Evaluation of ameliorative effect of curcumin on imidacloprid-induced male reproductive toxicity in wistar rats

Thirty-day oral exposure to acetamiprid induces biochemical and histological alterations in rat pancreas: protective effects of carnosine supplementation

Acetamiprid is a neonicotinoid insecticide used against various insect pests. Serious concerns are emerging regarding their adverse effects on non-target organisms and organs. This study aimed to investigate the mechanistic toxic effect of oral administration of acetamiprid at 21.7 and 43.4 mg/kg body weight on the histological structure and pancreatic function of male Wistar rats and the potential effect of carnosine in mitigating this toxicity for 30 consecutive days. Thirty-six animals were divided into six groups: the control group received distilled water, the second group received 200 mg/kg body weight of carnosine, two groups received 21.7 and 43.4 mg/kg of acetamiprid, and two groups received 21.7 and 43.4 mg/kg + 200 kg/kg body weight of acetamiprid and carnosine, respectively. Acetamiprid caused a significant decrease in body weight (p < 0.001), pancreatic somatic index (p < 0.001), and amylase level (p ≤ 0.0001) and increased lipase level (p ≤ 0.0001), blood glucose level (p ≤ 0.0001), histological scores (p ≤ 0.01), and malondialdehyde level (0.01 Collapse

Key Words

• Neonicotinoid insecticide
• Wistar rat
• carnosine
• pancreas
• subacute toxicity

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MESH Headings

• Animals
• Rats, Wistar
• Neonicotinoids/toxicity
• Neonicotinoids/administration & dosage
• Male
• Pancreas/drug effects
• Pancreas/pathology
• Pancreas/metabolism
• Carnosine/pharmacology
• Carnosine/administration & dosage
• Administration, Oral
• Insecticides/toxicity
• Insecticides/administration & dosage
• Amylases/metabolism
• Amylases/blood
• Rats
• Blood Glucose
• Oxidative Stress/drug effects
• Dietary Supplements
• Dose-Response Relationship, Drug

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Affiliation(s)

Imen Benchikh Laboratory of Applied Hydrology and Environment, Faculty of Science and Technology, University of Ain Temouchent, Ain Témouchent, Algeria Laboratoire de Nutrition, Pathologie, Agro-Biotechnologie et Santé (NuPABS), Department of biology, Faculty of Natural and Life sciences, Djillali Liabès University, Sidi Bel Abbès, Algeria
Kaddour Ziani Laboratory of Biotoxicology, Pharmacognosy and Biological Valorization of Plants, Department of Biology, University of Saida, Dr. Taher Moulay, Saida, Algeria
Abdelkrim Benalia Laboratory of Environment and Health Research (LRES), Faculty of Medicine, Djillali Liabès University, Sidi Bel Abbès, Algeria
Ahmed Abdelhammid Djebbar Laboratory of Environment and Health Research (LRES), Department of Biology, Faculty of Natural Sciences and Life, Djillali Liabès University, Sidi Bel Abbès, Algeria
Hayat Argoub Service of Anatomy & Pathology, University Hospital Center Hassani Adbelkader, Sidi Bel Abbès, Algeria
Méghit Boumediène Khaled Laboratoire de Nutrition, Pathologie, Agro-Biotechnologie et Santé (NuPABS), Department of biology, Faculty of Natural and Life sciences, Djillali Liabès University, Sidi Bel Abbès, Algeria

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Studies on ameliorative potentials of quercetin nanoparticles against imidacloprid induced subacute genotoxicity and histopathological alteration in Swiss albino mice

OBJECTIVE

Genotoxicity assays include micronucleus test, comet assay, and malformed sperm head used to investigate the protective potential of quercetin (Que) and Que nanoparticles against imidacloprid (IMI)-induced genotoxicity in Swiss albino mice.

METHODS

The ionic gelation procedure was used to synthesize the Que nanoparticles and characterized for their hydrodynamic diameter, zeta potential, scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, and encapsulation efficiency. A total of 48 mice were taken in eight groups with six animals in each group. Groups 1, 2, 3, and 4 received 3% gum acacia, 22 mg/kg IMI, 25 mg/kg Que and 25 mg/kg Que nanoparticles high dose (QNPs (HD)), respectively. Groups 5, 6, 7, and 8 received 22 mg/kg IMI + 25 mg/kg Que (IMI + Que), 22 mg/kg IMI + 25 mg/kg Que nanoparticles (IMI + QNPs (HD)), 22 mg/kg IMI + 12.5 mg/kg Que nanoparticle medium dose (IMI + QNPs (MD)), and 22 mg/kg IMI + 6.25 mg/kg Que nanoparticles low dose (IMI + QNPs (LD)), respectively.

RESULTS

The IMI causes genotoxicity in bone marrow cells by increasing the frequency of micronuclei and the comet tail length. Additionally, IMI is mutagenic to germ cells, as determined by a test for aberrant sperm heads. Both Que and Que nanoparticles lessen the genotoxicity that IMI induces when administered together or separately. Histopathological findings also revealed degenerative changes in bone marrow and testes in IMI administered group as compared to control.

CONCLUSION

Quercetin and Que nanoparticles showed marked ameliorative effect by restoring the degenerative changes produced by IMI.

Rosolic acid as a novel activator of the Nrf2/ARE pathway in arsenic-induced male reproductive toxicity: An in silico study

Male reproductive toxicity as a result of arsenic exposure is linked with oxidative stress and excessive generation of reactive oxygen species (ROS). It leads to an imbalance between ROS production and antioxidant defense mechanisms ultimately resulting in male infertility. The nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) is a transcription factor that responds to cellular stressors controlling the oxidative state, mitochondrial dysfunction, inflammation, and proteostasis. This study aims to investigate the potential of Rosolic acid (ROA) to act as a novel Nrf2 activator by mitigating oxidative stress to combat arsenic-induced male reproductive toxicity. The protein and ligands were prepared in the BIOVIA Discovery Studio, followed by protein-ligand docking using auto dock vina integrated with the PyRx-Virtual Screening Tool. Then the ADME properties were analyzed using the SwissADME tool to get a clear idea about the physicochemical properties, lipophilicity, water solubility, pharmacokinetics, and drug likeliness of ROA. It was followed by molecular dynamics simulation (MDS) studies using GROMACS. The 3D and 2D interaction maps revealed the interactions of Keap 1 with ROA. Keap1-ROA complex was found to have a binding energy of -7.8 kcal/mol. ROA showed 0 violations for Lipinski and 0 alerts each for PAINS and Brenk and a bioavailability score of 0.55. The BOILED-Egg representation showcases that ROA is predicted as passively crossing the blood-brain barrier (BBB). The MDS described 2FLU-ROA as a stable system. This work portrays that ROA can be a potent Nrf2 activator by exhibiting an inhibitory activity against the Keap1 protein and thus mitigating oxidative stress in arsenic-induced male reproductive toxicity.

Thiacloprid impairs reproductive functions of male Wistar rats

Global male infertility correlated to the rise of endocrine-disrupting chemicals, including insecticides, has grown into a pressing problem. Thiacloprid is one of the most commonly used neonicotinoids that accounts for more than 25% of the global pesticide industry. However, its impact on the reproductive system and male fertility has not been fully elucidated. The object of this study was to explore the adverse effects of thiacloprid on male Wistar rats' reproductive system. Thirty healthy male rats were separated into one of three groups: control group, and two groups that were orally administered with low (22.5 mg/kg) and high dose (62.1 mg/kg) of thiacloprid for 56 days. Thiacloprid significantly (p<0.05) reduced body weight and relative testicular weight, as well as sperm quality (count, motility, viability, and morphology), in a dose-dependent manner. THIA-treated groups revealed a large effect (d > 0.8) on semen quality with Cohen's d of (6.57, 8.82), (20.14, 23.54), and (2.81, 9.10) for count, motility, and viability respectively. Meanwhile, the serum testosterone level dropped while the levels of luteinizing and follicle-stimulating hormones increased. 17ꞵ-hydroxy steroid dehydrogenase and 3ꞵ-hydroxy steroid dehydrogenase levels were significantly decreased in a dose-dependent manner. The activity of the tested antioxidant enzymes catalase (CAT), glutathione reduced (GSH), and superoxide dismutase (SOD) exhibited a considerable decrease compared to the control group with a significant elevation in the lipid peroxidation activity as indicated by malondialdehyde (MDA) level. The testicular histology revealed degenerative changes in spermatogenic cells and interstitial tissue. Comet assay revealed DNA fragmentation in treated groups' testicular tissue. Thiacloprid exposure interferes with reproductive function and impairs male Wistar rat fertility. Such harmful consequences may also develop in humans frequently exposed to thiacloprid.

