The role of fenugreek seed extract in alleviating pancreatic toxic effects and altering glucose homeostasis induced by acetamiprid via modulation of oxidative stress, apoptosis, and autophagy.

Acetamiprid (ACMP) is a second-generation neonicotinoid that has been extensively used in the last few years. The present study examined the toxic effects of ACMP on the pancreas and glucose homeostasis through the evaluation of histological and biochemical changes and the possible ameliorative role of fenugreek seed extract (FG). Fifty adult albino rats were divided into 5 groups: negative control, positive control, FG-treated, ACMP-treated, and ACMP + FG-treated groups by oral gavage for 12 weeks. The ACMP-treated group highlighted significant elevations in plasma glucose, glycosylated haemoglobin levels (HbA1c), serum amylase, and serum lipase, along with a decrease in plasma insulin levels. In addition, significant increases in tumour necrosis factor- alpha (TNF-α) and malondialdehyde (MDA) were associated with reductions in the levels of interleukin 10 (IL-10), glutathione peroxidase, and catalase. Moreover, glucose-6-phosphatase and glycogen phosphorylase were significantly increased, with a significant reduction in hexokinase and liver glycogen stores. These biochemical changes were associated with histological changes in pancreatic sections stained by haematoxylin and eosin, Masson stain, and Orcein stain. ACMP-treated cells showed a marked reduction in ß- cell immune reactivity to insulin, with pronounced p53, and beclin 1 immune expression. The use of FG with ACMP induced partial protection except for hexokinase and glycogen phosphorylase.

Delivery of acetamiprid to tea leaves enabled by porous silica nanoparticles: efficiency, distribution and metabolism of acetamiprid in tea plants.

BACKGROUND: Pesticide residue and its poor utilization remains problematic in agricultural development. To address the issue, a nano-pesticide has been developed by incorporating pesticide acetamiprid in porous silica nanoparticles. RESULTS: This nano-pesticide had an acetamiprid loading content of 354.01 mg g-1. Testing LC50 value against tea aphids of the commercial preparation was three times that of the nano-pesticide. In tea seedlings (Camellia sinensis L.), acetamiprid was transported upward from the stem to the young leaves. On day 30, the average retained concentrations in tea leaves treated with the commercial preparation were about 1.3 times of that in the nano-pesticide preparation. The residual concentrations of dimethyl-acetamiprid in leaves for plants treated with the commercial preparation were about 1.1 times of that in the nano-pesticide preparation. Untargeted metabolomics of by LC-MS on the young leaves of tea seedlings under nano-pesticide and commercial pesticide treatments showed significant numbers of differentially expressed metabolites (P < 0.05 and VIP > 1). Between the nano-pesticide treatment group and the commercial preparation treatment group there were 196 differentially expressed metabolites 2 h after treatment, 200 (7th day), 207 (21st day), and 201 (30th day) in negative ion mode, and 294 (2nd h), 356 (7th day), and 286 (30th day) in positive ion mode. Preliminary identification showed that the major differentially expressed metabolites were glutamic acid, salicylic acid, p-coumaric acid, ribonic acid, glutamine, naringenin diglucoside, sanguiin H4, PG (34:2) and epiafzelechin. CONCLUSIONS: This work demonstrated that our nano-pesticide outperformed the conventional pesticide acetamiprid in terms of insecticidal activity and pesticide residue, and the absorption, transportation and metabolism of nano-pesticide in tea plant were different, which pave a new pathway for pest control in agricultural sector.

Residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and its metabolites during tea growing and tea brewing.

BACKGROUND: Tolfenpyrad and dinotefuran are two representative pesticides used for pest control in tea gardens. Their application may bring about a potential risk to the health of consumers. Therefore, it is essential to investigate the residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and metabolites from tea garden to teacup. RESULTS: An effective analytical method was established and validated to simultaneously determine tolfenpyrad, dinotefuran and its metabolites (DN and UF) in tea. The average recoveries of tolfenpyrad, dinotefuran, DN and UF were in the range 72.1-106.3%, with relative standard deviations lower than 11.8%. On the basis of the proposed method, the dissipation of tolfenpyrad and dinotefuran in fresh tea leaves followed first-order kinetics models with half-lives of 4.30-7.33 days and 4.65-5.50 days, respectively. With application amounts of 112.5-168.75 g a.i. ha-1 once or twice, the terminal residues of tolfenpyrad and total dinotefuran in green tea were lower than 19.6 and 7.13 mg kg-1 , respectively, and below their corresponding maximum residue limits . The leaching rates of tolfenpyrad and total dinotefuran during the tea brewing were in the ranges 1.4-2.3% and 93.7-98.1%, respectively. CONCLUSION: Tolfenpyrad and dinotefuran in tea were easily degraded. The RQc and RQa values for tolfenpyrad were 37.6% and 5.4%, which were much higher than for dinotefuran at 24.7% and 0.84%, respectively. The data indicated that there was no significant health risk in tea for consumers at the recommended dosages. The results provide scientific data regarding the reasonable use of tolfenpyrad and dinotefuran aiming to ensure safe tea consuption. © 2021 Society of Chemical Industry.

Comparation study on the metabolism destination of neonicotinoid and organophosphate insecticides in tea plant (Camellia sinensis L.).

