Aluminum Genotoxicity in Plants, Mammals, and Unicellular Eukaryotes: The Underlying Mechanisms

Aluminum (Al), the third most abundant metal in the Earth's crust, has been preserved for thousands or even millions of years. However, acidic rain and soil acidification, largely driven by human activities related to industrialization and the increased use of Al in daily life, have led to the mobilization of Al from its complex natural resources. This exposure has affected various microorganisms, including bacteria, fungi, protozoa, and yeast, as well as macroorganisms such as plants, animals, and humans, by introducing them to Al in its ionic form. To date, no biological role for Al has been defined in organisms; however, some beneficial effects have been shown, particularly on plant growth. The exposure of living organisms, particularly human cell lines, to chronic and high doses of Al has been the focus of numerous studies. The consequences of such exposure can vary significantly based on the type of organism, their sensitivity, the form of Al, and the dosage used. In plants, these consequences can include inhibited root growth, stunted development, reduced biomass, and disrupted nutrient uptake. In animals, Al exposure can lead to neurological impairments, impaired mineral metabolism, and bone abnormalities. In humans, it may result in encephalopathy, cognitive deficits, microcytic anemia, and an increased risk of Alzheimer's disease. Unicellular organisms, such as yeast and bacteria, may experience decreased cell viability, inhibited growth, and disrupted metabolic processes. This review discusses the genotoxicity of Al in plants, mammals, and yeast cells, as well as the subsequent detrimental effects on cell cycle and cell proliferation. It also explores the underlying mechanisms and pathways associated with these effects. Furthermore, the types of Al-induced cell death as a response mechanism to Al toxicity and the pathways involved in various cell types were discussed.