[Show abstract][Hide abstract] ABSTRACT: Zeaxanthin is a predominant xanthophyll in human eyes and may reduce the risk of cataracts and age-related macular degeneration. Spirulina is an algal food that contains a high concentration of zeaxanthin. In order to determine the zeaxanthin bioavailability of spirulina for dietary supplementation in humans, spirulina was grown in nutrient solution with ²H₂O for carotenoid labelling. Single servings of ²H-labelled spirulina (4.0-5.0 g) containing 2.6-3.7 mg zeaxanthin were consumed by fourteen healthy male volunteers (four Americans and ten Chinese) with 12 g dietary fat. Blood samples were collected over a 45 d period. The serum concentrations of total zeaxanthin were measured using HPLC, and the enrichment of labelled zeaxanthin was determined using LC-atmospheric pressure chemical ionisation-MS (LC-APCI-MS). The results showed that intrinsically labelled spirulina zeaxanthin in the circulation was detected at levels as low as 10 % of the total zeaxanthin for up to 45 d after intake of the algae. A single dose of spirulina can increase mean serum zeaxanthin concentration in humans from 0.06 to 0.15 μmol/l, as shown in our study involving American and Chinese volunteers. The average 15 d area under the serum zeaxanthin response curve to the single dose of spirulina was 293 nmol × d/μmol (range 254-335) in American subjects, and 197 nmol × d/μmol (range 154-285) in Chinese subjects. It is concluded that the relative bioavailability of spirulina zeaxanthin can be studied with high sensitivity and specificity using ²H labelling and LC-APCI-MS methodology. Spirulina can serve as a rich source of dietary zeaxanthin in humans.
The British journal of nutrition 02/2012; 108(4):611-9. · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Spirulina is a high-protein food supplement that contains carotenoids.
The objective of the study was to determine the vitamin A equivalence of spirulina beta-carotene in humans.
Spirulina was grown in a 23 atom% (2)H(2)O cultural solution. Spirulina beta-carotene showed the greatest enrichment as [(2)H(10)]trans beta-carotene. Ten healthy Chinese men with a mean (+/-SD) serum retinol concentration of 1.7 +/- 0.3 micromol/L and a body mass index (in kg/m(2)) of 23 +/- 3 consumed 5.8 micromol [(13)C(10)]retinyl acetate in oil as a reference dose with a breakfast containing 13 g fat. One week later, each subject consumed 7.9 mumol trans beta-carotene in spirulina with a breakfast containing 22 g fat. All subjects followed diets low in carotenoid and vitamin A. Forty blood samples were collected from each subject over a span of 56 d. Concentrations and enrichments of retinol and beta-carotene in serum samples were determined by using HPLC and a mass spectrometer.
Compared with the serum response to [(13)C(10)]retinyl acetate dose, the mean conversion factor of spirulina beta-carotene to retinol was 4.5 +/- 1.6 (range: 2.3-6.9) by weight. It was estimated that 80% of the conversion occurred within the first 24 h after spirulina administration.
In a group of well-nourished, normal-weight Chinese men following low-vitamin A diets, 4.5 mg spirulina beta-carotene consumed with 22 g fat has the same vitamin A activity as does 1 mg retinyl acetate.
American Journal of Clinical Nutrition 07/2008; 87(6):1730-7. · 6.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vitamin A (VA) kinetics, storage, and disposal rate were determined in well-nourished Chinese and U.S. adults using model-based compartmental analysis. [(2)H(8)]Retinyl acetate (8.9 micromol) was orally administered to U.S. (n = 12; 59 +/- 9 y; mean +/- SD) and Chinese adults (n = 14; 54 +/- 4 y) and serum tracer and VA concentrations were measured from 3 h to 56 d. Using the Windows version of the Simulation, Analysis and Modeling software, we determined that the average time from dosing until appearance of labeled retinol in serum was greater in U.S. subjects (40.6 +/- 8.47 h) than in Chinese subjects (32.2 +/- 5.84 h; P < 0.01). Model-predicted total traced mass (898 +/- 637 vs. 237 +/- 109 micromol), disposal rate (14.7 +/- 5.87 vs. 5.58 +/- 2.04 micromol/d), and system residence time (58.9 +/- 28.7 vs. 42.9 +/- 14.6 d) were greater in U.S. than in Chinese subjects (P < 0.05). The model-predicted VA mass and VA mass estimated by deuterated retinol dilution at 3 and 24 d did not differ. VA disposal rate was positively correlated with VA traced mass in Chinese (R(2) = 0.556), U.S. (R(2) = 0.579), and all subjects (R(2) = 0.808). Additionally, VA disposal rate was significantly correlated with serum retinol pool size (R(2) = 0.227) and retinol concentration (R(2) = 0.330) in all subjects. Our results support the hypothesis that VA stores are the principle determinant of VA disposal rate in healthy, well-nourished adults.
