Quercetin as an innovative therapeutic tool for cancer chemoprevention: Molecular mechanisms and implications in human health

Abstract

Cancer is a life-threatening disease afflicting human health worldwide. Recent advances in drug discovery infrastructure and molecular approaches have helped a lot in identifying the novel drug targets for therapeutic intervention. Nevertheless, the morbidity and mortality rates because of this disease keep on rising at an alarming rate. Recently, the use of natural and synthetic molecules as innovative therapeutic tools for cancer prevention has lead to the development of cancer chemoprevention. Cancer chemoprevention is a prophylactic strategy that involves the chronic administration of one or more natural or synthetic agents to block, to inhibit, or to suppress the process of cancer development before it becomes an invasive disease. Quercetin, a dietary bioflavonoid, can specifically retard the growth of cancer cells and behaves as a potent cancer chemopreventive agent. Quercetin has multiple intracellular targets in a cancer cell. Therefore, many mechanisms have been postulated to explain its chemopreventive action. The chemopreventive effects elicited by this natural molecule in different model systems are believed to include antioxidant/pro-oxidant action, regulation of redox homeostasis, apoptosis, cell cycle arrest, antiinflammatory action, modulation of drug metabolizing enzymes, alterations in gene expression patterns, inhibition of Ras gene expression, and modulation of signal transduction pathways. However, cell signaling networks have recently garnered attention as common molecular target for various chemopreventive effects of quercetin. In this review, we made an attempt to critically summarize the emerging knowledge on the role of quercetin in cancer chemoprevention and the underlying molecular mechanisms implicated in its chemopreventive and therapeutic effects.

Flavonoids as Anticancer Agents

“…Due to antioxidant properties, cocoa flavanols exerted beneficial effects in the protection from colon cancer [72,73]. Flavonol quercetin exerted potent cancer chemopreventive properties [74,75]. Recent studies showed that quercetin reduced the proliferation of hepatocellular carcinoma HepG2 cells decreasing the intracellular ROS level [76].…”

Programmed Cell-Death by Ferroptosis: Antioxidants as Mitigators

“…Polyphenols, as secondary metabolites of plants, are non-nutrient components of human diets, are attracting considerable interest due to their important bioactive ingredients, and are emerging as effective alternatives to synthetic compounds or drugs for the prevention and treatment of a variety of disorders [74] due to their antioxidant propensity. Although polyphenolic compounds possess beneficial therapeutic properties against numerous disorders, the mechanisms of action of most of them are not fully known.…”

The Important Herbal Pair for the Treatment of COVID-19 and Its Possible Mechanisms

“…The main active ingredients of AE against COVID-19 were found to be quercetin, kaempferol and luteolin. According to previous studies, quercetin has multiple biological activities, such as anti-in ammatory, anti-viral, anti-oxidative, anti-tumor actions 23,24 . A study reported that quercetin could interact with the HA2 subunit of In uenza A virus (IAVs), and it could inhibit the entry of the H5N1 virus using the pseudovirus-based drug screening system 25 .…”