Multi-targeted prevention and therapy of cancer by proanthocyanidins

Abstract

In recent years, a considerable emphasis has been focused on the importance of the naturally available botanicals that can be consumed in an individual's everyday diet and that can also be useful as a chemopreventive or chemotherapeutic agent for certain diseases, including cancers. A wide variety of botanicals, mostly dietary flavonoids or polyphenolic substances, have been reported to possess substantial anti-carcinogenic and antimutagenic activities because of their antioxidant and anti-inflammatory properties. Proanthocyanidins are considered as one of them, and are abundantly available in various parts of the plants, such as fruits, berries, bark and seeds. Their modes of action were evaluated through a number of in vitro and in vivo studies which showed their potential role as anti-carcinogenic agent. We summarize and highlight the latest developments on anti-carcinogenic activities of proanthocyanidins from different sources, specifically from grape seeds, and their molecular targets, such as NF-kappaB, mitogen-activated protein kinases, PI3K/Akt, caspases, cytokines, angiogenesis and cell cycle regulatory proteins and other check points, etc. Although the bioavailability and metabolism data on proanthocyanidins is still largely unavailable, certain reports indicate that at least monomers and smaller oligomeric procyanidins are absorbed in the gut. The modulation of various molecular targets by proanthocyanidins in vitro and in vivo tumor models suggests their importance, contribution and mechanism of action to the prevention of cancers of different organs.

Flavonoid consumption and esophageal cancer among black and white men in the United States

“…[10][11][12] Flavonoids and proanthocyanidins are potential mediators of the protective effect of raw fruit and vegetable consumption on esophageal cancer risk presumably because of their anticarcinogenic properties, including antioxidative, antimutagenic, antiinflammatory and antiproliferative effects. 7,8 The 2 flavonoid subclasses, anthocyanidins and isoflavonoids, that showed a protective effect in our study have various anticarcinogenic properties and are currently being tested in clinical trials. 20,21 Ref.…”

“…6 Monomeric flavonoids and proanthocyanidins have anticarcinogenic properties, including antioxidative, antimutagenic, antiinflammatory and antiproliferative effects, that vary in their mechanism of action, site and strength from 1 compound to another. 7,8 The lack of comprehensive flavonoid and proanthocyanidin databases for foods 9 has limited epidemiological investigations of their role in esophageal cancer prevention to only 3 case-control studies. [10][11][12] Total flavonoid consumption was inversely associated with esophageal cancer in 1 study 11 but was not associated with ESCC in another.…”

Proanthocyanidins Inhibit In vitro and In vivo Growth of Human Non–Small Cell Lung Cancer Cells by Inhibiting the Prostaglandin E2 and Prostaglandin E2 Receptors

“…Phytochemicals offer promising options for more effective treatment strategies for lung cancer. GSPs represent one such phytochemical agent that has been shown to have anticarcinogenic activity (25), including activity against lung cancer cells (28). As we had found that Figure 6.…”

“…Grape seed proanthocyanidins (GSP) have anticarcinogenic properties (25) and seem to exhibit minimal toxicity (26,27). GSPs are a mixture of polyphenols/flavanols and primarily contain proanthocyanidins (89%), which constitute dimers, trimers, tetramers, and oligomers/polymers of monomeric catechins and/or (−)-epicatechins (25,27). GSPs are readily available as an extract of grape seeds and this extract, rather than the individual constituents, is used in determining the chemotherapeutic effects of GSPs as it represents a feasible and affordable dietary phytochemical.…”

The Anti-Proliferative Activity of Vitis Vinifera Leaves of Water Extract Alone and in Combination With Doxorubicin Against Liver Cancer Cell Line.

“…Previous studies on some grape varieties have shown that most of the cultivars possess medicinal properties, such as anti-inflammatory and anti-cancer effects. [2,3] Through extracting natural compounds from fruits and leaves of Vitis vinifera in recent decades, a number of phenolic compounds, such as gallic acid, catechin, resveratrol and a wide variety of procyanidins have been isolated and studied for their biological activities and health-promoting benefits. [4] Phenolic substances are synthesized during the process of plant growth, whereas the presence of some stress factors, like ultraviolet radiation and disease also increase the synthesis of them.…”