ABSTRACT
BACKGROUND: Dietary intake of lycopene has been associated with a reduced risk of ovarian cancer, suggesting its chemopreventive potential against ovarian carcinogenesis. Lycopene's molecular mechanisms of action in ovarian cancer have not been fully understood. Therefore, in the present study, we investigated the effects of lycopene on the ovarian cancer formation using the laying hen model, a biologically relevant animal model of spontaneous ovarian carcinogenesis due to high incidence rates similar to humans. METHODS: In this study, a total of 150 laying hens at age of 102 weeks were randomized into groups of 50: a control group (0 mg of lycopene per kg of diet) and two treatment groups (200 mg or 400 mg of lycopene per kg of diet, or ~26 and 52 mg/d/hen, respectively). At the end of 12 months, blood, ovarian tissues and tumors were collected. RESULTS: We observed that lycopene supplementation significantly reduced the overall ovarian tumor incidence (P < 0.01) as well as the number and the size of the tumors (P < 0.004 and P < 0.005, respectively). Lycopene also significantly decreased the rate of adenocarcinoma, including serous and mucinous subtypes (P < 0.006). Moreover, we also found that the serum level of oxidative stress marker malondialdehyde was significantly lower in lycopene-fed hens compared to control birds (P < 0.001). Molecular analysis of the ovarian tumors revealed that lycopene reduced the expression of NF-κB while increasing the expression of nuclear factor erythroid 2 and its major target protein, heme oxygenase 1. In addition, lycopene supplementation decreased the expression of STAT3 by inducing the protein inhibitor of activated STAT3 expression in the ovarian tissues. CONCLUSIONS: Taken together, our findings strongly support the potential of lycopene in the chemoprevention of ovarian cancer through antioxidant and anti-inflammatory mechanisms.
ABSTRACT
In the present study, the effects of dietary supplementation of organic and inorganic Mn, Zn, Cu, and Cr mixtures using two different levels (80, 60, 5, and 0.15 mg/kg and 40, 30, 2.5, and 0.07 mg/kg, respectively) on the bioavailability of these trace minerals and Ca in late-phase laying hens were evaluated. Three hundred and sixty laying hens (Barred Rock) at 50 weeks of age were used, and the duration of study was 16 weeks. Each of the four dietary regimes was randomly assigned to six replicates, which included 15 hens each. Organic trace minerals were provided as methionine chelates; inorganic Mn, Zn, and Cr were provided as oxides; and Cu was provided as sulfate. The organic form significantly increased the concentrations of serum Mn, Zn, Cu, and Ca; egg Mn, Zn, Cu, and Cr; and eggshell Zn and Cr compared with the inorganic form. However, the form of trace minerals did not affect the concentrations of serum Cr and eggshell Mn, Cu, and Ca. High-level addition of trace minerals significantly increased serum Mn and Zn; egg Mn, Zn, Cu, and Cr; and eggshell Mn, Zn, and Cu concentrations compared with low-level addition but did not affect serum Cu, Cr, and Ca or eggshell Cr and Ca concentrations. While the organic form reduced the excretion of Mn, Zn, Cu, Cr, and Ca, the high-level supplement increased Mn, Zn, and Cu excretion. The addition level did not affect Cr and Ca excretion. These results demonstrate that dietary supplementation of an organic Mn, Zn, Cu, and Cr mixture increases the bioavailability of Mn, Zn, Cu, Cr, and Ca compared with inorganic sources and that a lower level of trace mineral supplementation results in lower mineral excretion, particularly in an organic form.
