The Impact of Individual and Combined Exposure to Aluminum and Chromium Particles on Oxidative Stress and Cellular Behavior in the Freshwater Ciliate Paramecium SP

Abstract

The cytotoxicity of metal mixtures has increasingly attracted the attention of scientists. In fact, living organisms are frequently exposed to complex mixtures of pollutants that arise especially as a result of industrialization. Combinations of these pollutants may have more harmful effects than the individual pollutants alone. Therefore, in order to accurately evaluate environmental studies, it is important to understand not only the toxicity of individual heavy metals, but also their interactions. In this context, the aim of this study is to evaluate the effect of four increasing concentrations (5µM, 10µM, 50µM and 100µM) of Aluminum and Chromium salts (separate and mixed) on a water pollution bio-indicator: the freshwater ciliate protist Paramecium sp.  Our results confirm the generation of reactive oxygen species (ROS) by inducing oxidative stress after metal treatment. This is evidenced by stimulation of catalase and GST activities, as well as the increase in GSH and MDA levels. Furthermore, cell behavior analysis revealed sensitivity to these metals, especially their mixtures. This effect is illustrated by changes in its trajectory and interruptions in its speed of movement.