Effects of lycopene on the insulin-like growth factor (IGF) system in premenopausal breast cancer survivors and women at high familial breast cancer risk

Naturally Occurring Phytochemicals to Target Breast Cancer Cell Signaling

Almost 70% of clinically used antineoplastic drugs are originated from natural products such as plants, marine organism, and microorganisms and some of them are also structurally modified natural products. The naturally occurring drugs may specifically act as inducers of selective cytotoxicity, anti-metastatic, anti-mutagenic, anti-angiogenesis, antioxidant accelerators, apoptosis inducers, autophagy inducers, and cell cycle inhibitors in cancer therapy. Precisely, several reports have demonstrated the involvement of naturally occurring anti-breast cancer drugs in regulating the expression of oncogenic and tumor suppressors associated with carcinogen metabolism and signaling pathways. Anticancer therapies based on nanotechnology have the potential to improve patient outcomes through targeted therapy, improved drug delivery, and combination therapies. This paper has reviewed the current treatment for breast cancer and the potential disadvantages of those therapies, besides the various mechanism used by naturally occurring phytochemicals to induce apoptosis in different types of breast cancer. Along with this, the contribution of nanotechnology in improving the effectiveness of anticancer drugs was also reviewed. With the development of sciences and technologies, phytochemicals derived from natural products are continuously discovered; however, the search for novel natural products as chemoprevention drugs is still ongoing, especially for the advanced stage of breast cancer. Continued research and development in this field hold great promise for advancing cancer care and improving patient outcomes.

Integral valorisation of tomato by-products towards bioactive compounds recovery: Human health benefits

The tomato processing industry is one of the world's most important markets. This industry aims to optimise production, minimise energy costs and waste streams while ensuring high-quality products. This sector produces substantial amounts of by-products frequently disposed of as waste rather than reintroducing them with a new intent into the supply chain. However, these by-products are rich in bioactive compounds (BC), including carotenoids, fibre, which exhibit antioxidant, anti-inflammatory and chemopreventive properties, and cardiovascular protection. Reusing these compounds is favourable to reducing the environmental impact and enables the development of added-value products with various possible uses such as food and feed additives, nutraceuticals, cosmeceuticals, etc. This review summarises relevant issues towards the recovery and valorisation of BC from industrial tomato by-products within a circular economy context.

The Anti-Cancer Activity of Lycopene: A Systematic Review of Human and Animal Studies

Lycopene is a nutraceutical with health-promoting and anti-cancer activities, but due to a lack of evidence, there are no recommendations regarding its use and dosage. This review aimed to evaluate the benefits of lycopene supplementation in cancer prevention and treatment based on the results of in vivo studies. We identified 72 human and animal studies that were then analysed for endpoints such as cancer incidence, improvement in treatment outcomes, and the mechanisms of lycopene action. We concluded that the results of most of the reviewed in vivo studies confirmed the anti-cancer activities of lycopene. Most of the studies concerned prostate cancer, reflecting the number of in vitro studies. The reported mechanisms of lycopene action in vivo included regulation of oxidative and inflammatory processes, induction of apoptosis, and inhibition of cell division, angiogenesis, and metastasis formation. The predominance of particular mechanisms seemed to depend on tumour organ localisation and the local storage capacity of lycopene. Finally, there is a need to look for predictive factors to identify a population that may benefit from lycopene supplementation. The potential candidates appear to be race, single nucleotide polymorphisms in carotene-cleaving enzymes, some genetic abbreviations, and insulin-like growth factor-dependent and inflammatory diseases.

Sustainable Valorization of Tomato By-Products to Obtain Bioactive Compounds: Their Potential in Inflammation and Cancer Management

Tomato producing and processing industries present undoubted potential for industrial discarded products valorization whether due to the overproduction of fresh tomatoes or to the loss during processing. Although tomato by-products are not yet considered a raw material, several studies have suggested innovative and profitable applications. It is often referred to as "tomato pomace" and is quite rich in a variety of bioactive compounds. Lycopene, vitamin C, β-carotene, phenolic compounds, and tocopherol are some of the bioactives herein discussed. Tomato by-products are also rich in minerals. Many of these compounds are powerful antioxidants with anti-inflammatory properties besides modulating the immune system. Several researchers have focused on the possible application of natural ingredients, especially those extracted from foods, and their physiological and pharmacological effects. Herein, the effects of processing and further applications of the bioactive compounds present in tomato by-products were carefully reviewed, especially regarding the anti-inflammatory and anti-cancer effects. The aim of this review was thus to highlight the existing opportunities to create profitable and innovative applications for tomato by-products in health context.

