Abstract
Studies have shown that onions exhibit a wide variety of health-promoting properties. The health benefits by the onion have been attributed to its ability to scavenge free radicals, to reduce blood lipids, to lower blood pressure, and to inhibit platelet aggregation. This study was performed to investigate whether onion extract supplementation would affect the blood markers of ethanol-induced fatty liver in rats. Initially, male Sprague-Dawley rats were housed singly in a room of controlled temperature and lighting and had free access to a nutritionally adequate AIN-93G and deionized water. The rats were trained for meal feeding to prevent a decline in food intake, as inevitably observed following an ethanol feeding. After the training period, rats were weight-matched and assigned to the following three groups: 1) a control group, fed the AIN-93G diet alone (control); 2) an ethanol group, fed the AIN-93G diet with ethanol at 4 g/day/kg body weight (ethanol); and 3) an onion group, fed the AIN-93G diet with ethanol plus supplemental freeze-dried onion powder at 500 mg/day/rat (ethanol + onion). All three group were meal-fed 7.0 g of their respective diets at 0900 h and 7.5 g at 1600 h for 28 days. At 0, 2, and 4 wk, blood was collected via the orbital sinus and organs were collected following overnight food deprivation. Both control and experimental groups continually gained weight throughout the study. No significant differences in the weights of the liver, kidneys, heart, spleen, and testis were observed. However, the serum level of triglycerides was significantly increased by ethanol but significantly decreased by onion extract. The activities of serum glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) at 4 wk were significantly increased by ethanol feeding but were significantly decreased by onion supplementation. However, no differences among groups were observed in the serum levels of alkaline phosphatase, gamma-glutamyl transpeptidase, bilirubin, and protein. These results provide that onion extract favorably affect alcoholic fatty liver by decreasing the serum concentration of triglyceride and the activities of GOT and GPT.
양파추출물이 알코올성 지방간에 미치는 영향을 알아보고자 흰쥐를 meal-feeding 방법으로 모든 쥐가 매일 같은 양의 식이를 공급받는 실험조건 하에서 에탄올 없이 정상식이만 섭취한 대조군, 에탄올과 정상식이와 함께 투여한 에탄올군, 양파추출물과 에탄올을 정상식이와 함께 투여한 에탄올양파추출물군으로 5마리씩 3그룹으로 나누어 사육하였다. 양파 추출물을 28일간 흰쥐에게 먹여 체중의 변화, 장기 무게 변화, 혈청 중의 glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GTP), total bilirubin, total protein, total cholesterol, triglyceride를 생화학적 검사를 통해 양파추출물이 에탄올로 유도된 지방간을 예방, 개선하는지 연구하였다. 대조군과 실험군 둘다 연구 시작부터 끝까지 지속적으로 체중 증가를 보였으나 그룹 간에 유의적인 차이를 보이지 않았다. 장기 무게는 각각의 그룹 간장, 신장, 심장, 비장, 고환 등의 무게에서 유의적인 차이점이 없었다. 혈중의 지방 변화를 보면 에탄올군에서는 혈중 중성지방이 유의적으로 증가하였고, 에탄올양파추출물군에서는 혈중 중성지방이 유의적으로 낮게 나타났다. 그러나 대조군과 에탄올양파추출물군 간에는 유의점이 없었다. GOT, GPT, ALP, GTP 의 4주간 실험한 혈중 농도에서 GOT와 GPT가 에탄올군에서 유의적으로 높았고, 에탄올양파추출물군에서는 유의적으로 낮게 나타났다. 이상의 실험 결과들을 종합해 볼 때, 양파추출물을 에탄올 식이와 함께 흰쥐에게 28일간 공급하였을 때, 지방간 관련 대표적인 혈액 지표인, 중성지방, GOT, GPT의 농도가 유의적으로 감소한다는 것을 이 실험을 통해서 확인할수 있었다.
