Search Results (96)

Fipronil (FPN), a widely used insecticide, poses health risks through environmental contamination. Although its toxicity is increasingly recognized, the impact of fipronil on glucose metabolism remains poorly understood. In this study, mice on a normal diet (ND) or high-fat diet (HFD) received a daily oral administration of fipronil (0, 0.25, 1, or 4 mg/kg) for 35 days. Blood glucose and insulin were measured, and glucose/insulin/pyruvate tolerance tests were performed. We found that fipronil compromised glucose tolerance in mice fed an ND. Gut microbiota composition was assessed by 16S rRNA sequencing and the expression of inflammatory factors was detected in the tissues. Serum fibroblast growth factor 15 (FGF15) and bile acid were determined. In HFD-fed mice, fipronil exacerbated glucose metabolic disorders and enhanced insulin resistance. These metabolic disturbances were associated with gut microbiota dysbiosis, particularly a marked reduction in Akkermansia muciniphila (A. muciniphila) abundance, and increased systemic inflammation. Fipronil exposure also decreased serum FGF15 and elevated serum bile acids. Our results suggest that fipronil disrupts glucose metabolism in association with gut microbiota alterations, impairment of the FGF15-bile acid axis, and induction of inflammation, highlighting its potential relevance to diabetes risk. Further studies are warranted to validate our findings. Full article

Termites are destructive structural pests causing significant economic losses worldwide. Although synthetic termiticides are effective, their extensive use raises environmental and health concerns, highlighting the need for safer, sustainable alternatives. This study evaluated the contact toxicity and repellency in a closed system of essential oils (EOs) from clove (Syzygium aromaticum), cinnamon (Cinnamomum zeylanicum), and star anise (Illicium verum) against Microcerotermes crassus workers. Chemical constituents (eugenol and anethole) were characterized by GC–MS/MS, and their activities were compared with those commercial termiticides (fipronil and cypermethrin). Clove and cinnamon oils exhibited strong toxicity, with LC₅₀ values decreasing from 208.6 to 70.6 µL/L and from 362.6 to 130.5 µL/L, respectively, over 24 h. Both achieved LT₅₀ values below 10 h at 250 µL/L and over 80% repellency at 100–500 µL/L within 3–12 h. Eugenol, the major constituent, showed comparable activity. In contrast, star anise oil, dominated by anethole, displayed weaker repellency but measurable termiticidal effects with a slower onset. These findings indicate that eugenol-rich oils may provide rapid-contact activity. In contrast, anethole-rich oils may offer slower but measurable termiticidal effects, suggesting distinct potential roles in future formulation development. The findings provide a foundation for developing nanoemulsion-based botanical termiticides with improved stability and field performance. Full article

Previous studies have demonstrated that Trichoderma metabolites triggered aggregation behavior in Coptotermes formosanus (Blattodea: Rhinotermitidae). Building on this, the present work systematically evaluated the behavioral effects of three specific Trichoderma metabolites—phenol, ethyl 2,4-dioxovalerate, and diglycolic acid—and their synergistic interactions with insecticides. We hypothesized that these metabolites attract C. formosanus through multiple behavioral mechanisms and enhance the toxicity of insecticides. Bioactivity showed that ethyl 2,4-dioxovalerate and diglycolic acid exhibited no significant toxicity. Phenol (5 × 10⁻² to 5 µg/cm) and ethyl 2,4-dioxovalerate (5 × 10⁻¹ µg/cm) elicited trail-following behavior. In the no-choice insecticide synergy test, phenol or diglycolic acid combined with imidacloprid (50 µg/g) resulted in substantially higher mortality compared to insecticides alone. The combination of metabolites with fipronil resulted in 100% mortality in termites. In two-choice aggregation tests, termite presence on metabolite-treated filter papers was significantly elevated compared to the controls. Fipronil (10 μg/g) alone significantly reduced termite aggregation. But when fipronil was combined with the metabolites, termite presence on the treated papers increased significantly, resulting in a substantial rise in mortality and demonstrating a clear attract–kill synergy. These findings identify Trichoderma metabolites as safe and effective behavioral regulators for C. formosanus. By enhancing insecticidal efficacy through attractant–toxicity synergy, they represent promising candidates for developing novel termite control strategies. Full article

