Non-enzymatic antioxidant responses of Mytilus galloprovincialis: Insights into the physiological role against metal-induced oxidative stress

The exposure to metals is known to generate oxidative stress in living organisms, which can result in the induction of protective antioxidant defences, both enzymatic and non-enzymatic. This work aims to obtain new data on the existing links among several non-enzymatic components of the antioxidant system, that are physiologically related to both metal sequestration and defense against metal-induced oxidative stress, using the blue mussels (Mytilus galloprovincialis) as a model organism. Specimens of this marine bivalve were experimentally exposed to cadmium (Cd), used as oxidative stress inducer. Cd, metallothionein (MT), glutathione (GSH), malondialdehyde (MDA) contents, and glutathione reductase (GR) activity in gills and in digestive glands were assessed at 0, 12, 24, 48, 72 and 96 h. The obtained results provide new data about the relationships among the non-enzymatic antioxidant cellular components considered in this study. These constitute the prompt physiological responses to the oxidative stress in blue mussels exposed to Cd in controlled laboratory conditions.