Neurotoxicity of Polycyclic Aromatic Hydrocarbons: A Systematic Mapping and Review of Neuropathological Mechanisms

Abstract

Several studies present the neurotoxic effects of polycyclic aromatic hydrocarbons (PAHs), a class of environmental pollutants capable of causing neurological deficits. However, a collective review approach to this research topic is scarce. This study presents the effect of PAHs on the central nervous system using a bibliometric approach. The neuropathological mechanisms of PAHs are also highlighted. Published articles were searched for in the Scopus and Web of Science databases from January 1979 to December 2020 using the keywords ‘polycyclic aromatic hydrocarbons’ and ‘neurotoxicity’. The total number of documents retrieved from both databases was 338. Duplicated documents (80) were excluded and 258 articles were used for the final analysis. Our findings revealed that there has been a significant increase in research outputs on this topic in the last ten years. The countries with the highest scientific productivity in this area are USA, China, France and Italy. The result also showed that, in the past few years, global scientific output in research relating to PAH neurotoxicity focused on neurodegeneration, cholinergic function, neurodevelopmental toxicity, behavioural studies, oxidative stress, neuroprotection and therapeutic intervention using different experimental models, including zebrafish, neuronal cell lines, Caenorhabditis elegans and rats. Recent studies also revealed the neuroprotective roles of some natural products against PAH-induced neurotoxicity. However, more investigation involving clinical trials is required to emphasize the observed neurotoxic effects.

Impact of polycyclic aromatic hydrocarbon exposure on cognitive function and neurodegeneration in humans: A systematic review and meta-analysis

“…It is known that some pathways of aryl-hydrocarbon neurotoxicity are common for PAHs, TCDD, dioxin-like agents, polyphenols, and similar xenobiotics. A review of the neuropathological mechanisms of PAHs highlights that these, together with their metabolites, may cross the blood–brain barrier causing neurological abnormalities that may include neuronal damage, impaired neurotransmitter regulation, parasympathetic dysregulation, and neurodegeneration ( 65 ). Preclinical studies hint at a common neuropathological mechanism of PAH action being the binding of these compounds to the aryl-hydrocarbon receptor (AhR), a cytosolic transcription factor that initiates a complex pathway leading to alteration of gene regulation.…”

“…Preclinical studies hint at a common neuropathological mechanism of PAH action being the binding of these compounds to the aryl-hydrocarbon receptor (AhR), a cytosolic transcription factor that initiates a complex pathway leading to alteration of gene regulation. AhR is also present in neural cells and can be involved in the mechanisms leading to PAH-induced neurological disorders ( 65 ).…”

Influence of Exposure Pathways on Tissue Distribution and Health Impact of Polycyclic Aromatic Hydrocarbon Derivatives

“…Brain endothelial cells are less permeable to chemicals, but PAHs and their derivatives are highly lipophilic compounds that can cross the blood−brain barrier and reach the brain. PAHs and the derivatives are neurotoxic, especially B[a]P. 170 Studies have reported that in differentiated human neuroblastoma SKN-SH cell lines, both parent PAHs and APAHs including dibenzothiophene and retene produce neurotoxicity in a concentration-dependent manner, and APAHs are more toxic than parent PAHs. 171 After acute exposure to 9,10-phenanthrenequinone in T. obscurus, four metabolic pathways are affected, and the 9,10phenanthrenequinone induced oxidative stress and causes neurotoxicity in fish.…”

Mechanism of action of anthocyanin on the detoxification of foodborne contaminants—A review of recent literature

“…These compounds have the potential to accumulate in the human body and induce carcinogenic, teratogenic, and mutagenic effects (Figure 2). Several studies have demonstrated that PAHs have adverse effects on various physiological systems, including the respiratory system (Leachi et al., 2020), circulatory system (Korashy & El‐Kadi, 2006), nervous system (Olasehinde & Olaniran, 2022), as well as the liver and kidney.…”