Astaxanthin deposition in the flesh of Atlantic Salmon, Salmo salar L., in relation to dietary astaxanthin concentration and feeding period

Atlantic salmon, Salmo salar L., were fed nine experimental diets containing from 0 to 200 mg astaxanthin per kg^?1 for six time periods, ranging from 3 to 21 months, in sea cages at Matre Aquaculture Research Station, Matredal, Norway. The sampled fish had an initial mean weight of 115 g and reached a weight of 3.2 kg at the termination of the experiment. Every third month, 10 fish from each dose and time group were sampled and the astaxanthin concentration in the flesh determined. The amount of astaxanthin in the flesh ranged from 0.7 to 8.9 mg kg^?1 at the termination of the experiment. This paper discusses deposition of astaxanthin in the flesh of Atlantic salmon in relation to dietary carotenoid levels in the 0–200 mg kg^?1 range and feeding times of 3–21 months. Under the conditions of this experiment, no significant effect on astaxanthin deposition rate could be achieved by increasing the astaxanthin level above 60 mg kg dry feed^?1. Atlantic salmon should be fed astaxanthin-supplemented diets during the whole seawater stage in order to obtain maximal astaxanthin level in the flesh.     

Effects of astaxanthin‐enriched yeast on mucosal IgA induction in the jejunum and ileum of weanling mice

The present study was conducted to clarify the effects of astaxanthin‐enriched yeast on the concentration of immunoglobulin A (IgA), the numbers of IgA antibody‐secreting cells (ASC) and the messenger RNA (mRNA) expression of IgA C‐region in the jejunum and ileum of weanling mice. Weanling mice were fed rodent feed or astaxanthin‐enriched yeast‐supplemented rodent feed for 7, 14 or 21 days. Supplemental astaxanthin‐enriched yeast increased the numbers of IgA ASC in the jejunum and ileum after 7, 14 and 21 days of treatment. Supplemental astaxanthin‐enriched yeast increased IgA concentrations in the jejunum after 21 days of treatment, but IgA concentrations in the ileum were not affected by the treatment. The mRNA expressions of IgA C‐region in the jejunum after 14 and 21 days of treatment and the ileum after 14 days of treatment were enhanced by supplementation of astaxanthin‐enriched yeast. These results indicate that supplementation of astaxanthin‐enriched yeast is effective to enhance the numbers of IgA ASC in the jejunum and ileum and IgA concentrations in the ileum of weanling mice.     

Marine carotenoids and cardiovascular risk markers

Marine carotenoids are important bioactive compounds with physiological activities related to prevention of degenerative diseases found principally in plants, with potential antioxidant biological properties deriving from their chemical structure and interaction with biological membranes. They are substances with very special and remarkable properties that no other groups of substances possess and that form the basis of their many, varied functions and actions in all kinds of living organisms. The potential beneficial effects of marine carotenoids have been studied particularly in astaxanthin and fucoxanthin as they are the major marine carotenoids. Both these two carotenoids show strong antioxidant activity attributed to quenching singlet oxygen and scavenging free radicals. The potential role of these carotenoids as dietary anti-oxidants has been suggested to be one of the main mechanisms for their preventive effects against cancer and inflammatory diseases. The aim of this short review is to examine the published studies concerning the use of the two marine carotenoids, astaxanthin and fucoxanthin, in the prevention of cardiovascular diseases.     

Phagocytosis of Astaxanthin-Loaded Microparticles Modulates TGFβ Production and Intracellular ROS Levels in J774A.1 Macrophages

Radiation-induced fibrosis is a serious long-lasting side effect of radiation therapy. Central to this condition is the role of macrophages that, activated by radiation-induced reactive oxygen species and tissue cell damage, produce pro-inflammatory cytokines, such as transforming growth factor beta (TGFβ). This, in turn, recruits fibroblasts at the site of the lesion that initiates fibrosis. We investigated whether astaxanthin, an antioxidant molecule extracted from marine and freshwater organisms, could help control macrophage activation. To this purpose, we encapsulated food-grade astaxanthin from Haematococcus pluvialis into micrometer-sized whey protein particles to specifically target macrophages that can uptake material within this size range by phagocytosis. The data show that astaxanthin-loaded microparticles are resistant to radiation, are well-tolerated by J774A.1 macrophages, induce in these cells a significant reduction of intracellular reactive oxygen species and inhibit the release of active TGFβ as evaluated in a bioassay with transformed MFB-F11 fibroblasts. Micro-encapsulation of bioactive molecules is a promising strategy to specifically target phagocytic cells and modulate their own functions.     

虾壳中虾青素提取工艺条件的确定及优化

为探讨南美白对虾虾壳中天然虾青素的提取工艺,试验通过比较不同的前处理方式、溶剂类型及提取次数对提取率的影响,确定酸浸泡脱钙前处理、乙醇溶剂提取及二次浸提等工艺技术。进一步通过单因素试验和正交试验进行条件优化,获得乙醇提取虾青素的最佳工艺参数为料液比1：10、pH3.0、温度60℃、时间3.5 h。在此条件下,虾类加工副产物中的天然虾青素提取率为271.3 μg·g-1。     

The Use of Natural Carotenoids and Growth Performance,Skin Pigmentation,and Immune Response in Fancy Carp (Cyprinus carpio)

Fancy carp were fed seven dietary treatments with natural pigment sources (tea, mulberry, cassava) at a specific rate to achieve a total carotenoid (TC) concentration in the diet of 25 mg/kg. Growth performance among treatments was not significantly different (p ≥ 0.05). TC and skin redness (a*) of fish fed tea leaves was higher than the other treatments (p ≤ 0.05). Fish fed with tea extract and cassava leaves had higher serum astaxanthin concentrations than the other groups (p ≤ 0.05). This group also retained serum astaxanthin and red color better than other groups two weeks post treatment (p ≤ 0.05). Phagocytic activity was significantly greater in fish fed carotenoid supplements compared with the control group (P ≤ 0.05). Therefore, dietary supplementation with 25 mg/kg tea leaves is sufficient to obtain good coloration in fancy carp as well as enhance immunity.     