Pharmacotherapeutic potential of malvidin to cure imidacloprid induced hepatotoxicity via regulating PI3K/AKT, Nrf-2/Keap-1 and NF-κB pathway

Imidacloprid (IMI) is one of the top-notch insecticides that adversely affects the body organs including the liver. Malvidin (MAL) is a natural flavonoid which exhibits a wide range of pharmacological properties. This research was designed to evaluate the protective ability of MAL to counteract IMI instigated liver toxicity in rats. Thirty-two rats were divided into four groups including control, IMI (5mg/kg), IMI (5mg/kg) + MAL (10mg/kg) and MAL (10mg/kg) alone treated group. The recommended dosages were administrated through oral gavage for 4 weeks. It was revealed that IMI intoxication disrupted the PI3K/AKT and Nrf-2/Keap-1 pathway. Furthermore, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme-oxygenase-1 (OH-1) and glutathione reductase (GSR) were reduced while upregulating reactive oxygen species (ROS) and malondialdehyde (MDA) levels after IMI treatment. Moreover, IMI poisoning increased the levels of ALT (Alanine aminotransferase), AST (Aspartate transaminase), and ALP (Alkaline phosphatase) while reducing the levels of total proteins and albumin in hepatic tissues of rats. Besides, IMI administration escalated the expressions of Bcl-2-associated protein x (Bax) and cysteine-aspartic acid protease-3 (Caspase-3) while downregulating the expressions of B-cell lymphoma 2 (Bcl-2). Similarly, IMI intoxication, increased the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). Furthermore, IMI disrupted the normal architecture of hepatic tissues. However, MAL treatment remarkably protected the liver tissues via regulating abovementioned disruptions.

Non-acute exposure of neonicotinoids, health risk assessment, and evidence integration: a systematic review

Neonicotinoid pesticides are utilized against an extensive range of insects. A growing body of evidence supports that these neuro-active insecticides are classified as toxicants in invertebrates. However, there is limited published data regarding their toxicity in vertebrates and mammals. the current systematic review is focused on the up-to-date knowledge available for several neonicotinoid pesticides and their non-acute toxicity on rodents and human physiology. Oral lethal dose 50 (LD50) of seven neonicotinoids (i.e. imidacloprid, acetamiprid, clothianidin, dinotefuran, thiamethoxam, thiacloprid, and nitenpyram) was initially identified. Subsequently, a screening of the literature was conducted to collect information about non-acute exposure to these insecticides. 99 studies were included and assessed for their risk of bias and level of evidence according to the Office of Health and Translation (OHAT) framework. All the 99 included papers indicate evidence of reproductive toxicity, hepatotoxicity, nephrotoxicity, neurotoxicity, immunotoxicity, and oxidative stress induction with a high level of evidence in the health effect of rodents and a moderate level of evidence for human health. The most studied type of these insecticides among 99 papers was imidacloprid (55 papers), followed by acetamiprid (22 papers), clothianidin (21 papers), and thiacloprid (11 papers). While 10 of 99 papers assessed the relationship between clothianidin, thiamethoxam, dinotefuran, and nitenpyram, showing evidence of liver injury, dysfunctions of oxidative stress markers in the reproductive system, and intestinal toxicity. This systematic review provides a comprehensive overview of the potential risks caused by neonicotinoid insecticides to humans and rodents with salient health effects. However, further research is needed to better emphasize and understand the patho-physiological mechanisms of these insecticides, taking into account various factors that can influence their toxicity.

Determination of biochemical and histopathological changes on testicular and epididymis tissues induced by exposure to insecticide Imidacloprid during postnatal development in rats

BACKGROUND

Imidacloprid is a neonicotinoid insecticide belonging to the chloronicotinyl nitroguanidine chemical family. Toxicity of IMD for mammals in scientific studies has shown high mutagenic, immunotoxic, teratogenic and neurotoxic effects. The present study was designed to assess the toxic effects of imidacloprid (IMD) on the testicular and epididymis tissues as well as testosterone levels of neonatal male rats.

METHODS

Neonatal male rats from postnatal day (PND) 1 to PND 26 were consecutively administered with different concentrations of IMD (1, 5 and 10 mg/kg) subcutaneously. The effect of IMD on body and organ weight, lipid profile, histopathological alterations, oxidative stress and altered testosterone levels were assessed in the testis and plasma.

RESULTS

The results of body weight gain showed a significant difference in group 4 (10 mg/kg) animals as compared to the control. A significant increase in total cholesterol and triglycerides, while a decrease in high-density lipoprotein concentrations was evident. Similarly, a significant decrease in concentrations of antioxidant enzymes (CAT and SOD) among all the IMD-treated groups was evident, when compared to the control. Increased production of ROS was also noticed in the highest-dose treatment group. Further, we observed that IMD-treated rats indicated histopathological changes in the testis and epididymis along with a significant decrease in the plasma testosterone concentrations among IMI-treated groups in contrast to the control. Histological examination of the testis of IMD-treated neonatal male rats also showed decreased spermatogenesis in the treated groups when compared to the control. Furthermore, an increase in lumen diameter and a decrease in epithelial height of seminiferous tubules were also observed in IMD-treated rats in comparison with the control.

CONCLUSION

It is concluded that sub-chronic exposure to IMD in neonatal male rats may induce histopathological changes in reproductive tissues and damage normal testicular functions via inducing oxidative stress, decrease in body weight, disturbing normal blood lipid profile and testosterone concentration. IMD exposure can induce pathophysiological effects calls for further evaluation of this widely used insecticide.

Cytotoxicity, morphological and ultrastructural effects induced by the neonicotinoid pesticide, imidacloprid, using a rat Leydig cell line (LC-540)

Imidacloprid is a systemic neonicotinoid insecticide widely used to combat agricultural pests and flea infestations in dogs and cats. Despite its low toxicity to mammals, imidacloprid is reported to cause male reproductive toxicity. This study evaluated the cytotoxic effects of 75-800 μM imidacloprid on a rat Leydig cell line (LC-540). The effect of exposure to 300, 400, and 500 µM imidacloprid on selected cytoskeletal proteins, mitochondrial morphology, lysosomal acidity, and ultrastructure were investigated. Cell viability was markedly reduced after 48 and 72 h of exposure to higher imidacloprid concentrations. The immunocytochemical analysis revealed that the cytoskeletal filaments exhibited disorganization, disruption, and perinuclear aggregation in treated LC-540 cells. Ultrastructurally, cytoplasmic vacuoles, autophagic vacuoles, lysosomes, and mitochondrial damage were detected. Changes in the mitochondrial morphology and lysosomes induced by imidacloprid were confirmed. The cytotoxicity of imidacloprid observed in LC-540 cells might be due to its mitochondrial damage and cytoskeletal protein disruption.

Immunomodulatory effect of imidacloprid on macrophage RAW 264.7 cells

The neonicotinoid imidacloprid was promoted in the market because of widespread resistance to other insecticides, plus its low mammalian impact and higher specific toxicity towards insects. This study aimed to evaluate the immunomodulatory effect of imidacloprid on macrophages. RAW 264.7 cells were incubated to 0-4000mg/L of imidacloprid for 24 and 96h. Imidacloprid presented a concentration-dependent cytotoxicity after 24h and 96h incubation for MTT reduction (3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) (EC₅₀ 519.6 and 324.6mg/L, respectively) and Neutral Red (3-amino-7-dimethylamino-2-methylphenazine hydrochloride) assays (EC₅₀ 1139.0 and 324.2mg/L, respectively). Moreover, imidacloprid decreased the cells' inflammatory response and promoted a mitochondrial depolarization. The complex II and succinate dehydrogenase (SDH) activities in RAW 264.7 cells incubated with imidacloprid increased more at 24h. These results suggest that imidacloprid exerts an immunomodulatory effect and mitochondria can act as regulator of innate immune responses in the cytotoxicity mediated by the insecticide in RAW 264.7 cells.

Curcumin alleviates ketamine-induced oxidative stress and apoptosis via Nrf2 signaling pathway in rats' cerebral cortex and hippocampus

AIMS

To investigate curcumin's protective effect on nerve damage caused by ketamine anesthesia via the Nrf2 signaling pathway. Rats and PC12 cells were used in this experiment to investigate the mechanism of nerve injury caused by ketamine anesthesia. Furthermore, our findings suggest that curcumin may affect oxidative stress and apoptosis by targeting the Nrf2 pathway, thereby alleviating the nerve injury caused by ketamine.