Potential inhibitory effect of lycopene on prostate cancer

Studying prostate cancer is important due to its high annual incidences and mortality rates in the world. Although prostate cancer mortality rates are reduced using new therapy, complicated routes and side effects of these current drugs require a daily available treatment for prevention. Lycopene is a natural, prominent, and effective product which has a high value in diet. The anti-cancer effect, non-toxicity, safety and preventive or therapeutic roles of lycopene have been investigated in several studies. In the current review, we have collected information about the anti-cancer, anti-progressive and apoptotic effects of lycopene on prostate cancer. This article is a summary of the most important original and review articles on lycopene and its anticancer effects that are systematically categorized and presents information about the molecular structure, different sources, biological functions, and its in-vivo and in-vitro effects of lycopene on variety of cancerous and normal cells. The clinical studies provide a clear image for continuous use of this adjunctive dietary for different type of cancers, especially prostate cancer in men. In addition, this article discusses the various molecular pathways activated by lycopene that eventually prevent or suppress cancer. Lycopene has been found to effectively suppress the progression and proliferation, arrest in-cell cycle, and induce apoptosis of prostate cancer cells in both in-vivo and in-vitro conditions. Additionally, lycopene showed that it could modulate the signaling pathways and their protein for the treatment or prevention of prostate cancer.

Effect of green tea and lycopene on the insulin-like growth factor system: the ProDiet randomized controlled trial

Whether prostate cancer (PCa) may be preventable by dietary interventions can be assessed in randomized trials using intermediate biomarkers of cancer risk or progression. We investigated whether lycopene or green tea modify circulating insulin-like growth factor (IGF) peptides in men at increased risk of PCa. Participants (aged 50-69 years) in one centre in the UK wide PCa testing and treatment trial (ProtecT) with prostate specific antigen between 2.0 and 2.95 ng/ml or negative biopsies, were randomized to daily lycopene (n = 44 assigned 15 mg capsules/day; 44 assigned a lycopene-rich diet; 45 assigned placebo) and green tea (n = 45 assigned 600 mg/day epigallocatechin gallate; 45 assigned green tea drink; 43 assigned placebo) for 6 months. The interventions significantly elevated the primary outcomes, serum epigallocatechin gallate and lycopene at 6 months of follow-up. We report here an exploratory analysis in which serum IGF-I, IGF-II, IGF binding protein (BP)-2 and IGFBP-3 were measured at baseline and 6 months of postintervention. A total of 133 men were randomized (34% of eligible men approached) and 130 had follow-up IGF peptides (98%). In intention-to-treat analyses, there was only weak evidence that lycopene or green tea influenced some aspects of serum IGF-I, IGF-II, IGFBP-2 or IGFBP-3. In men randomized to lycopene supplements, IGFBP-2 was nonsignificantly (50.9 ng/ml; 95% confidence interval: -51.2-152.9, P = 0.3) higher in comparison to placebo, whereas in men randomized to green tea supplements, IGFBP-3 was nonsignificantly (205.2 ng/ml; 95% confidence interval: -583.3-172.9, P = 0.3) lower than with placebo. In this small, pilot randomized controlled trial, there was little evidence that lycopene or green tea interventions influenced serum levels of IGF-I, IGF-II, IGFBBP-3 and IGFBP-2. However, the effects were imprecisely estimates and some observed trends may justify larger trials.

Regulation of cell signaling pathways by dietary agents for cancer prevention and treatment

Although it is widely accepted that better food habits do play important role in cancer prevention and treatment, how dietary agents mediate their effects remains poorly understood. More than thousand different polyphenols have been identified from dietary plants. In this review, we discuss the underlying mechanism by which dietary agents can modulate a variety of cell-signaling pathways linked to cancer, including transcription factors, nuclear factor κB (NF-κB), signal transducer and activator of transcription 3 (STAT3), activator protein-1 (AP-1), β-catenin/Wnt, peroxisome proliferator activator receptor- gamma (PPAR-γ), Sonic Hedgehog, and nuclear factor erythroid 2 (Nrf2); growth factors receptors (EGFR, VEGFR, IGF1-R); protein Kinases (Ras/Raf, mTOR, PI3K, Bcr-abl and AMPK); and pro-inflammatory mediators (TNF-α, interleukins, COX-2, 5-LOX). In addition, modulation of proteasome and epigenetic changes by the dietary agents also play a major role in their ability to control cancer. Both in vitro and animal based studies support the role of dietary agents in cancer. The efficacy of dietary agents by clinical trials has also been reported. Importantly, natural agents are already in clinical trials against different kinds of cancer. Overall both in vitro and in vivo studies performed with dietary agents strongly support their role in cancer prevention. Thus, the famous quote "Let food be thy medicine and medicine be thy food" made by Hippocrates 25 centuries ago still holds good.

