Network Toxicology Prediction and Molecular Docking-based Strategy to Explore the Potential Toxicity Mechanism of Metformin Chlorination Byproducts in Drinking Water.

BACKGROUND: Metformin (MET), a worldwide used drug for treating type 2 diabetes but not metabolized by humans, has been found with the largest amount in the aquatic environment. Two MET chlorination byproducts, including Y and C, were transformed into drinking water during chlorination. However, the potential toxicity of the byproducts in hepatotoxicity and reproduction toxicity remains unclear. METHODS: The TOPKAT database predicted the toxicological properties of metformin disinfection by-products. The targets of metformin disinfection by-products were mainly obtained from the PharmMapper database, and then the targets of hepatotoxicity and reproductive toxicity were screened from GeneCards. The overlapping targets of toxic component targets and the hepatotoxicity or reproduction toxicity targets were regarded as the key targets. Then, the STRING database analyzed the key target to construct a protein-protein interaction network (PPI) and GO, and KEGG analysis was performed by the DAVID platform. Meanwhile, the PPI network and compound- target network were constructed by Cytoscape 3.9.1. Finally, Discovery Studio 2019 software was used for molecular docking verification of the two toxic compounds and the core genes. RESULTS: Y and C exhibited hepatotoxicity, carcinogenicity, and mutagenicity evaluated by TOPKAT. There were 22 potential targets relating to compound Y and hepatotoxicity and reproduction toxicity and 14 potential targets relating to compound C and hepatotoxicity and reproduction toxicity. PPI network analysis showed that SRC, MAPK14, F2, PTPN1, IL2, MMP3, HRAS, and RARA might be the key targets; the KEGG analysis indicated that compounds Y and C caused hepatotoxicity through Hepatitis B, Pathways in cancer, Chemical carcinogenesis-reactive oxygen species, Epstein-Barr virus infection; compound Y and C caused reproduction toxicity through GnRH signaling pathway, Endocrine resistance, Prostate cancer, Progesterone-mediated oocyte maturation. Molecular docking results showed that 2 compounds could fit in the binding pocket of the 7 hub genes. CONCLUSION: This study preliminarily revealed the potential toxicity and possible toxicity mechanism of metformin disinfection by-products and provided a new idea for follow-up research.

Performance and mechanism of a novel S-scheme heterojunction sonocatalyst CuS/BaWO4 for degradation of bisphenol A by ultrasonic activation.

A novel CuS/BaWO4 heterojunction catalyst was prepared and characterized. Taking bisphenol A as the target pollutant for catalytic degradation, the sonocatalytic activity of CuS/BaWO4 composite was evaluated, and the combination with persulfate improved the sonocatalytic degradation of bisphenol A. The results showed that CuS/BaWO4 composite had good sonocatalytic degradation activity for bisphenol A, and the degradation rate was 70.99% ± 1.46%. After combined with persulfate, the degradation rate was further increased to 95.34% ± 0.10%, and the reaction time was relatively shortened. The results of the trapping experiment and calculated energy band positions showed that the formation of S-scheme heterojunction and the formation of hydroxyl radicals and holes were the key to the catalytic degradation of bisphenol A by CuS/BaWO4 composite. In this study, a new CuS/BaWO4 heterojunction sonocatalyst was synthesized. The catalyst can efficiently remove bisphenol A from the water environment and can be used as a potential solution for endocrine disruptor pollution in the water environment.

A novel flavonoid with antioxidant activity from Patrinia villosa (Thunb.) Juss.

Patrinia villosa (Thunb.) Juss (P. villosa), a perennial herb, is widely used as a medicinal plant in Chinese folk. This study aims to isolate and identify the chemical constituents from P. villosa and evaluate their antioxidant activity. Normal silica column chromatography, ODS silica column chromatography, Sephadex LH-20 column chromatography and semi-preparative HPLC methods were used to obtain a new compound named 3-n-pentadecyl-4'-methoxyluteolin (1) and two known compounds including luteolin-7-O-ß-D-glucuronide methyl ester (2) and apigenin-7-O-ß-D-glucuronide methyl ester (3). The antioxidant activity of these compounds was determined by DPPH and ABTS methods and the IC50 values were calculated. The IC50 values of ABTS scavenging activity of 1, 2 and 3 were 12.99 ± 0.09 µM, 7.13 ± 0.07 µM and 5.15 ± 0.08 µM, respectively, and the IC50 values of DPPH scavenging activity of 1, 2 and 3 were 51.86 ± 0.41 µM, 23.95 ± 0.71 µM and 25.06 ± 0.65 µM, respectively. All the compounds exhibited good antioxidant activities in vitro.

[Distribution of polybrominated diphenyl ethers in wild crucian carp and exposure estimation of dietary intake].

The concentration and distribution of PBDEs in liver, heart, brain, egg and muscle tissues of market farmed fish and wild river fish (crucian carp) from Taizhou, which is a large e-waste recycling site in China, were quantitatively measured using gas chromatography -negative chemical ion tandem mass spectrometry (GC-NCI-MS). The dietary intake of PBDEs via the consumption of fish by the population of this region was also estimated. The results showed that the concentrations of PBDEs in the muscle of river fish samples near the e-waste recycling site were significantly higher than those in the market farmed fish without obviously polluted sources of PBDEs. The distribution of PBDEs in various tissues was not even, and the highest and lowest mean concentrations of total PBDEs ( sigma PBDEs) were 18.82 ng x g(-1) and 1.97 ng x g(-1) (wet weight), in heart and egg tissues, respectively. A similar PBDE congener profiles in different tissues of farmed fish were found. Among PBDE congeners, BDE-47 was predominant in various tissues accounting for above 50% of the total PBDEs, and followed by BDE-183 (about 20%), BDE-99 and BDE-153. While different profiles of PBDEs in muscle tissues between wild fish in river and market farmed fish were observed, that BDE-47, -153 and -99 were dominant for the former type. These facts suggested primitive e-waste recycling behavior to be a pollution source of high levels of PBDEs in wild fish. The average estimated daily intake of PBDEs via river fish consumption by local residents near the e-waste recycling site in Taizhou was approximately 29.0 ng, slightly higher than that in other regions.

Image denoising using nonsubsampled shearlet transform and twin support vector machines.

Denoising of images is one of the most basic tasks of image processing. It is a challenging work to design a edge/texture-preserving image denoising scheme. Nonsubsampled shearlet transform (NSST) is an effective multi-scale and multi-direction analysis method, it not only can exactly compute the shearlet coefficients based on a multiresolution analysis, but also can provide nearly optimal approximation for a piecewise smooth function. Based on NSST, a new edge/texture-preserving image denoising using twin support vector machines (TSVMs) is proposed in this paper. Firstly, the noisy image is decomposed into different subbands of frequency and orientation responses using the NSST. Secondly, the feature vector for a pixel in a noisy image is formed by the spatial geometric regularity in NSST domain, and the TSVMs model is obtained by training. Then the NSST detail coefficients are divided into information-related coefficients and noise-related ones by TSVMs training model. Finally, the detail subbands of NSST coefficients are denoised by using the adaptive threshold. Extensive experimental results demonstrate that our method can obtain better performances in terms of both subjective and objective evaluations than those state-of-the-art denoising techniques. Especially, the proposed method can preserve edges and textures very well while removing noise.