Effects of Dietary Xylooligosaccharides on HMG-CoA Reductase Activity and Lipid Cmposition of Liver in Rat Fed High Cholesterol Diets

Xylooligo당이 고콜레스테를 식이 횐쥐에서 간조직 HMG-CoA Reductase 활성과 지질 초성에 미치는 영향

  • 김성옥 (대구가톨릭대학교 식품영양학과) ;
  • 최정화 (대구가톨릭대학교 식품영양학과) ;
  • 홍희진 (대구가톨릭대학교 식품영양학과) ;
  • 주길재 (경북대학교 농화학과) ;
  • 이인구 (경북대학교 농화학과) ;
  • 이순재 (경북대학교 농화학과)
  • Published : 2001.12.01

Abstract

This study was conducted to examine the effects of dietary xylooligosaccharides on HMG-CoA reductase activity and lipid composition of liver in rat fed high cholesterol diet. Sprague-Dawley male rats weighing 100 $\pm$ 10 g were randomly divided into groups of one normal diet, and four high cholesterol diet containing 1% cholesterol. The high cholesterol (1%) diet groups were classified into xylooligosaccharides free diet (C group), 5% xylooligosaccharides diet (C5XO group), 10% xylooligosaccharides diet (C10XO group), and 15% xylooligosaccharides diet (C15XO grcup) according to the levels of dietary xylooligosaccharides supplementation. The experimental diets were fed ad libitum for 4 weeks. The hepatic lipid contents, cholesterol and triglycerides in xylooligosaccharides supplemented groups were significantly lower than those of C group. An antithrombGsis index, a ratio of n-3 to n-6 fatty acids of liver was significantly increased in 10% xylooligosaccharides supplemented groups compared to that of C group. The activity of hepatic HMG-CoA reductase, a rate limiting enzyme of cholesterol biosynthesis, in xylooligosaccharides supplemented groups was more significantly increased than in C group. These results suggest that dietary xylooligosaccharide may be act as potential substitute for a dietary fiber to improve lipids metabolism in rat fed high cholesterol diet.

고콜레스테롤 식이 횐쥐에서 xylooligo당이 간장에서의 콜레스테롤대사에 미치는 영향을 관찰하였다. 실험동물은 100$\pm$10g의 Sprague-Dawley 횐쥐를 이용하여 정상 식이군과 1% 고콜레스테롤 실험군으로 나누고 다시 실험군은 1%의 고콜레스테롤 식이에 xylooligo당을 0%, 5%, 10% 및 15% 농도 첨가군(C, C5XO, C10XO 및 C15XO군)으로 나누어 4주간 자유섭식시킨 후 콜레스테롤 대사 개선효과를 알아보았다. 간조직중의 중성지방과 콜레스테롤함량은 정상군에 비해 C군에서는 각각 3.9배, 20배씩 증가되었으며 C군에 비해 C10XO군은 거의 절반으로 감소되었다. 간조직의 HMG-CoA reductase 활성은 정상군에 비해 C군은 45% 감소되었으나, xylooligo당 공급군에서는 정상군 수준이었다. 간조직중의 지방산 조성은 oleic acid( $C_{18:1}$)과 linoleic acid( $C_{18:2}$)은 정상군에 비해 C군에서 유의적(p<0.05)으로 증가되었고, ara chidonic acid( $C_{20:4}$)는 감소되었으나 xylooligo당 공급으로 증가되었다. 총포화지방산(SFA)은 정상군에 비해 고콜레스테롤 식이로 인해 감소되 었으나, xylooligo당 공급으로 정상화되었다. 고콜레스테롤군에서는 총 단일불포화지방산(MUFA)은 증가되었으나, xylooligo당 공급으로 감소되었다. 항혈전지수인 n-3/n-6 지방산 비는 정상군에 비해 C군에서 감소되었으나, xylooligo당 10% 공급군에서는 C군에 비해 유의적으로 증가하였다. 결론적으로 식이 xylooligo당은 고콜레스테롤 식이로 인한 고콜레스테롤 혈증이나 고지혈증의 위험인자인 콜레스테롤을 감소시킬 수 있는 콜레스테롤 대사 개선 기능이 우수하므로 기능성 식품 신소재나 식이섬유의 대용품으로도 활용될 수 있으리라 생각된다.다.

Keywords

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