Nickerson, J. G. | bioRxiv Science

bioRxiv2021

β-Carotene oxidation products - function and safety

{beta}-Carotene oxidation products have newly discovered bioactivity in plants and animals. Synthetic fully oxidized {beta}-carotene (OxBC) has application in supporting livestock health, with potential human applications. The safety of synthetic OxBC has been evaluated. An Ames test showed weak-to-moderate mutagenicity in only one cell line at high concentrations. A mouse micronucleus assay established a non-toxic dose of 1800 mg/kg body weight, and no bone marrow micronuclei were induced. Plant sources of {beta}-carotene inevitably contain varying levels of natural OxBC. Vegetable powders and dried forages can be especially rich. Intakes of natural OxBC for humans and livestock alike have been estimated. The exposure range for humans (1-22 mg/serving) is comparable to the safe intake of {beta}-carotene (<15 mg/d). In livestock, OxBC in alfalfa can contribute ~550-850 mg/head/d for dairy cattle but in forage-deficient poultry feed much less (~1 ppm). Livestock intake of supplemental synthetic OxBC is comparable to OxBC potentially available from traditional plant sources. Human intake of synthetic OxBC in meat from livestock fed OxBC is similar to a single serving of food made with carrot powder. It is concluded that consumption of synthetic OxBC at levels comparable to natural OxBC is safe for humans and animals.

biochemistry↗

bioRxiv2020

Effect of oxidized β-carotene-oxygen copolymer compounds on health and performance of pre- and post-weaned pigs

The discovery that a naturally occurring, biologically active {beta}-carotene-oxygen copolymer compound is the main product formed in spontaneously oxidized {beta}-carotene has stimulated interest in its potential health benefits. The copolymer, formed in nature or synthetically by the air-oxidation of {beta}-carotene, possesses beneficial immune modulating activities that previously had been attributed to {beta}-carotene itself. Support for these benefits is provided by previous studies showing that supplementation in feed with low parts-per-million levels of copolymer-rich, fully oxidized {beta}-carotene (OxBC) helped reduce the negative impact of subclinical necrotic enteritis in broilers and improved growth in weaned piglets. To further assess these potential benefits, two trials were conducted in swine raised under commercial conditions in Vietnam. Trial 1, a 140-day full-grow, post-wean study with 500 28-day-old pigs, compared 2, 4 or 8 ppm OxBC against both an unsupplemented and an antibiotic control group. OxBC and antibiotics each improved growth rate, feed efficiency, and body weight compared to the control (P<0.001). Animals receiving 4 and 8 ppm OxBC performed better than did animals on antibiotics (P<0.001). In starter pigs, OxBC reduced the occurrence of diarrhea dose-dependently (4 and 8 ppm) and to a greater extent than did antibiotics (P<0.001). Trial 2, a 49-day study with 420 piglets, was conducted in two-stages. In Stage 1 (pre-wean), OxBC in the transition (creep) feed produced a dose-dependent trend toward increased body weight over 21 days, reaching significance at the highest inclusion level (16 ppm) (P<0.001). In Stage 2 (post-wean), body weight gain showed a dose-dependent trend and was significant for both 8 ppm OxBC and the antibiotics at 28 days post-wean (P<0.001). Feed conversion was better at 8 ppm OxBC and for the antibiotic group (P<0.001). These findings support the concept that {beta}-carotene-oxygen copolymers help optimize immune function, and provide validation for the effectiveness of this strategy in enhancing animal performance in the absence of in-feed antibiotics.

immunology↗