Controlling Rhipicephalus microplus is currently one of the main challenges in livestock farming due to the significant economic losses it causes. Traditionally, managing this parasite has been based on the use of synthetic ixodicides, among which fipronil has proven to be highly effective. However, its low water solubility and the limitations of commercially available formulations can affect the bioavailability of this compound, favoring the emergence of resistance in tick populations. In this context, fipronil-loaded nanoparticles were developed using the Eudragit^® E PO polymer (NP_F) (Helm, Naucalpan, Mexico, Mexico), which were physicochemically characterized and evaluated against fipronil-susceptible R. microplus larvae. NP_F had an average size of 143.43 ± 1.88 nm, a polydispersity index (PDI) of 0.162 ± 0.01, a ζ (P ζ) of 21.16 ± 0.54, an encapsulation percentage (%E) of 7.36 ± 0.30, and an encapsulation efficiency percentage (%EE) of 66.28 ± 3.5%. Free fipronil showed an LC₅₀ of 0.582 µg/mL and an LC₉₀ of 2.503 µg/mL against R. microplus. The NP_F formulation showed an LC₅₀ of 0.427 µg/mL and an LC₉₀ of 2.092 µg/mL. These results suggest that incorporating fipronil into nanoparticles improves its ixodicide efficacy, positioning it as an innovative and promising alternative for the development of effective tick control formulations. Full article

The complexity of human exposure to surrounding chemicals warrants developing analytical methods that are capable of the simultaneous quantitation of many diverse environmental pollutants and their biomarkers for the needs of human biomonitoring (HBM). Examples include pesticides used in veterinary medicine, such as fipronil (FIP), imidacloprid and pyrethroids, as well as other chemicals, like bisphenols and flame retardants. The goal of this paper was to develop and validate a liquid chromatography-tandem mass spectrometry method for the quantification of selected organic contaminants in human urine. The method was then applied to real samples and used to assess the potential of a new FIP biomarker, fipronil-hydroxy (FIP-OH), for HBM. As a sample preparation protocol, enzymatic deconjugation followed by solid phase extraction were used. The method was successfully developed and validated for 16 organic pollutants and/or their metabolites, with lower limits of quantitation ranging from 0.5 to 2000 pg/mL. FIP-OH could not be included in the method, possibly due to its chemical instability. In an application study among pet owners, the detection rate for FIP was 71% (median: 3.32 pg/mL); several other chemicals were also commonly detected. The results of validation and application experiments confirm that the method can be used in HBM studies to quantify organic pollutants in urine. Full article

Chronic kidney disease of unknown origin (CKDu) is a public health concern, particularly in agricultural communities, with multiple environmental exposures hypothesized as potential contributors. This study employed a targeted exposure assessment using personal silicone wristbands to characterize chemical exposures among women living and working in CKDu-affected regions of Guatemala. Participants wore wristbands for seven days, passively sampling air and dermal exposures. Overall, 45 wristbands were collected from 37 female participants (19 sugarcane workers and 18 community members). Of the 1530 chemicals measured using a single semi-quantitative method, 103 were detected, with an average of 27 chemicals per wristband (range: 16–40). Polycyclic aromatic hydrocarbon (PAH) levels were higher in community members’ wristbands, whereas workers exhibited higher exposure to pesticides (i.e., pendimethalin and fipronil). Workers had worse kidney function compared to community members, with almost half of the workers having an estimated glomerular filtration rate, eGFR, <90 mL/min/1.73 m². Correlations were observed between kidney function markers and specific chemicals, with the strongest correlation between albumin-to-creatinine ratio and pyrene levels (ρ = 0.57, p < 0.01) among workers. Women in agricultural regions of Guatemala experience widespread exposure to diverse environmental chemicals, some of which may contribute to kidney function decline. Full article

