Alloxan 당뇨쥐(제1형 당뇨병 모델)와 OLETF 쥐(제2형 당뇨병 모델)에서 녹차 추출물의 고혈당 억제 효과 = Antihyperglycemic Effects of Green Tea Extract on Alloxan-Induced Diabetic and OLETF Rats

국문 초록 (Abstract)

녹차 추출물이 당뇨병의 고혈당에 미치는 영향을 알아보기 위하여 1형 당뇨병 모델인 alloxan 당뇨쥐와 2형 당뇨병모델인 OLETF 쥐에 녹차 추출물을 4주간 투여하면서 혈당을 측정하여 관찰하였다. 녹차 추출물 투여 후 1주, 2주, 3주 및 4주째에 꼬리 정맥에서 혈당을 측정한 결과 alloxan 당뇨쥐는 대조군에 비하여 각각 혈당이 161, 176, 177 및 181 mg/dL가 감소되었고, OLETF 쥐는 녹차 추출물 투여군이 대조군에 비하여 각각 28, 33, 38 및 28 mg/dL가 감소되어, 녹차 추출물 투여로 1형 당뇨병인 alloxan 당뇨쥐와 2형 당뇨병인 OLETF 쥐에서 모두 투여 1주일째부터 혈당의 증가 둔화가 나타나서 4주째까지 지속되었다. 녹차 추출물이 당뇨쥐의 식이섭취량 및 체중에 미치는 영향을 알아보기 위하여 실험동물에 녹차 추출물을 투여한 후 1주일 간격으로 식이소모량과 체중을 4주까지 측정한 결과, 식이소모량은 alloxan당뇨쥐와 OLETF 쥐에서 모두 대조군과 녹차 추출물 투여군 사이에 변화가 없었다. 녹차 추출물 투여 당뇨쥐에서혈청 중성지질량의 변화를 관찰한 결과 alloxan 당뇨쥐와 OLETF 쥐에서 모두 녹차 추출물 투여로 중성지질량의 변화가 없었다. 녹차 추출물 투여로 인한 조직세포 손상정도를 측정하기 위하여 alloxan 당뇨쥐와 OLETF 쥐를 대조군과 녹차 추출물 투여군으로 나누어 4주간 사육한 후 혈청 AST 활성도를 측정한 결과 녹차 추출물 투여로 혈청 AST 활성도 변화는 관찰되지 않았다. 이상의 실험 결과로 녹차 추출물을 당뇨병 쥐에 경구투여하면 혈당증가 억제효과가 나타나는데, 녹차 추출물의 혈당증가 억제효과는 1형이나 2형당뇨병 등 당뇨병의 형태와 상관없이 작용할 수 있는 것으로생각된다. 따라서 녹차 추출물은 당뇨병 치료를 위한 우수한 식사요법 보조제로 개발될 수 있을 것으로 기대된다. 또한 녹차 추출물에 함유된 혈당강하작용 물질의 검색과 작용 기전, 특성에 대한 연구가 계속된다면 우수한 혈당강하작용을 가진 물질이 개발될 수 있을 것으로 추측된다.

다국어 초록 (Multilingual Abstract)

This study was performed to investigate the antihyperglycemic effect of green tea extracts (GTE) in diabetic rats. Experimental animals used were alloxan-induced diabetic Sprague-Dawley (SD) rats; as a model of type 1 diabetes mellitus and Otsuka Long Evans Tokushima fatty (OLETF) rats, and as a model of type 2 diabetes mellitus. Animals were randomly assigned either to continue the ad libitum diet or begin a green tea extracts (GTE) contained diet. GTE extracted from green tea was supplemented in the diet (2%). Body weight, food intake, and blood glucose concentration were recorded for 4 weeks. Animals were killed and glucose, triglyceride, and asparate aminotransferase (AST) were analysed in blood. Food intake was not affected by GTE in both alloxan.induced diabetic and OLETF rats but body weight was slightly decreased by GTE in OLETF rats. The blood glucose concentration was markedly decreased by GTE supplementation in both alloxan-induced diabetic and OLETF rats; however, triglyceride and AST levels in serum of GTE treated animals were not changed. This study shows that GTE beneficially modulate blood glucose concentration in diabetic animals. Dietary supplementation with GTE could potentially contribute to nutritional strategies for the treatment of diabetes mellitus.

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