The possible role of Microcystin (D-Leu1 MC-LR) as antioxidant on Microcystis aeruginosa. In vitro and in vivo evidences.

MALANGA, G.; GIANNUZZI, L. AND HERNANDO M.

Murcia

Congreso; 2ª Congreso Iberoamericano y 6º Ibérico de Cianotoxinas, Murcia (España); 2019

2ª Congreso Iberoamericano y 6º Ibérico de Cianotoxinas, Murcia (España)

Microcystins constitute a serious threat to the quality of drinking water worldwide. However, the eco-physiological role of them is not yet completely known and it is suggested that MC can play a significant role in the antioxidant protection. The objective of this study was to evaluate the MC antioxidant capacity in vitro by Electronic Paramagnetic Resonance (EPR), highly specific for the different reactive oxygen species (ROS) and in vivo by long term (7 days) exposure of a Microcystis aeruginosa to high (29°C) temperature in addition to a 26°C control. It was observed an effective antioxidant activity of [D-Leu1]MC-LR against both radicals. In addition, significant increase in cellular biomass was observed under 29ºC being higher in [D-Leu1]MC-LR added cultures. The oxidation rate of 2,7-dichlorofluorescein di-acetate (DCFH-DA) was decreased during days 2, 5 and 7, in presence of MC, being significantly lower in the maximum exponential growth. In conditions of maximum ROS, at high temperature, the activity of the enzymatic antioxidant Catalase was significantly lower in [D-Leu1]MC-LR supplementation.Overall, [D-Leu1]MC-LR prevented cell damage in models of increased temperature by a possible ROS scavenger supporting the hypothesis of an antioxidant function of MC at least at the hydrophilic level.