A Comprehensive Study on the Mechanistic Way of Hexaflumuron and Hymexazol Induced Neurobehavioral Toxicity in Rats

Ameliorative potential of Populus alba leaf powder against hexaflumuron exposure in Nile tilapia: immune-antioxidant, biochemical, histological, and transcriptomic analysis

Contamination of the aquatic bodies with pesticides is a serious issue that hinders the aquaculture industry worldwide. Preventing aquatic pollution is a challenge, and finding eco-friendly strategies could help to overcome such a problem. Herein, we studied the antagonistic potential of dietary fortification of white poplar (Populus alba; PA) leaf powder against chronic hexaflumuron (HX) toxicity in Nile tilapia (Oreochromis niloticus). Fish (n = 200; 36.20 ± 1.55 g) were eventually grouped into four groups with five replicates and kept for 60 days. The C (control) and PA groups were fed basal diets fortified with 0 and 6 g PA/kg diet, respectively, without toxicant exposure. Additionally, the HX and PA + HX groups were exposed to 1/10 of 96-h lethal concentration 50 (96-h LC50) of HX (0.72 mg/L) and given the same diets as those of the C and PA groups, respectively. The biochemical, immune-antioxidant, survival, splenic gene expression, and tissue microstructure were assessed at the end of the exposure time. The outcomes of this research showed that exposure to HX resulted in biochemical disorders (elevated blood glucose, cortisol, alanine aminotransferase, aspartate aminotransferase, and creatinine) in Nile tilapia. Immune suppression (lowered complement 3 and immunoglobulin M) and oxidative stress (lowered superoxide dismutase and catalase activity and higher malondialdehyde) were consequences of HX toxicity. The splenic expression of nuclear factor-kappa β65, kelch-like ECH-associated protein 1, and heme oxygenase-1 was down-regulated by HX exposure. Various pathological changes were noted as consequences of HX exposure in the liver, kidney, and spleen tissues. By feeding on the PA diet, the fish survivability was increased (90%) compared to the non-fed group (76%). Additionally, the biochemical disorders were modulated, and immune responses were enhanced due to PA feeding. Amelioration of the oxidative stress condition (by improving the antioxidant enzyme activity and lowering malondialdehyde) and the immune gene expression were noticed when the HX-exposed Nile tilapia were fed on the PA diet. A noticeable soothing effect was noticed by feeding on the PA diet against the pathological changes in the Nile tilapia tissues. Overall, feeding on a 6 g PA/kg diet ameliorates the detrimental consequences of HX toxicity in Nile tilapia.

Epigallocatechin gallate-rich fraction alleviates histamine-induced neurotoxicity in rats via inactivating caspase-3/JNK signaling pathways

Ingestion of prominent levels of histamine (HIS) leads to dangerous effects on biological systems. The most frequent and active catechin in green tea is epigallocatechin gallate which has strong antioxidant properties. Our research intended to investigate the possible neuroprotective effect of epigallocatechin gallate-rich fraction (EGCGR) against HIS-inducing neurotoxicity. Six groups of male rats (n = 5) were used as follows: (1) Distilled water, (2&3) EGCGR (100-200 mg/kg BWT/day, respectively), (4) HIS (1750 mg/kg BWT/week, (5&6) HIS + EGCGR. Administration of HIS for 14 days induced severe neurobehavioral changes including depression, incoordination, and loss of spatial memory. Extensive neuronal degeneration with diffuse gliosis was the prominent histopathological lesion observed and confirmed by strong immunostaining of casp-3, Cox-2, and GFAP. Additionally, the HIS group showed a significantly higher MDA level with lower CAT and GSH activity than the control group. Moreover, HIS promoted apoptosis, which is indicated by increasing JNK, and Bax and decreasing Bcl-2 gene expressions. Otherwise, the oral intake of EGCGR with HIS improved all neurotoxicological parameters induced by HIS. We concluded that HIS could cause neurotoxicity via an upset of the equilibrium between oxidants and antioxidants which trigger apoptosis through modulation of JNK signaling pathway. Furthermore, EGCGR has either direct or indirect antihistaminic effects.

Exosomal therapy mitigates silver nanoparticles-induced neurotoxicity in rats

INTRODUCTION

Our investigation aims to appraise the neuroprotective impact of Bone Marrow-Mesenchymal Stem Cells (BM-MSCs) derived exosomes against Ag NPs-inducing neurotoxicity in rats.

MATERIALS AND METHODS

Twenty-four albino rats were divided into 3 groups. Group I (control negative), Group II (intraperitoneally injected with Ag NPs for 28 days, whereas Group III (intraperitoneally injected with Ag NP and BM-MSCs derived exosomes.

