RESUMEN
Although in vivo studies have been modeled using higher mammal systems, the lower vertebrate zebrafish (Danio rerio) has gained tremendous attention as a model system. Gold nanoparticles (GNPs) attract the interest of scientists due to their promising potential applications in medicine and targeted drug delivery. The purpose to use GNPs in vivo is that gold in bulk form is nontoxic and apply the positive potentials of nanoparticles. Bulk gold is century-long accepted as a safeto- use metal. Gold in its nanoform has distinct chemical and physical properties and the large amount of surface atoms make GNPs reactive. Moreover, GNPs can potentially access many cellular or subcellular structures, which are unreachable by the larger compound and may induce toxic effects. This paper addresses effects of spherical GNPs of average size 15 nm on reproductive organs after subacute exposure in adult male and female zebrafish. Gold nanoparticles were chemically synthesized and characterized by transmission electron microscope. The primary objective of this study was to determine if exposure to GNPs altered cellular morphology of gonads. The adult fish of both sexes were administered orally with these GNPs at a dose of 20 µg/gm. At the end of the study, quantification of gold content was estimated using two different tools: inductive coupled plasmon-atomic emission spectroscopy (ICP-AES) and inductive coupled plasmon-mass spectroscopy (ICP-MS). No gold metal accumulation was detected in treated group of male and female zebrafish at subacute exposures on estimation through ICP-AES. On analysis using ICP-MS, 0.44 ± 0.18 µg/gm organ weight was detected in ovaries and 4.6 ± 3.20 µg/gm organ weight was detected in testes of treated groups. However, the pattern of accumulation was found to be nonsignificant when compared with the control group at a p-value >0.05. Histopathological analysis of reproductive organs showed no significant changes in cellular morphology of testes and ovaries.
RESUMEN
Background: The need to identify causes of drug induced kidney failure has been underscored by International Conference on Harmonization (ICH) regulated agencies. In our earlier studies on adverse drug reaction (ADR) reported in Canada Vigilance Adverse Reaction Online Database it was observed that drugs azathioprine, clozaril/clozapine, diclofenac sodium, diflucan/ fluconazole, furosemide, indomethacin, metformin, micardis/ telmisartan, viread/tenofovir, and zyprexa/olanzapine lead to kidney failure. Method: Attempts have been made to understand the physiological process via bioinformatics perspective. This was done by active site identification for cytochrome P450 along with multidrug resistance protein 1 (MRP1). Docking against the drugs in these proteins that are categorically involved in drug binding based on their pharmacological actions are as per drug bank annotations. Results: Cytochrome P450 2C19 protein showed better interactions with drug indomethacin with a maximum score of -119.2 kcal/mol followed by drug clozaril with a score of -102.5 kcal/mol. This was finally followed by of drug zyprexa with a score of -101.0 kcal/mol. The residues which are actively involved with the drug indomethacin include Arg97 and Arg433. Drug clozaril shows interaction with Ala297. For drug zyprexa the residues like Arg97, Ala297 and Cys435 interact with the protein. For MRP1, even though it showed better binding scores for drugs azathioprine, indomethacin, diflucan and furosemide. But still, they are not able to interact within the pocket, leaving it empty during docking studies. Conclusion: Through this study, it was possible to identify active site pocket in the related proteins and the interacting amino acid residues of cytochrome P450 that may contribute to drug induced kidney failure.
RESUMEN
Genotoxic effects of silver nanoparticles (Ag-np) in a vertebrate model system were investigated. Effects and accumulation patterns of silver nanoparticles were studied using zebrafish embryos. Nanoparticles of silver were synthesized by chemical reduction of silver nitrate, using sodium borohydride as reducing agent and polyvinyl pyrolidene as a stabilizer. These nanoparticles were characterized by UV/ Vis spectrophotometer (absorption spectra), Transmission electron microscopy and were found to have the size range of 4 to 10 nm. Evaluation of cytotoxicity was carried out at various concentrations to obtain the LD50 value. Dose dependent decrease in percent viability was observed on exposure of embryos to different concentrations of silver nanoparticles with LD50 of 1.0 µg/ml. The results indicate that silver nanoparticles induce a dose-dependent toxicity in embryos and abrogate normal development.