Protective potential of thymoquinone against cadmium, arsenic and lead toxicity: a short review with emphasis on oxidative pathways.

Heavy metals are among the most important environmental pollutions used in various industries. Their extensive use has increased human susceptibility to different chronic diseases. Toxic metals exposure, especially cadmium, arsenic and lead, causes oxidative damages, mitochondrial dysfunction and genetic and epigenetic modifications. Meanwhile, thymoquinone (TQ) is an effective component of Nigella sativa oil that plays an important role in preventing the destructive effects of heavy metals. The present review discusses how TQ can protect various tissues against oxidative damage of heavy metals. This review is based on the research reported about the protective effects of TQ in the toxicity of heavy metals, approximately the last ten years (2010-2021). Scientific databases include Scopus, Web of Science and PubMed were searched using the following keywords either alone or in combination: cadmium, arsenic, lead, TQ and oxidative stress. TQ, as a potent antioxidant, can distribute to cellular compartments and prevent oxidative damage of toxic metals. However, depending on the type of toxic metal and the carrier system used to release TQ in biological systems, its therapeutic dosage range may be varied.