Small daily doses of orange heirloom ('Moonglow') tomatoes dose-dependently increase plasma and liver lycopene concentrations in rats.

Abstract

Lycopene in red tomatoes is mainly in the poorly bioavailable all-trans-isomeric form, while 'Moonglow', an orange heirloom tomato, contains more bioavailable cis-lycopene isomers. Consuming around 1.5 kg of red tomatoes daily is needed to achieve effective plasma lycopene levels (>0.45 μmol/L). This study hypothesized that small daily doses of 'Moonglow' tomatoes could achieve beneficial lycopene levels in rats. Female Sprague-Dawley rats were supplemented with 'Moonglow' tomato powder. In Study 1, rats received lycopene at 0, 0.05, 0.35, or 2.6 mg/kg body weight daily for five days. Plasma and liver lycopene concentrations increased dose-dependently. In Study 2, rats given 0.35 mg/kg daily showed dose- and time-dependent increases in lycopene. Plasma lycopene reached 0.42 μmol/L after four days, similar to beneficial human levels. These findings suggest that reasonable daily intake of 'Moonglow' tomatoes can achieve effective plasma lycopene concentrations.