Investigation of biological accumulation and eco-genotoxicity of bismuth oxide nanoparticle in fresh water snail Lymnaea luteola

Abstract

Bismuth is one of the significant heavy metals widely used in agricultural industry. Freshwater snails are sentinel organism models for aquatic ecosystem pollution. In the present study, we designed to understand the mechanism of bismuth oxide nanoparticle (Bi2O3NPs) toxicity on Lymnaea luteola (L. luteola) by using different biomarkers. The LC50 – 96 h of Bi2O3NPs was found 72.6 µg/ml for L. luteola and based on LC50 – 96 h of Bi2O3NPs three concentrations sub lethal I ~ 18.15 µg/ml, sub lethal II ~ 36.30 µg/ml, and sub lethal III ~ 48.4 µg/ml were selected for further study. The snails were exposed to above sub lethal concentrations of NPs for 7 days and specimens were harvested at 1, 3 and 7 days for assessment oxidative stress, apoptosis and eco genotoxicity. In general, Bi2O3NPs showed significant (p 0.05, 0.01) ecotoxic effect on snails in both concentrations and time of exposure. The generation ROS were maximum at sublethal III at day 7. After exposure to sublethal concentrations of Bi2O3NPs for day 1, 3 and 7 significantly elevated malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione S-transferase (GST) levels with simultaneous decline in glutathione (GSH) in pancreatic gland tissues of treated snails. Moreover, Bi2O3NPs elicited a significant percentage of apoptotic/necrotic heamocyte cells hemolymph of exposed snails. A parallel tendency was seen for the fragmentation of DNA as determined in terms of the percentage of tail DNA and olive tail moment in pancreatic gland tissue of exposed snails. This study highlights the toxic perturbation of Bi2O3NPs in water bodies and may be useful to monitor the application and disposal of NPs.