Microalgae potential to protect from heavy metals-induced carcinogenicity

Toxic elements are present naturally in the environment; however, during the last century, their level has been continuously rising in the air, water, and soil due to anthropogenic activities, including urban runoff, pesticides and fertilizers, industrial effluents, and vehicle emissions. Once released in the environment, they are extremely stable, and therefore humans can get in contact with them through different routes of exposure. In addition, because of their toxicities, they are increasingly threatening human health. Exposure to toxic elements such as heavy metals (HMs) might contribute to the onset of disorders through their ability to generate reactive oxygen species (ROS), which are involved in cell macromolecule injuries. Moreover, several heavy metals (arsenic (As), cadmium (Cd), nickel (Ni), chromium (Cr), and beryllium (Be)) are classified by the International Agency for Research on Cancer as group one carcinogens and can induce different types of cancer through various and heterogeneous mechanisms. Therefore, a better understanding of heavy metals etiopathogenesis in cancer development and the identification of new bioactive products to prevent heavy metal carcinogenicity is warranted. Microalgae, known for their wide range of biological activities, could possess a promising metalloprotective effect against heavy metal-induced carcinogenicity. This protective effect is mainly attributed to their antioxidant and anti-cancer capacities as well as their heavy metal chelating potential. This review discusses the mechanisms implicated in heavy metal carcinogenicity. In addition, a deep understanding of microalgae's mitigating roles and strategies against heavy metal carcinogenicity are reviewed.