Plants produce various compounds through their secondary metabolism, including phenolic compounds (polyphenols), terpenes (terpenoids), and alkaloids. Here, our focus is on flavonoids, a subgroup of phenolic compounds. These bioactive molecules can be found in fruits, seeds, and leaves. Due to their chemical structure—consisting of two aromatic rings (rings A and B) and a heterocyclic benzopyran-oxygenated ring (ring C)—flavonoids exhibit important biological and pharmacological activities. Different flavonoids have been isolated and characterized using diverse approaches such as biochemical analysis, tissue culture, and animal models to understand their potential effects on cells. Moreover, multiomics methodologies hold significance in comprehending the mechanisms by which flavonoids perform their effects. Research has demonstrated that these molecules possess antioxidant, anti-inflammatory, and antitumor activities and may also play a role in preventing neurodegeneration. Given these findings, considerable efforts have been made to further investigate how flavonoids interact within cells and to identify the specific pathways involved. In this context, we present some data that contribute to this understanding. These active compounds are considered important for human health due to their ability to mitigate oxidative stress.