RESULTS

There was a marked elevation of Malondialdehyde (MDA) along with a reduction of brain antioxidants, Gamma-aminobutyric acid (GABA) and Monoamine Oxidase (MAO) in the Ag NPs receiving group. Ag NPs upregulated c-Jun N-terminal Kinases (JNK) genes and c-Myc and downregulated the tissue inhibitors of metalloproteinases (TIMP-1) and Histone deacetylase 1 (HDAC1) genes. Otherwise, the co-treatment of BM-MSCs derived exosomes with Ag NPs could markedly increase the rat's body weight, activity and learning while, decreasing anxiety, restoring all the toxicological parameters and improving the microscopic appearance of different brain areas.

CONCLUSION

BM-MSCs-derived exosomes downregulated both apoptotic and inflammatory mediators and upregulated the antiapoptotic genes. BM-MSCs-derived exosomes exhibit a great therapeutic effect against the neurotoxic effects of Ag NPs.

Silicon-mediated resilience: Unveiling the protective role against combined cypermethrin and hymexazol phytotoxicity in tomato seedlings

Insecticides and fungicides present potential threats to non-target crops, yet our comprehension of their combined phytotoxicity to plants is limited. Silicon (Si) has been acknowledged for its ability to induce crop tolerance to xenobiotic stresses. However, the specific role of Si in alleviating the cypermethrin (CYP) and hymexazol (HML) combined stress has not been thoroughly explored. This study aims to assess the effectiveness of Si in alleviating phytotoxic effects and elucidating the associated mechanisms of CYP and/or HML in tomato seedlings. The findings demonstrated that, compared to exposure to CYP or HML alone, the simultaneous exposure of CYP and HML significantly impeded seedling growth, resulting in more pronounced phytotoxic effects in tomato seedlings. Additionally, CYP and/or HML exposures diminished the content of photosynthetic pigments and induced oxidative stress in tomato seedlings. Pesticide exposure heightened the activity of both antioxidant and detoxification enzymes, increased proline and phenolic accumulation, and reduced thiols and ascorbate content in tomato seedlings. Applying Si (1 mM) to CYP- and/or HML-stressed seedlings alleviated pigment inhibition and oxidative damage by enhancing the activity of the pesticide metabolism system and secondary metabolism enzymes. Furthermore, Si stimulated the phenylpropanoid pathway by boosting phenylalanine ammonia-lyase activity, as confirmed by the increased total phenolic content. Interestingly, the application of Si enhanced the thiols profile, emphasizing its crucial role in pesticide detoxification in plants. In conclusion, these results suggest that externally applying Si significantly alleviates the physio-biochemical level in tomato seedlings exposed to a combination of pesticides, introducing innovative strategies for fostering a sustainable agroecosystem.

Hexaflumuron insecticide exposure induces behavior alterations, hemato-biochemical disorders, antioxidant-immune dysfunction, and histopathological alterations in Nile tilapia (Oreochromis niloticus)

Hexaflumuron (HEX) insecticide is widely used in agriculture practices to fight crop insects. The toxicological effect of HEX on Nile tilapia (Oreochromis niloticus) was investigated in this study. Two hundred and forty fish (35.50 ± 1.45 g) were divided into six groups in four replicates (40 fish/group; 10 fish/replicate) and were exposed to six distinct HEX concentrations (0, 2, 4, 6, 8, and 10 mg L-1) for 96-h. The 96-h lethal concentration 50 (96-h LC50) of HEX was calculated to be 7.19 mg L-1. The fish exhibited reduced surface and middle swimming, aggressiveness, and tail-spreading behaviors with increasing bottom swimming and resting patterns after HEX exposure. HEX exposure resulted in body bleeding and fin rot. The erythrogram (red blood cell count, hemoglobin, and packed cell volume %) was significantly reduced with increased mean corpuscular volume by HEX exposure. HEX exposure decreased the white blood cells (WBCs) and differential WBC counts. Acute HEX exposure raised 8-hydroxy-2-deoxyguanosine level while lowering brain acetylcholine esterase activity. HEX exposure caused hepato-renal dysfunction and increased stress-related parameters (glucose and cortisol). Exposure to HEX reduced the immune responses (lysozyme, nitric oxide, immunoglobulin M, and complement 3). A substantial decrease in the antioxidant variables (reduced glutathione content and catalase) with increasing the malondialdehyde was noted by HEX exposure. Moreover, histopathological changes resulted from HEX exposure in the gills, liver, kidney, and spleen. These results indicate that HEX exposure induced behavioral changes, hepato-renal dysfunction, and immune-antioxidant disruption, indicating a possible physiological disruption in O. niloticus.

