Effects of Uncooked Powdered Food on Antioxidative System and Serum Mineral Concentrations in Rats Fed Unbalanced Diet

Antioxidative function of uncooked powdered food (Sangsik) was evaluated in rats consuming nutritionally unbalanced diet including 1％ cholesterol, high proportion of animal lipids (lard : soybean oil : 8 . 2) , sub-optimal levels of vitamin and mineral mixture along with 0.5% ethanol in drinking water. The uncooked powdered food tested in the present study was a mixture composed of 42 kinds of plant foods (cereals, legumes, seaweeds, vegetables, and fruits) supplemented with vitamins and minerals, and dietary fiber. Control rats were fed the semi-purified diet based on the AIN-93G composition, and nutritionally unbalanced rats were divided into 3 groups, and fed one of the following diets with 0.5% ethanol in drinking water for 5 weeks : unbalanced control diet (UC) ,20% Sangsik powder supplemented diet (S20), and 40% Sangsik powder supplemented diet (S40) . Food efficiency ratio was significantly higher in rats fed S40 compared to the value for rats fed UC (p < 0.05). Hepatic level of thiobarbituric acid reactive substances (TBARS) was significantly lower in rats fed UC compared to that for control rats (p < 0.05) , and was not influenced by dietary supplementation of the Sangsik powder. Hepatic superoxide dismutase (SOD) activity was significantly higher in rats fed UC compared to that for control rats (p < 0.05) , and significantly reduced in rats fed S20 or S40 compared to the value for unbalanced control rats. Feeding unbalanced control diet significantly reduced the ratio of hepatic GSH-Px ＋ catalase/SOD activities compared to the value for control rats, and this decrease in the ratio of antioxidant enzyme activities was reversed by adding the Sangsik powder to the diet at 20% (p <0.05) . Based on the results of antioxidant enzyme activities, feeding uncooked powdered diet appears to provide a favorable environment for body's antioxidative defense mechanism. Serum levels of Fe and Cu were significantly lower in rats fed the Sangsik powder supplemented diets compared to the value for unbalanced control rats (p < 0.05) , and levels of Se, Mn, and Zn were also tended to be decreased by dietary supplementation of the Sangsik powder. These results postulate the possibility that ingredients used in the uncooked powdered food may decrease the bioavailability of trace elements in rats.

생식제품 급여가 영양불균형식이를 섭취하는 흰쥐의 항산화체계 및 혈청 무기질 농도에 미치는 영향

본 연구에서는 비타민과 무기질을 sub-optimal 수준으로 섭취시키고 고콜레스테롤식이와 에탄올을 병행 섭취시키는 흰쥐를 대상으로 5주간 생식제품을 20％ (생식20군) 및 40% (생식40군) 수준으로 보충 섭취시킨 후, 체내 항산화체계에 미치는 영향을 평가하여 다음과 같은 결과를 얻었다. 일일 식이섭취량, 체중증가량 및 식이효율은 일반대조군과 영양불균형대조군 간에 유의적인 차이가 관찰되지 않았고, 생식40군의 경우 영양불균형대조군에 비해 식이효율이 유의하게 향상되었다 (p < 0.05) . 간조직의 지질과 산화물농도는 일반대조군에 비해 영양불균형대조군에서 유의하게 더 낮았으며 (p < 0.05), 식이내 생식첨가에 의해 영향을 받지 않았다. 간조직의 SOD 활성은 일반대조군에 비해 영양불균형대조군에서 유의적으로 증가하였고, 생식 섭취군의 경우 영양불균형대조군에 비해 유의하게 감소하였다 (p < 0.05), 간조직의 catalase 활성은 영양불균형대조군에서 일반대조군에 비해 유의하게 더 낮았으며 (p <0.05), 생식섭취에 의해 영향을 받지 않았다. 간조직의 (GSH-Px + catalase)/SOD 비율은 영양불균형대조군에서 일반대조군보다 유의하게 더 낮았으며, 영양불균형대조식이에 생식을 20％ 수준으로 첨가시킨 결과 유의하게 증가하였다 (P < 0.05). 영양불균형대조식이는 일반대조식이에 비해 혈중 Cu 농도를 유의하게 증가시켰다. 생식분말 섭취군의 경우 영양불균형대조군에 비해 Fe, Se, Mn, Zn 및 Cu 등의 무기질 섭취량이 더 많음에도 불구하고 혈중 농도는 오히려 더 낮게 나타났으며, 특히 Fe 및 Cu농도는 유의적으로 감소하였다. 이는 생식제품이 phytate 및 섬유질이 풍부한 전곡류 및 식물성식품들로 구성되어 있어 무기질의 생체이용률을 저하시키기 때문으로 사료되며, 생식제품의 장기 섭취시 이들 무기질 영양상태가 저하되지 않도록 주의가 필요할 것으로 생각된다.