Triazophos and its metabolite diethyl phosphate have different effects on endocrine hormones and gut health in rats

Synergistic risk in the gut and liver: Insights into the toxic mechanisms and molecular interactions of combined exposure to triazophos and fenvalerate in zebrafish

The simultaneous or sequential application of pesticides such as triazophos (TRI) and fenvalerate (FEN) in agriculture results in their residues co-existing in the environments. However, the impact of co-exposure to TRI and FEN on the gut-liver axis, along with the underlying mechanisms, remains unclear. Our results showed that exposure to FEN (96 h-LC50 value of 0.096 mg a.i. L-1) was more toxic to adult zebrafish compared to TRI (96 h-LC50 value of 6.75 mg a.i. L-1). Furthermore, the study aimed to reveal the toxic potencies of individual and combined exposure to TRI and FEN on the liver-gut axis in zebrafish (Danio rerio). Our results also indicated that pesticide exposure decreased tight junction molecule expression and increased intestinal inflammatory molecule expression in D. rerio, with co-exposure demonstrating enhanced toxicity. Co-exposure altered gut flora structure and species abundance. RNA-Seq sequencing revealed changes in liver gene expressions, particularly enrichment of P53 signaling. Molecular docking demonstrated FEN's stronger binding to P53 and Caspase3, correlating with its higher toxicity. Liver pathology confirmed exacerbated liver damage by individual and co-exposures, with co-exposure inducing more severe liver injury. qPCR results showed increased pro-apoptotic gene expression and decreased anti-apoptotic gene expression, with co-exposure exhibiting an interactive effect. Overall, this study identifies specific targets and pathways influenced by these pesticides, revealing toxicity mechanisms involving the gut-liver axis, which is crucial for environmental risk assessment of pesticide mixtures.

Comprehensive multi-omics investigation of sub-chronic toxicity induced by Cadmium and Triazophos Co-exposure in hook snout carps (Opsariichthys bidens)

The coexistence of heavy metals and pesticides poses a critical challenge in agricultural ecosystems. Traditional toxicity assessments often focus only on the individual impacts of either pesticides or heavy metals. Here, the untargeted metabolomics and 16 S rRNA sequencing were used to assess the individual and combined effects of cadmium (Cd) and triazophos (TRI) on hook snout carps (Opsariichthys bidens). Cd caused much more serious impacts on hepatic metabolism and gut microbiota than those in TRI. Combined Cd and TRI exposure synergistically affected hepatic metabolism, causing mitochondrial dysfunction and even oxidative damage. Simultaneously, 16 S rRNA sequencing highlighted significant variations in the composition and abundance of gut microbiota. A noteworthy connection emerged between these distinct microbiota profiles and disruptions in energy metabolism, ultimately leading to disorders in metabolites. These findings enhanced the understanding of risks posed by heavy metals and pesticides, providing insights for better environmental risk assessments of aquatic organisms.

Nano-quercetin mitigates triazophos-induced testicular toxicity in rats by suppressing oxidative stress and apoptosis

The present study was designed to evaluate the testicular toxicity of triazophos in rats and to check the ameliorative effect of nano-quercetin against triazophos-induced toxicity. Nano-quercetin was synthesized from quercetin and characterized. Male Wistar rats were divided into seven groups. The control group received olive oil as a vehicle orally. The high-dose triazophos group and the low-dose triazophos group received 1/10th LD50 of triazophos (7.6 mg/kg) and 1/20th LD50 of triazophos (3.8 mg/kg), respectively. Two groups of animals were dosed with quercetin and nano-quercetin, both at 50 mg/kg body weight orally. The final two groups received high-dose triazophos with co-administration of quercetin and nano-quercetin, respectively. Triazophos disrupted the male endocrine axis by reducing the levels of steroidogenic enzymes 3-β-HSD and 17-β-HSD in testicular cells, further reducing FSH and testosterone. Also, triazophos increased the reactive oxygen species, induced lipid peroxidation, decreased the mitochondrial membrane potential, and elevated the number of apoptotic cells in rat testes. Nano-quercetin ameliorated the testicular oxidative stress and apoptotic and endocrine parameters more efficiently than quercetin. Besides, nano-quercetin alleviated the histopathological and biochemical alterations of triazophos. It is concluded that nano-quercetin has higher anti-oxidant efficacy than quercetin in protecting rats against triazophos-induced testicular toxicity.

Diethyl phosphate disrupts hypothalamus-pituitary-adrenal axis endocrine hormones via nuclear receptors GR and Nur77: Integration of evidences from in vivo, in vitro and in silico approaches

Plenty of population epidemiology and cohort studies have found dialkyl phosphates (DAPs) in the urine were related to endocrine hormone disorders. However, we did not know whether these effects were caused by parent organophosphorus pesticides (OPs) or metabolite DAPs, especially the non-specific metabolite diethyl phosphate (DEP), which was the metabolic end product of most widely used diethyl OPs. In this study, animal experiments (in vivo), cell experiments (in vitro), small molecule-protein binding interaction experiments and computer molecular simulations (in silico) were used to explore the disturbing effects and molecular mechanisms of DEP on the hypothalamic-pituitary-adrenal (HPA) axis endocrine hormones. The animal experiments showed that chronic DEP exposure significantly disturbed the serum contents of HPA axis hormones in adult male rats. The target genes of glucocorticoid receptor (GR) in rat liver, including 11β-hsd1 and Pepck1 and PEPCK protein expressions, were down-regulated. Moreover, the gluconeogenic abilities of rats were impaired. However, it did not affect the expression of GR in the rat hypothalamus. These results indicated that the physiological functions of glucocorticoids and GR were damaged. Furthermore, spectroscopy experiments, cell experiments, molecular docking and molecular dynamics simulations also suggested that DEP can bind to nuclear receptors GR and Nur77, affecting their transcription factor functions, and the transcriptional expression levels of their downstream target genes were reduced. The biosynthesis and secretion of adrenocorticotropic hormone and glucocorticoids were blocked. Therefore, DEP can inhibit the production and physiological functions of HPA axis endocrine hormones by disrupting these related proteins and antagonizing nuclear receptors. These results were considered to provide a theoretical basis for strictly controlling the residue limits of OPs and their metabolites in foods, agricultural products and the environment. They also revealed new targets for evaluating the toxicities and risks of pesticide metabolites.