Role of dietary bioactive natural products in estrogen receptor-positive breast cancer

Estrogen receptor (ER)-positive breast cancer, including luminal-A and -B, is the most common type of breast cancer. Extended exposure to estrogen is associated with an increased risk of breast cancer. Both ER-dependent and ER-independent mechanisms have been implicated in estrogen-mediated carcinogenesis. The ER-dependent pathway involves cell growth and proliferation triggered by the binding of estrogen to the ER. The ER-independent mechanisms depend on the metabolism of estrogen to generate genotoxic metabolites, free radicals and reactive oxygen species to induce breast cancer. A better understanding of the mechanisms that drive ER-positive breast cancer will help optimize targeted approaches to prevent or treat breast cancer. A growing emphasis is being placed on alternative medicine and dietary approaches toward the prevention and treatment of breast cancer. Many natural products and bioactive compounds found in foods have been shown to inhibit breast carcinogenesis via inhibition of estrogen induced oxidative stress as well as ER signaling. This review summarizes the role of bioactive natural products that are involved in the prevention and treatment of estrogen-related and ER-positive breast cancer.

Selective inhibition of cell proliferation by lycopene in MCF-7 breast cancer cells in vitro: a proteomic analysis

Lycopene, a red pigmented carotenoid present in many fruits and vegetables such as tomatoes, has been associated with the reduced risk of breast cancer. This study sought to identify proteins modulated by lycopene during cell proliferation of the breast cancer cell line MCF-7 to gain an understanding into its mechanism of action. MCF-7 breast cancer cells and MCF-10 normal breast cells were treated with 0, 2, 4, 6, 8, and 10 μM of lycopene for 72 h. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tetrazolium reduction assay was used to measure cell proliferation and two-dimensional fluorescence difference gel electrophoresis to assess the changes in protein expression, which were identified using MALDI-ToF/ToF (matrix-assisted laser desorption ionization tandem time-of-flight) and Mascot database search. MTT and cell proliferation assays showed that lycopene selectively inhibited the growth of MCF-7 but not MCF-10 cells. Difference gel electrophoresis analysis revealed that proteins in the MCF-7 cells respond differently to lycopene compared with the MCF-10 cells. Lycopene altered the expression levels of proteins such as Cytokeratin 8/18 (CK8/18), CK19 and their post translational status. We have shown that lycopene inhibits cell proliferation in MCF-7 human breast cancer cells but not in the MCF-10 mammary epithelial cells. Lycopene was shown to modulate cell cycle proteins such as beta tubulin, CK8/18, CK19 and heat shock proteins.

Modulation of angiogenesis by dietary phytoconstituents in the prevention and intervention of breast cancer

Breast cancer is the leading cause of cancer-related deaths for women in the United States and the rest of the world. About 8% of women develop breast cancer during the course of their lives. Dietary habits are closely associated with both the risk and progression of breast cancer. Dietary agents have accumulated increasing importance with regards to the prevention and treatment of breast cancer. One such manner by which these compounds can target breast cancer development and progression is through interference with the angiogenic pathways. Angiogenesis is an intricate process that involves the development of new capillaries from previously existing blood vessels. Disruption of this pathway, therefore, provides a novel and effective avenue for therapeutic intervention of breast cancer. Various phytochemicals found in the diet kill breast cancer cells in vitro and prevent as well as suppress breast cancer progression in various preclinical animal models. This review examines the value of dietary phytoconstituents in the prevention and treatment of breast cancer through modulation of the intricate and complex process of angiogenesis. In addition, the potential benefits, challenges, and future directions of research on anti-angiogenic dietary phytochemicals in the prevention and intervention of breast cancer are also addressed.