METHODS

The rat cerebral cortex and hippocampus were stained with Nissl and immunohistochemistry to determine the number of neurons and the expression of Caspase-3, Bcl-2, and Bax. CCK-8 assay was used to determine the optimal concentration of ketamine, curcumin, and H₂ O₂ in PC12 cells. Flow cytometry was used to detect changes in reactive oxygen species and the rate of apoptosis in each group. To determine whether Nrf2 entered the nucleus, immunofluorescence was used. Both tissues and cells were subjected to RT-PCR and Western blotting detection at the same time. The levels of oxidative stress were determined using a malondialdehyde (MDA) and superoxide dismutase (SOD) assay kit.

RESULTS

Ketamine reduced the number of neurons in the cortex and hippocampus of rats. The proteins Bax and Caspase-3 were upregulated, while Bcl-2 was down-regulated in the cortex and hippocampus. The viability of PC12 cells has decreased. MDA content increased while SOD activity decreased in cortex, hippocampus, and PC12 cells. Ketamine had an effect on the expression of some genes in the Nrf2 signaling pathway as well as apoptosis. Curcumin pretreatment may be able to prevent ketamine-induced damage.

CONCLUSIONS

The oxidative stress and apoptosis caused by ketamine during growth of the cerebral cortex, hippocampus, and PC12 cells may be decreased by curcumin's activation of the Nrf2 signaling pathway. Our research provides a potential strategy for the secure administration of anesthetics in medical settings.

Effect of Neonicotinoid Pesticides on Japanese Water Systems: Review with Focus on Reproductive Toxicity

Neonicotinoid pesticides (NPs) are neurotoxic substances. They are highly effective as insecticides owing to their water solubility, permeability, and long-lasting activity. These molecules are structurally similar to nicotine and act as nicotinic acetylcholine receptor agonists. The administration of NPs to experimental animals reportedly causes neuromuscular and reproductive disorders. Moreover, recently reported problems caused by NPs include damage to land-dwelling creatures (such as mammals and birds), hydrobiology, and ecosystems. This review summarizes the recent reports on NP concentrations detected in river systems in several Japanese regions. These values were lower than the environmental standard values; however, seasonal variations were observed. Furthermore, reports on NP-induced testicular and ovarian toxicity were examined, revealing that the mechanism of injury is mainly driven by oxidative stress. The use of NPs is declining worldwide, except in Japan; therefore, continuous monitoring remains necessary.

Exposure to neonicotinoids and serum testosterone in men, women, and children

Neonicotinoids are the most used pesticides in the world and, despite being harmful to honeybees, they are considered safe for mammals. However, they have been associated with decreasing testosterone levels in several experimental animal models. In the present study, we aimed to determine the association of urinary neonicotinoids with serum testosterone in humans. We analyzed data on 2014 male and female participants to the National Health and Nutrition Examination Survey conducted between 2015 and 2016 aged 6 or older. In linear regression adjusted for age and potential confounders, serum total testosterone was 37.78% lower with 10-fold increase in urinary total neonicotinoids (95% CI: -58.82, -6.00), 20.81% lower with 10-fold increase in urinary 5-hydroxy-imidacloprid (95% CI: -34.94, -3.62) and 25.01% lower with 10-fold increase in urinary n-desmethyl-acetamiprid (95% CI: -39.80, -6.58) among males. Serum free androgen index (FAI) was also decreased with higher urinary n-desmethyl-acetamiprid. In females, serum total testosterone was 32.91% lower with 10-fold increase in urinary total neonicotinoids (95% CI: -54.93, -0.13), 21.32% lower with 10-fold increase in urinary 5-hydroxy-imidacloprid (95% CI: -29.31, -12.42) and 15.42% lower with urinary detection of 5-hydroxy-imidacloprid (95% CI: -22.80, -7.34). FAI was likewise reduced with higher urinary levels of 5-hydroxy-imidacloprid and N-desmethyl-acetamiprid. In conclusion, this study using a sample representative of the US population is the first to report that exposure to neonicotinoids is associated with decreased serum testosterone levels in humans. However, future prospective studies are warranted to confirm these findings.

Protective action of polysaccharides from Laurencia papillose (Rhodophyta) against imidacloprid induced genotoxicity and oxidative stress in male albino rats

Imidacloprid (IMI), the main component of neonicotinoid insecticides, promotes oxidative stress and genotoxicity in mammals. The aim of this experiment is to assess oxidative stress in liver cells and genotoxicity of erythrocytes for rats exposed to sub-lethal doses of IMI and the protective effects for Rhodophyta as antioxidant material versus imidacloprid. A total of 30 adult male albino rats (average body weight, 190–200 g) were divided into six groups (n=5) as follows: group 1 served as the control, group 2 received 200 mg/kg red algae, group 3 received 45 mg/kg IMI (high-dose group), group 4 received 22.5 mg/kg IMI (low-dose group), group 5 received 200 mg/kg red algae +45 mg/kg IMI, and group 6 received 200 mg/kg red algae +22.5 mg/kg IMI. After 28 d of treatment, the antioxidant activity of the crude extract of red algae was assessed in terms of free radical scavenging activity and found to be higher in TCA (75.57%) followed by DPPH (50.08%) at concentration 100 μg extract and a significant increase in lipid peroxidation and reductions in glutathione were observed in liver cells were intoxicated with high and low doses of IMI. Moreover decreases in catalase and glutathione peroxidase parameters in same previous groups which indicated oxidative stress. In addition significant increases in micronucleus frequency (MN) in the bone marrow of the rats as a genotoxicity marker which indicated DNA damage in erythrocytes cells with alterations in the histopathology of liver cells were also noted such as necrosis, inflammatory cells, infiltration, and necrobiotic changes. Whereas Rhodophyta succeeded in alleviation the oxidative damage and genotoxicity induced by the insecticide. In conclusion, IMI demonstrates hazardous effects, such as alterations in antioxidant status and mutagenicity of erythrocytes and polysaccharides from Rhodophyta has good antioxidant activity in vivo model systems against imidacloprid.

Ameliorative effects of a curcumin vitamin E nanocomposite coated with olive oil against cadmium chloride-induced testicular damage

In the current study, we synthesized and prepared a curcumin and vitamin E nanocomposite coated with olive oil (CEONC). Curcumin, vitamin E, and olive oil are fundamental organic antioxidants, and forming nanoparticles from these components endows them with special characteristics. We investigated the protective effect of CEONC on reproductive toxicity induced by cadmium chloride (CdCl2 ) in male rats. Forty rats (170-180 g) were randomly assigned to four groups: Group 1 (control) received oral distilled water; Group 2 intraperitoneal injection with CEONC (30 mg/kg); Group 3 received oral CdCl2 (5 mg/kg); and Group 4 received CdCl2 (5 mg/kg) followed by CEONC (30 mg/kg) for 4 weeks. After 50 days, we terminated the experiment and assessed male reproductive hormones, sperm motility, viability and morphology, and testes histopathology and conducted a comet assay. The results revealed that co-administration of CEONC with CdCl2 exposure increased reproductive hormone levels, improved sperm motility and viability, prevented sperm morphological changes, recovered the testicular histology, and decreased DNA damage in the testicular tissue compared to rats exposed to CdCl2 alone. CEONC administration produced no adverse effects and enhanced all sperm parameters. Our findings demonstrate that CEONC is a potential treatment for preventing reproductive damage induced by cadmium exposure.

Urinary neonicotinoid concentrations and pubertal development in Chinese adolescents: A cross-sectional study

BACKGROUND

Animal studies suggest that exposure to certain neonicotinoids may interfere with the normal function of endocrine system in mammals. However, evidence from human studies is limited.

OBJECTIVES

This study conducted a cross-sectional analysis to examine urinary neonicotinoids concentrations in Chinese adolescents and its association with pubertal development.

METHODS

774 urine samples from 439 boys (median age: 13.7 years; 25th-75th percentile: 12.7-14.5 years) and 335 girls (median age: 13.7 years; 25th-75th percentile: 12.7-14.5 years) were collected for determination of ten neonicotinoids (imidacloprid, nitenpyram, acetamiprid, thiacloprid, imidaclothiz, thiamethoxam, clothianidin, dinotefuran, flonicamid, sulfoxaflor) and one metabolite (N-desmethyl-acetamiprid). Urinary creatinine was detected for concentration adjustment. Pubertal development including pubic hair, axillary hair, genitalia (boys), testicular volume (boys) and breast (girls) assessed by Tanner stages and others (spermarche, facial hair for boys and menarche for girls) were obtained by physical examination and questionnaire. Logistic and bayesian kernel machine regression were used to investigate the association between neonicotinoids concentrations and pubertal developments.

