Assessment of genotoxicity induced by helminthes parasites in freshwater fishes of river Ganges

Several parasites have been shown to induce genotoxicity in humans and fish are important intermediate hosts for completing the life cycle of many parasites, posing a huge economic loss worldwide through the ecosystem food chain. In the present study, we assessed the genotoxic potential of helminth Rostellascaris sp. through a benchmark of comet assay and micronucleus (MNi) tests on the hepatocytes, muscle, and whole blood of infected fish Bagarius bagarius (Hamilton) collected from different sites of the river Ganges. The percentage of the mean tail length of the comet was 10.28 & PLUSMN;0.36 in the reticulocytes of the infected fish which was significantly (P < 0.05) longer compared to the control (2.86 & PLUSMN;0.12). Similarly, a significantly (P < 0.05) higher DNA damage was observed in hepatocytes of parasite-infected fish (12.15 & PLUSMN;0.24) when compared to the control (3.024 & PLUSMN;0.013). A comparatively higher DNA damage was observed in the hepatocytes than the reticulocytes, indicative of tissue-specific DNA damage as hepatocytes are the biomarkers of metabolic functions prone toward biotic stress. A higher induction of MN was observed in infested fish (0.18 & PLUSMN;0.07) as compared to the control. Our results suggest that parasites contribute to the induction of cellular and DNA damage in fish during the progression of the host-parasite interaction.