Absorption, Metabolism, and Disposition of Flavonoids and Their Role in the Prevention of Distinctive Cancer Types

Abstract

Flavonoids consist of a large family of polyphenolic molecules like flavones, flavonols, flavanols, isoflavones, flavanones, and anthocyanidins which are ubiquitously distributed in nature and are present in a wide array of plant products, including fruits, vegetables, and green tea. Because of their powerful antioxidant, anti-inflammatory, and anticancer properties, rigorous research is going on with a number of flavonoids (quercetin, quercitrin, rutin, morin, kaempferol, etc.) to investigate their disease-preventive and health-promoting benefits in humans. Several studies have shown that the cancer prevention and pharmacotherapeutic potential of different flavonoids depend on the type of flavonoid and its chemical structure, bioavailability, effective blood levels, and pharmacokinetic and pharmacodynamic characteristics. Many in vivo and in vitro studies conducted with different types of flavonoids have revealed diverse effects against different types of cancers. However, the major flavonoids (apigenin, luteolin, kaempferol) found in vegetarian diet have depicted limited possibility of curing cancer. In vitro studies done with apigenin and luteolin have shown effectiveness against cervical cancer cells, while kaempferol produced oncolytic effects against gastric and ovarian cancer cells. These flavonoids and their metabolites have revealed different anticancer effects due to their rapid metabolism in the small intestine and liver. Cancers comprise a group of noncommunicable diseases characterized by long-term debilitating illnesses that cause heavy burden on the healthcare system. At present, certain types of cancers are incurable, and palliative interventions are directed to delay the spread of malignant cancer and to ameliorate the painful episodes associated with cancer. The purpose of this review is to focus on the absorption, distribution, metabolism, and excretion (ADME) of different flavonoids and to evaluate the immune-boosting, cancer-preventive, and therapeutic potential of flavonoids against different types of cancers.