Natural Products as Cancer Chemo Preventive Agents: Where We Stand

Abstract

This work briefly reviews cancer chemoprevention. This is a very challenging field, as products with a high level of toxicity such as chemotherapeutic agents may be proposed and accepted only under life-threatening conditions. Cancer chemoprevention is otherwise limited to completely safe substances, preferably having neither toxic nor side effects, administered in relatively low amounts. Phases of clinical trials, therapeutic end-points, and biomarkers of chemoprevention are difficult to be defined. The clinical trials needed to prove the efficacy of chemopreventive agents must be very long and extremely widespread to achieve significance, with many variables difficult to control, and therefore subjected to many confounding factors. This makes them almost impossible. It is, therefore, no surprise, if the progress of chemoprevention has been so far very limited. There are only a few examples of direct use of chemopreventive agents, under investigation, but with anything but established protocols, in addition to indirect uses such as general supplementation with antioxidant, anti-inflammatory, and immune-supportive agents. Cancer chemoprevention remains a potentially very rewarding approach, certainly worth further study, but extremely difficult to pursue, in need of different methodological approaches to producing valuable chemopreventive compounds of clear dosages and benefits.

Polyphenol content, antioxidant and antiproliferative effects of a plant mixture composed of four medicinal plants with hepatoprotective potential

“…Phytochemicals such as resveratrol and curcumin have been investigated for their potential as chemoprotective agents (Boretti, 2022;Xiao et al, 2018). However, most studies were preclinical since clinical trials gave negative or null results (Boretti, 2022). Findings of the present study pave the way for future inquiries to increase our understanding of this plant mixture's chemoprotective mechanism of action.…”

“…Many preclinical reports have been dedicated to the chemopreventive effect of phytochemical compounds. Phytochemicals such as resveratrol and curcumin have been investigated for their potential as chemoprotective agents (Boretti, 2022;Xiao et al, 2018). However, most studies were preclinical since clinical trials gave negative or null results (Boretti, 2022).…”

Revisiting the antioxidant-prooxidant conundrum in cancer research

“…The widespread belief that these compounds help prevent cancer by reducing free radicals has led to a surge in their use in developed nations [3]. Additional research conducted in separate labs has demonstrated that most of these compounds can trigger cell death by apoptosis, inhibit antiapoptotic pathways, halt cell proliferation, and alter several critical proteins involved in cancer cell growth [4]. Although they have shown anticancer effects in both laboratory and animal studies, no specific mechanism has been identified to explain these effects.…”

Editorial: Targeting tumor EMT-related signaling by natural products

“…In the last few years, many natural products and their derivatives have been explored as cytotoxic, antiproliferative or antioxidant agents and have also shown antitumor effects in preclinical and clinical research ( Boretti, 2022 ). In comparison to synthetic medications, natural compounds have a higher amount of stiffness, which enhances protein cross-talk.…”