Influence of fucoidan on the intestinal absorption of iron, cobalt, manganese and zinc in rats

Effect of the interaction of seaweed extracts containing laminarin and fucoidan with zinc oxide on the growth performance, digestibility and faecal characteristics of growing piglets

Seaweed extracts (SWE) rich in laminarin and fucoidan have shown promise as a supplement for weaned piglets. However, successful application in pig nutrition depends on their bioactivity in the presence of additives such as ZnO. In the present study, a 2 × 2 factorial experiment was carried out to investigate the effect of the interaction between SWE and ZnO on the growth performance, digestibility and faecal characteristics of 192 weaned piglets (6·5 kg). The piglets were penned in groups of 4 (n 12 pens). The study consisted of two phases after weaning: a starter diet period from the day of weaning (0 d) to 21 d and a transition diet period from 21 to 40 d. The dietary treatments were as follows: (1) control diet; (2) control diet+ZnO; (3) control diet+SWE; (4) control diet+ZnO+SWE. Diets containing ZnO improved the faecal consistency of the piglets throughout the experimental period (0-40 d). An effect of the interaction between ZnO and SWE on several variable was observed. The diet containing only SWE or ZnO improved the feed conversion efficiency of the piglets during the transition diet period; however, this effect was not observed when the diet containing both ZnO and SWE was fed. The diet containing only SWE increased the N and organic matter digestibility of the piglets; however, this effect was not observed in the presence of ZnO. An interaction between ZnO and SWE was observed, whereby the faecal counts of Escherichia coli were decreased when piglets were fed the diet containing only SWE, but not when fed the diet containing both SWE and ZnO. In summary, SWE and ZnO improve growth performance when given alone, but not when given in combination. The biological effect of SWE on selected digestibility and faecal characteristics was markedly different when compared with that of ZnO.

Effect of fucoidan extracted from mozuku on experimental cartilaginous tissue injury

We investigated the effect of fucoidan, a sulfated polysaccharide, on acceleration of healing of experimental cartilage injury in a rabbit model. An injured cartilage model was surgically created by introduction of three holes, one in the articular cartilage of the medial trochlea and two in the trochlear sulcus of the distal femur. Rabbits in three experimental groups (F groups) were orally administered fucoidan of seven different molecular weights (8, 50, 146, 239, 330, 400, or 1000 kD) for 3 weeks by screening. Control (C group) rabbits were provided water ad libitum. After the experimental period, macroscopic examination showed that the degree of filling in the fucoidan group was higher than that in the C group. Histologically, the holes were filled by collagen fiber and fibroblasts in the C group, and by chondroblasts and fibroblasts in the F groups. Image analysis of Alcian blue- and safranin O-stained F-group specimens showed increased production of glycosaminoglycans (GAGs) and proteoglycans (PGs), respectively. Some injured holes were well repaired both macroscopically and microscopically and were filled with cartilage tissues; cartilage matrices such as PGs and GAGs were produced in groups F 50, F 146, and F 239. Thus, fucoidan administration enhanced morphologically healing of cartilage injury.

Non-everted oxygenated rat intestinal segments as a measure of neutral detergent fiber effects on iron absorption

Iron absorption in the presence of varying amounts and sizes of dietary fiber was measured. A method using non-everted rat intestinal segments perfused in oxygen was refined. Neutral detergent fiber (NDF), a component of dietary fiber, was extracted from cooked pinto bean (Phaseolus vulgaris). The NDF did not affect iron absorption in intestinal segments from iron replete rats. However, 4 and 6 mg of NDF/ml significantly decreased iron absorption in the intestinal segments from anemic rats. NDF with a smaller particle size of 0.125 mm increased iron absorption relative to that absorbed with 0.180 mm particles. Histological examination validated using non-everted intestinal segments perfused with oxygen as a method for studying dietary effects on iron absorption. Segments which are not everted are less prone to damage. Perfusion with oxygen maintained metabolic activity in the tissue during the experiment.

The influence of tin, nickel, and cadmium on the intestinal absorption of iron

The influence of increasing doses of cadmium, nickel, and tin on the net absorption of fluid as well as upon the absorption of 59Fe, administered as 59Fe-(FeSO4), from tied-off jejunal segments of male Sprague-Dawley rats were investigated. The three metals examined decreased the net absorption of fluid from the jejunal segments progressively with increasing metal doses. Cadmium was the most potent inhibitor of fluid absorption followed by tin and nickel. Tin, cadmium, and nickel diminished the absorption of 59Fe with increasing doses. The content of 59Fe of the jejunal tissue was not statistically significantly influenced by nickel, whereas tin as well as cadmium diminished the content of 59Fe significantly. Cadmium decreased the content of 59Fe to a greater extent than tin. Obviously nickel influences the rate-limiting process of iron absorption, i.e., the transfer of iron from mucosal cells into blood. Tin and cadmium appear to interact with the process of iron uptake on the surface within the mucosal cells as well as with the iron-releasing process at the contraluminal side. Cadmium as compared with tin is a stronger inhibitor for the processes involved in iron absorption.

Iron absorption during the development of hexachlorobenzene-induced porphyria in rats

The absorption of iron [59Fe-(FeSO4)] from jejunal loops was studied in rats after acute and subacute exposure to hexachlorobenzene (HCB). Female rats were given orally 100 mg HCB/kg body weight or fed a diet with 0, 500, 1,000, or 2,000 parts/10(6) HCB for 1 and 4 weeks. Male rats were fed on diets with 0 and 2,000 parts/10(6) HCB only. An increase in total urinary porphyrins and a decrease in the ratio of coproporphyrin to uroporphyrin in individual 24-h urine samples indicated different stages of porphyria in the rats at the time of determination of iron absorption. After acute oral administration of HCB, iron absorption decreased to about 70% of control values. After feeding the animals on HCB-containing diets, relative liver weight as well as total plasma protein increased depending on time and dose. The absorption of iron was not altered after 1 week of HCB exposure. After 4 weeks, the uptake of iron into the carcass decreased to less than 40% of control values, independently of dose and sex. The uptake of iron into the liver, expressed as percentage of the amount absorbed by the intestine, decreased significantly after 1 and 4 weeks of HCB feeding. No correlation could be observed between iron metabolism and urinary porphyrin excretion. The development of HCB-induced porphyria in rats is apparently not accelerated by an increased iron absorption.