β-Carotene supplements are often taken by individuals living with HIV-1. Contradictory results from in vitro studies suggest that β-carotene may inhibit or induce cytochrome P450 enzymes and transporters. The study objective was to investigate the effect of β-carotene on the steady-state pharmacokinetics of nelfinavir and its active metabolite M8 in HIV-1 infected individuals. Twelve hour nelfi...

We evaluated the role of dietary vitamin C, vitamin E, and beta-carotene, as well as long-term vitamin E and beta-carotene supplementation, on the incidence of common cold episodes. A cohort of 21,796 male smokers was drawn from the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study, which examined the effects of 50 mg per day vitamin E and 20 mg per day beta-carotene on lung cancer. Diet a...

For the quanti®cation of aand b-carotene including the cis-isomers of b-carotene in carrot juices and vitamin supplemented (ATBC) drinks, a rapid and artefact-free method was developed. The analytical procedure involves the extraction of carotenes with a mixture of acetone-hexane and their determination by HPLC using a C30 stationary phase. No saponi®cation prior to HPLC is required. The method...

The carotenoid pigments are very conspicuous in nature, owing to their yellow to red hues, and occur without exception in photosynthetic tissue. They are responsible for the colour in some species of yeast, bacteria and fungi as well as many vegetables and fruits. Although animals are incapable of de nmo synthesis, they are able to deposit the carotenoid pigment as absorbed or with some alterat...

The Bulgarian orange-fruited mutant cultivar Oranzheva kapiya is characterized with a high content of the antioxidant β-carotene. To identify the mutation leading to the accumulation of β-carotene and develop a suitable molecular marker for this trait, the genes for geranyl-geranyl pyrophosphate synthase, capsanthin-capsorubin synthase and β-carotene hydroxylase were studied both in the mutant ...

The first dedicated step in plant xanthophyll biosynthesis is carotenoid hydroxylation. In Arabidopsis thaliana, this reaction is performed by both heme (LUT1 and LUT5) and non-heme (CHY1 and CHY2) hydroxylases. No mutant completely abolishing alpha- or beta-carotene hydroxylation has been described to date. We constructed double and triple mutant combinations in CHY1, CHY2, LUT1, LUT5 and LUT2...

There is a growing body of interest on the role of beta-carotene and other carotenoids in human chronic diseases, including cancer. While epidemiological evidence shows that people who ingest more dietary carotenoids exhibit a reduced risk for cancer, results from intervention trials indicate that supplemental beta-carotene enhances lung cancer incidence and mortality among smokers. A possible ...

This paper describes micro-Raman spectroscopy of ultra-high molecular weight polyethylene wear debris isolated from revised knee replacements. The novel application of micro-Raman spectroscopy to the analysis of in vivo-generated wear debris was used to evaluate the chemical nature of individual, retrieved polyethylene particles. The analysis revealed the presence of beta-carotene on particles ...

Carotenoids in eukaryotic phototrophic organisms can be classified into two groups; β-carotene and its derivatives, and α-carotene and its derivatives. We re-examined distribution of α-carotene and its derivatives among various taxa of aquatic algae (17 classes) and land plants. α-carotene and its derivatives were found from Rhodophyceae (macrophytic type), Cryptophyceae, Euglenophyceae, Chlora...

The red yeast Xanthophyllomyces dendrorhous is an established platform for the synthesis of carotenoids. It was used for the generation of novel multi oxygenated carotenoid structures. This was achieved by a combinatorial approach starting with the selection of a β-carotene accumulating mutant, stepwise pathway engineering by integration of three microbial genes into the genome and finally the ...