8주령의 F1B golden Syrian 햄스터에게 동맥경화 유발식이와 함께 녹차 추출물을 각각 500 혹은 1,000 mg/kg b.w.의 양을 매일 경구투여하면서 6주간 사육하였을 때 햄스터 체내의 지질대사와 대동맥 내에서의 지방의 축적 정도에 미치는 영향을 조사하였다. 실험 결과 녹차추출물의 경구투여는 동맥경화유발식이를 섭취하는 햄스터의 혈중 중성지방과 총콜레스테롤치를 농도의존적으로 감소시켰고, 대동맥궁내에서의 지방의 축적을 예방하였다. 특히 녹차추출물 1,000 mg/kg b.w. 투여는 동맥경화유발식이를 섭취한 햄스터에서 간장내의 LDL receptor mRNA level을 증가시키는 경향을 보였다. 이러한 결과로 볼 때 녹차 추출물의 투여는 동맥경화유발식이를 섭취한 햄스터의 혈중 콜레스테롤치를 감소시키고 LDL receptor의 발현을 증가시킴으로써 동맥경화를 예방할 수 있음을 보여주었다.
This study examined the effects of green tea extract supplementation (500 or 1,000 mg/kg b.w. per day) in conjunction with an atherogenic diet (10% coconut oil (w/w), 0.1% cholesterol) on plasma lipid composition, regression of pre-existing foam cells, and on the mRNA levels of hepatic HMG-CoA reductase and LDL receptor. Compared to groups fed only with the atherogenic diet, the addition of green tea extract to atherogenic diet-fed groups significantly down-regulated plasma triglyceride and total cholesterol levels, dose-dependently. Supplementation of 1,000 mg/kg b.w. of green tea extract with the atherogenic diet induced significant up-regulation of both HMG-CoA reductase and LDL receptor messenger RNA levels in liver as compared to the group receiving green tea extract supplementation at 500 mg/kg b.w. The F1B hamsters fed the atherogenic diet had greater foam cell accumulation compared to those fed a normal diet, or the atherogenic diet supplemented with green tea extract. Regression of fatty streak lesions was achieved by atherosclerosis in fat- and cholesterol-fed hamsters and this effect was associated with down-regulation of plasma cholesterol and up-regulation of hepatic LDL receptor expression.
