua.

Mechanisms of resistance to thiamethoxam and dinotefuran compared to imidacloprid in the brown planthopper: Roles of cytochrome P450 monooxygenase and a P450 gene CYP6ER1

The brown planthopper (BPH, Nilaparvata lugens) has developed high resistance to the first-generation neonicotinoids (imidacloprid). With commercialization and widespread field use of the second-(thiamethoxam) and third-(dinotefuran) generation neonicotinoids, resistance to these insecticides is also reported. We investigated the cytochrome P450 monooxygenase-mediated detoxification in thiamethoxam- and dinotefuran- resistant in comparison to imidacloprid-resistant strains of BPH. In the three moderately resistant BPH strains selected separately with the three insecticides from a same susceptible strain, P450 activities were significantly enhanced over the susceptible control. Seven of 26 tested P450 genes were up-regulated and CYP6ER1 was a strongly over-expressed gene in all the three resistant strains. Knockdown of CYP6ER1 in the susceptible insects reduced P450 activity, retarded nymph growth and significantly increased sensitivity to each one of the three neonicotinoids. Taken together, we show that enhanced P450 activity and over-expression of CYP6ER1 gene are involved in BPH resistance to thiamethoxam and dinotefuran as to imidacloprid. These findings are of significance in management thiamethoxam and dinotefuran resistance in the BPH, especially in the management of potential cross-resistance to the three generations of neonicotinoids.

Nuclear factor erythroid-derived 2-related factor 2 activates glutathione S-transferase expression in the midgut of Spodoptera litura (Lepidoptera: Noctuidae) in response to phytochemicals and insecticides

Detoxication enzymes play an important role in insect resistance to xenobiotics such as insecticides and phytochemicals. We studied the pathway for activating the expression of glutathione S-transferases (GSTs) in response to selected xenobiotics. An assay of the promoter activity of GST epsilon 1 (Slgste1) of Spodoptera litura led to the discovery of a cis-regulating element. An antioxidant response element was activated in response to indole-3-carbinol (I3C) and chlorpyrifos (CPF) and was able to bind with the xenobiotic sensor protein nuclear factor erythroid-derived 2-related factor 2 (SlNrf2). SlNrf2 and Slgste1 were responsive to reactive oxygen species induced by I3C and CPF in a S. litura cell line, as well as in S. litura midguts. SlNrf2 RNA interference (RNAi) reduced the message RNA levels of Slgste1 and the peroxidase activity of GSTs in response to I3C, xanthotoxin, CPF and deltamethrin. SlNrf2 RNAi and inhibitor treatment of GST activity decreased the viability of I3C-treated cells. These results indicate that SlNrf2 activates the expression of GSTs in response to oxidative stresses caused by exposure to xenobiotics.

Biochemical basis of synergism between pathogenic fungus Metarhizium anisopliae and insecticide chlorantraniliprole in Locusta migratoria (Meyen)

We challenged Locusta migratoria (Meyen) grasshoppers with simultaneous doses of both the insecticide chlorantraniliprole and the fungal pathogen, Metarhizium anisopliae. Our results showed synergistic and antagonistic effects on host mortality and enzyme activities. To elucidate the biochemical mechanisms that underlie detoxification and pathogen-immune responses in insects, we monitored the activities of 10 enzymes. After administration of insecticide and fungus, activities of glutathione-S-transferase (GST), general esterases (ESTs) and phenol oxidase (PO) decreased in the insect during the initial time period, whereas those of aryl acylamidase (AA) and chitinase (CHI) increased during the initial period and that of acetylcholinesterase (AChE) increased during a later time period. Activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) decreased at a later time period post treatment. Interestingly, treatment with chlorantraniliprole and M. anisopliae relieved the convulsions that normally accompany M. anisopliae infection. We speculate that locust mortality increased as a result of synergism via a mechanism related to Ca²⁺ disruption in the host. Our study illuminates the biochemical mechanisms involved in insect immunity to xenobiotics and pathogens as well as the mechanisms by which these factors disrupt host homeostasis and induce death. We expect this knowledge to lead to more effective pest control.

Impacts of oxidative stress on acetylcholinesterase transcription, and activity in embryos of zebrafish (Danio rerio) following Chlorpyrifos exposure

Organophosphate pesticides cause irreversible inhibition of AChE which leads to neuronal overstimulation and death. Thus, dogma indicates that the target of OP pesticides is AChE, but many authors postulate that these compounds also disturb cellular redox processes, and change the activities of antioxidant enzymes. Interestingly, it has also been reported that oxidative stress plays also a role in the regulation and activity of AChE. The aims of this study were to determine the effects of the antioxidant, vitamin C (VC), the oxidant, t-butyl hydroperoxide (tBOOH) and the organophosphate Chlorpyrifos (CPF), on AChE gene transcription and activity in zebrafish embryos after 72h exposure. In addition, oxidative stress was evaluated by measuring antioxidant enzymes activities and transcription, and quantification of total glutathione. Apical effects on the development of zebrafish embryos were also measured. With the exception of AChE inhibition and enhanced gene expression, limited effects of CPF on oxidative stress and apical endpoints were found at this developmental stage. Addition of VC had little effect on oxidative stress or AChE, but increased pericardial area and heartbeat rate through an unknown mechanism. TBOOH diminished AChE gene expression and activity, and caused oxidative stress when administered alone. However, in combination with CPF, only reductions in AChE activity were observed with no significant changes in oxidative stress suggesting the adverse apical endpoints in the embryos may have been due to AChE inhibition by CPF rather than oxidative stress. These results give additional evidence to support the role of prooxidants in AChE activity and expression.

Cloning and expression of ophB gene encoding organophosphorus hydrolase from endophytic Pseudomonas sp. BF1-3 degrades organophosphorus pesticide chlorpyrifos

Chlorpyrifos is an organophosphate pesticide that has adverse effect on animals and plants. We isolated endophytic bacterial strain, Pseudomonas sp. BF1-3, from balloon flower root which can hydrolyze chlorpyrifos. A gene (ophB) encoding a protein involved in chlorpyrifos degradation from this strain was cloned into Escherichia coli DH5α for confirming enzyme activity. After sequencing, total 1024bp nucleotide sequences were found in the open reading frame of ophB. The chlorpyrifos degradation patterns by E. coli DH5α (ophB) were observed. During incubation in minimal salt (M9) medium supplemented with chlorpyrifos (100mgL(-1)), the E. coli DH5α harboring ophB degraded about 97% initial chlorpyrifos (100mgL(-1)) and accumulated 86mgL(-1) 3,5,6-trichloro-2-pyridinol (TCP) within 9 days. In addition, optical density (OD) of E. coli DH5α (ophB) culture at 600nm was increased from 0.172 to 1.118 within 2 days of inoculation in the chlorpyrifos supplemented M9 medium. The estimated molecular weight of purified OphB protein was determined to be 31.4kDa by SDS-PAGE. The OphB enzyme was most active at pH 8 and an optimal temperature around 35°C. These results indicate that endophytic bacteria are supposed to be useful for biological control of environments contaminated with pesticides.