Journal of Nutrition 05/2008; 138(5):971-7. · 4.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: In order to evaluate the effect of coenzyme Q10 (CQ) or combined with carotenoids (lycopene and lutein, LL) or/and mineral nutrients (zinc and selenium, ZS) on the antioxidant defense system, The rats were randomized into 6 groups: control, CQ [CQ 10 mg/(kg x d)], CQ+ ZS[CQ 10 mg/(kg x d), Zn 1 mg/(kg x d), Se 4 microg/(kg x d)], CQ+ LL [CQ 10 mg/(kg x d), Lutein 1 mg/(kg x d), Lycopene 2 mg/(kg x d)], CQ + ZS + LL [CQ 10 mg/(kg x d), Zn 1 mg/(kg x d), Se 4 microg/(kg x d), Lutein 1 mg/(kg x d), Lycopene 2 mg/(kg x d)] and VE [VE 2 mg/(kg x d)], and then fed with a diet based on AIN-76 rodent diet but containing 4% lard as well as 4% corn oil. The supplement were given by oral for 8 weeks, and the plasma and liver antioxidant enzymes activity, malondialdehyde levels and lymphocyte DNA damage were determined. The results showed that the groups treated with CQ had a higher plasma SOD and TOAC level and liver SOD and GPX activity than those of the control group. Combination treatments further enhanced antioxidant enzymes activity and reduced MDA levels & DNA damage. Most of the parameters had reached statistical significance in comparison with the control. These findings suggested that CQ exerted antioxidative effects in rats, and when it was supplemented in combination with other antioxidants, the effects were raised to some extent.
Wei sheng yan jiu = Journal of hygiene research 05/2008; 37(3):311-3.
[Show abstract][Hide abstract] ABSTRACT: Flavonoids may be natural components came from many vegetables and fruits. A variety of heath effects of these compounds were found. However, a few safety studies indicated that certain adverse effects of these compounds could influence on human health, which could involve genotoxic/carcinogenic effects or interaction with thyroid hormone biosynthesis. Isoflavones' estrogenic activity could influence on sexual development of young animals and children. Furthermore, flavonoids could inhibit the absorption of some nutrients, interact with certain drug pharmacokinetics and affect neurobehavioral development. In this paper, the potential toxicities of flavonoids from recently published papers were reviewed.
Wei sheng yan jiu = Journal of hygiene research 10/2007; 36(5):640-2.
[Show abstract][Hide abstract] ABSTRACT: The objective of this research was to study the effectiveness of NaFeEDTA-fortified soy sauce for controlling iron deficiency in a high-risk population. This was an 18-month, randomized, placebo-controlled intervention trial in 14,000 residents aged three years or older in Bijie City, Guizhou Province, China, using sodium-iron ethylene diamine tetraacetate (NaFeEDTA)-fortified soy sauce (29.6 mg Fe/100 ml). The study data included measurements of food consumption, hemoglobin, serum ferritin, and serum retinol. The results showed that the diet consisted primarily of cereals, fruits, and vegetables, with very little meat. Food consumption remained unchanged during the study period and was similar in the fortified and control groups. The average daily soy sauce consumption of the group consuming the fortified product was 16.4 ml per person, which provided 4.9 mg of iron from NaFeEDTA. At the end of the trial, all age and sex subgroups receiving NaFeEDTA had significantly higher hemoglobin levels, a lower prevalence of anemia, and higher plasma ferritin levels than the controls. The effects became statistically significant after six months of intervention and were maintained throughout the study period. We conclude that NaFeEDTA-fortified soy sauce was highly effective in controlling iron deficiency and reducing the prevalence of iron-deficiency anemia in men, women, and children. NaFeEDTA-fortified soy sauce is affordable and was well accepted by the study population.
