Biogenic Synthesis of Silver Nanoparticles Using Catharanthus roseus and Its Cytotoxicity Effect on Vero Cell Lines.

Background: Type 2 diabetes mellitus (DM2) is a chronic and sometimes fatal condition which affects people all over the world. Nanotherapeutics have shown tremendous potential to combat chronic diseases­including DM2­as they enhance the overall impact of drugs on biological systems. Greenly synthesized silver nanoparticles (AgNPs) from Catharanthus roseus methanolic extract (C. AgNPs) were examined primarily for their cytotoxic and antidiabetic effects. Methods: Characterization of C. AgNPs was performed by UV−vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and atomic force microscopy (AFM). The C. AgNPs were trialed on Vero cell line and afterwards on an animal model (rats). Results: The C. AgNPs showed standard structural and functional characterization as revealed by FTIR and XRD analyses. The zetapotential analysis indicated stability while EDX analysis confirmed the formation of composite capping with Ag metal. The cytotoxic effect (IC50) of C. AgNPs on Vero cell lines was found to be 568 g/mL. The animal model analyses further revealed a significant difference in water intake, food intake, body weight, urine volume, and urine sugar of tested rats after treatment with aqueous extract of C. AgNPs. Moreover, five groups of rats including control and diabetic groups (NC1, PC2, DG1, DG2, and DG3) were investigated for their blood glucose and glycemic control analysis. Conclusions: The C. AgNPs exhibited positive potential on the Vero cell line as well as on experimental rats. The lipid profile in all the diabetic groups (DG1-3) were significantly increased compared with both of the control groups (p < 0.05). The present study revealed the significance of C. AgNPs in nanotherapeutics.

Analysis of multiple pesticide residues in market samples of okra and associated dietary risk assessment for consumers.

European Union Reference Laboratory method for Fruits and Vegetables (EURL-FV-2010-M1) for the quantification of pesticide residues was verified for the determination of multiple pesticide residues in okra. The targeted pesticides were extracted using acetonitrile with citrate buffer salts followed by cleanup with primary secondary amine (PSA) and analyzed on LC-MS/MS. The recoveries for all the targeted pesticides were within an acceptable range of 70.1-116.6% and precision in terms of RSD was 0.3-18.1%, respectively. The limit of quantification ranged from 0.002 mg/kg for carbofuran to 0.5 mg/kg for α-cypermethrin. The status of pesticide residues in okra (n = 21) available to consumers in the main markets of Pakistan has been determined by using this verified method. Sixty-two percent of the tested samples were contaminated out of which three samples were non-compliant with European Union maximum residue limits (EU-MRL). The pesticides violating the EU-MRL were bifenthrin, thiamethoxam, and triazophos. For all the detected pesticides, estimated daily intake (EDI) ranged between 1.40 × 10-6 and 1.78 × 10-4 mg/kg of body weight, chronic exposure risk (%ADI) ranged from 0.0073 to 1.8%, and acute exposure risk (%ARfD) ranged from 0.01 to 24.20%. The results exhibited insignificant risk from chronic exposure and minor to medium level of risk from acute exposure of these pesticides to human health.

Determination of pesticide residues in dates using UHPLC-QqQ-MS/MS: method development and validation.

A modified, efficient, and sensitive acetate-buffered QuEChERS extraction method was developed for the quantitative study of 16 commonly applied multiclass pesticides on date palm fruit. The date palm fruit samples were rehydrated by adding water during comminution. Samples were extracted with acidified acetonitrile, buffered with acetate salt. To minimize the matrix interferences, clean-up of the rehydrated samples was optimized by comparison with different sorbents (alumina, silica gel, florisil, primary secondary amine (PSA), and chitosan). The method validation parameters were evaluated as per European Union (EU) guidelines (SANTE/12682/2019). For 16 pesticides, % recovery of 69 to 121.8% with an associated precision (RSD ≤ 20%) was achieved at the fortification levels that were 0.5 to 2 times of European Union maximum residue limits (EU-MRLs). The validated method was successfully employed for the analysis of date palm fruit samples (n = 20) collected from various markets. Forty percent (40%) of samples (n = 8) were found to be contaminated with various pesticides. The most frequently detected residues were carbofuran, carbaryl, metalaxyl, tebuconazole, triazophos, and pyriproxyfen. The concentration of all the detected pesticides in real samples was below the EU-MRLs.

Cu(2+) and Fe(2+) mediated photodegradation studies of soil-incorporated chlorpyrifos.

The influences of Cu(2+) and Fe(2+) on the photodegradation of soil-incorporated chlorpyrifos were investigated in the present study. The soil samples spiked with chlorpyrifos and selected metal ions were irradiated with UV light for different intervals of time and analyzed by HPLC. The unsterile and sterile control soil samples amended with pesticides and selected metals were incubated in the dark at 25 °C for the same time intervals. The results of the study evidenced that photodegradation of chlorpyrifos followed the first-order kinetics. The dissipation t0.5 of chlorpyrifos was found to decrease from 41 to 20 days under UV irradiation. The rate of chlorpyrifos photodegradation was increased in the presence of both metals, i.e., Cu(2+) and Fe(2+). Thus, initially observed t0.5 of 19.8 days was decreased to 4.39 days in the case of Cu(+2) and 19.25 days for Fe(+2). Copper was found to increase the rate of photodegradation by 4.5 orders of magnitude while the microbial degradation of chlorpyrifos was increased only twofold. The microbial degradation of chlorpyrifos was only negligibly affected by Fe(2+) amendment. The studied trace metals also affected the abiotic degradation of the pesticide in the order Cu(2+) > Fe(2+).