Dietary Combination of Fish Oil and Hemoglobin Hydrolysates Alters Serum and Liver Lipid Contents in Rat

Fish oil has been shown to have anti-inflammatory and anti-cancer effects, and to reduce serum triacylglycerol (TAG) levels by stimulating lipid oxidation and inhibiting lipogenesis in the liver. A small number of studies have demonstrated the synergistic effect of fish oil and other bioactive components. This study examined the effect of fish oil in combination with porcine hemoglobin (Hb) hydrolysates on serum and liver lipid contents in rats. Male Wistar rats were divided into four groups;one group was fed a casein and soybean oil-based semi-purified basal diet and other three groups were fed the basal diet supplemented with 2% fish oil, 0.175% Hb hydrolysates, and 2% fish oil plus 0.175% Hb hydrolysates, respectively, for 4 weeks. The fish oil diet decreased serum and liver TAG contents but did not change serum and liver cholesterol levels. The dietary combination of fish oil and Hb hydrolysates decreased serum and liver TAG and cholesterol contents owing to the additive effect of both compounds, and this diet reduced the serum non-high-density lipoprotein cholesterol content as a result of a synergistic effect. This hypolipidemic effect was in part caused by enhanced excretion of fecal fatty acids, neutral steroids, and acidic steroids. The results of this study suggest that the combined intake of fish oil and Hb hydrolysates may play beneficial roles in the prevention of cardiovascular disease as compared with fish oil alone.

Phosphorus Balance in Rats with Hypophosphatemia Induced by Lanthanum Carbonate

To examine whether lanthanum carbonate can induce a low phosphorus status in experimental animals, we examined phosphorus balance in rats administered lanthanum carbonate. Male 8-week-old Wistar rats were fed a basal case-in-based semi-purified diet or the basal diet supplemented with 0.45% or 0.90% lanthanum as lanthanum carbonate for 4 weeks. Lanthanum administration did not influence body or several organ weights and liver function. In rats administered lanthanum, a very small quantity of lanthanum was detected in several organs although the apparent absorption was almost zero. The highest lanthanum concentration was observed in the liver followed by the femur and kidney. Lanthanum was not clearly detected in the brain. Differences in organ lanthanum between 0.45% and 0.90% administration groups were not significant;lanthanum accumulation in the body is very low and may reach a plateau in a certain range of intake. Serum phosphorus was decreased and fecal phosphorus was increased by lanthanum administration dose-dependently. Urinary phosphorus excretion was significantly decreased by lanthanum. Since urinary phosphorus of rats fed 0.45% lanthanum diet decreased to near zero, the highest phosphorus balance was observed in rats fed 0.45% lanthanum diet. This high balance is considered to be adaptation to the low phosphorus status induced by lanthanum carbonate. These results indicate that lanthanum carbonate can induce hypophosphatemia without any direct side effects and be used to examine the effect of removing phosphorus from the diet in animal nutritional studies.