Interaction of Tomato Lycopene and Ketosamine against Rat Prostate Tumorigenesis

Abstract

Prior investigations on the beneficial effect of dietary processed tomato products and lycopene on prostate cancer risk suggested that lycopene may require the presence of other constituents to exert its chemopreventive potential. We investigated whether ketosamines, a group of carbohydrate derivatives present in dehydrated tomato products, may interact with lycopene against prostate tumorigenesis. One ketosamine, FruHis, strongly synergized with lycopene against proliferation of the highly metastatic rat prostate adenocarcinoma MAT-LyLu cell line in vitro. The FruHis/lycopene combination significantly inhibited in vivo tumor formation by MAT-LyLu cells in syngeneic Copenhagen rats. Energybalanced diets, supplemented with tomato paste, tomato powder, or tomato paste plus FruHis, were fed to Wistar-Unilever rats (n = 20 per group) treated with N-nitroso-N-methylurea and testosterone to induce prostate carcinogenesis. Survival from carcinogenesis was lowest in the control group (median survival time, 40 weeks) and highest in the group fed the tomato paste/FruHis diet (51 weeks; P = 0.004, versus control). The proportions of dying rats with macroscopic prostate tumors in the control, tomato paste, tomato powder, and tomato paste/FruHis groups were 63% (12 of 19), 39% (5 of 13), 43% (6 of 14), and 18% (2 of 11), respectively. FruHis completely blocked DNA oxidative degradation at >250 Mmol/L in vitro, whereas neither ascorbate nor phenolic antioxidants from tomato were effective protectors in this assay. FruHis, therefore, may exert tumor-preventive effect through its antioxidant activity and interaction with lycopene. [Cancer Res 2008;68(11):4384-91]

A Dietary Tomato Supplement Prevents Prostate Cancer in TRAMP Mice

“…Prolonged heating of whole tomatoes, including their seeds and skins, maximized the concentration of flavonoids and carotenoids (21) and promoted the formation of ketosamine (14).…”

“…However, in prostate cancer patients, tomato supplementation reduces serum prostate-specific antigen levels (11), whereas lycopene has no effect (12). In rats, tomato supplementation reduces carcinogenesis-induced mortality more efficiently than lycopene (13)(14)(15). Again, in the Dunning R3327-H prostate cancer model, the intake of whole foods, such as tomatoes and broccoli, slowed tumor growth more effectively than lycopene alone (16).…”

“…Again, in the Dunning R3327-H prostate cancer model, the intake of whole foods, such as tomatoes and broccoli, slowed tumor growth more effectively than lycopene alone (16). Tomatoes contain other anticancer phytochemicals [see U.S. Department of Agriculture National Nutrient Database for Standard Reference: release 19 (2006), pdf available from http://www.nal.usda.gov/fnic/ foodcomp/cgi-bin/measure.pl?MSRE_NO=11548xyz1100 xyzTomato%20powderxyzxyz], whereas constituents already present in small amounts or newly formed during processing also contribute to their final in vivo efficacy (14).…”

Determinação da atividade antioxidante e do teor total de polifenol em amostras de chá de ervas comercializadas em sachets

“…: β-caroteno e licopeno) e polares (ex. : luteína e zeaxantina) apresentam comprovadas propriedades antioxidantes, e diversos estudos têm atribuído a esses compostos também atividade anticancerígena 24,25 .…”

Dietary Manipulation for Therapeutic Effect in Prostate Cancer

“…In a provocative study of androgen expressing prostate cancer cell lines treated with serum from rats fed a control diet, or diets supplemented with red, or yellow tomato (containing no lycopene), connexin43 (a protein regulating cell growth) was upregulated by both the red and yellow tomato supplemented diet (Gitenay et al, 2007). This suggests tomato compounds other than lycopene may have a role in reducing prostate cancer cell growth; one such candidate might be FruHis, a carbohydrate derivative found in tomato products (Mossine et al, 2008). However, in humans at least, dietary lycopene has been shown to affect gene expression, regardless of whether it is included in its food matrix (Talvas et al, 2010) In a transgenic mouse model, early intervention with selenium, vitamin E and lycopene supplements was able to significantly reduce prostate cancer and liver metastases (Venkateswaran et al, 2009).…”