RESULTS

High detection rates ranged from 72.0% to 100.0% for all neonicotinoids. Boys and girls with thiacloprid concentration at the >75th percentile had lower stage of genitalia development (OR: 0.83, 95% CI: 0.33-0.93) and higher stage of axillary hair development (OR: 1.46, 95% CI: 1.12-3.41), respectively, compared with those at the <25th percentile. The estimate change in genitalia stage was significantly different at or above the 75th percentile concentration of neonicotinoids mixture compared to the 50th percentile concentration. No associations were found between other urinary neonicotinoids and other indicators of puberty.

CONCLUSIONS

Higher thiacloprid concentration was associated with delayed genitalia development in boys and early axillary hair development in girls. Neonicotinoids mixture was negatively associated with genitalia stage in the joint effect. Given the characteristic of the cross-sectional study, our results need further confirmation of the causal relationship.

Neonicotinoids: mechanisms of systemic toxicity based on oxidative stress-mitochondrial damage

Neonicotinoids are the most widely used pesticides in the world. However, research studies have shown that it can affect the cognitive abilities and health of non-target bees and other wild pollinators by inducing DNA damage, apoptosis and mitochondrial damage, injure to its central nervous system, and it is even developmentally neurotoxic to mammals and humans, with mitochondria being an important target of neonicotinoids. Therefore, this article reviews the role of mitochondrial morphology, calcium ions (Ca²⁺) homeostasis, respiratory function, apoptosis, and DNA damage in neonicotinoids-induced systemic toxicity. Additionally, it evaluates the protective effects of various active substances including vitamin C, N-acetylcysteine (NAC), curcumin (CUR), glutathione reduced (GSH), caffeic acid phenethyl ester (CAPE), resveratrol, and thymoquinone (TQ) on neonicotinoids-induced toxicity. This review manuscript found that mitochondria are important targets to neonicotinoids. Neonicotinoids can cause DNA damage, apoptosis, protein oxidation, and lipid peroxidation in non-target organisms by altering mitochondrial Ca²⁺ homeostasis, inhibiting mitochondrial respiration, and inducing reactive oxygen species (ROS) production. Several active substances (vitamin C, NAC, CUR, GSH, resveratrol, CAPE, and TQ) play a protective role against neonicotinoid-induced systemic toxicity by inhibiting ROS signaling pathways, apoptosis, and lipid peroxidation. This review manuscript emphasizes the importance and urgency of the development of neonicotinoid antidotes, emphasizes the prospect of the application of targeted mitochondrial antidotes, and prospects the development of neonicotinoid antidotes in order to provide some strategies for the prevention of neonicotinoid toxicity.

Effects of Sub-Chronic Exposure to Imidacloprid on Reproductive Organs of Adult Male Rats: Antioxidant State, DNA Damage, and Levels of Essential Elements

Although considered a good alternative to organophosphate pesticides, there are reports indicating adverse effects of neonicotinoid insecticides on reproduction. Our aim was to assess the effects of exposure to low doses of imidacloprid on antioxidant state, DNA damage, and concentration of essential elements in the testes and epididymis using a rat model. Adult male Wistar rats were orally treated with doses comparable to currently proposed health-based reference values: 0.06 (ADI), 0.80 (10× AOEL), or 2.25 (1/200 LD50) mg/kg b.w./day for 28 consecutive days. Exposure to 2.25 mg/kg b.w./day of imidacloprid resulted in a significantly lower testis weight (1.30 ± 0.17 g compared to 1.63 ± 0.15 g in controls). Treatment with 0.06 mg/kg b.w./day increased the level of reduced glutathione in the epididymis (73%), while the activities of epididymal glutathione peroxidase and superoxide dismutase significantly increased in all treated rats (74-92% and 26-39%, respectively). Exposure to imidacloprid resulted in a low, but significant, level of DNA damage in testicular sperm cells regardless of the concentration applied (<28% compared to the negative control). Higher concentrations of Mo were measured in the testes of rats treated with 0.80 and 2.25 mg/kg b.w./day (72.9 ± 7.9 and 73.9 ± 9.1 mg/g, respectively) compared to the control animals (60.5 ± 7.8 mg/g). Higher concentrations of Na were measured in the testes of rats treated with 2.25 mg/kg b.w./day (1679 ± 82 mg/g compared to 1562 ± 56 mg/g in controls). The fact that such low doses of imidacloprid were able to produce measurable biological effects calls for the further evaluation of this widely used insecticide.

Spermiogenesis toxicity of imidacloprid in rats, possible role of CYP3A4

This study evaluated the adverse effects of low-dose imidacloprid (IMI) on the characteristics of sperm from male Wistar rats. Thirty mature male rats were equally divided into three groups and orally administered vehicle (Control Group), acceptable daily intake (ADI) concentration of IMI (Group 1), and IMI at a dose 10-fold that of the ADI (Group 2) for 90 days. The findings revealed that IMI caused abnormalities in sperm concentrations and morphologies, accompanied by an imbalance of the gonadal hormone testosterone. Histopathological damage and decrease of testosterone levels were observed in testes from rats treated with IMI. However, estradiol and gonadotropin levels were unchanged after IMI treatment. IMI inhibited the activity of cytochrome P450 3A4 (CYP3A4) and left itself existed in the organism of rats. The indicators relating to sperms and CYP3A4 activity were recovered when rats were co-treated with IMI and CYP3A4 inducer rifampicin together. These results indicated that low-dose IMI exposure caused sperm abnormalities through affecting on the spermiogenesis in testis. Inhibition of CYP3A4 activity by IMI largely contributed to its sperm toxicity. Thus, IMI exposure at doses close to real-world settings resulted in sperm toxicity on rats, which might be a potential risk factor for human reproductive diseases.

Crucial roles of 3D-MoO2-PBC cocatalytic electrodes in the enhanced degradation of imidacloprid in heterogeneous electro-Fenton system: Degradation mechanisms and toxicity attenuation

Imidacloprid (IMI), as the most-consumed pesticide, has posed a severe threat to the water ecosystem due to its recalcitrance and inefficient elimination in the traditional wastewater treatment. Herein, a heterogeneous electro-Fenton (EF) system coupled with 3D-MoO₂-porous biochar (PBC) cocatalytic electrodes, abbreviated as 3D-MPE-EF, is initially applied to promote the elimination of IMI in the agrochemical wastewater from pesticide production. The elimination rate of IMI by 3D-MPE-EF system is 18.15 times higher than that by traditional EF system at pH 7.0. The utilization of 3D-MoO₂-PBC electrodes sufficiently compensates for inherent deficiencies of traditional EF system. The circular utilization of Fe is also addressed by 3D-MoO₂-PBC cocatalytic electrodes to reduce the consumption of Fe²⁺ and the deposition of iron mud. Through comparison, MoO₂ is considered the most appropriate cocatalyst in terms of the reutilization of Fe and degradation of IMI. Eight mechanisms are identified in the degradation pathways of IMI by UPLC-Q-TOF-MS. The ecotoxicities of IMI are remarkably attenuated in the 3D-MPE-EF system. This study provides insights into the roles of 3D-MoO₂-PBC cocatalytic electrodes in the enhanced elimination of IMI in heterogeneous EF system.

Thiamethoxam-induced oxidative stress, lipid peroxidation, and disturbance of steroidogenic genes in male rats: Palliative role of Saussurea lappa and Silybum marianum

Thiamethoxam (TMX) belongs to the neonicotinoid insecticide family and may evoke marked endocrine disruption. In this study, the reproductive toxicity of TMX on male rats was assessed along with the ability of Saussurea lappa (costus roots) and/or Silybum marianum extract (SM) to alleviate TMX toxicity. Male rats were allocated to seven groups and orally treated daily for 4 weeks: Control (saline), Costus (200 mg/kg), SM (150 mg/kg), TMX (78.15 mg/kg), TMX-costus, TMX-SM, and TMX-costus-SM (at the aforementioned doses). Compared with control group, TMX administration induced reductions in testicular levels of glutathione and antioxidant activities of SOD and CAT. In addition, TMX-exposed rats showed lower serum testosterone hormonal levels as well as higher malondialdehyde and nitric acid levels were detected in TMX-administered rats. On a molecular basis, mRNA expressions of StAR, CYP17a, 3β-HSD, SR-B1, and P450scc genes were significantly down-regulated in TMX group, whereas the expression of LHR and aromatase genes was up-regulated. Moreover, TMX-induced testicular damage was confirmed by histopathological screening. Importantly, however, the administration of either costus roots or SM significantly alleviated all aforementioned TMX-induced changes, indicating the effective antioxidant activities of these plant products. Interestingly, simultaneous treatment with costus root and SM provided better protection against TMX reproduction toxicity than treatment with either agent alone.