The absorption, distribution, metabolism and primary risk evaluation data of four neonicotinoids and two organophosphate insecticides in tea plant (Camellia sinensis L.) were compared. 22 neonicotinoid metabolites and 2 organophosphate metabolites were identified. The amount ratio of each neonicotinoid metabolite to its corresponding parent (M/P) was lower than 0.076 in the treated time. The organophosphates (omethoate and methamidophos) increased sharply, with M/Ps as high as 1.111 and 0.612. The risks evaluation of insecticides and their metabolites in treated leaves on day seven showed that the chronic risk was from the lowest 0.0759 (clothianidin) to highest 43.6409% (dimethoate), and the acute risk was highest 0.0370 for all targets. The calculated combined toxicity of leaves treated with acephate reached 1.5 folds in mature, 1.5 folds in tender leaves than no metabolites, and which of dimethoate were 2.1 folds in mature and 3.7 folds in tender leaves.

Honeybee dietary neonicotinoid exposure is associated with pollen collection from agricultural weeds.

Neonicotinoid insecticides have been linked to bee declines. However, tracking the primary exposure route for bees in the field has proven to be a major logistical challenge, impeding efforts to restore pollinator health in agricultural landscapes. We quantified neonicotinoid concentrations and botanical species composition in 357 pollen samples collected from 114 commercial honeybee colonies placed along a gradient of agricultural intensity between June and September. Neonicotinoid concentrations increased through the season, peaking at the end of August. As a result, concentrations in pollen were negatively associated with collection from woody and crop plants that flower early-mid season, and positively associated with collection from herbaceous plants that flower mid-late season. Higher clothianidin and thiamethoxam residues were correlated with samples containing a greater proportion of pollen collected from agricultural weeds. The percentage of agricultural land within 1500 m was positively correlated with thiamethoxam concentration; however, this spatial relationship was far weaker than the relationship with the proportion of pollen collected from herbaceous plants. These results indicate that both plant species identity and agricultural dominance are important in determining honeybee neonicotinoid exposure through the pollen diet, but that uncultivated plants associated with agriculture are the source of the greatest acute exposure.

Neonicotinoid insecticidal seed-treatment on corn contaminates interseeded cover crops intended as habitat for beneficial insects.

Neonicotinoid seed treatments are extensively used to systemically protect corn from invertebrate herbivory. Interseeding cover crops can promote beneficial insect communities and their ecosystem services such as predation on pests, and this practice is gaining interest from farmers. In this study, cereal rye (Secale cereale) and hairy vetch (Vicia villosa) were planted between rows of early vegetative corn that had been seed-treated with thiamethoxam. Thiamethoxam and its insecticidal metabolite, clothianidin were quantified in cover crop leaves throughout the growing season. Thiamethoxam was present in cereal rye at concentrations ranging from 0 to 0.33 ± 0.09 ng/g of leaf tissue and was detected on six out of seven collection dates. Cereal rye leaves contained clothianidin at concentrations from 1.05 ± 0.22 to 2.61 ± 0.24 ng/g and was present on all sampling dates. Both thiamethoxam and clothianidin were detected in hairy vetch on all sampling dates at rates ranging from 0.10 ± 0.05 to 0.51 ± 0.11 ng/g and 0.56 ± 0.15 to 9.73 ± 5.04 ng/g of leaf tissue, respectively. Clothianidin was measured at a higher concentration than its precursor, thiamethoxam, in both plant species on every sampling date. Neonicotinoids entering interseeded cover crops from adjacent treated plants is a newly discovered route of exposure and potential hazard for non-target beneficial invertebrates. Future research efforts should examine the effects of systemic insecticides on biological communities in agroecosystems whose goal is to diversify plant communities using methods such as cover cropping.

Determinations of dinotefuran and metabolite levels before and after household coffee processing in coffee beans using solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry.

BACKGROUND: Coffee is one of the most popular beverages in the world. However, as daily consumables, coffee beans may contain pesticide residues that are capable of causing adverse health effects. Thus, we investigated residue dynamics in coffee beans using supervised field trials under Good Agricultural Practice conditions and determined the effects of household coffee processing on the coffee-bean pesticide residues dinotefuran and its metabolites 1-methyl-3-(tetrahydro-3-furylmethyl) urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl) guanidine (DN). RESULTS: The recovery rate of dinotefuran and its metabolites UF and DN was in the range 73.5%-106.3%, with a relative SD < 10%. The limits of detection and limits of quantification for dinotefuran, UF and DN were all 0.003 and 0.01 mg kg-1 , respectively. Dissipation experiments were conducted over 2015 and 2016 and showed a mean half-life of 40.8 days. Coffee processing procedures were performed as described for traditional household coffee processing in Ethiopia. Dinotefuran contents were reduced by 44.4%-86.7% with washing of coffee beans and the roasting process reduced these contents by 62.2%-100%. DN residues were not detected in roasted coffee beans before day 21 or in brewed coffee before day 35 and UF residues were not detected in brewed coffee before day 35. Kruskal-Wallis analyses indicated large variations in the stability of pesticide residues between processing methods (P ≤ 0.05). Reductions of pesticide concentrations with washing were also significantly lower than those following roasting (P = 0.0001) and brewing processes (P = 0.002). Moreover, processing factors were less than one for all processing stages, indicating reductions of pesticides contents for all processing stages. CONCLUSION: The cumulative effects of the three processing methods are of paramount importance with respect to an evaluation of the risks associated with the ingestion of pesticide residues, particularly those in coffee beans. © 2018 Society of Chemical Industry.