Toxicity and oxidative damage of different silver nanoparticles to Caenorhabditis elegans / 中国药理学与毒理学杂志

ABSTRACT

Objective: To investigate the toxic effects of three types of silver nanoparticles (AgNPs) 20 and 50 nm uncoated nanosilver (AgNPs-20 and AgNPs-50) and 20 nm polyvinylpyrrolidone coated nanosilver (AgNPs-PVP-20) to Caenorhabditis elegans (C.elegans). Methods: Wild type C. elegans were exposed to 1% hydroxypropyl methylcellulose (vehicle group) and AgNPs-20, AgNPs-50, AgNPs-PVP-20 (1,10 and 100 mg·L-1) for 48 h, respectively. The survival, head thrash and body bend frequency of the nematodes were recorded. The levels of reactive oxygen species (ROS), malondialdehyde (MDA) and glutathione (GSH) in nematodes were detected by DCFH-DA fluorescence probe, TBA method and colorimetry, respectively. Results: Compared with vehicle group, the survival rate of nematodes was decreased in each dose group of AgNPs-PVP-20,10 and 100 mg·L-1groups of AgNPs-50 and AgNPs-20 (P<0.01). The relative mean lifespan of nematodes in each dose group of AgNPs-PVP-20 was significantly decreased (P<0.01), while that of AgNPs-20, AgNPs-50 (10 and 100 mg·L-1) was decreased (P<0.05). The frequency of head thrashes in 10 and 100 mg·L-1of the three AgNPs groups was decreased (P<0.05), and the frequency of body bends in each dose group of AgNPs-PVP-20 was significantly reduced (P<0.01). The body bends in 100 mg·L-1groups of AgNPs-20 and AgNPs-50 were decreased (P<0.05). The fluorescence intensity of ROS in the three AgNPs groups was significantly higher than that of the control group (P<0.01). Compared with the control group, the content of MDA was increased and the content of GSH decreased (P<0.05) in AgNPs-PVP-20 (10 and 100 mg·L-1) groups. There was no significant difference in MDA or GSH contents between AgNPs-50 and control groups. Conclusion: The relative mean lifespan of nematodes, the head thrash frequency and body bend frequency of nematodes were decreased to different extents with the increasing dose in each of the AgNPs groups, whereas the oxidative stress level of nematodes was increased unexpectedly in all the test samples. The toxic effect of AgNPs-PVP-20 is the strongest, followed by AgNPs-20 and AgNPs-50.