Antioxidant Metabolism Pathways in Vitamins, Polyphenols, and Selenium: Parallels and Divergences

Abstract

Free radicals (FRs) are unstable molecules that cause reactive stress (RS), an imbalance between reactive oxygen and nitrogen species in the body and its ability to neutralize them. These species are generated by both internal and external factors and can damage cellular lipids, proteins, and DNA. Antioxidants prevent or slow down the oxidation process by interrupting the transfer of electrons between substances and reactive agents. This is particularly important at the cellular level because oxidation reactions lead to the formation of FR and contribute to various diseases. As we age, RS accumulates and leads to organ dysfunction and age-related disorders. Polyphenols; vitamins A, C, and E; and selenoproteins possess antioxidant properties and may have a role in preventing and treating certain human diseases associated with RS. In this review, we explore the current evidence on the potential benefits of dietary supplementation and investigate the intricate connection between SIRT1, a crucial regulator of aging and longevity; the transcription factor NRF2; and polyphenols, vitamins, and selenium. Finally, we discuss the positive effects of antioxidant molecules, such as reducing RS, and their potential in slowing down several diseases.

Electrophilic Compounds in the Human Diet and Their Role in the Induction of the Transcription Factor NRF2

“…The thiol groups of the Keap1 sensor can interact with several phytochemicals, each of which can cause NRF2 activation [ 95 ]. Keap1 has at least 25 reactive Cys-SH thiols, leading to a variety of effects on the sensor’s response to electrophilic substances [ 96 ].…”

The Role of NRF2 in Cerebrovascular Protection: Implications for Vascular Cognitive Impairment and Dementia (VCID)

“…In addition, the aging process can potentially be slowed down by NAD-dependent enzymes such as SIRT1 that serve to protect the endothelium from oxidative stress [74]. In light of the complex interconnection between NRF2 and SIRT1, it is highly likely that targeting NRF2 might also mitigate vascular aging indirectly through regulating SIRT1 signaling [75][76][77]. The following review of NRF2 functions in different cell types in the brain vasculature is intended to provide a better understanding of its protective role in VCID (Figure 3).…”

Michael Acceptors as Anti-Cancer Compounds: Coincidence or Causality?

“…These compounds have attracted attention due to their potential anti-cancer effects mediated by the modulation of various tumorigenic mechanisms [ 287 ]. For example, astragalin, a Kaempferol derivative, inhibits the proliferation and migration of human colon cancer cells via the NF-κB signaling pathway, induces cancer cell apoptosis and arrests the cell cycle [ 288 ]. Kaempferol itself plays a chemopreventive role by inhibiting carcinogenesis and cancer progression while suppressing metastasis-related behaviors in breast cancer cells [ 289 ].…”