The protective role of resveratrol against sulfoxaflor-induced toxicity in testis of adult male rats

This work was designed to explore the protective role of resveratrol (RES) against sulfoxaflor (Sulfx)-induced reproductive toxicity in adult male rats. The animals were divided into six groups: Control group, Sulfx treated groups (79.5 and 205 mg/kg/day), RES treated group (20 mg/kg/day), RES + Sulfx treated groups (20 mg/kg Res + 79.5 or 205 mg/kg Sulfx) orally for 28 consecutive days. Testicular samples were collected from all groups at the end of the treatment period. Tissue supernatants were isolated for oxidative stress and cellular energy parameters; tissue samples were prepared for histopathological examination. In addition, caspase-3 activity was calculated to assess spermatogenesis. Finally, DNA laddering assay was performed to detect DNA fragmentation as a hallmark of apoptosis. Our results showed that Sulfx treatment induced a significant increase in testicular levels of MDA, NOx, GSSG and reduced GSH level and cellular energy parameters in a dose-dependent manner compared to the control group. The results were confirmed by histopathological study which showed pathological changes in Sulfx treated groups. A significant increase in caspase 3 and DNA fragmentation was also observed. However, concomitant administration of RES to Sulfx -treated rats showed significant modulation against Sulfx-induced reproductive toxicity and attenuated the biochemical, apoptotic and histopathological changes. In conclusion, our results suggest that exposure to Sulfx at the two selected doses induces testicular toxicity and these effects can be ameliorated by supplementation of RES.

Imidacloprid increases intestinal permeability by disrupting tight junctions

The neonicotinoid pesticide, imidacloprid (IMI), is frequently detected in the environment and in foods. It is absorbed and metabolized by the intestine; however, its effects on intestinal barrier integrity are not well studied. We investigated whether IMI disrupts the permeability of the intestinal epithelial barrier via in vivo tests on male Wistar rats, in vitro assays using the human intestinal epithelial cell line, Caco-2, and in silico analyses. A repeated oral dose 90-day toxicity study was performed (0.06 mg/kg body weight/day). IMI exposure significantly increased intestinal permeability, which led to significantly elevated serum levels of endotoxin and inflammatory biomarkers (tumor necrosis factor-alpha and interleukin-1 beta) without any variation in body weight. Decreased transepithelial electrical resistance with increased permeability was also observed in 100 nM and 100 μM IMI-treated Caco-2 cell monolayers. Amounts of tight junction proteins in IMI-treated colon tissues and between IMI-treated Caco-2 cells were significantly lower than those of controls. Increased levels of myosin light chain phosphorylation, myosin light chain kinase (MLCK), and p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB p65) phosphorylation were found in IMI-exposed cells compared with control cells. Furthermore, the barrier loss caused by IMI was rescued by the MLCK inhibitor, ML-7, and cycloheximide. Pregnane X receptor (PXR, NR1I2) was inhibited by low-dose IMI treatment. In silico analysis indicated potent binding sites between PXR and IMI. Together, these data illustrate that IMI induces intestinal epithelial barrier disruption and produces an inflammatory response, involving the down-regulation of tight junctions and disturbance of the PXR-NF-κB p65-MLCK signaling pathway. The intestinal barrier disruption caused by IMI deserves attention in assessing the safety of this neonicotinoid pesticide.

Mitochondrial dysfunction and oxidative stress in liver of male albino rats after exposing to sub-chronic intoxication of chlorpyrifos, cypermethrin, and imidacloprid

The adverse effects of chlorpyrifos, cypermethrin, and imidacloprid on mitochondrial dysfunction and oxidative stress biomarkers were studied in rat liver. The liver deficiency was also confirmed by histological analysis and gel electrophoresis. Each insecticide was administered orally with five doses per week for 28 days to male albino rats at 1/50 of the LD₅₀ per insecticide. The results demonstrated that the mitochondrial dysfunction was confirmed by a significant decrease in NADH dehydrogenase and ATPase activities. Oxidative stress biomarkers include malondialdehyde (MDA), and protein carbonyl content (PCC) were significantly increased. However, superoxide dismutase (SOD) and glutathione S-transferase (GST) as antioxidant enzymes were significantly decreased in the mitochondria of the rat liver. HPLC analysis showed a significant increase of the 8-hydroxy-2'-deoxyguanosine (8-OH-2DG) as a biomarker of the DNA damage in rat liver. In addition, the residue levels of 0.96 and 0.29 μg/mL serum were found for cypermethrin and imidacloprid, respectively. However, chlorpyrifos not detected using the HPLC analysis. Blue native polyacrylamide gel electrophoresis (BN-PAGE) analysis showed a change in the pattern and sequence of complexions of the electron transport chain in liver mitochondria with treatment by such insecticides. The hepatic histological examination also showed symptoms of abnormalities after exposure to these insecticides.

Testicular deficiency associated with exposure to cypermethrin, imidacloprid, and chlorpyrifos in adult rats

The testicular deficiency associated with exposure to three widely used insecticides in Egyptian agriculture was evaluated. Animals were orally treated with sub-lethal dose (1/50 of the oral LD₅₀) of cypermethrin (CYP), imidacloprid (IMC), and chlorpyrifos (CPF) at 5, 9 and 1.9 mg/kg/day, respectively, five times a week for one month. The CYP, IMC, and CPF exposure resulted in a significant decline in animal body weight, sperm count, motility, normality, and viability with increased head and tail deformities. Significant reduction in serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), testis superoxide dismutase (SOD), and reduced glutathione (GSH) levels. In contrast, catalase (CAT), lipid peroxidation (LPO), and protein carbonyl content (PCC) levels were significantly stimulated. Jointly, obtained results were confirmed by microscopic examination of testis sections. The present data concluded that the CYP, IMC, and CPF have a public health impact and violently interferes with male rat reproductive system.

Thymol alleviates imidacloprid-induced testicular toxicity by modulating oxidative stress and expression of steroidogenesis and apoptosis-related genes in adult male rats

The present work was designed to assess the potential ameliorative effect of thymol on the testicular toxicity caused by imidacloprid (IMI) in adult male rats. Forty adult male rats were allocated into four groups; control group was given corn oil, thymol-treated group (30 mg/kg b.wt), IMI-treated group (22.5 mg/kg b.wt), and IMI + thymol-treated group. All administrations were done by gavage every day for duration of 56 days. As a result, the IMI exposure caused a significant decline in the body weight change, reproductive organ weights, sperm functional parameters, and serum level of testosterone, widespread histological alterations, and apoptosis in the testis. Additionally, the IMI-treated rats exhibited a remarkable increment in the serum levels of follicle stimulating hormone and luteinizing hormone. Also, IMI induced testicular oxidative stress, as indicated by elevated malondialdehyde (MDA) levels and a marked decline in the activity of antioxidant enzymes and reduced glutathione (GSH), and total antioxidant capacity (TAC) levels. Moreover, IMI treatment significantly downregulated the mRNA expression of steroidogenic genes and proliferating cell nuclear antigen (PCNA) immunoexpression in the testicular tissue. However, thymol co-administration significantly mitigated the IMI-induced toxic effects. Our findings suggested that IMI acts as a male reproductive toxicant in rats and thymol could be a potential therapeutic option for IMI reprotoxic impacts.

Comparison of the toxicity of pure compounds and commercial formulations of imidacloprid and acetamiprid on HT-29 cells: Single and mixture exposure

Neonicotinoids, which are widely used worldwide, including in Turkey, are an insecticide group that are synthetic derivatives of nicotine. Recently, they have attracted attention due to their toxic effects on non-target organisms, especially bees. Numerous studies have shown that neonicotinoids have been found in detectable levels in the environment and cause various undesirable effects on living organisms, including humans and other mammals. In this study, the possible toxic effects of imidacloprid and acetamiprid, commonly used neonicotinoids, are investigated by their pure forms and commercial formulations on HT-29 cells with individual and combined exposures. According to our results, imidacloprid and acetamiprid induced cytotoxicity by caspase-mediated apoptosis, mitochondrial membrane depolarization, DNA damage, and oxidative stress under these experimental conditions. It is worth mentioning low doses of DNA damage, mixture exposure causes toxic effects at lower concentrations than individual exposure, and formulation groups are at the forefront of toxicity formation, though this varies depending on the parameters.

