Astaxanthin decreased oxidative stress and inflammation and enhanced immune response in humans

Nutrition & Metabolism Astaxanthin decreased oxidative stress and inflammation and enhanced immune response in humans Jean Soon Park 0 Jong Hee Chyun 2 Yoo Kyung Kim 2 Larry L Line 1 Boon P Chew 0 0 School of Food Science, Washington State University , Pullman, WA 99164- 6376 USA 1 La Haye Labs, Inc , Redmond, WA , USA 2 Food and Nutrition, Inha University , Incheon , Korea Background: Astaxanthin modulates immune response, inhibits cancer cell growth, reduces bacterial load and gastric inflammation, and protects against UVA-induced oxidative stress in in vitro and rodent models. Similar clinical studies in humans are unavailable. Our objective is to study the action of dietary astaxanthin in modulating immune response, oxidative status and inflammation in young healthy adult female human subjects. Methods: Participants (averaged 21.5 yr) received 0, 2, or 8 mg astaxanthin (n = 14/diet) daily for 8 wk in a randomized double-blind, placebo-controlled study. Immune response was assessed on wk 0, 4 and 8, and tuberculin test performed on wk 8. Results: Plasma astaxanthin increased (P < 0.01) dose-dependently after 4 or 8 wk of supplementation. Astaxanthin decreased a DNA damage biomarker after 4 wk but did not affect lipid peroxidation. Plasma C-reactive protein concentration was lower (P < 0.05) on wk 8 in subjects given 2 mg astaxanthin. Dietary astaxanthin stimulated mitogen-induced lymphoproliferation, increased natural killer cell cytotoxic activity, and increased total T and B cell subpopulations, but did not influence populations of Thelper, Tcytotoxic or natural killer cells. A higher percentage of leukocytes expressed the LFA-1 marker in subjects given 2 mg astaxanthin on wk 8. Subjects fed 2 mg astaxanthin had a higher tuberculin response than unsupplemented subjects. There was no difference in TNF and IL-2 concentrations, but plasma IFN-g and IL-6 increased on wk 8 in subjects given 8 mg astaxanthin. Conclusion: Therefore, dietary astaxanthin decreases a DNA damage biomarker and acute phase protein, and enhances immune response in young healthy females. - Introduction Studies have reported important functions played by natural carotenoids in regulating immunity and disease etiology [1,2]. Specifically, interest in the biological activity of astaxanthin, an oxycarotenoid found in high amounts in the carapace of crustaceans and in the flesh of salmon and trout, has increased in recent years. In vitro studies have demonstrated that astaxanthin is several fold more active as a free radical antioxidant than b-carotene and a-tocopherol [3]. Using a rodent model, we [4] and others [5,6] have demonstrated that astaxanthin stimulated immune response in mice. Mice supplemented with astaxanthin had increased ex vivo splenocyte antibody response to T-dependent antigens [6], lymphoblastogenic response and cytotoxic activity [4]. Moreover, these studies also showed that astaxanthin was consistently more active than other carotenoids such as b-carotene, lutein and canthaxanthin. In addition to immunoregulatory activity, astaxanthin also inhibited mammary tumor growth. We [7] reported that dietary astaxanthin inhibited mammary tumor growth in mice. Astaxanthin has been shown to reduce bacterial load and gastric inflammation in Helicobacter pylori-infected mice [5], and to protect against UVAinduced oxidative stress [8]. Immune cells are particularly sensitive to oxidative stress due to a high percentage of polyunsaturated fatty acids in their plasma membranes, and they generally produce more oxidative products [1]. Overproduction of reactive oxygen and nitrogen species can tip the oxidant: antioxidant balance, resulting in the destruction of cell membranes, proteins and DNA. Therefore, under conditions of increased oxidative stress (e.g. during disease states), dietary antioxidants become critical in maintaining a desirable oxidant:antioxidant balance. While studies on the immunomodulatory role of dietary astaxanthin have been reported in rodents, similar studies in humans are not available. We hypothesize that dietary astaxanthin will act as a potent antioxidative and anti-inflammatory agent; through these and other mechanisms, astaxanthin can enhance immune response. Our objective is to study the possible immune-enhancing, antioxidative and anti-inflammatory activity of dietary astaxanthin in humans. Subjects and methods Study participants and study design Free-living healthy female college students with an average age of 21.5 yr (20.2-22.8 yr) and BMI of 21.6 (16.327.5) were participants in this study. Participants were recruited from Inha University (Seoul, Korea) through flyers and emails, and all were native Koreans. Subjects with a history of diabetes, alcohol abuse, cancer or smoking were excluded; exclusion criteria also included those taking antioxidant supplements. Prior to the initiation of dietary supplementation, a three-day dietary record was obtained from each subject who provided informed consent. During the study, subjects were allowed to consume their normal diets but were advised to refrain from eating astaxanthin-rich foods such as salmon, lobster, and shrimp. Subjects were ranked based on BMI (age was within a very narrow range) and groups of 3 participants with similar BNI were randomly assigned to receive daily: 0 (control; Con), 2 mg (2Asta), or 8 mg (8Asta) astaxanthin (109 g astaxanthin complex/kg oleoresin concentrate from Haematococcus plu vialis, astaZanthin, La Haye Laboratories Inc., Redmond, WA) (n = 14 subjects/diet) for 8 wk in a double-blind, placebo-controlled study. Astaxanthin was administered as a softgel capsule taken every morning, and all softgel capsules were externally identical. Blinding was further ensured by assigning consecutive numbers to the dietary treatments and maintaining a master list until the study was completed. The astaxanthin complex used in this study came from a supercritical CO2 extract of Haematococcus pluvialis. Astaxanthin in the H. pluvialis extract is entirelythe 3S, 3S enantiomer, and is primarily monoesterified with smaller quantities of diester and free astaxanthin. The astaxanthin complex also contains small amounts (<15%) of mixed carotenoids including lutein, b-carotene and canthaxanthin. To minimize subject-to-subject and assay-to-assay variation due to different sampling days, blood was drawn from all 42 subjects on one day for each of wk 0, 4 and 8. Immune function and oxidative status was assessed within 24 h of blood collection. All procedures were approved by the Institutional Review Board (IRB #4421) of Washington State University. Analytical procedures HPLC Astaxanthin content in plasma was analyzed by reverse phase HPLC (Alliance 2690, Waters, Milford, MA) as previously described [9]. Trans-b-apo-8carotenal (Sigma Chem. Co., St. Louis, MO) was used as the internal standard. Mobile phase used was acetonitrile:methanol:water, 47:47:16 (v/v/v), and samples were eluted through a 5-m s (...truncated)