Quercetin in Cancer Treatment, Alone or in Combination with Conventional Therapeutics?
Cancer is a problem of global importance, since the incidence is increasing worldwide and therapeutic options are generally limited. Thus, it becomes imperative to find new therapeutic targets as well as new molecules with therapeutic potential for tumors. Flavonoids are polyphenolic compounds that may be potential therapeutic agents. Several studies have shown that these compounds have a higher anticancer potential. Among the flavonoids in the human diet, quercetin is one of the most important. In the last decades, several anticancer properties of quercetin have been described, such as cell signaling, pro-apoptotic, anti-proliferative and anti-oxidant effects, growth suppression. In fact, it is now well known that quercetin has diverse biological effects, inhibiting multiple enzymes involved in cell proliferation, as well as, in signal transduction pathways. On the other hand, there are also studies reporting potential synergistic effects when combined quercetin with chemotherapeutic agents or radiotherapy. In fact, several studies which aim to explore the anticancer potential of these combined treatments have already been published, the majority with promising results. Actually it is well known that quercetin can act on the chemosensitization and radiosensitization but also as chemoprotective and radioprotective, protecting normal cells of the side effects that results from chemotherapy and radiotherapy, which obviously provides notable advantages in their use in anticancer treatment. Thus, all these data indicate that quercetin may have a key role in anticancer treatment. In this context, this review is focused on the relationship between flavonoids and cancer, with special emphasis on the role of quercetin.
Ana Filipa
AF
Brito
Marina
M
Ribeiro
Biophysics Unit - Faculty of Medicine, University of Coimbra, Polo III - Polo das Ciencias da Saude, Azinhaga de Santa Comba, Celas, 3000-548 Coimbra, Portugal. mabrantes@fmed.uc.pt.
Ana Margarida
AM
Abrantes
Ana Salomé
AS
Pires
Ricardo Jorge
RJ
Teixo
José Guilherme
JG
Tralhão
Maria Filomena
MF
Botelho
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology* / Q000627:therapeutic use; D018432:Drug Resistance, Multiple / Q000187:drug effects; D051272:Glucose Transporter Type 1 / Q000037:antagonists & inhibitors; D006801:Humans; D009369:Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000473:pathology; D009389:Neovascularization, Pathologic; D011794:Quercetin / Q000494:pharmacology* / Q000627:therapeutic use
D051272:Glucose Transporter Type 1; D011794:Quercetin