Emerging environmental stressors and oxidative pathways in marine organisms: Current knowledge on regulation mechanisms and functional effects

Abstract

Oxidative stress is a critical condition derived from the imbalance between the generation of reactive oxygen

Environmental safety of nanocellulose: an acute in vivo study with marine mussels Mytilus galloprovincialis

“…80 Similarly, there is a demonstrated link between inflammatory and oxidative stress processes as well as between oxidative stress responses and xenobiotic metabolism in bivalves. 81,82 However, our results in oxidative stress-related parameters and xenobiotic transformation reactions did not seem to be affected by NC exposures. Oxidative stress caused by the induction of reactive oxygen species has been recognized as the most common pathway affected by nanomaterial exposure and has recently been evoked in NC.…”

“…36,37,84 Even if pro-inflammatory pathways can trigger ROS production, this, in turn, is a signal of enhanced antioxidant defenses, and this is a timely process that requires adequate receptor activation, gene transduction and translation; in mussels, 48 h may be insufficient. 82 Xenobiotic metabolism can also enhance ROS formation, but the nature of this stressor is not likely to induce these mechanistic defenses nor was any interference observed in the metabolic capacity as a consequence of NC exposures at the catalytic level. 48 Based on the results presented above, it can thus be stated that the fibers were likely unable to enter the cells because neither changes in oxidative stress nor enzymes involved in biotransformation were observed.…”

Cellular adaptations of the scleractinian coral Madracis pharensis to chronic oil pollution in a Mediterranean shipwreck

“…Cells are able to neutralize the negative effects of oxyradicals through a complex network of low molecular weight scavengers and enzymes, collectively recognized as antioxidant system, universally developed to counteract the naturally occurring production of ROS from several cellular pathways of aerobic metabolism, as mitochondrial electron transport chain and active phagocytosis (Benedetti et al, 2015(Benedetti et al, , 2022Lushchak, 2011;Regoli and Giuliani, 2014). Reduced glutathione, ascorbic and uric acid scavenge ROS by directly acting as reducing agents on oxyradicals, but are also fundamental co-factors for the functioning of other antioxidants, enzymes that catalyze highly specific reactions, as superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidases (GPx) and glutathione S-transferases (GST), the main involved (Lushchak, 2011).…”

Cellular disturbance and thermal stress response in mussels exposed to synthetic and natural microfibers

“…In this respect, a better understanding of the specific biological effects of MFs is urgent, focusing on possible differences between synthetic and natural fibers, as well as the possibility that the effects caused by MFs ingestion trigger vulnerability and susceptibility of organisms toward additional stressors, including those occurring at a later stage after MFs exposure. Indeed, organisms' health status is challenged by multiple stressors, not necessarily acting in synchronous mode, but rather through additive, synergistic or antagonistic effects (Crain et al, 2008): even a limited disturbance provoked by a single factor may interfere in a more complex network of biological responsiveness (Benedetti et al, 2022).…”

“…In this context, the aim of the present study was to compare the effects of synthetic (polyester and polyamide) and natural (cotton) microfibers in the Mediterranean mussel Mytilus galloprovincialis integrating results on ingestion and elimination of MFs with the measurement of a wide spectrum of cellular responses reflecting the possible biological targets of MFs: similarly to MPs, also MFs could be recognized by immunocytes as foreign particles, altering their phagocytic activity and subpopulations ratio, and promoting proinflammatory pathways which trigger ROS production and oxidative pressure, which may result in cellular and genotoxic damages (Avio et al, 2015;Pittura et al, 2018;Benedetti et al, 2022). In mussels, the activation of stress-defense mechanisms is mediated, among others, by the cholinergic system (Liu et al, 2018a) and sustained by energy reserves like neutral lipids deriving from beta-oxidation of fatty acids and stored in the digestive gland (Bocchetti and Regoli, 2006).…”