[Show abstract][Hide abstract] ABSTRACT: To explore the interaction role of selenium and zinc in diet on bone development in rats exposed to lead, and to observe the change of bone mineral content (BMC) and bone mineral density (BMD).
Wean male Wistar rats were fed with diet added with different levels of selenium, zinc and lead for 12 weeks.
Long-term exposure to lead may inhibit the development of bone and reduce BMC and BMD, however, selenium and zinc in the diets could improve the inhibit effect of lead on weight and length, BMC and BMD of rat bone.
The present study indicated that supplementing suitable amount of selenium or/and zinc could interact the side effect of lead, and increase the BMC and BMD of rat bone. The interaction mechanism of iron and zinc on bone exposed to lead in diets needs to be explore in further.
Wei sheng yan jiu = Journal of hygiene research 10/2004; 33(5):584-6.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this paper was to explore the effect of iron and zinc in diet on development of bone in growing rats exposed to lead and observed the change of bone mineral content (BMC) and bone mineral density (BMD).
The growing rats were fed with diet added with different levels of iron, zinc and lead for 12 weeks.
Long-term exposure to lead may inhibit the development of bone and reduce BMC and BMD, it can be improved the weight and length of bone and increased BMC and BMD following the increased in iron and zinc levels in the diets, but the lead level of bone increases.
Supplementary suitable iron or/and zinc could improve the BMC and BMD, the mechanism of iron and zinc in diets on bone exposed to lead should be further research.
Wei sheng yan jiu = Journal of hygiene research 08/2004; 33(4):461-3.
[Show abstract][Hide abstract] ABSTRACT: The present study was carried out to determine the conversion factor of synthetic 2H-labelled β-carotene to vitamin A in Chinese adults by using a stable-isotope dilution technique. Fifteen healthy volunteers aged 50–60 years were recruited for a 55 d experiment. The volunteers (nine males and six females) were each given a physiological dose of [2H8]β-carotene (6 mg) in oil on the first day of the experiment, and a reference dose of [2H8]retinyl acetate (3 mg) in oil was given on the fourth day. Serum samples were collected at 0, 3, 5, 7, 9, 11, and 13 h on the first and the fourth days of the study, daily for 10 d, and then weekly from days 14 to 56. β-Carotene and retinol were extracted from serum and isolated by HPLC, and their enrichments were respectively determined by using GC–electron capture negative chemical ionisation-MS and LC–atmospheric pressure chemical ionisation interface-MS. Four of the subjects exhibited β-carotene to vitamin A conversion factors of >29·0:1 on a molar basis and were termed ‘poor converters’. In the eleven normal converters (seven males and four females), the calculated conversion factors of β-carotene to retinol ranged from 2·0:1 to 12·2:1 with an average of 4·8 (sd 2·8):1 on a molar basis, and from 3·8:1 to 22·8:1 with an average of 9·1 (sd 5·3):1 on a weight basis. The 52 d post-intestinal absorption conversion was estimated to be about 30 % of the total converted retinol.