Nutritional supplements, COX-2 and IGF-1 expression in men on active surveillance for prostate cancer

BACKGROUND

Nutritional factors are associated with reduced risk of prostate cancer progression, yet mechanisms remain unclear. We examined the effects of lycopene and fish oil supplements versus placebo on the normal prostate microenvironment, among men pursuing active surveillance for low-burden prostate cancer. We hypothesized that lycopene or fish oil supplements would down-regulate insulin-like growth factor-1 (IGF-1) and cyclooxygenase 2 (COX-2) gene expression, respectively, reflecting putative proliferation (IGF-1) and inflammatory (COX-2) pathways relevant to carcinogenesis.

METHODS

We conducted a 3-month randomized, double-blinded, clinical trial comparing prostate tissue gene expression profiles (assessed by qRT-PCR) among men with favorable-risk prostate cancer receiving either 30 mg/day lycopene, 3 g/day fish oil (including 1,098 mg eicosapentaenoic and 549 mg docosahexaenoic fatty acids) or placebo.

RESULTS

Among 69 men (22 assigned to lycopene, 21 to fish, and 26 to placebo), there was no difference in the change from baseline to the 3 months in IGF-1 expression level between the placebo and lycopene arms (p = 0.93) nor in COX-2 expression between the placebo and fish arms (p = 0.99).

CONCLUSION

Compared to placebo, 3-month intervention with lycopene or fish oil did not significantly change IGF-1 and COX-2 gene expression in the normal prostate microenvironment in men with low-burden prostate cancer. Further analysis of global gene expression profiles may shed light on the bioactivity and relevance of these nutrients in prostate cancer.

Tomato Consumption and Health: Emerging Benefits

Tomatoes and tomato products are one of the most familiar vegetables in the American diet. Quantitatively, they are the most consumed nonstarchy vegetable and are the most significant source of dietary lycopene; a powerful antioxidant that has greater bioavailability after cooking and processing (eg, canning). A large body of research supports an inverse relationship between consuming tomatoes and tomato products and risk of certain cancers, while emerging research is exploring the protective relationship between tomato intake and a host of conditions, including cardiovascular disease, osteoporosis, ultraviolet light—induced skin damage, and cognitive dysfunction. Initial studies of tomato consumption and disease risk reduction focused on lycopene and antioxidant activity. More recent hypotheses recognize the advantages of the whole tomato; and hence, research on the role of tomato products in health and disease risk reduction extends beyond antioxidant function to include other protective mechanisms such as antithrombotic and anti-inflammatory functions. Increasing daily vegetable intake in the American diet offers the potential to yield significant health benefits. In addition to the specific benefits of tomato consumption, encouraging greater tomato and tomato product consumption may help increase overall vegetable intake because of their wide availability, well-established acceptability, cost-effectiveness, and convenience of multiple forms. Leveraging emerging science about tomatoes and tomato products may be one simple and effective strategy to help individuals increase vegetable intake, leading to improved overall eating patterns, and ultimately, better health.

An update on the health effects of tomato lycopene

Lycopene is a non-provitamin A carotenoid that is responsible for the red to pink colors seen in tomatoes, pink grapefruit, and other foods. Processed tomato products are the primary dietary lycopene source in the United States. Unlike many other natural compounds, lycopene is generally stable to processing when present in the plant tissue matrix. Recently, lycopene has also been studied in relation to its potential health effects. Although promising data from epidemiological, as well as cell culture and animal, studies suggest that lycopene and the consumption of lycopene containing foods may affect cancer or cardiovascular disease risk, more clinical trial data is needed to support this hypothesis. In addition, future studies are required to understand the mechanism(s) whereby lycopene or its metabolites are proven to possess biological activity in humans.

Are the health attributes of lycopene related to its antioxidant function?

A variety of epidemiological trials have suggested that higher intake of lycopene-containing foods (primarily tomato products) or blood lycopene concentrations are associated with decreased cardiovascular disease and prostate cancer risk. Of the carotenoids tested, lycopene has been demonstrated to be the most potent in vitro antioxidant leading many researchers to conclude that the antioxidant properties of lycopene are responsible for disease prevention. In our review of human and animal trials with lycopene, or lycopene-containing extracts, there is limited support for the in vivo antioxidant function for lycopene. Moreover, tissue levels of lycopene appear to be too low to play a meaningful antioxidant role. We conclude that there is an overall shortage of supportive evidence for the "antioxidant hypothesis" as lycopene's major in vivo mechanism of action. Our laboratory has postulated that metabolic products of lycopene, the lycopenoids, may be responsible for some of lycopene's reported bioactivity.