Exposure to Organophosphate and Neonicotinoid Insecticides and Its Association with Steroid Hormones among Male Reproductive-Age Farmworkers in Northern Thailand

Several studies indicated organophosphate (OP) and neonicotinoid (NEO) insecticides are endocrine disruptors; however, data are scarce. This cross-sectional study recruited 143 male farmworkers aged 18-40 years in Fang district, Chiang Mai province, northern Thailand. OP exposure was assessed by measuring urinary dialkylphosphate (DAPs) using a gas-chromatography flame photometric detector. Urinary NEOs, their metabolites (NEO/m) and serum steroid hormones were measured using liquid chromatography-tandem mass spectrometry. Characteristics of participants were determined by face-to-face interviews. DAPs and five NEO/m were detected in more than 60% of samples. The concentration of diethylphosphate was highest among DAP metabolites (geometric mean concentration (GM: 23.9 ng/mL) and the concentration of imidacloprid (IMI) was highest among NEO/m (GM: 17.4 ng/mL). Linear regression models showed that the IMI level was positively associated with testosterone, dehydrocorticosterone (DHC) and dehydroepiandrosterone (DHEA) levels. Imidacloprid-olefin and DHEA levels were positively associated. Thiamethoxam (THX) were inversely associated with DHC and deoxycorticosterone levels. Clothianidin (CLO), THX and N-desmethyl-acetamiprid levels were positively associated with the androstenedione level. CLO and THX levels were inversely associated with the cortisone level. In conclusion, the association between NEO insecticides exposure and adrenal androgens, glucocorticoids and mineralocorticoids, suggest potential steroidogenesis activities. Our findings warrant further investigation.

Effects of low-level imidacloprid oral exposure on cholinesterase activity, oxidative stress responses, and primary DNA damage in the blood and brain of male Wistar rats

Imidacloprid is a neonicotinoid insecticide that acts selectively as an agonist on insect nicotinic acetylcholine receptors. It is used for crop protection worldwide, as well as for non-agricultural uses. Imidacloprid systemic accumulation in food is an important source of imidacloprid exposure. Due to the undisputable need for investigations of imidacloprid toxicity in non-target species, we evaluated the effects of a 28-day oral exposure to low doses of imidacloprid (0.06 mg/kg b. w./day, 0.8 mg/kg b. w./day and 2.25 mg/kg b. w./day) on cholinesterase activity, oxidative stress responses and primary DNA damage in the blood and brain tissue of male Wistar rats. Exposure to imidacloprid did not cause significant changes in total cholinesterase, acetylcholinesterase and butyrylcholinesterase activities in plasma and brain tissue. Reactive oxygen species levels and lipid peroxidation increased significantly in the plasma of rats treated with the lowest dose of imidacloprid. Activities of glutathione-peroxidase in plasma and brain and superoxide dismutase in erythrocytes increased significantly at the highest applied dose. High performance liquid chromatography with UV diode array detector revealed the presence of imidacloprid in the plasma of all the treated animals and in the brain of the animals treated with the two higher doses. The alkaline comet assay results showed significant peripheral blood leukocyte damage at the lowest dose of imidacloprid and dose-dependent brain cell DNA damage. Oral 28-day exposure to low doses of imidacloprid in rats resulted in detectable levels of imidacloprid in plasma and brain tissue that directly induced DNA damage, particularly in brain tissue, with slight changes in plasma oxidative stress parameters.

DNA of crayfish spermatozoa as a target of waterborne pesticides - An ex vivo approach as a tool to short-term spermiotoxicity screening

The spermiotoxic properties of aquatic contaminants might be the cause of low fertilization rate and decreased prolificacy, affecting the success of the impacted populations. The genotoxic potential of pesticides in spermatozoa as an undesirable effect on non-target organisms, namely aquatic invertebrates with external fertilization, emerges as a key question in ecogenotoxicological research. Thus, this study aimed to clarify if DNA integrity of red swamp crayfish (Procambarus clarkii) spermatozoa is affected by waterborne pesticides at environmentally relevant concentrations. By adopting an ex vivo approach, six pesticides were addressed in a short-term assay: herbicides glyphosate (9 and 90 μg L^-1) and penoxsulam (2.3 and 23 μg L^-1); insecticides dimethoate (2.4 and 24 μg L^-1) and imidacloprid (13.1 and 131 μg L^-1); fungicides pyrimethanil (2.2 and 22 μg L^-1) and imazalil (16 and 160 μg L^-1). Genotoxicity was observed in higher concentrations of glyphosate, penoxsulam, dimethoate, pyrimethanil, and imazalil. Imidacloprid was the only pesticide that did not cause non-specific DNA damage, although displaying pro-oxidant properties. Overall, the present study demonstrated the suitability of the ex vivo approach on spermiotoxicity screening, highlighting the potential ecological impact of pesticides on non-target species, such as P. clarkii, compromising sperm DNA integrity and, subsequently, the population success.

Insecticides and ovarian functions

Insecticides, a heterogeneous group of chemicals, are widely used in agriculture and household practices to avoid insect-inflicted damage. Extensive use of insecticides has contributed substantially to agricultural production and the prevention of deadly diseases by destroying their vectors. On the contrary, many of the insecticides are associated with several adverse health effects like neurological and psychological diseases, metabolic disorders, hormonal imbalance, and even cancer in non-target species, including humans. Reproduction, a very selective process that ensures the continuity of species, is affected to a greater extent by the rampant use of insecticides. In females, exposure to insecticides leads to reproductive incapacitation primarily through disturbances in ovarian physiology. Disturbed ovarian activities encompass the alterations in hormone synthesis, follicular maturation, ovulation process, and ovarian cycle, which eventually lead to decline in fertility, prolonged time-to-conceive, spontaneous abortion, stillbirths, and developmental defects. Insecticide-induced ovarian toxicity is effectuated by endocrine disruption and oxidative stress. Oxidative stress, which occurs due to suppression of antioxidant defense system, and upsurge of reactive oxygen and nitrogen species, potentiates DNA damage and expression of apoptotic and inflammatory markers. Insecticide exposure, in part, is responsible for ovarian malfunctioning through disruption of hypothalamic-pituitary-gonadal axis. The current article is focused on the adverse effects of insecticides on ovarian functioning, and consequently, on the reproductive efficacy of females. The possible strategies to combat insecticide-induced toxicity are also discussed in the latter part of this review. Environ. Mol. Mutagen. 61:369-392, 2020. © 2020 Wiley Periodicals, Inc.

Imidacloprid exposure suppresses cytokine production and neutrophil infiltration in TLR2-dependent activation of RBL-2H3 cells and skin inflammation of BALB/c mice

Imidacloprid suppressed TNF-α and IL-6 production and neutrophil infiltration, without altering mast cell degranulation.

Colibri® insecticide induces male reproductive toxicity: alleviating effects of Lannea acida (Anacardiaceae) in rats

Background

Imidacloprid, a neonicotinoid insecticide, has been associated to severe reproductive toxicity in mammals. Although some preventive measures have been reported, curative strategies are yet to be explored. The present study was designed to investigate the alleviating effects of Lannea acida on the reproductive toxicity of colibri®, a commercial formulation of imidacloprid, in adult male rats.

Materials and methods

Seventy rats were orally administered with colibri® (22.5 mg/kg, 10 mL/kg) for 14 days and treated for other 14 or 28 days with either aqueous or methanol extracts of L. acida (170 or 340 mg/kg). Control animals were similarly treated with clomiphene citrate or vitamin E. Sexual organ weights, spermatozoa characteristics, sexual hormones, stress markers and testis histology were evaluated at the end of each treatment period.

Results

Colibri® exposition induced reproductive toxicity marked by a decrease in sex organ weights, spermatozoa count, motility and viability. Colibri® also decreased testosterone, luteinizing hormone, follicle stimulating hormone concentrations and increased testicular oxidative stress. Spermatozoa morphology and testis histology were also severely altered. Similar to clomiphene citrate and vitamin E, treatment with L. acida extracts significantly (p ≤ 0.05–0.001) reversed the above-mentioned damages, especially after 28 days of treatment with aqueous (340 mg/kg) and methanol (170 mg/kg) extracts.

Conclusion

Present results indicate that L. acida exerts curative effects against colibri®-induced male reproductive toxicity. These results justify the use of this plant as fertility enhancer and suggest that it could be an alternative in the management of pesticide-derived male infertility.