Novel insights on the probable mechanism associated with histamine oral model-inducing neuropathological and behavioral toxicity in rats

Histamine (HIS) is an important chemical mediator that causes vasodilation and contributes to anaphylactic reactions. Recently, HIS is an understudied neurotransmitter in the central nervous system, and its potential role in neuroinflammation and neurodegeneration is a critical area of research. So, the study's goal is to investigate the consequences of repeated oral intake of HIS on the rat's brain and explore the mechanistic way of its neurotoxicity. Thirty male rats were divided into three groups (n = 10). The following treatments were administered orally to all rats every day for 14 days. Group (1) was given distilled water, whereas groups (2 & 3) were given HIS at dosage levels 250 and 500 mg/kg body weight (BWT), respectively. Brain tissue samples were collected at 7- and 14-days from the beginning of the experiment. Our results revealed that continuous oral administration of HIS at both doses for 14 days significantly reduced the BWT and induced severe neurobehavioral changes, including depression, dullness, lethargy, tremors, abnormal walking, and loss of spatial learning and memory in rats. In all HIS receiving groups, HPLC data showed a considerable raise in the HIS contents of the brain. Additionally, the daily consumption of HIS causes oxidative stress that is dose- and time-dependent which is characterized by elevation of malondialdehyde levels along with reduction of catalase activity and reduced glutathione levels. The neuropathological lesions were commonly observed in the cerebrum, striatum, and cerebellum and confirmed by the immunohistochemistry staining that demonstrating moderate to strong caspase-3 and inducible nitric oxide synthase expressions in all HIS receiving groups, mainly those receiving 500 mg/kg HIS. NF-κB, TNF-α, and IL-1β gene levels were also upregulated at 7- and 14-days in all HIS groups, particularly in those getting 500 mg/kg. We concluded that ROS-induced apoptosis and inflammation was the essential mechanism involved in HIS-mediated neurobehavioral toxicity and histopathology.

Ameliorative effects of rutin and rutin-loaded chitosan nanoparticles on testicular oxidative stress and histological damage induced by cyclophosphamide in male rats

Cyclophosphamide (CP) is broadly used to kill various tumor cells; however, its repeated uses have been reported to cause reproductive dysfunction and infertility. Natural flavonoid, rutin (RUT), possesses strong antioxidant and antiapoptotic activity that is attributed to ameliorate the reproductive dysfunction induced by CP. Many previous studies proved that the formulation of flavonoids in nanoemulsion has a promising perspective in mitigating the side effects of chemotherapy. Therefore, the main objective of this study was to investigate the ameliorative effects of RUT and RUT-loaded chitosan nanoparticles (RUT-CH NPs) against CP-induced reproductive dysfunction in male rats. For this aim, thirty-six male albino rats were randomly allocated into six groups as follows: control, RUT, RUT-CH NPs, CP, CP + RUT, and CP + RUT-CH NPs. In the CP groups, a single intraperitoneal injection of CP (150 mg/kg bwt) was administered on the first day of the experiment. RUT and RUT-CH NPs were orally administered either alone or with CP injection at a dose of 10 mg/kg bwt per day for 60 days. The results revealed that CP administration caused significant testicular oxidative stress damage through increasing the nitric oxide and malondialdehyde levels as well as decreasing the total antioxidant capacity and reduced glutathione contents. It also impaired spermatogenesis and steroidogenesis via altering the transcription levels of CYP11A1, HSD-3b, StAR, Bax, bcl-2, and Nrf-2 genes. Otherwise, the oral intake of either RUT or RUT-CH NPs with CP injection effectively attenuated these alterations and significantly improved the microscopic appearance of testicular tissue. In conclusion, this study highlights the potential of RUT either free or NPs in mitigating CP-induced testicular dysfunction via its antioxidant and anti-apoptotic properties.

