Anthocyanin and Lycopene Contents Do Not Affect β-Carotene Bioefficacy from Multicolored Carrots (Daucus carota L.) in Male Mongolian Gerbils

Abstract

Background: Anthocyanins and carotenoids are phytochemicals that may benefit health through provitamin A carotenoid (PAC), antioxidant, and anti-inflammatory activities. These bioactives may mitigate chronic diseases. Consumption of multiple phytochemicals may impact bioactivity in synergistic or antagonistic manners.

Objectives: Two studies in weanling male Mongolian gerbils assessed the relative bioefficacy of β-carotene equivalents (BCEs) to vitamin A (VA) with simultaneous consumption of the non-PAC lycopene or anthocyanins from multicolored carrots.

Methods: After 3-wk VA depletion, 5-6 gerbils were killed as baseline groups. The remaining gerbils were divided into 4 carrot treatment groups; the positive control group received retinyl acetate and the negative control group was given vehicle soybean oil (n = 10/group; n = 60/study). In the lycopene study, gerbils consumed feed varying in lycopene sourced from red carrots. In the anthocyanin study, gerbils consumed feed varying in anthocyanin content sourced from purple-red carrots, and positive controls received lycopene. Treatment feeds had equalized BCEs: 5.59 ± 0.96 μg/g (lycopene study) and 7.02 ± 0.39 μg/g (anthocyanin study). Controls consumed feeds without pigments. Serum, liver, and lung samples were analyzed for retinol and carotenoid concentrations using HPLC. Data were analyzed by ANOVA and Tukey's studentized range test.

Results: In the lycopene study, liver VA did not differ between groups (0.11 ± 0.07 μmol/g) indicating no effect of varying lycopene content. In the anthocyanin study, liver VA concentrations in the medium-to-high (0.22 ± 0.14 μmol/g) and medium-to-low anthocyanin (0.25 ± 0.07 μmol/g) groups were higher than the negative control (0.11 ± 0.07 μmol/g) (P < 0.05). All treatment groups maintained baseline VA concentrations (0.23 ± 0.06 μmol/g). Combining studies, serum retinol had 12% sensitivity to predict VA deficiency, defined as 0.7 μmol/L.

Conclusions: These gerbil studies suggested that simultaneous consumption of carotenoids and anthocyanins does not impact relative BCE bioefficacy. Breeding carrots for enhanced pigments to improve dietary intake should continue.

Keywords: anthocyanins; bioefficacy; carotenoids; carrot (Daucus carota); lycopene; vitamin A; β-carotene.