Dietary astaxanthin supplementation for hatchery‐cultured red king crab,Paralithodes camtschaticus,juveniles

We conducted large‐scale production trials in Seward, Alaska, USA to investigate effects of dietary astaxanthin supplementation on survival, growth and shell colouration of recently settled juvenile (C1–C4) red king crabs (Paralithodes camtschaticus). We supplemented a control diet of commercial crustacean feeds with astaxanthin, and fed these diets to juvenile king crabs at densities of 2000 and 4000 crabs m^?2 for 56 days. We assessed survival and growth by counting crabs and individually measuring carapace width and weighing crabs at the start and end of the experiment, and quantified crab colour (hue, saturation, brightness) in digital photographs. Diets containing astaxanthin had higher survival, suggesting that astaxanthin may provide nutritional or immune system benefits. Crabs had lower hue, higher saturation and lower brightness values when fed diets containing astaxanthin, suggesting that red king crab colouration is plastic and responds to diet. Astaxanthin is likely an important dietary component for hatchery or laboratory reared red king crab juveniles, and should be considered for aquaculture and other rearing of this and possibly other crustacean species.     

Scavenging Capacity of Marine Carotenoids against Reactive Oxygen and Nitrogen Species in a Membrane-Mimicking System

Carotenoid intake has been associated with the decrease of the incidence of some chronic diseases by minimizing the in vivo oxidative damages induced by reactive oxygen (ROS) and nitrogen species (RNS). The carotenoids are well-known singlet oxygen quenchers; however, their capacity to scavenge other reactive species, such as peroxyl radical (ROO^•), hydroxyl radical (HO^•), hypochlorous acid (HOCl) and anion peroxynitrite (ONOO⁻), still needs to be more extensively studied, especially using membrane-mimicking systems, such as liposomes. Moreover, the identification of carotenoids possessing high antioxidant capacity can lead to new alternatives of drugs or nutritional supplements for prophylaxis or therapy of pathological conditions related to oxidative damages, such as cardiovascular diseases. The capacity to scavenge ROO^•, HO^•, HOCl and ONOO⁻ of seven carotenoids found in marine organisms was determined in liposomes based on the fluorescence loss of a fluorescent lipid (C₁₁-BODIPY^581/591) due to its oxidation by these reactive species. The carotenoid-bearing hydroxyl groups were generally more potent ROS scavengers than the carotenes, whilst β-carotene was the most efficient ONOO⁻ scavenger. The role of astaxanthin as an antioxidant should be highlighted, since it was a more potent scavenger of ROO^•, HOCl and ONOO⁻ than α-tocopherol.     

Astaxanthin Inhibits Proliferation and Induces Apoptosis of Human Hepatocellular Carcinoma Cells via Inhibition of Nf-Κb P65 and Wnt/Β-Catenin in Vitro

Hepatocellular carcinoma (HCC) is a malignant tumor that can cause systemic invasion; however, the exact etiology and molecular mechanism are unknown. Astaxanthin (ASX), a powerful antioxidant, has efficient anti-oxidant, anti-inflammatory, and other activities, and has great research prospects in cancer therapy. We selected the human hepatoma cell lines, LM3 and SMMC-7721, to study the anti-tumor effect and related mechanisms of ASX. The cell lines were treated with different concentrations of ASX, and its solvent DMSO as a control, for different time periods and the results were determined using CCK8, qRT-PCR, WB, apoptotic staining, and flow cytometry. ASX induced significant apoptosis of HCC cells, and its effect may have been caused by NF-κB p65 and Wnt/β-catenin down-regulation via negative activation of PI3K/Akt and ERK. Antitumor research on ASX has provided us with a potential therapy for patients with hepatomas.     

The effects of synthetic pigments on pigmentation of Pethia conchonius (Hamilton, 1822)

This study evaluated the effects of diets containing 20, 40, 60, 80 and 100 mg kg^?1 diet astaxanthin or canthaxanthin on Pethia conchonius (Hamilton, 1822) pigmentation. A completely randomized experimental design was developed with ten treatments and three replicates. Three hundred rosy barb with a mean weight of 0.92 ± 0.06 g were assigned to thirty aquaria for period of eight weeks. Carotenoid contents of fish fed canthaxanthin were always lower than those fed astaxanthin. Yellowness (b*) was not affected by pigments. While Luminosity (L*) decreased in fish fed astaxanthin diets, this parameter increased by feeding on canthaxanthin. The most pronounced effect was higher a* values in fish fed astaxanthin. Astaxanthin retention rate was higher than that of canthaxanthin. The present results demonstrate that canthaxanthin cannot be considered as a proper replacement with astaxanthin. Inclusion of 80 and 100 mg astaxanthin kg^?1 diet can be suitable dietary levels to ensure pigmentation and this condition may improve market value of rosy barb.