Characterization of the molecular differential responses in marine benthic macroinvertebrates exposed to polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are organic chemicals that can induce oxidative stress, genotoxicity, immunotoxicity, endocrine disruption, and developmental toxicity and are carcinogenic. Marine benthic macroinvertebrates are used as biomarkers for elucidating the level of environmental pollution due to their sedentary nature and ability to accumulate toxic compounds over an extended period. Antioxidant defence systems in macroinvertebrates protect cells from reactive oxygen species formed during oxidative stress, and they also counteract the effect of the pollutants through various physiological adaptations and differential expression of specific enzymes. A literature review on molecular studies on various marine benthic macroinvertebrates phyla was evaluated to understand their response to different PAH exposures. Literature shows that genomic tools can define toxicant-specific gene transcriptome variations, which can be utilized to identify the principal pathways that are affected. The review addresses analytical methods, similarities, and differences in antioxidant enzymes and the expression of various genes studied. The comprehensive analysis of literature reveals that several studies have explored the responses of organisms to PAH pollution; this included genes such as CYP450s, GST, SOD, GPx, CAT, and HSPs. Numerous studies have consistently demonstrated notable up-regulations in these genes, establishing their characterization as PAH-sensitive genes, highlighting the critical role played by them for cellular defence and detoxification mechanisms. PAHs can affect organisms depending on exposure time, kind, matrix, and pollutant dose. Benthic macroinvertebrates are robust bioindicators for PAH assessments; thus, environmental risk assessments need a standardized quality and assurance methodology for contamination exposures and biomarker interpretation.