Urinary monitoring of neonicotinoid imidacloprid exposure to pesticide applicators

Neonicotinoid pesticides have recently drawn attention worldwide owing to their potential adverse effects on non-target organisms and ecosystems. Exposure to imidacloprid, the most widely used neonicotinoid insecticide, is of particular concern among rural populations because of its ubiquitous use in agriculture. Hence, biological monitoring of urinary imidacloprid and its major metabolite 6-chloronicotinic acid (6-CNA) was performed using Polar Enhanced Polymer solid-phase extraction by LC-MS/MS with mean recoveries of 78.3-109.8% and limits of quantitation at 0.029-0.038 ng/mL. Imidacloprid was detected in 100% of urine samples from rural applicators at concentrations of 0.21-8.91 ng/mL (0.06-9.60 μg/g creatinine) and 0.11-24.58 ng/mL (0.66-57.40 μg/g creatinine) before and after pesticide application, respectively. Significant increase in urine concentration (3.52- to 3.77-fold) of imidacloprid and 6-CNA was observed after local imidacloprid field application (p ≤ 0.001). The estimated absorbed daily dose (ADD) for imidacloprid was 0.52-248.05 μg/kg/d, indicating that attention should be paid to potential health risks for applicators because of increased imidacloprid exposure at level of significance (p < 0.05). This study is the first to report ADD estimation for imidacloprid, thereby providing an important reference for further human health risk evaluation.

Effect of acetamiprid on the immature murine testes

Neonicotinoids, such as acetamiprid (ACE), a pesticide used worldwide, are believed to be safe for human use. These molecules are structurally similar to nicotine, act as nicotinic acetylcholine receptor (nAChR) agonists, and were shown to be associated with neuromuscular and reproductive disorders, but these experiments were primarily performed in mature animals. In this study, the effects of ACE on the testes of immature mice were examined. The exposure of 3-week-old mice to ACE-containing water for 180 days led to a decrease in body weight and mildly affected spermatogenesis. Additionally, the expression of testosterone-metabolism genes, nAChR subunit genes, and proliferation-associated genes decreased in the testes of ACE-treated mice. Our results show that immature rodents may be less sensitive to ACE than mature ones, that mice may be more likely to accumulate ACE than rats, and that the development of disorders may be affected by the accumulation of ACE in the testes.

Potentiating effect of imidacloprid on arsenic-induced testicular toxicity in Wistar rats

BACKGROUND

It is an established fact that humans and animals are exposed to more than one chemical concurrently from various sources such as food, air and water. In the past, much emphasis was laid on evaluating the toxic effects of a single chemical. Nowadays an increased attention is being paid to the interaction of xenobiotics with one another. Therefore, a study was aimed to evaluate the potentiating effect of imidacloprid (IMI) on arsenic-induced testicular toxicity in rats.

METHODS

Adult male Wistar rats randomly divided into eight groups with six in each were subjected to daily oral administrations for 28 days. Group I served as control, group II received IMI at the dose rate of 16.9 mg/kg body weight, group III, IV and V received arsenic at the dose rate of 50, 100 and 150 ppb in drinking water whereas group VI, VII and VIII received both arsenic and IMI.

RESULTS

Repeated oral administrations of IMI or arsenic (150 ppb) alone resulted in a significant (P < 0.05) elevation in the levels of malondialdehyde (MDA) and advanced oxidation protein product (AOPP) along with significant (P < 0.05) decline in total thiols and antioxidant enzymatic activities indicating reduced antioxidant defense in testicular tissue of exposed rats. These findings were further corroborated with histological alterations in testes like fluid accumulation in interstitial spaces in IMI administered rats. Similarly, rats provided access exclusively to arsenic-containing drinking water induced degenerative changes in seminiferous tubules in a concentration-dependent manner. Concurrent administration of IMI and arsenic produced more severe antioxidant and histopathological alterations of testes as compared to exposure to either toxicant.

CONCLUSIONS

Reduced antioxidant activities, increased MDA and AOPP levels with severe histopathological alterations in testes of rats on concurrent exposure indicated that IMI potentiated the arsenic-induced testicular toxicity in Wistar rats.

Imidacloprid as reproductive toxicant and endocrine disruptor: investigations in laboratory animals

Imidacloprid, a neonicotinoid insecticide, has been used worldwide due to its selective toxicity for insects. Its residues may enter the food chain, which is why it is important to investigate the potential adverse effects of imidacloprid exposure. This review summarises current knowledge of the reproductive toxicity and disruptive endocrine effects of imidacloprid in laboratory animals. Investigations, conducted mostly on laboratory rats, have shown adverse effects of imidacloprid on the reproductive ability in both parental and offspring generation as well as on the development of the offspring. Like many pesticides, imidacloprid may also act as endocrine disrupting chemical (EDC). It may disrupt the metabolic homeostasis, contribute to obesity, and disrupt steroidogenesis by inhibiting cytochrome P450 (CYP) enzyme activities. All these adverse effects of imidacloprid may pose a serious risk for reproduction and development with long-term consequences in adulthood.

Research Progress on Reversing Multidrug Resistance in Tumors by Using Chinese Medicine

Multidrug resistance (MDR) is a major cause of cancer chemotherapy failure, and it is important to develop suitable reversal agents to overcome MDR. A majority of chemical reversal agents have acceptable reversal effects. However, the toxicity and adverse reactions associated with these agents restricts their clinical use. Chinese medicines (CMs) have lower toxicities and adverse reactions and are associated with multiple components, multiple targets and reduced toxicity. CMs have several advantages and could reverse MDR, decrease drug dosage, enhance patient compliance and increase efficacy. This review summarizes the current progress of CM reversal agents..

Parastar insecticide induced changes in reproductive parameters and testicular oxidative stress biomarkers in Wistar male rats

Parastar is an insecticide formulation of lambda-cyhalothrin and imidacloprid, and it is largely used for crop production improvement in Santa, North West Region of Cameroon. This study aimed at evaluating the effects of Parastar on reproductive parameters and testicular oxidative stress in adult albino Wistar male rats. Twenty rats (154 g ± 28 g) were divided into four groups of five animals each and treated daily with either distilled water (10 mL/kg), 1.25, 2.49 or 6.23 mg/kg of Parastar, respectively, for 35 days. After treatment, animal reproductive function was evaluated through fertility tests, sperm characteristics, testosterone levels and organ weights, while oxidative stress biomarkers were determined on testicular homogenates. Parastar administration resulted into increased seminal vesicle and prostate weights, while body weight remained unaffected. Parastar dose-dependently reduced sperm density and mobility, and the highest dose decreased serum testosterone levels. Parastar also modulated stress biomarkers with increased thiobarbituric acid reactive substances levels, decreased glutathione levels and inhibition of catalase and superoxide dismutase activities. In conclusion, Parastar negatively affected male reproductive function through alteration of testosterone levels, sperm parameters and induction of oxidative stress in rats.

Comparative analysis of the protective effects of curcumin and N-acetyl cysteine against paracetamol-induced hepatic, renal, and testicular toxicity in Wistar rats

This study aimed to investigate the possible protective role of curcumin (CUR) vs. N-acetyl cysteine (NAC) against paracetamol (PCM)-induced oxidative damage and impairment of liver, kidney, and testicular functions, as well as hematotoxicity, in albino rats. A large single dose of PCM induced lipid peroxidation along with a significant decline in glutathione content and catalase activity in the liver, kidneys, and testicles. The apparent oxidative damage was associated with evident hepatic, renal, and testicular dysfunction, which was confirmed in histopathological lesions, and increased serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities. PCM decreased serum total protein, albumin, and globulin contents; increased bilirubin, urea, and creatinine contents; and induced hematotoxicity. PCM also reduced the sperm cell count, sperm motility, and alive sperm rate and increased the sperm abnormality rate. Pretreatment of PCM-intoxicated animals with CUR or NAC substantially alleviated the increase in malondialdehyde and maintained the antioxidants at control levels. These pretreatments also minimized liver, kidney, and testicular histopathological changes and normalized their functions. CUR similarly mitigated the PCM hemato- and hepatotoxicity compared with NAC. However, it exhibited a pronounced nephroprotection, rather than reproductive protection as did NAC. Our findings demonstrate that a large single dose of PCM is not only associated with hepatotoxicity but also nephrotoxicity and reproductive toxicity. Both CUR and NAC administration provided substantial organ protection with pronounced efficacy against PCM nephrotoxicity with CUR and reproductive toxicity with NAC, which was possibly mediated through their antioxidant activities, as well as their specific characteristics.

Curcumin and Quercetin Ameliorated Cypermethrin and Deltamethrin-Induced Reproductive System Impairment in Male Wistar Rats by Upregulating The Activity of Pituitary-Gonadal Hormones and Steroidogenic Enzymes

Background

Dietary antioxidants protect tissues and organs against insecticides/xenobiotic-induced damage. In the present study, we evaluated the results of exposure to synthetic pyrethroid insecticides, cypermethrin (Cyp) and deltamethrin (Del) and possible protective effects of curcumin and quercetin on reproductive system in male Wistar rats.

