This predominant NPAH molecule can also pollute the aquatic ecosystems which poses genotoxic effects, specifically mutagenic, and oxidative stress to sub-organism levels of biological organization like fishes. Several researches have pointed out that the accumulation of 1-nitropyrene is a possible bioindicator of oxidative stress and genotoxicity among several fish species (e.g. red sea bream, marbled flounder, and tilapia) and as well as of aquatic pollution evaluation. This paper describes the related researches of the environmental 1-nitropyrene exposure as bioindicator oxidative stress and genotoxicity.
Detections and Their Principles
Evaluation of bioindicator to oxidative stress and genotoxicity can be conducted with an experiment on a representative fish organism in the locality, where different concentrations and different exposure time of 1-nitropyrene are set. Blood samples are analyzed for its genotoxic effects via micronuclei (MN) analysis, nuclear abnormality (NA) analysis, and DNA oxidation analysis. Liver samples are analyzed for its activities on glutathione peroxidase and assays on lipid peroxidation and carbonyl protein. Concentrations of 1-NP in the aqueous environment are analyzed using high performance liquid chromatography (HPLC) with mass-spectrometry detection.
Micronuclei (MN) and Nuclear Abnormality (NA) Analysis
These tests are used for detecting chromosomal damage. Micronuclei are ovoid or circular bodies containing fragmented or whole chromosomal material that separate from the nuclei. Their presence reflects the structural and/or numerical chromosomal aberrations arising during mitosis [2]. The nuclear abnormality test serves as a compliment to MN test which has been used as an evaluation to cytogenetic damage in fish species. The abnormalities present in erythrocytes can be classified as notched, lobed, blebbed, and vacuolated, in addition to the typical micronuclei [3].
Assays of Oxidative-Damaged Target
The continuous efflux of reactive oxygen species (ROS), which may be in radical and radical form with high reactivity, from endogenous, where 1-NP belongs, and exogenous sources results in continuous and accumulative oxidative damage to cellular components and alters many cellular functions. Most of the targets that are vulnerable to these attacks are proteinaceous enzymes, lipidic membranes, and DNA as displayed in a series of chain reactions and target attacks shown in Figure 2 [4]. The degree of damage on each target by 1-NP exposure can be assessed with proper instrumentation and biochemical analyses.