The roles of polyphenols in cancer chemoprevention

Abstract

Abstract.Oxidative stress imposed by reactive oxygen species (ROS) plays a crucial role in the pathophysiology associated with neoplasia, atherosclerosis, and neurodegenerative diseases. The ROS-induced development of cancer involves malignant transformation due to altered gene expression through epigenetic mechanisms as well as DNA mutations. Considerable attention has been focused on identifying naturally occurring antioxidative phenolic phytochemicals that are able to decrease ROS levels, but the efficacies of antioxidant therapies have been equivocal at best. Several studies have shown that some antioxidants exhibit prooxidant activity under certain conditions and potential carcinogenicity under others, and that dietary supplementation with large amounts of a single antioxidant may be deleterious to human health. This article reviews the intracellular signaling pathways that respond to oxidative stress and how they are modulated by naturally occurring polyphenols. The possible toxicity and carcinogenicity of polyphenols is also discussed.

Bioactive Compounds in small Fruits and their Influence on Human Health

“…Among them, raspberry, strawberry, blueberry, bilberry, cloudberry and cranberry demonstrated high antimicrobial activity against human pathogens Salmonella, Bacillus cereus and Staphylococcus (34,35).…”

“…Phenolic content in small berry fruits In recent years many research projects were targeted at studying of the bioactive berry compounds, their characterization and utilization in functional foods and clinical assessment of antimicrobial properties for human health (34,36,41,42,43,44). Aside with that the number of reports contributing the benefi cial biological activity to the fruit phenolics increased (1,18,22,25,40,42,43).…”

Handbook of Plant Food Phytochemicals

“…These data indicate that phytochemicals may show complex interactions or have synergistic effects with other components (reviewed in [89,171]). For example co-administration of quercetin and isorhamnetin has been found to increase uptake of both in rats and in Caco-2 cells [124].…”

“…Numerous peer reviewed publications support a protective role for plant phenolic compounds (especially flavonoids); isothiocyanates from Brassica species; polyacetylenes from carrot (Daucus carota) and flavonols and cysteine sulfoxides from onion (A llium cepa) in human health (reviewed in [29,39,89,190]) , and these crops will form the basis for this review. Onion (Allium cepa) is believed to be the major source of human flavonol intake.…”

High Levels of Phytophenolics and Antioxidant Activities in <i>Oryza Sativa</i> – Unpolished Thai Rice Strain of Leum Phua

“…Phenolics in phytochemical plants are highly efficient in radical scavenging activities [8,9]. In addition, the phytophenolics of dietary fruits and vegetables are also related to cancer prevention [9,10]. High consumption of the red color in unpolished Thai rice in rats has been associated with low levels of oxidative stress marker [11].…”