Natural polyphenols in cancer therapy

Abstract

Natural polyphenols are secondary metabolites of plants involved in defense against different types of stress. Extracts containing these compounds have been used for thousands of years in traditional eastern medicine. Polyphenols act on multiple targets in pathways and mechanisms related to carcinogenesis, tumor cell proliferation and death, inflammation, metastatic spread, angiogenesis, or drug and radiation resistance. Nevertheless, reported effects claimed for polyphenols are controversial, since correlations between in vitro effects and in vivo evidence are poorly established. The main discrepancy between health claims versus clinical observations is the frequent use of nonphysiologically relevant concentrations of these compounds and their metabolites in efficacy and mechanistic studies. The present review will discuss how in vivo administration correlates with polyphenol metabolism, toxicity, and bioavailability. Analysis of the general application of polyphenols in cancer therapy will be complemented by potential applications in the therapy of specific tumors, including melanoma, colorectal and lung cancers. Possible pharmaceutical formulations, structural modifications, combinations, and delivery systems aimed to increase bioavailability and/or biological effects will be discussed. Final remarks will include recommendations for future research and developments.

Multifunctional T Lymphocytes Generated After Therapy With an Antitumor Gallotanin-Rich Normalized Fraction Are Related to Primary Tumor Size Reduction in a Breast Cancer Model

“…Animal models cannot precisely reproduce what will happen in patients; however, the beneficial role of natural polyphenols on human health and specifically in cancer have been widely documented, 62 which reinforces the idea that the results observed in this study may be relevant for cancer patients. We will evaluate the effect of P2Et treatment on tumor growth in immunodeficient NOD mice to investigate the actual role of IR in tumor growth control.…”

Thymus vulgaris alleviates UVB irradiation induced skin damage via inhibition of MAPK/AP‐1 and activation of Nrf2‐ARE antioxidant system

“…Skin chronically exposes to solar UV radiation resulting in oxidative stress, inflammation, ROS‐mediated DNA damage, disorder of cellular signalling pathways, which accelerate skin photoageing 21. Botanicals possessing antioxidant, anti‐inflammatory and immunomodulatory properties, are promising to be exploited as therapeutic agents for a variety of skin disorders, including photoageing 22. TV extract and one of its major compounds rosmarinic acid have been shown to protect human keratinocytes against UVA and UVB induced damages 23.…”

Emodin: One Main Ingredient of Shufeng Jiedu Capsule Reverses Chemoresistance of Lung Cancer Cells Through Inhibition of EMT

“…To address these limitations, many efforts are being done such as continuous development of new drugs and forms of chemotherapy [14]. Recently, natural extracts are being more interesting and important efforts as an adjuvant to chemotherapeutic drugs, because they can relieve the side effects and enhance the effects of both radiotherapy and chemotherapy [15]. Natural extracts are substance made by extracting a part of a natural raw material, often by using a solvent such as ethanol or water.…”