Antioxidative Properties of Flavonoids

Evidence accumulates that a family of plant compounds, known as flavonoids, can prevent or slow down the progression of cardiovascular diseases, cancer, inflammatory and neurodegenerative diseases. Flavonoids are considered beneficial, this is often attributed to their powerful antioxidant properties. In this role, certain types of flavonoids are considered to be far more powerful than the two most common antioxidants, vitamin C and vitamin E, at preventing cellular damage brought on by free radicals. Interestingly, flavonoids exert those activities not only through direct radical scavenging, but also through regulating nitric oxide, and chelating metals. In addition, flavonoids are thought to facilitate/promote other important biological processes, resulting in modulation of enzymes, a decrease in leukocyte immobilization, inhibition of cell proliferation and angiogenesis, and effects on signaling pathways. The results of in vitro studies have demonstrated that the antioxidative property of flavonoids is unambiguous; however it is still not supported by strong consistent evidence in vivo. Therefore, the antioxidant theory as a mechanism of action of flavonoids is controversial. As a result, flavonoids are hypothesized to exert their activities partly through cell signaling pathways. This review intends to acquaint the reader with different pathways in which flavonoids function or might function. Furthermore, we will provide insight into the beneficial health effects of these substances.