Association of Dietary Quercetin With Reduced Risk of Proximal Colon Cancer

Abstract

Quercetin is a flavonol that appears to be protective against several cancers, but its possible role in prevention of colorectal cancer is not yet well studied. We evaluated dietary intakes of quercetin and risk of colorectal cancer in a large case-control study conducted in Metropolitan Detroit, MI (n = 2664). The protective effects of quercetin intake, as assessed by food frequency questionnaire, were confined to risk of proximal colon cancer. Stratified analyses showed that the protective effects of quercetin on risk of proximal colon cancer were significant only when fruit intake or the Healthy Eating Index score were high, or when tea intake was low, with odds ratios (OR) for the highest versus the lowest quartile = 0.49, 0.44, and 0.51, respectively. Increased quercetin intake had no protective effects when tea intake was high. Interestingly, increased intake of quercetin was associated with increased risk of distal colon cancer when total fruit intake was low (OR for the highest versus the lowest quartile = 1.99). These results suggest that quercetin can have disparate effects on colon cancer risk depending on whether dietary intakes of fruit or tea are high, and that quercetin had protective effects only on proximal, not distal, colon cancer.

Quercetin Potentiates Apoptosis by Inhibiting Nuclear Factor-kappaB Signaling in H460 Lung Cancer Cells

“…18,19) In addition to these beneficial effects, quercetin plays preventive and therapeutic roles in various types of cancer and cancer cells. [20][21][22][23][24][25] However, the anticancer effect of quercetin in NSCLC cells has been rarely addressed, and the underlying molecular mechanism remains to be determined.…”

“…18,19) In addition to these beneficial effects, quercetin plays preventive and therapeutic roles in various types of cancer and cancer cells. [20][21][22][23][24][25] However, the anticancer effect of quercetin in NSCLC cells has been rarely addressed, and the underlying molecular mechanism remains to be determined.Here, we investigated the growth inhibitory role of quercetin in three NSCLC cell lines and found that its effect is p53-independent and triggered by apoptosis. Subsequent microarray analysis using H460 cells indicated that quercetin enhances the expression of genes associated with death receptor signaling and cell cycle inhibition, but decreases the expression of genes involved in nuclear factor (NF)-κB activation.…”

Comparative Studies of the Phytochemical, Antioxidant and Antimicrobial Properties of Cashew Leaf, Bark and Fruits Extracts

“…Natural antioxidants are however gaining desired attention for their ability to protect the human body from these free radicals mediated oxidative stress reactions [9,14]. Antioxidants mediate these reactions by free radical scavenging, peroxide decomposition, suppression of singlet oxygen, enzymatic inhibition and increasing the levels of endogenous defences [16,17].…”

ObtainingAntioxidants from Botanic Matrices Applying Novel Extraction Techniques

“…These modified foods are classified as functional foods because they contain, besides the basic nutrition, co mponents that provide health benefits [1]. The continued ingestion of food supplemented with antio xidant substances cause inhibitory effects on the proliferation o f carcinogenic cells in human beings [2][3][4]. These effects appear because the antioxidant substances are able to perform so me functions, as free radical scavenging, peroxide deco mposition, suppression of singlet oxygen, enzy matic inhibit ion [1] and increasing the levels of endogenous defences [5].…”