Dissipation patterns, residue analysis, and risk evaluation of hexaflumuron in turnip and cauliflower under Chinese growth conditions

Hexaflumuron has been globally registered over 2 decades to control the pests in brassicaceous vegetables, while data on its dissipation and residues in turnip and cauliflower is scarce. Herein, field trials were carried out at six representative experimental sites to study the dissipation behaviors and terminal residues of hexaflumuron in turnip and cauliflower. The residual amounts of hexaflumuron were extracted using a modified QuEChERS and analyzed with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the chronic dietary risk to Chinese populations was evaluated, and the maximum residue limit (MRL) in cauliflower, turnip tubers, and turnip leaves was calculated by the OECD MRL calculator. The single first-order kinetics model was the best-fitted kinetics model for hexaflumuron dissipation in cauliflower. The indeterminate order rate equation and first-order multi-compartment kinetic model were the best formulae for hexaflumuron dissipation in turnip leaves. The half-lives of hexaflumuron ranged from 0.686 to 1.35 and 2.41 to 6.71 days in cauliflower and turnip leaves, respectively. The terminal residues of hexaflumuron in turnip leaves of 0.321-9.59 mg/kg were much higher than in turnip tubers of < 0.01-0.708 mg/kg and cauliflower of < 0.01-1.49 mg/kg at sampling intervals of 0, 5, 7, and 10 days. The chronic dietary risk of hexaflumuron in the preharvest interval of 7 days was lower than 100% and much higher than 0.01%, indicating acceptable but nonnegligible health hazards for Chinese consumers. Therefore, MRL values of hexaflumuron were proposed as 2, 0.8, and 10 mg/kg in cauliflower, turnip tubers, and turnip leaves, respectively.

Potential Mechanisms of Imidacloprid-Induced Neurotoxicity in Adult Rats with Attempts on Protection Using Origanum majorana L. Oil/Extract: In Vivo and In Silico Studies

Imidacloprid (IMI) insecticide is rapidly metabolized in mammals and contributes to neurotoxicity via the blocking of nicotinic acetylcholine receptors, as in insects. Origanum majorana retains its great antioxidant potential in both fresh and dry forms. No data is available on the neuroprotective effect of this plant in laboratory animals. In this context, aerial parts of O. majorana were used to prepare the essential oil (OMO) and methanol extract (OME). The potential neuroprotective impact of both OMO and OME against IMI-induced neurotoxicity in rats was explored. Forty-two rats were divided into 6 groups, with 7 rats in each one. Rats were daily administered the oral treatments: normal saline, OMO, OME, IMI, IMI + OMO, and IMI + OME. Our results revealed the identification of 55 components in O. majorana essential oil, most belonging to the oxygenated and hydrocarbon monoterpenoid group. Moreover, 37 constituents were identified in the methanol extract, mostly phenolics. The potent neurotoxic effect of IMI on rats was confirmed by neurobehavioral and neuropathological alterations and a reduction of both acetylcholine esterase (AchE) activity and dopamine (DA), serotonin (5HT), and γ-aminobutyric acid (GABA) levels in the brain. Exposure of rats to IMI elevates the malondialdehyde (MDA) levels and reduces the antioxidant capacity. IMI could upregulate the transcription levels of nuclear factor-κB (NF-κB), interleukin-1 β (IL-1β), and tumor necrosis factor (TNF-α) genes and express strong caspase-3 and inducible nitric oxide synthase (iNOS) immunostaining in most examined brain areas. On the other hand, rats coadministered OMO or OME with IMI showed a marked improvement in all of the studied toxicological parameters. In conclusion, cotreatment of O. majorana extracts with IMI can protect against IMI neurotoxicity via their potent antioxidant, anti-inflammatory, and anti-apoptotic effects. Thus, we recommend a daily intake of O. majorana to protect against insecticide's oxidative stress-mediated neuroinflammatory stress and apoptosis. The molecular docking study of linalool, rosmarinic acid, γ-terpene, and terpene-4-ol justify the observed normalization of the elevated iNOS and TNF-α levels induced after exposure to IMI.

Widespread use of toxic agrochemicals and pesticides for agricultural products storage in Africa and developing countries: Possible panacea for ecotoxicology and health implications

Chemicals used for storage majorly possess insecticidal activities - deterring destructive insect pests and microorganisms from stored agricultural produce. Despite the controversy about their safety, local farmers and agro-wholesalers still predominantly use these chemicals in developing countries, especially Africa, to ensure an all-year supply of agriproducts. These chemicals could have short- or long-term effects. Despite the state-of-the-art knowledge, factors such as poor education and awareness, limited agricultural subventions, quests for cheap chemicals, over-dosage, and many more are the possible reasons for these toxic chemicals' setback and persistent use in developing countries. This paper provides an up-to-date review of the environmental and ecological effects, as well as the health impacts arising from the indiscriminate use of toxic chemicals in agriproducts. Existing data link pesticides to endocrine disruption, genetic mutations, neurological dysfunction, and other metabolic disorders, apart from the myriad of acute effects. Finally, this study recommended several naturally sourced preservatives as viable alternatives to chemical counterparts and emphasized the invaluable role of education and awareness programs in mitigating the use in developing nations for a sustainable society.