Materials and Methods

In this controlled experimental study, 42 male Wistar rats were randomly divided into 7 groups of 6 animals. Group A served as control, group B was exposed to Cyp (2 mg/kg.bw), group C was exposed to Del (2 mg/kg.bw), group D was exposed to Cyp+Del (2 mg/kg.bw each), group E was exposed to Cyp+Del and treated with curcumin (100 mg/kg.bw), group F was exposed to Cyp+Del and treated with quercetin (100 mg/kg.bw) and group G was exposed to Cyp+Del and treated with quercetin+curcumin for 45 days.

Results

Exposure to Cyp and Del caused decreases in reproductive organs weight, sperm count, sperm motility, level of sex hormones viz. testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH), steroidogenic enzymes viz. 3β-hydroxyl steroid dehydrogenase (3β-HSD) and 17β-HSD, non-enzymatic antioxi- dant glutathione (GSH) and enzymatic antioxidants viz. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) activity and increases in sperm abnormalities and lipid peroxidation (LPO). The exposure also adversely affected the histo-achitecture of testes. Single and combined treatment with curcumin and quercetin significantly ameliorated Cyp and Del-induced damage in reproductive system.

Conclusion

Curcumin and quercetin protected against Cyp and Del-induced reproductive system toxicity and oxidative damage in rats. The increases in activities of 3β-HSD and 17β-HSD with concomitant increases in testosterone were mainly responsible for ameliorating effects of curcumin and quercetin. Curcumin showed slightly better activity as compared to quercetin. The combination of both antioxidants offered more protection compared to each one alone.

Imidacloprid exposure cause the histopathological changes, activation of TNF-α, iNOS, 8-OHdG biomarkers, and alteration of caspase 3, iNOS, CYP1A, MT1 gene expression levels in common carp (Cyprinus carpio L.)

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IMI toxication was evaluated with three different methods.

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Pathological lesions were observed after IMI exposure in gills, liver and brain.

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IMI exposure induced iNOS, 8-OHdG and TNF-α activation in gills, liver and brain.

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IMI exposure caused upregulation iNOS, caspase 3 and MT1 expressions in brain.

Imidacloprid (IMI) is a neonicotinoid that is widely used for the protection of crops and carnivores from insects and parasites, respectively. It is well known that imidacloprid exposure has a harmful effect on several organisms. However, there is little information about imidacloprid toxicity in aquatic animals, particularly fish. Thus, in the current study, we assessed the histopathological changes; activation of iNOS, 8-OHdG and TNF-α; and expression levels of caspase 3, iNOS, CYP1A and MT1 genes in the common carp exposed to imidacloprid. For this purpose, fish were exposed to either a low dose (140 mg/L) or a high dose (280 mg/L) of imidacloprid for 24 h, 48 h, 72 h and 96 h. After IMI exposure, we detected hyperplasia of secondary lamellar cells and mucous cell hyperplasia in the gills, as well as hydropic degeneration in hepatocytes and necrosis in the liver. Moreover, 8-OHdG, iNOS and TNF-α activation was found particularly in the gills and liver but also moderately in the brain. Transcriptional analysis showed that caspase 3 expression was altered low dose and high doses of IMI for 72 h and 96 h exposure (p < 0.05), iNOS expression was up-regulated with both low and high doses of IMI and in a time-dependent manner (p < 0.05, p < 0.01, p < 0.001), CYP1A expression was not significantly changed regardless of the dose of IMI and exposure time (p > 0.05) except with low and high doses of IMI for 96 h (p < 0.05), and lastly, MT1 gene expression was up-regulated only in the brain with low doses of IMI for 96 h and high doses of IMI for 48 h, 72 h and 96 h exposure (p < 0.05, p < 0.01). Our results indicated that acute IMI exposure moderately induce apoptosis in the brain but caused severe histopathological lesions, inflammation, and oxidative stress in the gills, liver, and brain of the common carp.

Mechanism of Neonicotinoid Toxicity: Impact on Oxidative Stress and Metabolism

Thousands of tons of neonicotinoids are widely used around the world as broad-spectrum systemic insecticides and veterinary drugs. Researchers originally thought that neonicotinoids exhibited low mammalian toxicity. However, following their widespread use, it became increasingly evident that neonicotinoids could have various toxic effects on vertebrates and invertebrates. The primary focus of this review is to summarize the research progress associated with oxidative stress as a plausible mechanism for neonicotinoid-induced toxicity as well as neonicotinoid metabolism. This review summarizes the research conducted over the past decade into the production of reactive oxygen species, reactive nitrogen species, and oxidative stress as aresult of neonicotinoid treatments, along with their correlation with the toxicity and metabolism of neonicotinoids. The metabolism of neonicotinoids and protection of various compounds against neonicotinoid-induced toxicity based on their antioxidative effects is also discussed. This review sheds new light on the critical roles of oxidative stress in neonicotinoid-induced toxicity to nontarget species.

Beneficial effects of curcumin nano-emulsion on spermatogenesis and reproductive performance in male rats under protein deficient diet model: enhancement of sperm motility, conservancy of testicular tissue integrity, cell energy and seminal plasma amino acids content

Background

Malnutrition resulting from protein and calorie deficiency continues to be a major concern worldwide especially in developing countries. Specific deficiencies in the protein intake can adversely influence reproductive performance. The present study aimed to evaluate the effects of curcumin and curcumin nano-emulsion on protein deficient diet (PDD)-induced testicular atrophy, troubled spermatogenesis and decreased reproductive performance in male rats.

Methods

Juvenile rats were fed the protein deficient diet (PDD) for 75 days. Starting from day 60 the rats were divided into 4 groups and given the corresponding treatments for the last 15 days orally and daily as follows: 1st group; curcumin group (C) received 50 mg/kg curcumin p.o. 2^ndgroup; curcumin nano-form low dose group (NCL) received 2.5 mg/kg nano-curcumin. 3rd group; curcumin nano-form high dose group (NCH) received 5 mg/kg nano-curcumin. 4th group served as malnutrition group (PDD group) receiving the protein deficient diet daily for 75 days and received distilled water ingestions (5 ml/kg p.o) daily for the last 15 days of the experiment. A normal control group was kept under the same conditions for the whole experiment and received normal diet according to nutrition requirement center daily for 75 days and received distilled water ingestions (5 ml/kg p.o) daily for the last 15 days of the experiment.

Results

PDD induced significant (P < 0.05) reduction in serum testosterone level, sperm motility, testicular GSH, CAT, SOD, testicular cell energy (ATP, ADP and AMP), essential and non-essential amino acids in seminal plasma, an increase in testicular MDA, NOx, GSSG and 8-OHDG. Data was confirmed by histological examination and revealed pathological alteration in the PDD group. Ingestion of curcumin (50 mg/kg) and curcumin nano-emulsion (2.5 and 5 mg/kg) showed significant (P< 0.05) amelioration effects against PDD-induced disrupted reproductive performance as well as biochemical and pathological alterations and the overall results of the nano-emulsion (5 mg/kg) were comparable to curcumin (50 mg/kg).

Conclusions

The present study suggests that administration of curcumin nano-emulsion as a daily supplement would be beneficial in malnutrition- induced troubled male reproductive performance and spermatogenesis cases.

Paracetamol: overdose-induced oxidative stress toxicity, metabolism, and protective effects of various compounds in vivo and in vitro

Paracetamol (APAP) is one of the most widely used and popular over-the-counter analgesic and antipyretic drugs in the world when used at therapeutic doses. APAP overdose can cause severe liver injury, liver necrosis and kidney damage in human beings and animals. Many studies indicate that oxidative stress is involved in the various toxicities associated with APAP, and various antioxidants were evaluated to investigate their protective roles against APAP-induced liver and kidney toxicities. To date, almost no review has addressed the APAP toxicity in relation to oxidative stress. This review updates the research conducted over the past decades into the production of reactive oxygen species (ROS), reactive nitrogen species (RNS), and oxidative stress as a result of APAP treatments, and ultimately their correlation with the toxicity and metabolism of APAP. The metabolism of APAP involves various CYP450 enzymes, through which oxidative stress might occur, and such metabolic factors are reviewed within. The therapeutics of a variety of compounds against APAP-induced organ damage based on their anti-oxidative effects is also discussed, in order to further understand the role of oxidative stress in APAP-induced toxicity. This review will throw new light on the critical roles of oxidative stress in APAP-induced toxicity, as well as on the contradictions and blind spots that still exist in the understanding of APAP toxicity, the cellular effects in terms of organ injury and cell signaling pathways, and finally strategies to help remedy such against oxidative damage.