Seed treatments with insecticides are important tools for managing corn stunting disease complex (CSDC) transmitted by Dalbulus maidis (Hemiptera: Cicadellidae) by reducing the initial leafhoppers’ population and, consequently, the risk of pathogen transmission. We evaluated the effect of insecticides used in seed treatment on both healthy and spiroplasma-infected leafhoppers, the persistence of the seed treatment effect on disease symptom severity, and its impact on corn productivity. At the V2 stage, imidacloprid/thiodicarb was the most effective, resulting in 100% mortality of healthy leafhoppers and 85.7% mortality of infective ones, thus preventing spiroplasma transmission. Thiamethoxam and methomyl + fipronil/thiamethoxam showed a high total mortality after 72 h, but only for the infective leafhoppers, with a total mortality of healthy leafhoppers around 40%, reducing the number of plants with symptoms by 80% and 90%, respectively. Our results prove that there is a difference between the chemical molecules and that the infected leafhoppers are more susceptible. Insecticide seed treatment was effective until the V2 growth stage, and imidacloprid/thiodicarb was the most effective product tested. Infective leafhoppers were more susceptible to insecticide seed treatments, and the infestation by the corn leafhopper carrying spiroplasma in the early stages of plant development heavily reduced corn yield. Full article

Fipronil (FIP) and imidacloprid (IMID) are two of the most commonly used ectoparasiticides to control parasites in pets. Compared with those of farm animals, their environmental risks have generally been considered low because of their limited use; however, the growing pet population and evolving treatment practices make this assumption challenging. To assess these risks, water samples were collected at an animal shelter in Italy to monitor the abundance of ectoparasiticides in aquatic environments. Additionally, laboratory-based ecotoxicological assays were carried out on a range of marine non-target species across different trophic levels (algae, copepods, and mussels). In vitro toxicity tests on human epithelial cell cultures were also implemented to examine potential cytotoxic effects at the levels of human exposure detectable in a domestic setting after pet treatment. Wastewater samples from the shelter contained 0.18 µg L⁻¹ of IMID, 0.50 µg L⁻¹ of FIP, and 0.20 µg L⁻¹ of FIP-sulfone, with these concentrations remaining stable for 60 days. Chronic exposure to FIP and IMID at 30.0 µg L⁻¹ impaired the mobility of the copepods. The EC₁₀ and EC₂₀ values were determined to be 1.7 (0.06–6.59) µg L⁻¹ and 2.8 (0.436–8.51) µg L⁻¹ for FIP and 2.6 (0.80–6.33) µg L⁻¹ and 7.6 (3.12–15.8) µg L⁻¹ for IMID, respectively. FIP and IMID exposure led to lipid peroxidation in the digestive glands and gills of mussels, whereas only IMID exposure increased acetylcholinesterase activity in the digestive glands at concentrations between 0.5 and 5.0 µg L⁻¹. Additionally, both fipronil and imidacloprid triggered the production of reactive oxygen species and lipid peroxidation and decreased the viability of human keratinocyte cells in a concentration-dependent manner. These findings highlight the persistence and potential risks of FIP and IMID, stressing the need for stricter regulations and further research on chronic environmental exposure to safeguard ecosystems and public health. Full article

