Genotoxicity of refinery waste assessed by some DNA damage tests.
Refinery waste effluent is well known to contain polycyclic aromatic hydrocarbons, phenols and heavy metals as potentially genotoxic substances. The aim of the present study was to assess the genotoxic potential of Mathura refinery wastewater (MRWW) by various in vitro tests including the single cell gel electrophoresis, plasmid nicking assay and S1 nuclease assay. Treatment of human lymphocytes to different MRWW concentrations (0.15×, 0.3×, 0.5× and 0.78×) caused the formation of comets of which the mean tail lengths increased proportionately and differed significantly from those of unexposed controls. The toxic effect of MRWW on DNA was also studied by plasmid nicking assay and S1 nuclease assay. Strand breaks formation in the MRWW treated pBR322 plasmid confirmed its genotoxic effect. Moreover, a dose dependent increase in cleavage of calf thymus DNA in S1 nuclease assay was also suggestive of the DNA damaging potential of MRWW. A higher level of ROS generation in the test water sample was recorded which might be contributing to its genotoxicity. Interaction between the constituents of MRWW and calf thymus DNA was also ascertained by UV-visible spectroscopy.
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh, India.
Amit Kumar
AK
Gupta
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh, India.
Irshad
I
Ahmad
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, Uttar Pradesh, India. Electronic address: masood_amua@yahoo.co.in.
Masood
M
Ahmad
D020552:Comet Assay; D004247:DNA; D004249:DNA Damage; D006801:Humans; D007202:Indicators and Reagents; D007220:Industrial Waste; D059392:Petroleum Pollution; D010636:Phenols / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D062065:Wastewater / Q000737:chemistry / Q000633:toxicity*
D004247:DNA; D007202:Indicators and Reagents; D007220:Industrial Waste; D010636:Phenols; D011084:Polycyclic Aromatic Hydrocarbons; D062065:Wastewater; C427203:calf thymus DNA
Comet assay; Genotoxicity; ROS (reactive oxygen species); Refinery wastewater; in vitro DNA damage