Lycopene's Effects on Cancer Cell Functions within Monolayer and Spheroid Cultures.

Lycopene, a compound that blocks the action of free radicals and oxygen molecules, is found in tomatoes and tomato-based products and linked to a reduced incidence of cancer. Increasing willingness of patients to maintain a healthy lifestyle by supplemental intake of nutrients and acceptance of alternative therapeutics has boosted research into nutraceuticals. The potential of lycopene to prevent or treat cancer has been investigated, but outcomes are inconsistent and its mode of action is still unknown. Further studies are needed to understand the role of lycopene in cancer prevention and treatment. The impact of lycopene on viability, proliferation, migration, and invasion of five different cancer cell lines was determined using monolayer and spheroid cultures. Cell viability was significantly reduced upon lycopene treatment at physiologically attainable concentrations. Cell proliferation, migration, and invasion did not change upon lycopene treatment. Ovarian cancer spheroids initially showed a decreased proliferation and after 14 days increased cell viability upon lycopene treatment, confirming the potential of lycopene to reduce cancer cell growth in short-term cultures and also indicate enhanced cell viability over prolonged exposure. This study cannot substantiate that lycopene inhibits cell functions associated with tumor growth, even in a 3D cancer model that mimics the natural tumor microenvironment.

The potential role of lycopene for the prevention and therapy of prostate cancer: from molecular mechanisms to clinical evidence.

Lycopene is a phytochemical that belongs to a group of pigments known as carotenoids. It is red, lipophilic and naturally occurring in many fruits and vegetables, with tomatoes and tomato-based products containing the highest concentrations of bioavailable lycopene. Several epidemiological studies have linked increased lycopene consumption with decreased prostate cancer risk. These findings are supported by in vitro and in vivo experiments showing that lycopene not only enhances the antioxidant response of prostate cells, but that it is even able to inhibit proliferation, induce apoptosis and decrease the metastatic capacity of prostate cancer cells. However, there is still no clearly proven clinical evidence supporting the use of lycopene in the prevention or treatment of prostate cancer, due to the only limited number of published randomized clinical trials and the varying quality of existing studies. The scope of this article is to discuss the potential impact of lycopene on prostate cancer by giving an overview about its molecular mechanisms and clinical effects.