Synergistic Interactions Between Anticancer Chemotherapeutics and Phenolic Compounds and Anticancer Synergy Between Polyphenols

Abstract

Chemoprevention has recently gained a new dimension due to the possibility of studying the mechanisms of action of chemopreventive agents at the molecular level. Many compounds have been proved to inhibit early stages of carcinogenesis in experimental models. These compounds include both recognized drugs (such as tamoxifen and nonsteroidal anti-inflammatory drugs) and natural constituents of edible and therapeutic plants, particularly polyphenols. Phenolics are characterized by high structural diversity and, consequently, a very broad spectrum of biological activities. They are increasingly looked upon as a valuable alternative or a support for synthetic drugs, as evidenced by a growing number of clinical trials regarding the use of phenolic compounds and polyphenol-rich extracts in chemoprevention and therapy. In the present work, we discuss the effectiveness of natural polyphenols as cancer preventive and therapeutic agents resulting from their synergy with synthetic or semisynthetic anticancer drugs as well as with other phenolic compounds of plant origin.

Protective Effect of Cocoa Seeds Extract Application on PCNA Expression in Albino Mice Receiving DMBA Exposure

“…[17] Some of the recent studies indicated that natural components of various plants such as cocoa, curcuma, green tea, soya and others have ability to prevent and cure cancer, through modulation of some signaling pathways, having some biological activities such as antiproliferative, proapoptotic and anti-angiogenic, so it can halt the carcinogenesis process. [18] Polyphenol compounds contained in cocoa extract have been identified to have chemopreventive effect, through several mechanisms including antiproliferation, induction of apoptosis, oxidation prevention, detoxification enzyme induction, host immune system regulation, antiinflammatory activity, and prevention of cellular signal that can produce carcinovenesis [19]. The application of cocoa extract before oxidative stress prevented DNA damage and increased the activity of antioxidant enzyme glutathion reductase and glutatihion peroxidase in cells induced with pro-oxidant, tetrabuthylhydroperoxide.…”

Antiangiogenic compounds: well-established drugs versus emerging natural molecules

“…Still, each drug is administered to different types of cancer and at distinct doses among patients, they result in more or fewer side effects in the body. In this sense, it becomes essential to develop new drugs with lower or no toxicity, and with the ability to prevent pathological angiogenesis [19]. Researchers have thus focused in antiangiogenic molecules that occur naturally in plants.…”

“…Resistance is usually acquired when the tumor is able to growth, by enabling VEGF/VEGFR-2 independent pathways, thus promoting tumor angiogenesis [112]. An alternative to overcome the antiangiogenic drugs resistance is by their combination with other conventional therapies, including chemotherapy or radiation [19]. Combined therapies may have a synergistic effect when compared to the single drug therapies [115].…”

“…Chemoprevention is a promising anticancer approach with reduced secondary effects in comparison with synthetic drugs [18]. Chemoprevention consists in using other active molecules, such as naturally occurring anticancer agents, to inhibit or reverse some processes of carcinogenesis, including pathological angiogenesis [19]. In the next section (Section 2) a survey of selected angiogenesis pathways and therapeutic targets will be presented, with emphasis on molecular mechanisms that have been targeted by natural molecules or natural sources.…”

Investigation of bioactive compounds with anti-cancer potential in Carica papaya leaves

“…This clearly indicates that the cytotoxic effect of Carica papaya leaf juice is not due to a single compound, but likely a number of constituents acting together to produce the overall effect. Many examples supporting this phenomenon can be found in reviews about additive or synergistic interactions in traditional and herbal phytomedicines (Williamson, 2001, Lewandowska et al, 2014, Ulrich-Merzenich et al, 2009, Rather et al, 2013. The assessment of synergism represents an emerging area in phytochemical research, seeking to explore improved therapeutic effects from herbal drugs used in traditional medicine (Zhang et al, 2014).…”