The British journal of nutrition 01/2004; 91(01). · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present study was carried out to determine the conversion factor of synthetic (2)H-labelled beta-carotene to vitamin A in Chinese adults by using a stable-isotope dilution technique. Fifteen healthy volunteers aged 50-60 years were recruited for a 55 d experiment. The volunteers (nine males and six females) were each given a physiological dose of [(2)H8]beta-carotene (6 mg) in oil on the first day of the experiment, and a reference dose of [(2)H8]retinyl acetate (3 mg) in oil was given on the fourth day. Serum samples were collected at 0, 3, 5, 7, 9, 11, and 13 h on the first and the fourth days of the study, daily for 10 d, and then weekly from days 14 to 56. beta-Carotene and retinol were extracted from serum and isolated by HPLC, and their enrichments were respectively determined by using GC-electron capture negative chemical ionisation-MS and LC-atmospheric pressure chemical ionisation interface-MS. Four of the subjects exhibited beta-carotene to vitamin A conversion factors of >29.0:1 on a molar basis and were termed 'poor converters'. In the eleven normal converters (seven males and four females), the calculated conversion factors of beta-carotene to retinol ranged from 2.0:1 to 12.2:1 with an average of 4.8 (sd 2.8):1 on a molar basis, and from 3.8:1 to 22.8:1 with an average of 9.1 (sd 5.3):1 on a weight basis. The 52 d post-intestinal absorption conversion was estimated to be about 30 % of the total converted retinol.
British Journal Of Nutrition 01/2004; 91(1):121-31. · 3.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: beta-carotene (beta-C) is a major and safe vitamin A source for a vast population in China. But there is little understanding on beta-C-vitamin A equivalence in Chinese population. This study was designed to evaluate intestinal and whole-body conversion of beta-C to vitamin A in some Chinese adults by using a stable isotope dilution technique.
Fifteen healthy adult farmer volunteers (9 males and 6 females) aged 50-60 years from a few villages of China's eastern Shandong Province were recruited in a 55-days experiment. A Physiological dose of 2H8 beta-C (11011 nmole or 6 mg) in oil was given with a liquid diet (25% energy from fat) to the volunteers in the first day of the study. Three days after the 2H8 beta-C dose, the volunteers each took a reference dose of 2H8 RAC (8,915 nmole or 3 mg) in oil with the same liquid diet. Serum samples were collected at 0, 3, 5, 7, 9, 11, 13 hours of the first and the fourth days of study, and fasting serum samples were also collected daily in first 10 days and then weekly at 14th, 21st, 28th, 35th, 42nd, 49th, and 56th day after a 12-hour overnight fast, beta-C and retinol were extracted from serum and isolated by high performance liquid chromatography. The serum retinol and beta-C enrichments were respectively determined by using a gas chromatography/electron capture negative chemical ionization mass spectrometry (GC/ECNCI-MS) and liquid chromatograph/mass spectrometry with an atmospheric pressure chemical ionization interface (LC/APCI-MS).
All the subjects responded well to the 2H8 retinyl acetate reference dose. However, the responses to the 2H8 beta-C dose were unexpectedly Poor in 4 of the 15 subjects. The repeated GC-MS analysis on the backup serum samples confirmed that these 4 subjects responded less efficiently to ingested 2H8 beta-C dose. These 4 subjects referred as to poor converters will be re-examined to confirm the observation. Therefore, the data of beta-C metabolism of the 4 poor converters were not analyzed together with that of the 11 normal converters. In the normal converters (7 males and 4 females), the calculated conversion factor of beta-C to retinol in1, 6, 13, 20, 27, 34, 41, and 52 days are 7.1 +/- 3.4, 5.6 +/- 2.7, 5.4 +/- 2.9, 5.1 +/- 2.8, 5.0 +/- 3.0, 5.0 +/- 2.9, 4.9 +/- 2.9, 4.8 +/- 2.8 to 1 on a molar basis respectively, and the corresponding post intestinal absorption conversion is estimated as (19.7 +/- 17.8)%, (22.7 +/- 20.5)%, (26.3 +/- 21.2)%, (27.8 +/- 22.7)%, (28.6 +/- 22.7)%, (29.5 +/- 22.8)% and (30.1 +/- 22.1)% of the total converted retinol.
The different time conversion of beta-C to vitamin A in the tested Chinese adults had been quantitatively determined by using a stable isotope reference method, and the long term as 52 days conversion factor value was 9.1 to 1 on a weight basis, and about 30% of total converted retinol came from absorbed intact beta-C.
Wei sheng yan jiu = Journal of hygiene research 06/2003; 32(3):215-21.