An in vivo analysis of Cr6+ induced biochemical, genotoxicological and transcriptional profiling of genes related to oxidative stress, DNA damage and apoptosis in liver of fish, Channa punctatus (Bloch, 1793)

Abstract Present study was designed to assess the hexavalent chromium (Cr 6+ ) mediated oxidative stress that induces DNA damage and apoptosis in adult fish, Channa punctatus (35 ± 3.0 g; 14.5 ± 1.0 cm; Actinopterygii). Fishes were maintained in three groups for 15, 30 and 45 d of exposure periods. They were treated with 5% (Group T1) and 10% (Group T2) of 96 h-LC 50 of chromium trioxide (Cr 6+ ). Controls were run for the similar duration. A significant (p  sod, cat, gsr, nox-1, p53, bax, bcl-2, apaf-1 and casp3a ) establishes the impact of oxidative stress due to in vivo , Cr 6+ accumulation in liver as compared to control (0 mg/L), in a dose and exposure-dependent manner. Initially, the increased level of reactive oxygen species (ROS) in liver coincided with that of enhanced mRNA expression of antioxidant enzymes, sod, cat, gsr and nox-1 but, later, the overproduction of ROS, after 45 d of exposure of Cr 6+ , resulted in a significant (p  p53. Our findings also unveil that the up-regulation of bax, apaf-1 and casp3a and down-regulation of bcl-2 are associated with Cr 6+ -induced oxidative stress mediated-apoptosis in liver of test fish. Aforesaid molecular markers can, thus, be efficiently utilized for bio-monitoring of aquatic regimes and conservation of fish biodiversity.