The protective potentials of Tribulus terrestris (TT) and L-arginine (L-Arg) against reproductive toxicity induced by fipronil (FPN) in male rats were investigated. A total of 36 male rats were allocated into six groups: control, TT, L-Arg, FPN, FPN + TT, and FPN + L-Arg groups. The body and sex organ weights, semen criteria, serum testosterone levels, and testicular oxidative stress were determined. Sexual behavior, testicular and penile androgen receptor (AR), penile nitric oxide synthase (NOS), immunohistochemistry of proliferating cell nuclear antigen (PCNA), and histopathology were also assessed. FPN disrupted reproductive health by influencing the expression and activity of NOS and AR, leading to compromised erectile function, sexual dysfunction, and hormonal imbalance. Significant improvements in body weight, reproductive organ weights, the expression of NOS and AR, and testosterone levels were observed in the TT- and L-Arg-treated groups. Behavioral assessments indicated improved sexual performance in the TT- and L-Arg-treated groups. Histopathological studies of the testes and penis tissue, immunohistochemical expression of PCNA in testicular tissues, and biochemical analyses further confirmed the protective effects of TT and L-Arg. Collectively, these findings highlighted the potential of TT and L-Arg in counteracting FPN-induced reproductive impairments. Full article

The use of pesticides in agriculture can leave residues in the treated crops. Pesticides are also potential contaminants of ground and surface water, as reported in many countries. The development of efficient analytical methods to quantify pesticides in water samples is a challenge due to the low levels present. The objective of this work was to develop and validate a method for pesticide analysis in water using sample lyophilization followed by UHPLC–MS/MS and to determine pesticide levels in samples from a Brazilian hydrographic basin. In total, 77 compounds were included, of which 28 were considered only qualitatively. The method was applied to analyze 142 water samples collected during the dry and rainy seasons of 2021–2022, of which 90 were surface and 52 were groundwater samples. In total, 19 compounds were detected in the samples (≥LOD), mainly atrazine (72.5%), atrazine-2-hydroxy (50%), fipronil (18.3%), and pirimiphos-methyl (15.5%). Most compounds (17) were detected during the rainy season regardless of the environmental compartment. Twenty-five samples had quantified levels of the compounds (≥LOQ), of which 80% were collected during the dry season, and 58.3% were groundwater samples (up to 1.045 µg L⁻¹ of 2,4-D in an artesian well). The highest concentrations found in surface water were of atrazine-2-hydroxy (0.171 and 0.179 µg L⁻¹), levels that represent a potential risk to aquatic organisms (risk quotient of 1.1). This work provides an analytical method for determining pesticides in water that can be applied to other environmental pollutants. Although the levels found in the samples complied with Brazilian legislation, constant monitoring should be conducted in the region to guarantee safe levels of the pesticide in water. Full article

Fipronil, a widely used phenylpyrazole insecticide, is known to disrupt circulating thyroid hormone (TH) levels in rodents. Concentrations of fipronil and its metabolites (fipronil sulfone and fipronil sulfide) in serum samples collected in 2009–2011 were measured for 131 Japanese pregnant women by a sensitive and accurate liquid chromatography-tandem mass spectrometric method developed in our laboratory to relate TH levels. Fipronil sulfone was detected in all the subjects with the median being 21 ng/L (min–max: 6.8–89), but fipronil and fipronil sulfide were detected in none of the subjects (detection limit: 5.0 and 1.2 ng/L, respectively), indicating a rapid and exclusive oxidative conversion to fipronil sulfone upon exposure. The median concentration of fipronil sulfone was lower than those previously reported for general populations in other countries by one order of magnitude. There were no attributes or dietary habits of the subjects that significantly vary the serum fipronil sulfone concentrations. Multiple regression analyses found no significant association between serum concentrations of fipronil sulfone and free thyroxine- or thyroid-stimulating hormone levels, indicating the absence of adverse effects on circulating TH levels probably due to the lower exposure levels of the present subjects. The present result would be valuable for establishing a dose–effect relationship of fipronils in humans on population levels. Full article

