An apple a day to prevent cancer formation: Reducing cancer risk with flavonoids

Abstract

The purpose of this review is to update and discuss key findings from in vitro and in vivo studies on apple and its biocompounds, with a special focus on its anticancer role. Several studies have proposed that apple and its extracts exhibit a variety of biological functions that may contribute to health benefits including beneficial effects against chronic heart and vascular disorders, respiratory and pulmonary dysfunction, diabetes, obesity, and cancer. In this review, we summarize the molecular mechanism(s) of various components in apple, as established in previous studies that indicated their growth-inhibitory effects in various cancer cell types. Moreover, an attempt is made to delineate the direction of future studies that could lead to the development of apple components as a potent chemopreventive/chemotherapeutic agent against cancer.

Keywords: apple; cancer chemoprevention; phloretin; type 2 glucose transporter.

Figure 1

Chemical structures of some selected typical biocompounds in apple juice belonging to the structural classes of hydroxycinnamic acids, dihydrochalcones, flavan-3-ols (catechins and procyanidins), flavonols (quercetin-glycosides), and triterpenoids.

Figure 2

Apple polyphenol phloretin inhibits growth of cancer cells through inhibition of type 2 glucose transporter. Our groups have demonstrated that phloretin can induce growth arrest of cells in the G₀/G₁ phase, induce apoptotic cell death, and inhibit tumor cells migration and metastasis. All these effects can be attributed to the phloretin-induced intracellular glucose deprivation.