A 10% Tomato Diet Selectively Reduces Radiation-Induced Damage in TRAMP Mice

A mechanistic updated overview on lycopene as potential anticancer agent

The potent relation between lycopene intake and reduced incidence of a variety of cancers has an increasing interest. This comprehensive review aims to highlight the in vivo and in vitro research evaluating the anticancer mechanisms of lycopene by underlining the experiment conditions. In addition to these, the general characterization of lycopene has been explained. A collection of relevant scientific pharmacological articles from the following databases PubMed/MedLine, Web of Science, Scopus, TRIP database, and Google Scholar on the mechanisms of anticancer molecular action and cellular effects of lycopene in various types of tumors was performed. The anticancer potential of lycopene has been described by various in vitro cells, animal studies, and some clinical trials. It has been revealed that the anticancer potential of lycopene is mainly due to its powerful singlet-oxygen quencher characteristics, simulation of detoxifying/antioxidant enzymes production, initiation of apoptosis, inhibition of cell proliferation and cell cycle progression as well as modulations of gap junctional communication, the growth factors, and signal transduction pathways. It has been highlighted that the anticancer properties of lycopene are primarily linked to factors including; dose, presence of drug delivery systems, type of cancer, tumor size, and treatment time.

Tomatoes, Lycopene, and Prostate Cancer: What Have We Learned from Experimental Models?

Human epidemiology suggests a protective effect of tomatoes or tomato phytochemicals, such as lycopene, on prostate cancer risk. However, human epidemiology alone cannot reveal causal relations. Laboratory animal models of prostate cancer provide opportunities to investigate hypotheses regarding dietary components in precisely controlled, experimental systems, contributing to our understanding of diet and cancer risk relations. We review the published studies evaluating the impact of tomatoes and/or lycopene in preclinical models of prostate carcinogenesis and tumorigenesis. The feeding of tomatoes or tomato components demonstrates anti-prostate cancer activity in both transplantable xenograft models of tumorigenesis and models of chemically- and genetically-driven carcinogenesis. Feeding pure lycopene shows anticancer activity in most studies, although outcomes vary by model system, suggesting that the impact of pure lycopene can depend on dose, duration, and specific carcinogenic processes represented in different models. Nonetheless, studies with the transgenic adenocarcinoma of the mouse prostate (TRAMP) model of carcinogenesis typically demonstrate similar bioactivity to that of tomato feeding. In general, interventions that commence earlier in carcinogenesis and are sustained tend to be more efficacious. Accumulated data suggest that lycopene is one, but perhaps not the only, anticancer bioactive compound in tomatoes. Although it is clear that tomatoes and lycopene have anti-prostate cancer activity in rodent models, major knowledge gaps remain in understanding dose-response relations and molecular mechanisms of action. Published and future findings from rodent studies can provide guidance for translational scientists to design and execute informative human clinical trials of prostate cancer prevention or in support of therapy.