Trichlorfon blocks androgen synthesis and metabolism in rat immature Leydig cells

Peroxidase-mimetic carbon dot based nanozyme hydrogel colorimetric sensor for visual trichlorfon detection

Organophosphorus pesticide residues pose considerable threats to the environment and public health and have become a global concern. This paper reports the development of a visual sensing platform for the detection of trichlorfon based on a carbon-based nanozyme (abbreviated as Fe-CDs) with peroxidase-mimetic catalytic activity in conjunction with acetylcholinesterase (AChE). The peroxide-mimetic enzyme activity of Fe-CDs can be inhibited by sulfhydryl (-SH) compounds, and AChE can decompose thiocholine (ATCh) to produce -SH-containing thiocholine (TCh), leading to the inability of Fe-CDs to oxidise 3,3',5,5'-tetramethylbenzidine (TMB) to turn the solution blue, while trichlorfon can inhibit the activity of AChE, thereby recovering the blue colour. This platform achieves sensitive detection of trichlorfon with a linear range of 200-50,000 pM and a detection limit of 157.57 pM and has been successfully applied to the detection of trichlorfon in Chinese cabbage. In addition, encapsulating Fe-CDs, ATCh and TMB in sodium alginate hydrogels and using a smartphone and colour analysis software, a colorimetric hydrogel portable kit is developed, realising the simple and rapid detection of the trichlorfon residue in real samples. This study provides a direct, simple and rapid strategy for the detection of trichlorfon in agricultural products and offers a potential on-site detection tool for food safety monitoring.

Effect of the defoliant tribufos on the reproductive ability of Japanese quail (Coturnix japonica)

As a cotton defoliator, tribufos (S,S,S-tributyl phosphorotrithioate) is widespread in the environment. It can cause neurotoxicity in chickens, reproductive toxicity in rats, and can also cause headaches and nausea in humans. However, little is known about its impact on the reproduction of birds. Here, by analyzing the differences in reproductive indexs and histopathological characteristics, we investigated the chronic effects of 32 mg a.i./kg, 160 mg a.i./kg and 800 mg a.i./kg tribufos treatment on the reproductive ability of Japanese quail (Coturnix japonica). The results indicated that 32 mg a.i./kg and 160 mg a.i./kg tribufos treatment significantly reduced the food intake of quails, significantly increased the broken egg rate, and had adverse effects on gonads and liver tissue. The 160 mg a.i./kg tribufos treatment also significantly reduced the average egg production. Moreover, 800 mg a.i./kg treatment had significant negative effects on feed intake (FI), body weight (BW), eggshell thickness, egg production (EP), fertilization rate, hatchability and progeny 14-d survival rate, and it also significantly increased the broken egg rate. In addition, tribufos exposure caused lesions in quail gonads and liver tissue. Overall, our results revealed that tribufos had adverse effects on the reproductive ability of Japanese quail, especially at high concentrations.