Fipronil (FPN), a widely used pesticide, is associated with significant immunotoxic effects, particularly impacting thymocyte survival and immune homeostasis. This study explores the mechanistic pathways underlying FPN-induced apoptosis and oxidative stress. Short-term FPN exposure (1–10 mg/kg) notably suppressed the expression of both anti-apoptotic (Bcl-2, Bcl-6, Mcl-1) and pro-apoptotic (Bnip3, Bim) genes in thymic tissues in vivo. Additionally, in isolated primary thymocytes, FPN directly decreased the expression of Bcl-2, Bcl-6, Mcl-1, and Bnip3 expression, coupled with a significant increase in pro-apoptotic Bim expression in a dose-dependent manner. FPN treatment directly led to elevated reactive oxygen species (ROS), lipid peroxidation, mitochondrial membrane depolarization, reduced cellular metabolic activity, and depleted intracellular calcium and glutathione (GSH) levels, indicating mitochondrial dysfunction and oxidative stress. Annexin V/PI staining confirmed that FPN induced late-stage apoptosis and necrosis in primary thymocytes. These findings elucidate the immunotoxic effects of FPN on thymocytes, highlighting its detrimental impact on immune system integrity, thymic development, and T cell maturation through oxidative damage and mitochondrial-mediated apoptosis. Full article

Soil treatments and baits are two primary chemical control strategies for subterranean termites. Baiting is targeted and eco-friendly but requires ongoing maintenance, while soil treatments provide immediate, long-lasting protection with potential environmental concerns. Previously, we found that termites differentially manage deceased individuals based on their postmortem chemical signatures, potentially circumventing chemical controls. Given the distinct differences in the synthetic termiticides used for soil treatments (fast-acting) and baits (slow-releasing), we hypothesized that termites would respond differently to corpses treated with these two methods. To test this hypothesis, in Reticulitermes flavipes, we (1) profiled postmortem chemicals in termites exposed to different termiticides and (2) documented live termite responses to these corpses. Significant variations in postmortem chemical signatures, particularly 3-octanol and 3-octanone, were found among termites exposed to different termiticides, especially bifenthrin and fipronil. However, these variations did not lead to significantly different undertaking behaviors, indicating a complex relationship between death cues and termite behavior. Contrary to our hypothesis, except for bifenthrin, the fundamental undertaking behaviors were consistent despite differences in retrieval timing. This suggests that termiticides alone do not fully dictate termite undertaking behavior. Understanding termite corpse management is crucial for evaluating termiticide effectiveness, highlighting the need for an integrated pest management approach. Full article

Pesticide residues still pose a risk to human health. With the rapid development of rapid testing technology, the levels of different types of pesticide residues in agricultural products can be identified in a shorter period; thus, the safety of food can be guaranteed. However, the effectiveness of commercially available testing products has yet to be evaluated. In this study, colloidal gold immunochromatographic qualitative testing products manufactured by 34 companies were tested for their assay performance on Emamectin Benzoate, Isocarbophos, and fipronil with standardized cowpea samples. The results indicated that most of the evaluated products were identified as having ‘passed’. Most pesticide residue rapid test immunoassay products can be considered ideal means for testing certain pesticide residues. However, further evaluation of pesticide residue rapid test immunoassay products is needed, as detection technologies are still developing. Full article

Yellow crazy ants (YCAs) are an invasive ant with a pantropical distribution, largely due to the international movements of ships and produce. This invasive ant has the capacity to impact a broad range of environmental, domestic and agricultural situations and has the ability to develop into supercolonies and dominate landscapes if uncontrolled. YCAs have been detected in several locations in Australia. During 2018 in New South Wales, YCAs were detected in two locations in the Lismore region. Several awareness techniques were used to gain community support and engagement in the response program. The eradication program relied on the insecticide fipronil (several formulations), and the program subsequently used surveillance data to demonstrate that eradication had been achieved. We used the scenario tree analysis with stochastic models to estimate the likelihood of eradication. We combined the results of the passive and active surveillance systems to predict a 70.4% (62.7–80.7) probability of freedom of detecting one nest, 84.4% (73.9–94.4) probability of freedom for two nests and 98% (93.1–99.9) probability of freedom for five nests. The results from the scenario tree analysis were used to inform program managers regarding the termination of the eradication and surveillance activities. Full article